Many fish, corals and other marine life are suffering in ever warmer waters, with more frequent underwater heatwaves, acidification caused by man-made carbon dioxide in the atmosphere and a decline in levels of oxygen, the world’s leading climate scientists said.

“Over the 21st century, the ocean is projected to transition to unprecedented conditions,” the Intergovernmental Panel on Climate Change (IPCC) said in a special report about the oceans and the cryosphere – the world’s frozen regions. It was compiled by more than 100 authors from 36 nations.

The report is the most detailed look at the impact of climate change ranging from melting glaciers on the world’s highest mountains to the depths of the oceans that cover 71% of the Earth’s surface.

This is a reminder that CHN is small independent news site, dedicated to bringing you news from all over the world. That’s expensive and we need our readers to help. Here’s how you can, even for a few dollars a month.

“The open sea, the Arctic, the Antarctic and the high mountains may seem far away to many people,” said Hoesung Lee, chair of the IPCC. “But we depend on them and are influenced by them directly and indirectly in many ways.” Melting Himalayan glaciers, for instance, provide water to grow crops or generate hydropower before flowing into the oceans.

The report points to alarming signs of an accelerating melt of Antarctica that could herald an irreversible thaw from the world’s biggest store of frozen ice, ahead of Greenland.

Even so, sea level rise could be limited to 43cm by 2100, and around a metre by 2300, if the world sharply cuts greenhouse gas emissions in line with a goal set by almost 200 nations in the 2015 Paris Agreement to limit warming to 2C above pre-industrial times, it said.

Climate news in your inbox? Sign up here

But a future with no meaningful action and rising greenhouse gas emissions could push up sea levels by 84cm by 2100, about 10cm higher than estimated in the most recent IPCC global assessment in 2014 because of Antarctica’s quickening melt.

On that track, seas could rise by anywhere between 2.3 and 5.4 metres by 2300, it said. That would redraw maps of the world, make entire low-lying nations in the Pacific Ocean uninhabitable and swamp coasts from Bangladesh to Miami.

Lee said that there were worrying signs that the world was losing the race against climate change. “We need to take immediate and drastic action to cut emissions right now,” he said.

“Humanity is exacting a terrible toll on the ocean,” Norway’s prime minister Erna Solberg and Palau president Tommy Remengesau Jr. wrote in CNN on Monday. “Global warming, combined with the negative impacts of numerous other human activities, is devastating our ocean, with alarming declines in fish stocks, the death of our reefs, and sea level rise that could displace hundreds of millions of people.”

Authors said those different futures for rising seas highlighted stark choices now.

“Although many of the messages may seem depressing … there are actual, positive choices that can be made to limit the worst impacts of climate change,” said Michael Meredith, of the British Antarctic Survey.

Nerilie Abram, of Australian National University, also said: “We see changes in all of these areas, from the tops of high mountain to the depths of the oceans and the polar region …We see two very different futures ahead of us.”

The report was published two days after leaders failed to match UN secretary general Antonio Guterres’ call for nations to cut global greenhouse gas emissions by 45% below 2010 levels by 2030 at a summit in New York.

Global CO2 output continues to rise. Guterres said such immediate action was needed to get on track to limit warming to 1.5C, the toughest goal of the Paris Agreement. Global average temperatures are already up about 1C.

The UN asked for climate plans. Major economies failed to answer

Delegates to the IPCC said Saudi Arabia, OPEC’s top oil producer, had repeatedly sought changes at the Monaco meeting, partly to weaken links to an IPCC report in 2018 that examined ways to achieve the 1.5C goal.

Largely at Saudi insistence, Wednesday’s text, for instance, merely said it “follows” the 1.5C report and another about climate change and land issued this year. Many other delegates had favoured the word “complements” to underscore that the reports are part of a family of scientific studies.

Delegates said the Saudis pushed to water down any wording that would link this report to the IPCC’s 1.5 degrees report. In Katowice, the COP only “noted” the 1.5C report, under pressure from Saudis, Americans etc, stopping short of “welcoming” it. 

Saudi Arabia seemed to worry that the Santiago COP may “welcome” this new report. If so, it could implicitly endorse the findings in the 1.5C report if they were strongly connected in the text, so they wanted to loosen any links.

Some authors said wrangling over wording ended up helping because authors tightened the scientific findings.

Martin Sommerkorn, an author with the WWF conservation group, said that “the report ended up stronger because of a defence of the science.”

Delegates said the wrangling contributed to delay the meeting, with an all-night session lasting into Tuesday, from a scheduled finish on Monday.

They also said that the US delegation did not stand in the way of the science, even though US president Donald Trump plans to pull out of the Paris Agreement.

Climate science on 1.5C erased at UN talks as US and Saudis step in

Among other findings, the report said the maximum catch of fish in the oceans, already falling because of factors including over-fishing and pollution as well as warming waters, would fall by between 20 and 24% this century unless governments take strong action to rein in greenhouse gas emissions.

And fish stocks would be driven polewards or to the depths as the waters warm, perhaps causing conflicts over dwindling resources.

The report said extreme high tides or storm surges that historically happened only once a century could become at least annual events by 2100, exacerbated by rising sea levels. And a melt of permafrost could release methane and undermine infrastructure in mountains or polar regions.

“The impacts of human-made carbon emissions on our oceans are on a much larger scale and happening way faster than predicted,” said Taehyun Park, global climate political advisor with Greenpeace East Asia.

The post Dying oceans rising faster than predicted, UN warns in stark report appeared first on Climate Home News.

Only a few days earlier, on 3 March, Antarctic sea ice reached its own new record summer low since satellite observations began in 1979.

And on 13 February the total area of frozen ocean in the two hemispheres was at its lowest: 16.21 million square kilometres, which is about 2m sq km less than the average global minimum for 1981 to 2010.

In effect, the NASA scientists report, the world had lost a chunk of sea ice of an area bigger than Mexico.

“It has been quite extraordinary for several months in the Arctic,” says Julienne Stroeve, professor of polar observation at University College London. “Pretty much all through October, November, December, January, February and now March, we have been tracking record low conditions. I don’t think there has ever been a time in the Arctic when we have seen so many months of just record consecutive low conditions.”

Source: NSIDC

The most dramatic losses of sea ice have over the decades been observed in summer – where the decline has been measured at 14% per decade. Winter shrinkage has been at a much lower rate: about 3% per decade. But the ice has been thinning as well as dwindling in area, and temperatures earlier in the winter were unusually high: 20°C above the average for the time of the year.

Nobody can be sure what will happen once the spring thaw has begun, but polar scientists are expecting the worst. “We are pretty much poised to have really low summer ice conditions,” Stroeve says.

The frozen ocean around the Antarctic continent, too, has scientists worried. Sea ice fell to 2.11m sq km on 3 March. This is below the previous lowest minimum on record, exactly 20 years ago.

The two poles are very different. The Arctic is an ocean surrounded by land, while the Antarctic is a vast continent ringed by ocean, therefore the dynamics of ice formation and loss are not the same. And in recent years, the extent of sea ice in Antarctica had been growing. But this March, at the close of the Antarctic summer, there was a dramatic change.

“It is tempting to say that the record low we are seeing is global warming finally catching up with Antarctica,” says Walt Meier of NASA’s Goddard Space Flight Centre in Maryland.

“However, this might just be an extreme case of pushing the envelope of year-to-year variability. We’ll need to have several more years of data to be able to say there has been a significant change in the trend.”

Both polar regions are affected by natural variation. But the suspicion is that the long-term trend in global warming driven by human combustion of fossil fuels that dump vast quantities of greenhouse gases into the atmosphere must be playing a part. One research group recently proposed that human action might be responsible for at least half and perhaps 70% of Arctic warming.

Weekly briefing: Sign up for your essential climate news update

Southern polar sea ice reached its peak at the end of August, and November, December, January and February all saw rapid declines.

“We have been at record low levels,” says Emily Shuckburgh, deputy head of polar oceans at the British Antarctic Survey. “There is a lot of year-to-year variability, and it was only a couple of years ago we saw a maximum.

“This is just one year where there is a lot of variability, and really understanding what the implications are is the research challenge.”

This article was originally published by Climate News Network.

The post Polar sea ice hits record new low appeared first on Climate Home News.

In September 2016, the global sea ice area swerved wildly away from the paths plotted by in previous year since satellite measurement began in 1978. By mid-January, the ice was lower than ever recorded.

The milestone was reported by the Arctic Sea Ice Blog using data from the US government’s National Snow and Ice Data Centre.

Scientists at Nasa and the British Antarctic Survey reviewed the graph and confirmed that the findings were in line with their own observations.

Source: Wipneus

This year’s anomaly occurred because for the first time since measurement began, very low Arctic ice has coincided with very low Antarctic ice.

In the Arctic, where the surface temperature has increased more than anywhere else on earth, sea ice levels have been almost continuously dropping. This winter has been another exceptionally poor one for the annual refreezing.

“In the Arctic, there’s definitely that connection between the substantial warming and the substantial sea ice decrease,” said Dr Claire Parkinson, a senior scientist at Nasa. “In the Antarctic case there hasn’t been substantial warming so the connection is not as clear.”

Source: NSIDC

In the Antarctic, sea ice coverage has actually been increasing since records began – despite predictions that it would decline in a warming climate. This trend was broken in 2016 in emphatic fashion. But scientists have warned against attributing this to climate change.

“[Antarctica is] probably the worst place on earth to look for a signal of increasing greenhouse gases, because natural variability is so large there,” said professor John Turner from the British Antarctic Survey. “People have said to me ‘is this global warming suddenly kicking in?’ I don’t think there’s any evidence of that.”

Turner said there was a “real danger in making assumptions from a very short record”. After watching the Antarctic for less than forty years, he said, we cannot have witnessed all of its natural variations. “We have to be aware of the surprises that the system has in store for us.”

Source: NSIDC

Southern sea ice is more volatile than its Arctic counterpart because it hugs the fringe of the continent and is exposed to rough, ice breaking weather. Antarctic sea ice almost completely disappears every year, making it much thinner and more fragile than thick Arctic ice that can last for years.

Variability makes it harder to understand trends. No-one yet understands why ice around Antarctica has been stubbornly growing. There have been a number of theories put forward, including the cooling influence of the ozone hole. But in light of this year’s switcheroo, “all those speculations need to be reconsidered”, said Parkinson.

We do know what caused the major decline in 2016 – a slackening of the winds that govern the Southern Ocean weather. This sent down warmer northerly winds, that buffeted and melted the sea ice. This effect was particularly dramatic in November.

Source: NSIDC

But the underlying mechanics of the climate that are changing the Antarctic’s ice remain mysterious and the search for human fingerprints has proved elusive.

This highlights a weakness in combining Arctic and Antarctic sea ice into one measure and then trying to draw conclusions about global warming, said Turner.

“It’s a very unnatural thing to do, to add together Arctic and Antarctic sea ice, because they really are not connected in any way and they will come in and out of phase.” It is mere coincidence that in 2016 the two combined to such dramatic effect, he said.

The post Global sea ice at lowest area ever recorded appeared first on Climate Home News.

The proposal, which was shared with Climate Home, passed the scientific committee of the UN Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) on Thursday.

Russia has the power to veto the move when it goes to a full commission debate in Tasmania next week, however, and has consistently opposed territorial limits to fishing vessels in the far south.

The collapse of an ice shelf provides a one-of-a-kind scientific laboratory, said Phil Trathan, a scientist at the British Antarctic Survey and one of the authors of the proposal. The newly open waters provide a window into the hidden processes of ocean ecosystems.

“All of these areas are covered by ice and when that goes then there’ll be a whole new community develop under there. And given that a lot of communities develop quite slowly in the Antarctic then we can look at how they develop through time,” said Trathan speaking from Hobart, where the CCAMLR meeting is taking place.

“If fisheries are going to exploit those areas before we have a chance to look at them scientifically then it’s a lost opportunity.”

Weekly briefing: Sign up for your essential climate politics update

Antartica’s great ice shelves project out over the ocean from the fringes of the land. They are in a state of rapid decline, losing a total of 310 cubic km of ice every year.

Once a shelf becomes too thin to support its own weight, it collapses in dramatic style, as was witnessed by satellites when the 3,250 sq km Larsen B ice shelf disintegrated within a few months at the beginning of 2002.

The type of research Trathan describes was conducted by a group from the British Antarctic Survey in 2009, which took measurements from the sea around the former Larsen B shelf. They found massive phytoplankton blooms occurred as a result of nutrients running off the freshly exposed coastlines. These were storing as much carbon as 6,000-17,000 ha of tropical rainforest, uncovering a never before known carbon sink.

“Looking at that without the impact of fishing is really important,” said Trathan.

Worthy though it may be, the politics of CCAMLR are fraught and dominated by a Russian delegation that has continually blocked attempts to protect southern seas from fishing exploitation. Russia has active toothfish interests in the region and stymied the creation of two massive marine protected areas (MPAs) in the Ross sea and East Antarctic.

Report: Elephant seals enlisted in Antarctic sea ice study

On the surface, observers are perennially upbeat that Russia will be constructive each time CCAMLR meets. This time around, there has been a huge diplomatic effort on the part of outgoing US secretary of state John Kerry, who has spoken directly to his Russian counterpart Sergey Lavrov about the MPA proposals.

Kerry has personally championed an MPA in the Ross sea and is motivated to secure it before the end of his tenure.

But people close to the meeting expressed doubts about whether Russia would allow any progress in a year foreign relations between the US and Russia have deteriorated severely.

Climate Home approached the Russian delegation for comment.

The post Antarctic ice shelf collapse pits fishing against science appeared first on Climate Home News.

And the mammals have delivered a potentially ominous message: because fresh water is melting from the sea ice, the density of southern ocean surface waters is significantly reduced.

If there is too dramatic a reduction, the all-important dense waters that descend to the depths and power the ocean conveyor system that drives circulation − and climate − could falter.

The southern elephant seal, Mirounga leonine, has been pressed into service as an all-weather submersible to investigate and record data from the polynya system− polynyas are patches of ocean, surrounded by shelf ice, that fail to freeze − of the southern ocean sea ice.

Antarctic bottom water

And the researchers report in Nature Communications journal that their study “highlights the susceptibility of Antarctic bottom water to increased freshwater input from the enhanced melting of the ice shelves, and ultimately the potential collapse of Antarctic bottom water formation in a warming climate”.

The choice of elephant seals rather than humans is a simple one: shipboard research is all but impossible in the Antarctic winter.

Biologists had already enrolled the elephant seals – by sedating them, and gluing to their bulging necks a data monitor and radio transmitter that falls off with the next moulting season – to settle their own marine biological questions

So physicists and oceanographers have now taken advantage of the temperature and salinity data radioed back to them from each animal’s 60 dives a day.

“Like a constantly emptied and refilled ice tray in the fridge, polynyas can generate up to 20 metres of sea ice growth in a winter”

“We became very interested in the seal data once we saw they were foraging in the polynya regions, in particular the fact they were there through the winter, a critical period of time for dense shelf water formation, and a time that we really struggle to observe in any other way,” says Guy Williams, a physical oceanographer at theUniversity of Tasmania’s Institute for Marine and Antarctic Studies.

Sea ice freezes as fresh water and rejects the salt into the water beneath it. This creates an insulating layer that cuts off the ocean from the freezing atmosphere, so sea ice never gets deeper than two metres.

But Dr Williams told Climate News Network: “In polynyas, the surface of the ocean remains open, while the freezing continues, as newly-formed ice is swept away by persistent offshore winds. And certain topographic effects − coast, glacier tongues, icebergs − also help to keep the area open.

Ocean basins

“Like a constantly emptied and refilled ice tray in the fridge, polynyas can generate up to 20 metres of sea ice growth in a winter, and, correspondingly, a much greater amount of salt rejection.

“It leads to this very important water mass called dense shelf water – dense enough once it escapes the continental shelf to mix all the way to the bottom of the ocean basins in the production of Antarctic bottom water.”

This is the agency that drives the global ocean overturning system, a planetary-scale phenomenon, carrying heat around the globe and nutrients and dissolved atmospheric oxygen and carbon dioxide to deep layers of the ocean.

“Any reduction to Antarctic bottom water will slow the conveyor belt, and equally thin the conveyor belt, as the density, and depth to which it ultimately goes, decreases,” Dr Williams said.

This article was produced by Climate News Network

The post Elephant seals enlisted in Antarctic sea ice study appeared first on Climate Home News.

Geoscientists from the University of Edinburgh and a US colleague report in Geophysical Research Letters that they looked at satellite imagery of West Antarctica’s coastline along a 2,000 km stretch and found that the region has lost 1,000 square kilometres of ice in four decades. The surprise is not that melting occurs, but that it has been happening for such a long time.

Frazer Christie, a PhD student, and partners analysed data from NASA, the US Geological Survey and the European Space Agency to find that ice has been retreating along almost the entire coast of Antarctica’s Bellingshausen Sea since satellite records began.

Some of the largest changes – where ice has thinned rapidly and retreated several kilometres since 1975 – matched those places where the ice front is deepest.

“We knew that ice had been retreating from this region recently, but now, thanks to a wealth of freely available satellite data, we know this has been occurring pervasively along the coastline for almost half a century,” Christie says.

Colder water

He and his colleagues blame warmer ocean waters, rather than warmer atmosphere.

But, paradoxically, a study from the University of Washington in Seattle, US, reports that the waters lapping the continent are not warming substantially − because of a steady upwelling of much colder water from the depths of the Southern Ocean.

They don’t say warming will not happen, in response to human emissions of greenhouse gases in the atmosphere. Researchers have consistently and repeatedly warned that melting is on the way and is happening faster than previously thought.

ICYMI: Davis station said goodbye to the sun for six weeks on Thursday. https://t.co/7OpgP8OypQ pic.twitter.com/u2l722y0zN

— antarctica.gov.au (@AusAntarctic) June 6, 2016

But, for the moment, the southern waters may not seem any warmer because winds are pushing the relatively warm surface water towards the equator, allowing ocean currents to upwell from depths of thousands of metres to keep the surface at low temperatures. So warming in the region could take several centuries.

The study, published in Nature Geoscience, addresses the puzzle that while global average temperatures have increased, and Arctic polar temperatures and those around the West Antarctic peninsula have increased faster than average, the Southern Ocean has stayed cool.

“With rising carbon dioxide, you would expect more warming at both poles, but we only see it at one of the poles, so something else must be going on,” says oceanographer Kyle Armour, lead author of the study. “We show that it’s for really simple reasons, and ocean currents are the hero here.”

Pattern of warming

The study – as other scientists have pointed out – highlights once again the role of the oceans in controlling the pattern of global warming.

Emily Shuckburgh, head of the Open Oceans Research Group at the British Antarctic Survey, says: “It should be noted that, as a whole, the Southern Ocean has shown considerable warming, from the surface to depths of more than 1,000 metres, and that changes to the circulation in the Southern Ocean have been bringing more relatively warm water up under the ice sheets, melting them from below.

“The result of this paper highlights the important role the ocean itself has in shaping the patterns and magnitude of surface temperature change, and it emphasises the limitations of using surface temperature as a simple indicator of the accumulation of heat in the Earth system resulting from the anthropogenically-enhanced greenhouse effect.”

This article was produced by the Climate News Network

The post The puzzle of Antarctica’s long-term ice loss appeared first on Climate Home News.

According to a report in London’s Financial Times, Lloyd’s says the US government’s National Flood Insurance Program (NFIP), which subsidises insurance cover for householders in regions vulnerable to floods and storms, encourages irresponsible house building.

Lloyd’s also says the NFIP subsidy regime is financially unsustainable. Because of claims related to disasters such as Hurricane Katrina in 2005 and superstorm Sandy in 2012, the NFIP has now run up debts of more than $24 billion.

Insurance companies have been among those at the forefront of analysing the financial implications of climate change and assessing climate-related risk worldwide.

Concerted action

In the run-up to the UN conference on climate change in Paris last December, insurance companies pressed for more concerted action on global warming, saying it posed a serious threat to the future of the industry.

Insurers say rising payouts related to climate change and weather in heavily-insured western countries such as the US result in less money being made  available to provide affordable insurance in developing countries, where it is most needed.

A report by Munich Re, one of the insurance industry’s leaders in analysing climate change, says the world’s most deadly and costly catastrophe in 2015 was the Nepal earthquake in April, resulting in at least 9,000 dead and billions of dollars worth of damage.

“As is so often the case in developing countries, only a fraction of the $4.8 billion in overall losses caused by the quake and the aftershocks was insured – $210 million,” says Munich Re.

The situation in the US is the reverse, with heavy NFIP subsidies and other local, state-controlled schemes for too many homes built in areas exposed to storms and flooding.

“Intended as a disaster relief programme, the federal flood insurance scheme is really a land development policy”

The most glaring example is along the coast of Florida, a region that is regularly hit by hurricanes and giant storms. Coastal lands are also threatened by sea level rise related to climate change. Yet despite these risks, the area has seen a steep rise in population and housebuilding.

In 1992, Hurricane Andrew hit the Florida coast, causing an estimated 65 deaths and causing $25 billion of damage to housing and businesses.

With encouragement from insurance schemes subsidised at federal and state levels, the damaged areas have all been redeveloped. And insurance experts say that if a similar storm were to hit the Florida coast now, more lives could be at risk and losses would amount to $50 billion.

Bargain prices

Professor Omri Ben-Shahar, an expert on insurance law at the University of Chicago, argues in an article in Forbes magazine that government subsidies mean that flood policies are being sold at bargain prices.

He says the system is hard to justify, with middle-class taxpayers living inland having to subsidise mostly upper-income owners of coastal homes.

“Government-provided insurance made sure that premiums were low enough to sustain ongoing development and a massive relocation of population to regions which, we now know, are borderline inhabitable,” says Ben-Shahar.

“Intended as a disaster relief programme, the federal flood insurance scheme is really a land development policy.”

After the government had to pay out massive amounts in claims in 2012 in the aftermath of super-storm Sandy, the US Congress decided to phase out the NFIP scheme and its insurance subsidies. As a result, insurance premiums in some coastal areas rose tenfold.

An intense lobbying campaign followed, and much of the NFIP scheme is now back in place.

This article was produced by Climate News Network

The post Top insurer urges US to stop subsidising climate-risk homes appeared first on Climate Home News.

As warm seas wash the ice shelf, the land-based mass of ice could begin to retreat, cross a critical threshold in the present century and then withdraw 300 kilometres inland.

In the course of doing so it would spill tremendous quantities of water into the oceans: enough to raise global sea levels by 2.9 metres and threaten cities that are home to billions. 

And here is the bad news: glaciologists have known for decades that West Antarctica’s ice sheets are unstable.

But the Totten glacier is part of the East Antarctic Ice Sheet, a mass of ice most researchers had believed to be stable and highly unlikely to lose much of its ice, even in a warming world.

Scientists from Australia, New Zealand, the US and Britain report in Nature that they explored the underlying geology of the Totten glacier to build up a picture of its advance and retreat over many millions of years.

Report: Giant Antarctic ice shelf could collapse by end of century

“The evidence coming together is painting a picture of East Antarctica being much more vulnerable to a warming environment than we thought,” said Martin Siegert, co-director of the Grantham Institute at Imperial College London. “This is something we should worry about.

“Totten Glacier is losing ice now, and the warm ocean water that is causing this loss has the potential to also push the glacier back to an unstable place.”

The identification of a weak spot in the bastion of frozen water that embraces East Antarctica is new. But alarm about the rate of melting and the potential for change across the world’s last largely uninhabited continent is not.

In the past few years researchers have pinpointed the insidious effect  of warming sea currents, and identified immediate hazards to the glaciers of the fast-warming West Antarctic region.

“Totten Glacier is only one outlet for the ice of the East Antarctic Ice Sheet, but it could have a huge impact”

They have, in separate studies, warned that climatologists may have under-estimated the pace of change and even proposed scenarios in which the loss of ice over the whole continent could become inexorable.

But nobody expected any of these things to happen, or even begin to happen, in a human lifespan.

Even in a rapidly-warming world, Antarctica will remain the coldest place on Earth, sheathed by 30 million cubic kilometres of ice, containing 70% of the planet’s fresh water, a mass so vast that – were it to melt entirely – sea levels would rise by 60 metres.

The latest study suggests that rapid melting could begin within the next century. 

“Totten Glacier is only one outlet for the ice of the East Antarctic Ice Sheet, but it could have a huge impact,” said Professor Siegert.

“The East Antarctic Ice Sheet is by far the largest mass of ice on earth, so any small changes could have a big influence globally.”

This article was produced by the Climate News Network

The post Antarctic glacier melt could add 3 metres to sea levels – study appeared first on Climate Home News.

Emperor penguins on Antarctica (Credit: Pixabay)

By Tim Radford 

Sea level rise is likely to be a problem too big to handle. Geoengineers will not be able to magic away the rising tides, according to new research.

In particular, they will not be able to pump water from the sea and store it as ice on the continent of Antarctica. That is because, unless they pump it enormous distances, that will only accelerate the flow of the glaciers and it will all end up back in the sea again, a study in the journal Earth System Dynamics says. 

Geoengineering is sometimes produced as the high-technology solution to the environmental problems of climate change: if humans don’t change their ways and start reducing greenhouse gas emissions, say the proponents of technofix, human ingenuity will no doubt devise a different answer.

But, repeatedly, closer examination has made such solutions ever less plausible. Scientists have dismissed the idea that the melting of the Arctic can be reversed, have only tentatively conceded that technology could dampen the force of a hurricane, and have found that – instead of cooling the Earth – attempts to control climate change could either make things worse or seriously disrupt rainfall patterns.   On balance, scientists believe that most of the big geo-engineering ideas won’t work. 

Deep freeze

And now a team from the Potsdam Institute for Climate Impact Research has poured cold water on the idea of pouring cold water onto the ice cap.

The idea is a simple one. Are sea levels rising 3mm a year because the world is warming? Then pump the sea high onto the Antarctic landmass where it will freeze and stay frozen for a millennium.

But to be sure of that, say the Potsdam team, at least 80% of the water would have to be pumped 700 km inland. That would take more than 7% of the annual global primary energy supply just to balance the current rate of sea level rise.

But even in a world recently committed to a warming of less than 2C, the seas are going to go on rising. Sea levels could rise at least 40cm by the end of the century – or possibly 130cm, with devastating consequences for low-lying coastlines: rich megacities might be able to build defences, but the poorest communities would be swept away.

Coastlines redrawn

“We wanted to check whether sacrificing the uninhabited Antarctic region might theoretically enable us to save populated shores around the world. Rising oceans are already increasing storm surge risks, threatening millions of people worldwide, and in the long run can redraw the planet’s coastlines,” said Katja Frieler, the Potsdam scientist who led the study.

The Antarctic ice sheet rises to 4,000 metres above sea level. In theory wind power could deliver energy to take the water far enough inland that it would not simply precipitate glacial discharge back into the sea.

But that would mean engineers would have to build 850,000 wind energy plants on Antarctica, which could hardly be good for the ecosystem of the only landmass and coastline on Earth still more or less in the condition nature intended.

Nor is it technically or economically plausible. The implicit message from such studies is: start preparing to adapt to higher sea levels, and take steps to stop them getting any higher.

“Even if this was feasible, it would only buy time – when we stop the pumping one day, additional discharge from Antarctica will increase the rate of sea-level rise even beyond the warming-induced rate”

“The magnitude of sea-level rise is so enormous, it turns out it is unlikely that any engineering approach imaginable can mitigate it,” said co-author Anders Levermann, who heads Global Adaptation Strategies at Potsdam and is a scientist at Columbia University’s Lamont-Doherty Earth Observatory.

“Even if this was feasible, it would only buy time – when we stop the pumping one day, additional discharge from Antarctica will increase the rate of sea-level rise even beyond the warming-induced rate. This would mean putting another sea-level debt onto future generations.”

As so often after such studies, the scientists do have an answer: reduce the hazard by reducing the carbon dioxide emissions that fuel global warming. That means a drastic cut in the use of fossil fuels and a massive switch to wind and solar power worldwide.

“If we’d continue to do business as usual and churn out emissions, not even such an immense macro-adaptation project as storing water on Antarctica would suffice to limit long-term sea-level rise – more than 50 metres in the very long term without climate change mitigation,”  said Professor Levermann. “So either way, rapid greenhouse gas emission reductions are indispensable if sea-level rise is to be kept manageable.”

This article was produced by Climate News Network

The post Antarctica geoengineering idea flawed say scientists appeared first on Climate Home News.

Antarctica (Pic: NASA/Flickr)

By Tim Radford

European researchers have once again warned that the thinning of the Antarctic ice shelf means that the flow of glaciers on the frozen continent could accelerate, with a consequent rise in sea levels.

They examine, in two separate studies, the increasingly precarious state of some of the ice shelf. When the shelf, consisting of ice floating on the ocean, melts, it makes no difference to sea levels. But the floating ice does have an effect on the land.

It serves as a brake on the pace of glaciers on their journey down to the sea – and the combined impact of warmer atmospheres and warmer seas in the Southern Ocean are rapidly thinning much of the ice shelf.

Johannes Fürst, a researcher at the University of Erlangen-Nuremberg’s Institute of Geography in Germany, and colleagues report in Nature Climate Change that they analysed years of ice thickness data from European Space Agency satellites and airborne measurements.

Land-borne ice

They calculated that only 13% of the total ice shelf area of Antarctica could be called “passive” ice − that is, it plays no role in buttressing or slowing the land-borne ice.

But in the last 20 years, observers have measured the successive losses to large areas of the Larsen ice shelf off the Antarctic Peninsula, and these have resulted in an alarming acceleration of glacial flow on land, even though Antarctica remains the coldest continent on Earth. In some cases, the speed of flow has increased eightfold.

Dr Fürst says: “In contrast to the situation in Greenland, the loss of inland ice in West Antarctica is not caused by melting. It is much too cold for that to happen. The decrease is due to the glaciers flowing into the sea at a faster rate than 20 years ago − what we call dynamic ice loss.

“As ice shelves continuously lose ice by calving, it is essential to know how far the recession of ice shelves may progress before buttressing potential is reduced.”

This is not the only such warning. But science flourishes by replication.

Scientists led by Johannes Sutter, from the Alfred Wegener Institute’s Helmholtz Centre for Polar and Marine Research report in Geophysical Research Letters that they used computer simulations to examine the stability of the West Antarctic ice sheet and to explore what must have happened during a warm spell between Ice Ages 125,000 years ago.

Shrink and retreat

Their computer model seems to confirm the fears of successive researchers: ice is lost in two stages. First, the shelves shrink and retreat, and then the ice masses in the hinterland begin to speed up in their slide toward the sea.

As sea levels rise, the “grounding line” – the level where the ice is stuck to the rock – also retreats, and the glaciers begin to float and melt even faster.

But what happens, and how swiftly it happens, depends on human response to global warming, driven by the combustion of fossil fuels and the release of the greenhouse gas carbon dioxide into the atmosphere.

“Our study identifies critical temperature limits in the Southern Ocean,” Dr Sutter says. “If the ocean temperature rises by more than 2C compared with today, the marine-based West Antarctic ice sheet will be irreversibly lost. This will then lead to a significant Antarctic contribution to sea level rise of some three to five metres.

“Given a business-as-usual scenario of global warming, the collapse of West Antarctica could proceed very rapidly, and the West Antarctic ice masses could completely disappear within the next 1,000 years.”

This article was produced by Climate News Network

The post Warmer oceans speed up Antarctic ice loss appeared first on Climate Home News.

Icebergs in Patagonia, Argentina. Geographers measured icebergs at least 18 km in length through 175 satellite images taken between 2003-13 (Flickr/ Denisbin)

By Alex Pashley

Icebergs that break off Antarctica could account for twice as much carbon dioxide stored in the Southern Ocean than previously believed, a study on Monday suggested.

The drifting blocks the size of Manhattan sustain far greater amounts of phytoplankton – which remove CO2 through photosynthesis – in their trail as they melt, satellite imagery revealed.

Icebergs at least 18 km (11.2 miles) in length were found to fertilise the ocean for hundreds of kilometres and up to a month after passing, and are now thought to store up to 20% of the ocean’s carbon.

Satellites monitored changing ocean colour on concentrations of chlorophyll, a green pigment, according to the study published in journal Nature.

Report: Hi-res models capture West Antarctic ice melt danger 
Report: Rate of Antarctic ice melt to double by 2050
Report: 90% of ice lost from Antarctica comes from underside of icebergs

“This new analysis reveals that giant icebergs may play a major role in the Southern Ocean carbon cycle,” said Grant Bigg, lead author and geographer at the University of Sheffield, UK. “We detected substantially enhanced chlorophyll levels, typically over a radius of at least four-10 times the iceberg’s length.”

Icebergs are forecast to increasingly ‘calve’ from ice sheets as the burning of fossil fuels warms the planet, raising sea levels, according to the UN climate science panel. That could lead to greater carbon sequestration through increased meltwater.

“This is very much a secondary negative feedback at best, so it is not the answer to climate change,” Bigg said in an email to Climate Home.

The post Giant icebergs fertilise the ocean, sucking carbon – study appeared first on Climate Home News.

The Fluorescence Explorer (FLEX) mission will be ESA’s eighth Earth Explorer, measuring carbon and water cycles (Pic: ESA/ATG medialab)

By Ed King

The world’s top greenhouse gas polluters are being watched from space, where there’s no hiding the fumes pumped into the atmosphere.

Over the past two decades, a network of increasingly sophisticated satellites run by US, Russian, Japanese and European operators have been propelled into orbit, collecting data on a variety of emissions, including carbon dioxide, nitrogen and methane.

In May, China plans to launch its first carbon monitoring module, the result of four years of research by scientists at the Changchun Institute of Optics and Fine Mechanics and Physics.

The investments reflect a growing desire for more data on the causes and impacts of climate change, Johann-Dietrich Wörner, director general of the European Space Agency, tells Climate Home.

“What is needed in the future is data fusion – using data from space, in situ and airborne systems,” he says.

“If we put them together we get a full picture of the whole world, and we can get a picture of CO2 from natural and industrial sources.”

Global average concentrations of CO2 passed the 400 parts per million mark in 2015, a sharp rise from 100ppm in the pre industrial era.

A compelling picture of heavy CO2 emissions in China’s eastern industrial heartlands, India, Europe and North America is already available online, derived from NASA satellites and ground measurements.

“If you have enough satellites you can easily identify hotspots and the development of these hotspots,” Wörner says.

High concentrations of CO2 from rainforests in Brazil, the Congo and Indonesia are also evident from satellite imagery, a concern given the role those regions play as carbon sinks.

So too are images of calving glaciers in Antarctica,and shrinking sea ice in the Arctic, signs say climate scientists of a changing climate.

But while the pictures and data seem clear, Wörner says there’s a need for greater cooperation among the space superpowers to collect and share their findings.

The reason is simple: trust. Satellites offer a level of transparency that’s painful to many governments.

According to one source in a space agency, China asked the EU and US to stop all satellite flights over Beijing during the 2008 Olympics, worried that they would reveal high levels of pollution.

“This cannot be the job of just one country or organisation, because it will not be accepted by others,” says Wörner.

“What is important is we have a global network of data so we have a common understanding.

“Of course an EU satellite can cover the world but acceptance will be raised if we have satellites from different countries.”

NASA leads on Earth Science satellite numbers with around a dozen hurtling around the planet.

Of the ESA’s 10, CryoSat measures thickness in continental ice sheets, Envisat orbits the Polar regions while Sentinel-1 and Sentinel-2 monitor land and ocean atmosphere and weather patterns.

Their findings are clear – and worrying – admits Wörner. Arctic ice is freezing at winter but its extent has gradually reduced year on year. Rainforest are getting smaller and smaller.

The data is slowly filtering into UN efforts to reduce emissions.

In Paris last December, 195 governments agreed to an ongoing series of five-yearly reviews of progress in slashing emissions and greening their economies.

Establishing a set of common reporting metrics is deemed vital, otherwise some may be tempted to fiddle the books and make overly-ambitious carbon cutting claims.

China is a case in point. Its emission estimates are based on how much coal, gas or oil is produced and burnt, added to ‘proxy data’ for agriculture and waste.

Experts frequently question the numbers, and a recent admission that coal had been under-reported by 17% adds credence to fears the data is dodgy.

Satellites don’t hold all the answer – and they won’t slow emissions – but they may help clear up the picture of who is polluting where, says Wörner.

“Politicians look to the data seriously and say – is this reliable? The best way is to have global data coordination.”

The post No hiding for polluters as carbon-tracking satellite numbers rise appeared first on Climate Home News.

(Flickr/Antarctic and Southern Ocean Coalition)

By Tim Radford

Antarctica, the planet’s largest desert, is home to 90% of the world’s ice – enough to raise global sea levels by at least 60 metres. So what happens to its ice and snow is a matter of serious concern to all of us.

One group has just predicted that, by 2050, the rate at which the ice shelves melt will double. Another reports that powerful winds are not just shifting Antarctica’s snow, but are also blowing 80 billion tonnes of it away, into the sea or the atmosphere.

Both cases exemplify the challenges of climate research and the construction of projections for the future.

Inland glaciers

Ice shelves are already afloat: if they melt, that will make no difference to sea levels. But floating ice that is fixed to the continental shelf also serves as a brake on the flow of glaciers further inland. So without the ice shelf “doorstops”, these could start to shed ice ever faster, and accelerate sea level rise.

Luke Trusel, postdoctoral scholar at the Woods Hole Oceanographic Institution in the US, and colleagues report in Nature Geoscience that they foresee a doubling of surface melting of the ice shelves by 2050.

If greenhouse gas emissions from fossil fuel combustion continue at the present rate, by 2100 the melting may surpass the levels associated with collapse of the shelves.

“Our results illustrate just how rapidly melting in Antarctica can intensify in a warming climate,” Dr Trusel says. “This has already occurred in places like the Antarctic Peninsula, where we’ve observed warming and abrupt ice shelf collapses in the last few decades.

“Our models show that similar levels of melt may occur across coastal Antarctica near the end of the century, raising concerns about future ice shelf stability.”

Meanwhile, the journal Geophysical Research Letters reports how Indrani Das, a research scientist at the Lamont-Doherty Earth Observatory at Columbia University in the US, and colleagues have been looking at how much snow the winds can shift in the hostile climate of the southern continent.

What we are seeing is that East Antarctica – already among the driest regions on Earth – is a bit drier than we thought

Antarctica is technically a desert – with an average 166 mm of precipitation a year – but snow that falls tends to stay, and becomes packed ever tighter with the decades.

Researchers have for almost a century assumed that the wind simply picked up surface snow and deposited it in drifts somewhere else on the continent.

But there are places where persistent katabatic winds flowing downwards from mountains rake the surface so fiercely that the snow is lifted away from the continent altogether.

The scientists identified one place where winds have removed 18 metres of snow – the equivalent of two centuries of precipitation. It cannot melt, but it can sublimate or become vapour.

Scour zones

They calculate from satellite imagery that, in what they call the “scour zones” that cover about 7% of the continent, snow is being exported, and the continent might be losing some 80 billion tonnes a year.

This means that climate scientists have been overestimating the surface mass of Antarctica by 80 billion tonnes a year, and some of this windblown snow must be ending up in the sea.

Like the rates of ice shelf melt right now, these figures are relatively modest, but they are a reminder of how much climate scientists still have to learn about the complex physics of ice, climate and atmospheric circulation.

“What we are seeing is that East Antarctica – already among the driest regions on Earth – is a bit drier than we thought,” said Ted Scambos, senior research scientist at the US National Snow and Ice Data Centre, and one of the co-authors. “It’s more likely that it is losing ice, and adding to sea level.”

This article was produced by the Climate News Network

The post Rate of Antarctic ice melt to double by 2050 – study appeared first on Climate Home News.

Icebergs in eastern Greenland (Flickr/ Mariusz Kluzniak)

By Megan Darby

Melting polar icecaps have become emblematic of climate change.

In the highly polarised US debate, reports of ice shrinking or growing are used as ammunition on both sides.

Yet nearly half (47%) of people overestimate their grasp of the evidence, a study of polling data shows.

Among Tea Party supporters, 61% said they had “moderate” or “great” understanding of climate change but scored low on a factual test.

These are right wingers who support low taxes, minimal government and are strongly associated with scepticism about human-caused global warming.

“These patterns suggest that the false sense of understanding has ideological roots,” the researchers, from the University of New Hampshire, concluded.

“More directly than previous studies, these results support the conclusion that Tea Party supporters’ sense of understanding about climate change disproportionately reflects ideology rather than science knowledge.”

Report: Shock Antarctic ice loss discovered by European satellite

Led by Lawrence Hamilton, the study draws on a series of surveys in New Hampshire 2010-15.

Early rounds included three questions on polar ice: two that had political implications and one that didn’t.

First they asked whether Arctic summer sea ice covered more or less area than 30 years ago.

Measurements show it has shrunk and seven out of ten respondents gave that answer. That topped 80% among Democrats fell as low as 40% for Tea Party supporters.

“We see some people rejecting scientific reports about melting Arctic sea ice,” the researchers commented, “and eager to accept weakly founded claims of recovery.”

Then pollsters invited people to speculate on how much a warming Arctic would impact weather where they lived. Democrats were notably more likely than Tea Partiers to say it would have “major effects”, with Republicans in the middle.

Report: This snowball disproves global warming, says Inhofe

To a multiple choice question on what will most affect sea level, people of all parties were similarly (un)likely to answer correctly. Only 30% identified Greenland and Antarctic land ice as having a bigger impact than Arctic sea ice or glaciers.

In later surveys, two more questions were added about the geography of the North and South Poles – uncontentious facts.

Some 38% of people knew the North Pole was characterised by floating sea ice. Less than half (46%) were aware that the South Pole was a landmass covered in thick ice. Only 8% correctly answered both these and the question on sea ice.

Meanwhile, 26% were confident they knew “a great deal” about climate change and 52% “a moderate amount”.

“Our surveys find a paradoxical combination of high self-assessed understanding of climate change with generally low knowledge of basic facts,” the report noted.

“The polar questions are by no means a broad test of climate knowledge, but they involve background information that anyone moderately well informed about climate should know.”

Arctic sea ice decline and sea level rise have featured high in public discussions on climate change, it went on.

“Someone paying little attention to the issue might have less reason to know North from South Pole, but anyone who is paying attention should have seen them discussed repeatedly.”

The post Tea Party supporters score high on climate ideology, low on facts appeared first on Climate Home News.

Antarctica’s Larsen B ice shelf is likely to collapse into hundreds of icebergs before the end of the decade, according to NASA

By Tim Radford

Scientists have measured the rate of thinning of the great sea ice shelf of the Antarctic Peninsula and have identified the mechanisms at work above and below the shelf. 

The collapse of floating sea ice makes no direct difference to global sea levels – but the effects could nevertheless lead to higher waters everywhere.

Paul Holland, of the British Antarctic Survey (BAS), and research colleagues from the US report in the journal The Cryosphere that they used satellite measurements and radar studies between 1998 and 2012 to confirm that the Larsen C ice shelf has lost four metres of ice, and is a metre lower at the surface.

This is the largest of three shelves that have been under study for decades; the Larsen A and Larsen B shelves have already broken off and drifted north to warmer waters.

The Antarctic Peninsula is one of the fastest-warming regions of the world: 2.5°C in the last 50 years.

“What’s exciting about this study is we now know that two different processes are causing Larsen C to thin and become less stable,” says Dr Paul Holland, lead author of the BAS study.

“Air is being lost from the top layer of snow (called the firn), which is becoming more compacted, probably because of increased melting by a warmer atmosphere.

“We know also that Larsen C is losing ice, probably from warmer ocean currents or changing ice flow. If this vast ice shelf − which is over two and a half times the size of Wales, and 10 times bigger than Larsen B − was to collapse, it would allow the tributary glaciers behind it to flow faster into the sea. This would then contribute to sea-level rise.”

A collapse of the shelf could occur within a century. When the two companion Larsen glaciers broke away, the glaciers that flowed from the ice-capped continent towards the sea began to accelerate.

News: Shrinking Antarctic ice shelf raises sea level concerns 

Offshore ice, held fast to the shoreline, is a factor that helps keep glacier flow at its proverbially glacial pace. Once it has gone, the frozen rivers of ice onshore naturally begin to flow faster.

“We expect that sea-level rise around the world will be something in excess of 50 cm higher by 2100 than it is at present, and that will cause problems for coastal and low-lying cities,” says David Vaughan, director of science at the BAS.

“Understanding and counting up these small contributions from Larsen C and all the glaciers around the world is very important if we are to project, with confidence, the rate of sea-level rise into the future.”

The study is a confirmation of earlier research in which other groups, using different approaches, have already identified shelf ice loss and have warned that Antarctic melting could accelerate. Satellite-based measurements have also linked glacial melting with an acceleration in sea level rise.

Precision measurement of sea level rise is not easy. Oceans rise and fall with the tides, the water isn’t level anyway, and salinity and temperature differences in the oceans, and gravitational anomalies in the ocean basins, all mean that the ocean surfaces naturally undulate.

And the continents don’t keep still. Land surfaces from which researchers base their measurements also slowly rise or fall.

Accelerated rise

Christopher Watson, senior lecturer in the School of Land and Earth at the University of Tasmania, Australia, and colleagues report in Nature Climate Change that a different approach to the problem suggests that – contrary to previous estimates – sea level rise has accelerated in the last decade.

He and his colleagues searched not just global positioning satellite evidence from the surface waters but also from the land for signs of “bias” in the data. They also used evidence from hourly tide gauges from around the world and recalculated the rate of change.

What they found was that, overall, sea level rise in the last two decades has been at a rate just under, rather than just over, 3mm a year.

But the overestimate for the first six years of the survey had been much higher, which in turn suggested that the rate of rise had actually accelerated during this century, in a way that is consistent with the rate of glacial melting − at least from the Greenland and West Antarctic ice caps.

This article was produced by the Climate News Network 

The post Giant Antarctic ice shelf could collapse by end of century appeared first on Climate Home News.

Ronge Island in Antarctica (Pic: David Stanley/Flickr)

By Tim Radford

Scientists in the US report that the volume of Antarctic shelf ice is diminishing, and that there has been an 18% shrinkage in the mass of some ice floating on coastal waters over the last 18 years.

And because much of the loss has been off West Antarctica, where shelf ice helps to keep the ice sheet stable, it could mean that global sea levels will rise even faster as a result of increased glacial flow into the ocean.

The findings once again raise concern about the link between man-made emissions of greenhouse gases and the dangerous new world of global warming, climate change and sea level rise.

Fernando Paolo, a researcher at the Scripps Institution of Oceanography at the University of California, San Diego, and colleagues report in the journal Science that they used continuous radar altimetry measurements − taken from three European Space Agency satellites between 1994 and 2012 − to compose a high-resolution record of shelf ice thickness.

Declined swiftly

They found that the total volume of shelf ice – the thickness multiplied by the shelf area – around Antarctica stayed more or less the same from 1994 to 2003, but then declined very swiftly.

The ice shelves of West Antarctica lost ice during the entire period, and although East Antarctica had been gaining shelf ice, these gains ceased after 2003. Some shelves had lost 18% of their volume.

“Eighteen per cent over the course of 18 years really is a substantial change,” Paolo says. “Overall, we show not only that the total ice shelf volume is decreasing, but we see an acceleration in the last decade.”

Shelf ice is frozen sea, so when it melts, it makes no difference to sea levels. But there could be an indirect effect.

“The ice shelves buttress the flow from grounded ice into the ocean, and that flow impacts sea levels rise, so that’s a key concern from our new study,” says co-author Helen Fricker, a glaciologist at the Scripps Institution.

IN PICTURES: Global coral reef survey highlights climate threat

In climate science, one such study is never enough: such conclusions need support from other studies. But the ice volume measurements are likely to add to growing concern about West Antarctica.

One earlier study looked at the potential loss of ice from West Antarctica by examining the “grounding lines” of the terrestrial glaciers, and found evidence of continuous and accelerating retreat. In effect, the West Antarctic ice sheet could be approaching a point of no return, scientists reported.

And a second group used other satellite measurements to calculate that ice was being lost from the southern continent at an increasing rate – around 150 cubic kilometres a year from West Antarctica.

So the Scripps study indirectly backs up earlier findings. It calculates that most mass has been lost from ice shelves in the Amundsen and Bellingshausen seas, off the coast of West Antarctica.

These account for less than 20% of the total West Antarctic ice-shelf area, but contribute more than 85% of the total ice-shelf volume loss from West Antarctica.

Slow process

Were the West Antarctic ice sheet to melt completely – a long, slow process at almost any temperatures – sea levels would rise by more than three metres worldwide.

At current rates, a couple of the ice shelves off the western coast of the continent could disappear completely within 100 years, the Scripps team says.

Although the Arctic is one of the fastest-warming places on the planet, and although this warming has been directly linked to man-made climate change, the pattern of temperature shifts in the southern hemisphere has been more ambiguous.

The Scripps team have now begun to think about possible reasons for the loss of shelf ice in the far south, and one factor might be the cycle of El Niño events – natural and periodic bubbles of Pacific ocean warmth that have waxed and waned at intervals and changed the prevailing weather patterns worldwide through history.

“We’re looking into connections between El Niño events in the tropical Pacific and changes in the Antarctic ice sheet,” Paolo says. “It’s very far apart, but we know these teleconnections exist. That may ultimately allow us to improve our models for predicting future ice loss.”

This article was produced by the Climate News Network

The post Shrinking Antarctic ice shelf raises sea level concerns appeared first on Climate Home News.

Antarctic sea ice as visualised by NOAA. The pink line is the median extent of ice from 1981-2010 (Pic: NOAA)

By Ed King and Sophie Yeo

Sea ice coverage in the Antarctic continues to increase, according to data released on Thursday by the US National Oceanic and Atmospheric Administration (NOAA).

The ocean’s sea ice levels were 44.6% higher than the 1981-2010 average, breaking a prevous record set in 2008 by 220,000 square miles.

The growth came in a month NOAA says was the second warmest January on record since 1880, 0.77C above the 20^th century average.

NOAA says the warmest January was back in 2007, 1.84C above the average.

In contrast to Antarctica, the Arctic’s sea ice coverage was down 6.3% on the 1981-2010 average.

RTCC asked Ted Scambos, a senior research scientist at the National Snow and Ice Data Center in Boulder, Colorado, to explain the high Antarctic sea ice levels.

Here’s what he had to say:

“The reason it was a record in January was wind patterns in the time between December and January but Antarctic sea ice has been very high – record breaking high – for much of the last two years, and that’s more of a mystery.

We can talk about wind patterns pushing things around and making things more extensive, but there’s a broader underlying question and that is these wind patterns we are seeing are not necessarily record breaking or extreme, yet sea ice is record breaking and extreme – so why are we seeing high levels of sea ice now when for the past 30 years we’ve seen climate patterns come and go, and ice has stayed within a certain range of extent?

And that’s more of a mystery. I don’t want to claim it’s something that we understand completely. Many folks – John Turner for example, at the British Antarctic Survey – say this is within the realm of natural variability.

I don’t particularly agree with that. I think there must be some other factor going on, and there’s a couple of ideas for what that might be.

The ozone hole is just beginning to decrease in intensity and that had an impact to strengthening the tendency towards circumpolar winds around Antarctica. As that fades, we’re seeing less of a tendency to hold everything close to Antarctica and more variability perhaps in the weather. It’s very controversial.

Another hypothesis that has been published is the extensive amount of melt that has been going on around the perimeter of Antarctic. What you have is very thick ice well below the surface of the sea coming in and meeting the ocean.

Deep down in the ocean surrounding Antarctic the ocean is fairly warm, and in fact in some areas new pulses of warm water are reaching the coast of Antarctic. The melting ice that comes from the continent is less dense and it tends to rise up in the ocean and spread up in a layer surrounding Antarctica. The water is already cold and slightly fresher.

Mostly what it means is this cold slightly fresh water is conducive to sea ice formation. It doesn’t mix very well with warm water below it or around it. This may be a factor in producing more ice around Antarctica because of this slight freshening and melting around the edges of Antarctica.

Antarctica is definitely seeing the effects of climate change. Temperatures on the continent show profound warming in the peninsula and west Antarctica.

This increased sea ice is happening despite global warming and in part the wind changes that we’ve seen pushing the ice out into the ocean further away from the continent, the changes in those wind patterns have to do with global warming and possibly the reduction in the strength of the ozone hole. So that complex system is to blame for seeing these trends for more sea ice surrounding Antarctica.”

The post Antarctic sea ice soars, as Arctic coverage diminishes appeared first on Climate Home News.

Icebergs float near the Thurston Island calving front off of western Antarctica (Pic: NASA/Jim Yungel)

By Tim Radford

The Antarctic ice shelf is under threat from a silent, invisible agency – and the rate of melting of glaciers has trebled in the last two decades.

The ocean waters of the deep circumpolar current that swirl around the continent have been getting measurably warmer and nearer the ocean surface over the last 40 years, and now they could be accelerating glacier flow by melting the ice from underneath, according to new research.

And a separate study reports that the melting of the West Antarctic glaciers has accelerated threefold in the last 21 years.

If the West Antarctic ice sheet were to melt altogether – something that is not likely to happen this century – the world’s sea levels would rise by 4.8 metres, with calamitous consequences for seaboard cities and communities everywhere.

Researchers from Germany, Britain, Japan and the US report in Science journal that they base their research on long-term studies of seawater temperature and salinity sampled from the Antarctic continental shelf.

This continued intrusion of warmer waters has accelerated the melting of glaciers in West Antarctica, and there is no indication that the trend is likely to reverse.

Other parts of the continent so far are stable – but they could start melting for the first time.

“The Antarctic ice sheet is a giant water reservoir,” said Karen Heywood, professor of environmental sciences at the University of East Anglia, UK.

“The ice cap on the southern continent is on average 2,100 metres thick and contains 70% of the world’s fresh water. If this ice mass were to melt completely, it could raise global sea level by 60 metres. That is not going to happen, but it gives you an idea of how much water is stored there.”

Extra heat

Temperatures in the warmest waters in the Bellinghausen Sea in West Antarctica have risen from 0.8°C in the 1970s to about 1.2°C in the last few years.

“This might not sound much, but it is a large amount of extra heat available to melt the ice,” said Sunke Schmidtko, an oceanographer at the Geomar Helmholtz Centre for Ocean Research in Kiel, Germany, who led the study.

“These waters have warmed in West Antarctica over 50 years. And they are significantly shallower than 50 years ago.”

The apparent rise of warm water, and the observed melting of the West Antarctic ice shelf, could be linked to long-term changes in wind patterns in the southern ocean.

Although melting has not yet been observed in other parts of the continent, there could be serious consequences for other ice shelves.

The shelf areas are where the Antarctic krill – the little shrimp that plays a vital role in the Antarctic ocean food chain – are getting warmer, with unpredictable consequences for spawning cycles, and then for ocean biodiversity.

Meanwhile, according to US scientists writing in Geophysical Research Letters, the glaciers of the Amundsen Sea in West Antarctica are shedding ice faster than any other part of the region.

Tyler Sutterley, a climate researcher at the University of California Irvine, and NASA space agency colleagues used four sets of observations to confirm the threefold acceleration.

They took their data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites, from a NASA airborne project called Operation IceBridge, from an earlier satellite called ICESat, and from readings by the European Space Agency’s Envisat satellite.

Loss calculated

The observations spanned the period 1992 to 2013 and enabled the researchers to calculate the total loss of ice, and also the rate of change of that loss.

In all, during that period the continent lost 83 gigatonnes, or 83 billion metric tonnes, of ice per year on average. Since Mount Everest weighs an estimated 161 billion tonnes, this is as if the ice cap lost an Everest’s worth of ice every two years.

After 1992, the rate of loss accelerated by 6.1 billion tonnes a year, and between 2003 and 2009 the melt rate increased by 16.3 gigatonnes a year on average. So the increasing rate of loss is now nearly three times the original figure.

“The mass loss of these glaciers is increasing at an amazing rate,” said Isabella Velicogna, Earth system scientist at both UC Irvine and the NASA Jet Propulsion Laboratory.

This article was produced by the Climate News Network

The post Rising concern over invisible threat to Antarctic glaciers appeared first on Climate Home News.

Sea ice is reaching summer lows in the Arctic
(Pic: Flickr / David Astley)

By Sophie Yeo

Arctic ice reached its 2014 minimum of 5.01 million square kilometres last week, the sixth lowest extent since records began.

The minimum ever recorded at the North Pole was 3.29m sq km in 2012 – and the eight lowest years have been the last eight years.

Meanwhile, sea ice in the Antarctic has advanced beyond 20m sq km for the first time – and it is still growing.

Ice levels in the Arctic have recovered from their all-time low, but are still on a shrinking trend, said Julienne Stroeve of the National Snow and Ice Data Centre. “We have been telling this story for a long time, and we are still telling it,” she said.

NSIDC records showed that, this year, ice momentarily dipped below 5million sq km to 4.98m on 16 September, but the official figure is taken from a five day average.

Satellite data shows that one part of the Laptev Sea was completely clear from sea ice for the first time this summer.

Ice free Arctic

One of the most important questions for climate scientists is when the Arctic will experience its first sea ice-free summer.

Peter Wadhams from the University of Cambridge, also speaking at the Royal Society, predicted that this could happen within the next five years.

“I would still nail my colours to 2015 as a possibility [for an ice free Arctic in the summer],” he said, adding that projections that there could still be ice by the end of the century were “so unrealistic” based on projections of CO2 emissions that they shouldn’t have been included in the IPCC.

The majority of the scientists at the conference disagreed with his statements, however, with NASA’s Gavin Schmidt describing them as “unjustified” and not based in physics.

Rod Downie, head of WWF UK’s polar programme, said that this year’s new Arctic minimum should prompt new action from leaders as they meet in New York this week for a landmark UN summit hosted by Ban Ki-moon.

“As David Cameron prepares to meet other global leaders at the UN climate change summit in New York, the increased frequency of extreme weather that is predicted for the UK as a result of a warming Arctic should serve as a reminder that we need urgent action now to tackle climate change,” he said.

Antarctic

When it came to the Antarctic, scientists admitted they were puzzled by the expanding sea ice.

“All the climate models say it should be going down and it’s actually going up, and it’s making news,” said Shroeve, adding that the trend is expected to give ammunition to those seeking to discredit climate science.

She suggested that one reason for the increase could be strengthened polar winds pushing ice out from the shore, with no further land to constrain it from expanding. The extreme variability of natural processes in the region could also be behind the jump in ice cover.

The majority of ice at the South Pole is on land, and researchers have found that those ice caps are shrinking. Another study said Antarctic ice melt could raise sea levels up to 37cm by the end of the century.

The post Antarctic sea ice reaches record high, as Arctic hits 2014 minimum appeared first on Climate Home News.

Rising concern: warming would cause more Antarctic ice to break off and melt

By Alex Kirby

An international study says warming is affecting not only the Arctic but also the Antarctic – and that could significantly raise global sea levels much faster than previously predicted.

The effect of climate change on the world’s two polar regions looks like a stark contrast: the Arctic is warming faster than most of the rest of the Earth, while most of Antarctica appears to remain reassuringly locked in a frigid embrace.

But an international scientific team says the reality is quite different. The Antarctic is warming too, it says, and the southern ice could become the main cause of global sea level rise during this century − far sooner than previously thought.

The study, led by the Potsdam Institute for Climate Impact Research (PIK) in Germany, found that ice discharge from Antarctica could contribute up to 37 centimetres to global sea levels by 2100.

The study is the first comprehensive estimate of the full range of Antarctica’s potential contribution to global sea level rise based on physical computer simulations. It combines state-of-the-art climate models and observational data with various ice models.

The results of the study − published in the European Geosciences Union’s journal, Earth System Dynamics − reproduce Antarctica’s recent contribution to sea level rise, as observed by satellites over the last two decades.

“If greenhouse gases continue to rise as before, ice discharge from Antarctica could raise the global ocean by an additional 1 to 37 centimetres this century,” says the study’s lead author, Anders Levermann, PIK professor of dynamics of the climate system.

“This is a big range – which is exactly why we call it a risk. Science needs to be clear about the uncertainty, so that decision-makers on the coast and in coastal mega-cities like Shanghai or New York can consider the potential implications in their planning processes.”

Recent impacts

The scientists analysed how rising global average temperatures resulted in a warming of the ocean around Antarctica, influencing the melting of the Antarctic ice shelves.

Antarctica currently contributes less than 10% to global sea level rise and is a relatively minor player in comparison with the impact of the oceans’ increasing thermal expansion and the melting of glaciers.

But the major contributors to future long-term sea level rise are expected to be the huge volumes of ice locked up in Greenland and the Antarctic ice sheets. The marine ice sheets in West Antarctica alone could raise sea level by several metres over a period of several centuries.

The study’s computed projections for this century’s sea level contribution are significantly higher than the upper end of the latest projections by the Intergovernmental Panel on Climate Change. These suggest a probable rise by 2100 of around 60cm, although other estimates put the figure almost twice as high.

Even if governments can agree and enforce strict climate policies limiting global warming below the international target level of a maximum 2°C increase, Antarctica’s contribution to global sea level rise is expected still to range from 0 to 23cm this century.

A co-author of the study, Robert Bindschadler, from the NASA Goddard Space Flight Center, said: “This paper is a critical input to projections of possible future contributions of diminishing ice sheets to sea level by a rigorous consideration of uncertainty of not only the results of ice sheet models themselves but also the climate and ocean forcing driving the ice sheet models.

“Billions of dollars, euros, yuan, etc, are at stake, and wise and cost-effective decision-makers require this type of useful information from the scientific experts.”

But major modeling challenges still remain. Datasets of Antarctic bedrock topography, for instance, are still inadequate, and some physical processes of interaction between ice and ocean cannot yet be sufficiently simulated.

The team also emphasises that the study’s results are limited to this century, while all 19 of the comprehensive climate models used show that the impacts of atmospheric warming on Antarctic ice shelf cavities will hit with a time delay of several decades.

However, Levermann says: “Earlier research indicated that Antarctica would become important in the long term. But pulling together all the evidence, it seems that Antarctica could become the dominant cause of sea level rise much sooner.” − Climate News Network

The post Antarctic ice melt could boost sea levels 37cm by 2100 appeared first on Climate Home News.

Pic: Trey Ratcliff/Flickr

By Gerard Wynn

The prospective collapse of West Antarctic glaciers, reported this week, appears to meet a condition spelled out by the UN climate panel for more rapid sea level rise this century.

Sea level rise is a concern because of a global impact on the world’s coastlines, a threat even at low levels of global warming, and a lag effect which may reduce urgency to curb rising greenhouse gas emissions.

Two studies published this week painted a similarly bleak picture for a particular part of West Antarctica.

They agreed that glaciers draining into the Amundsen Sea were on the verge of irreversible collapse, even at the relatively low levels of warming seen now.

The largest, the Thwaites glacier, would contribute about 0.6 metres sea level rise, while all six would add about 1.2 metres in total.

The scientists agreed that the glaciers would disappear entirely within a few centuries, at present rates of retreat; one lead author projected that they were on track to disappear entirely in 200 years.

The two studies also agreed that the glaciers additionally supported ice sheets further inland, whose accelerated slide into the sea might add a further 3 metres or so to sea levels, but they did not discuss the timescale for such an outlook.

The studies were published against the backdrop of a recent UN climate panel report which found that sea level rise had accelerated over the past few decades and posed a serious threat.

The UN Intergovernmental Panel on Climate Change (IPCC) publishes a regular update every six years or so, based on the scientific literature.

In its latest review, it said last September that the rate of ice loss from West Antarctic and northern Antarctic Peninsula glaciers and ice sheets had hugely increased in the past decade, rising to around 147 billion tonnes of ice annually in 2011 compared with 30 billion tonnes in 2002.

That supported the findings of the two studies published this week, which found that the rate of ice loss from the West Antarctic glaciers had increased steadily over the past 40 years.

The IPCC reported that 100 billion tonnes a year of ice sheet loss was equivalent to about 0.28 millimetres annual sea level rise, meaning that Antarctic losses were already a major contributor to annual sea level rise, responsible for nearly half a centimetre (4.1 mm) a decade.

Accelerate

The IPCC reported that sea level rise had nearly doubled, to 3.2 cm per decade since the early 1990s compared with 1.7 cm a decade over the past century.

And it said that that sea level rise would accelerate this century as a result of increased ice loss and thermal expansion of the sea. It projected sea levels would rise above present levels by 0.26 to 0.98 metres by 2100.

But sea levels would rise faster this century, perhaps by several tens of centimetres, if West Antarctic glaciers collapsed, it said.

“Based on current understanding, only the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause global mean sea level to rise substantially above the likely range during the 21st century,” it said.

It cast doubt on such an outcome, reporting uncertainty in the scientific literature over the prospect for instability and irreversible decline of the West Antarctic glaciers and surrounding ice sheets.

Underestimate

The reason the West Antarctic glaciers are vulnerable is because they are all grinding along the sea bed, up to a point where they detach from the rock and rise upwards to form ice shelves on the sea surface.

As a result, they are more exposed to the sea, which is far warmer than the Antarctic air above.

“Some studies have found an acceleration of ice loss as well as enhanced basal ice-shelf melting, but the short period of observations does not allow one to either dismiss or confirm that these changes are associated with destabilization of the West Antarctic ice sheet,” the IPCC report said.

But the latest studies appeared to reject such doubts, projecting that the glaciers were now in a state of irreversible collapse.

Their findings appeared to meet the IPCC’s condition, of glacier collapse, for more rapid sea level rise this century potentially exceeding 1 metre.

One of the studies projected that the glaciers were on track to disappear entirely within two centuries.

“They are retreating at rates of about 1km a per year,” said Eric Rignot, from the University of California, a glaciologist at NASA’s Jet Propulsion Laboratory, and lead author of the study published in the journal Geophysical Research Letters.

“If these glaciers sustained this rate of retreat they would disappear completely in a couple of centuries,” he told reporters on Monday.

Future

The two new studies also have implications for expected sea level rise beyond this century.

The IPCC quoted one seminal study, published last year, which estimated around 2.5 metres long-term sea level rise would occur over several thousands of years, for every degree Celsius sustained warming above pre-industrial levels.

Melting of Antarctic ice sheets would contribute about 1.6 metres of that sea level rise, estimated the study published in the US Proceedings of the National Academy of Sciences.

According to the studies published this week, however, melting of West Antarctic glaciers would contribute around 1.2 metres in the next few centuries alone, and in as little as 200 years.

That would imply much faster sea level rise and at lower temperatures, in the context of warming presently of around 0.8C above pre-industrial levels.

One uncertainty in the recent papers, however, is the exact cause for the decline of these glaciers: are they continuing a long-run decline as a result of natural factors, or is it a direct result of climate change?

Rignot suggested the latter, saying stronger winds were driving warmer seas polewards.

Certainly, the studies multiply the doubts over sea level rise: they illustrate an urgency to pin down sea level projections, and improve our understanding of the human costs of continuing rises in greenhouse gas emissions.

There is an ample, geological precedent for substantial sea level rise which would re-write global coastlines and inundate islands, cities and coastal infrastructure.

The IPCC last September reported that in the last interglacial period of milder climate between ice ages, global sea levels were 5 to 10 metres higher than at present. That interglacial period, 116,000 to 129,000 years ago, corresponded with sustained polar temperatures at least 2C warmer than today.

The post New Antarctic studies suggest more rapid sea level rise this century appeared first on Climate Home News.

The calving front of the Thwaites ice shelf in Antarctica (Pic: NASA)

By Gerard Wynn

West Antarctic glaciers have started an unstoppable slide into the sea, as a result of warmer seas, which will in turn drain vast ice sheets and add several metres to global sea levels, two studies concluded.

The studies investigated a particular part of West Antarctica where the retreat of glaciers is fastest.

The speed of retreat and discharge of ice had increased almost continuously over the past forty years, and faster than previously thought, implying that expected sea level rise would have to be revised upwards.

The speed of the retreat shocked scientists writing in the journal Geophysical Research Letters.

“We’ve passed the point of no return,” said lead author Eric Rignot, from the University of California and also a glaciologist at NASA’s Jet Propulsion Laboratory.

“It’s just a matter of time before these glaciers completely disappear into the sea.”

The investigation was into six glaciers draining into the Amundsen Sea, including the large Pine Island and Thwaites glaciers.

Together, all six contained enough ice to raise global sea levels by 1.2 metres. They drained ice sheets which held ice equivalent to several more metres.

“This retreat will have major consequences for sea level rise worldwide,” said Rignot. “It will raise sea levels by 1.2 metres. Its retreat will also influence adjacent sectors of the West Antarctic ice sheet which could triple this contribution to sea level.”

The critical factor leading to the speed of melt was the fact that the bellies of the glaciers were travelling underwater along a sea bed sloping inland in deep valleys.

As a result, as they melt, more of the ice is detached from the sea bed, and so the faster the glaciers slide into the sea.

The authors of the Geophysical Research Letters article measured the point at which the end of the glaciers leave the sea bed, called the grounding line.

They found that the ground line was retreating by an average rate of about one kilometre a year. If they maintained that rate of retreat, the glaciers would disappear entirely in a couple of centuries.

The only way the retreat would slow is if there were an obstacle on the bed, or if the glaciers were retreating over land which was rising upwards, instead of downwards.

“But we don’t see that in any of these glaciers,” said Rignot.

“This system is evolving very fast and is progressing exactly as you would expect if it was about to collapse to the sea. There’s a bunch of feedbacks that makes this retreat unstoppable.”

Warmer seas were responsible for the retreat: climate change was the ultimate cause, not so much because of an observed global warming of seas, however, but because of stronger winds which were driving warmer seas polewards, said Rignot.

This is your earth on climate change: Collapse of Antarctic ice sheet “almost certainly unstoppable," scientists say. http://t.co/rCsuRj6KAA

— John Podesta (@Podesta44) May 13, 2014

A separate study, also published this week, made similar conclusions regarding ice sheet collapse in the same part of West Antarctica, focusing on the Thwaites Glacier.

The study, published in the journal Science, concluded that the glacier would disappear in a matter of centuries.

As in the NASA study, the authors concluded that because of the particular, local circumstances, including topography, the ice sheet collapse may be inevitable.

The edge of the Thwaites glacier sits on a bay which will get rapidly deeper as the glacier retreats further, hastening the collapse of ice into the sea.

The authors took a modelling approach, using various assumptions for melt rates to estimate how long it would take for the glacier to collapse.

“Our simulations provide strong evidence that the process of marine ice-sheet destabilization is already under way on Thwaites Glacier. The similarity between our highest melt rates and present observations suggests that collapse may be closer to a few centuries than to a millennium.”

The post West Antarctic glaciers have ‘passed point of no return’ appeared first on Climate Home News.

Pic: feserc/Flickr

By Gerard Wynn

East Antarctica may become a large contributor to future sea-level rise beyond this century, with ocean warming of 1C or more, a paper published in the journal Nature Climate Change found this week.

The impact of polar ice melt on global sea level rise has largely focused to date on the Arctic, because of rapid warming there.

In Antarctica, the focus has been in the so-called West Antarctic ice sheet, because of higher temperatures than in the rest of the continent, and because much of the ice there is below sea level.

But a separate, East Antarctic ice sheet, called the Wilkes Ice Sheet, is dammed from sliding and melting into the sea by a small amount of ice, found authors from the Potsdam Institute for Climate Impact Research.

While it would take several thousand years to drain the ice sheet into the sea, this process would become irreversible after sustained warming over just a few centuries.

With the dam removed, enough ice would reach the sea to cause 3 to 4 metres sea level rise over a period of 25,000 years, they calculated.

They calculated that the amount of ice holding back the ice sheet was equivalent to just 8 centimetres of sea level rise.

The amount of ice that reached the sea depended on the amount of sustained warming, between 1 and 2.5C local ocean temperature, and its timescale, from 200 to 800 years.

“We show here that the removal of a specific coastal ice volume equivalent to less than 80mm of global sea-level rise at the margin of the Wilkes Basin destabilizes the regional ice flow and leads to a self-sustained discharge of the entire basin and a global sea-level rise of 3–4 metres.

“Beyond the threshold of 80 mm, only unstable states exist and the ice sheet enters a phase of self-sustained retreat in all of our simulations.”

Historical

The authors based their findings both on a new understanding of the topography under the ice sheets, which suggested the potential for melt water to be carried towards the sea, and also on an understanding of the historical record of ice melt in the region.

Topographical analysis showed that the Wilkes Basin is the largest region with land below sea level in East Antarctica.

The authors reported that there was a precedent for the discharge of melt water from the region, contributing to global sea level rise.

“During the mid- to late Pliocene (4.8-3.5 million years ago) massive ice discharge occurred from the unstable margins of Adélie and Wilkes Land due to ice-stream surges that were linked to rapid grounding-line retreat during a warming climate.

“The Pliocene, featuring temperature and CO2 levels similar to end-of-this-century projections, may have had a significantly smaller ice sheet in East Antarctica’s Wilkes Basin, posing the question of the stability of its present marine-based ice.”

The authors pinned the stability of the ice sheet on a small volume of ice they called an ice plug.

“A small volume of ice (to be referred to as the ‘ice plug’) is the deciding factor for the stability of the marine-based ice.”

The post Ocean warming could weaken East Antarctic ice sheets appeared first on Climate Home News.

(Pic: NASA Goddard)

By Ed King

It appears to have come as a major surprise to many observers, but as the crew of the Akademik Shokalskiy have discovered, there is still ice in Antarctica.

A collection of scientists and journalists were airlifted off the stranded vessel today (follow the LIVE RESCUE here), which has been trapped in Antarctic pack ice 1,500 nautical miles south of Hobart since Christmas Eve.

The farcical end to the much-hyped Spirit of Mawson expedition has led to feverish activity among climate contrarians on Twitter, claiming it’s proof global warming is over-hyped.

Earlier today the Australian newspaper ran an editorial claiming it’s a “hard lesson for those who persistently exaggerate the impact of global warming.”

“Sea ice has been steadily increasing, despite the Intergovernmental Panel on Climate Change’s gloomy forecasts,” it adds.

So in these chilly times it’s worth reflecting on what the IPCC’s latest report, which the Australian’s comment team appear not to have read, actually says about Antarctica.

Below are a few key excerpts from its ‘Summary for Policymakers’, which you can download here.

Antarctic sea ice growth:

“It is very likely that the annual mean Antarctic sea ice extent increased at a rate in the range of 1.2 to 1.8% per decade (range of 0.13 to 0.20 million km2 per decade) between 1979 and 2012.”

Reasons for sea ice growth:

“There is low confidence in the scientific understanding of the small observed increase in Antarctic sea ice extent due to the incomplete and competing scientific explanations for the causes of change and low confidence in estimates of natural internal variability in that region”

Future sea ice projections:

“In the Antarctic, a decrease in sea ice extent and volume is projected with low confidence for the end of the 21st century as global mean surface temperature rises.”

This is from the same report that said scientists are more confident than they ever have been over the causes and potential dangers of climate change.

In reality, the fact there’s lots of ice floating in the sea next to the South Pole is nothing new, and sadly does not prove the overall warming trend has stopped.

Perhaps of greater concern is the amount of ice on the mainland, as this could have major implications for sea levels.

Here’s what the IPCC says about the Antarctic’s ice sheet loss:

“The average rate of ice loss from the Antarctic ice sheet has likely increased from 30 [–37 to 97] Gt yr–1 over the period 1992–2001 to 147 [72 to 221] Gt yr–1 over the period 2002 to 2011. There is very high confidence that these losses are mainly from the northern Antarctic Peninsula and the Amundsen Sea sector of West Antarctica.”

Late last month the The European Space Agency’s Cryosat satellite revealed that 150 cubic kilometres of the Antarctic’s ice sheet are drifting into the Southern Ocean each year: a much faster rate than the calculation for 2010.

Antarctic scientists and oceanographers calculated that the melting of ice from the West Antarctic peninsula was causing global sea levels to rise by 0.28mm a year. The latest survey suggests this rate is 15% higher.

Further research

The comical end to the Mawson adventure may also have longer-term implications for research in Antarctica.

The New York Times’ Andrew Revkin reports that Australian, Chinese and French teams studying in Antarctica may have to change their plans due to the diversion of ice-breakers to help the stranded Akademik Shokalskiy.

Joe McConnell, an American ice-sheet researcher currently at the South Pole told him that, once emergency requests were sent by the Russian ship, the Australian ice breaker Aurora Australis had to turn around and cancel plans to resupply missions on the mainland.

“The short- and long-term impacts on the Australian science program are pronounced as you can imagine and I understand it is the same for both the Chinese and French programs since their icebreakers were diverted, too,” he tells Revkin.

“Many of these guys can’t complete the research they’ve been planning for years because some or all of their science gear still is on the Aurora.”

That criticism aside, bloggers at the DataSciNZ website say the expedition may have unwittingly helped raise awareness of the unsual sea ice cover in that part of the Antarctic.

“It will be interesting to unpack how the AAE [Austrasian Antarctic Expedition] leaders prepared for risk, and what information they had available,” they write.

“More broadly, it will also be very interesting to understand the reasons for the extensive sea ice cover reported around Antarctica this season, in the context of the  climate system.

“In this sense, the #SpiritOfMawson may have an important but unexpected role in raising awareness.”

The post Breaking news: there is ice in Antarctica appeared first on Climate Home News.

1 – Fossil fuels main cause of Beijing smog
Fossil fuel combustion makes the largest contribution to Beijing’s deadly air pollution, according to a new study by the Chinese Academy of Sciences. The Think Progress website reports that the study found that coal burning, industrial pollution and secondary inorganic aerosols are altogether responsible for 69% of the city’s haze, while the burning of trash, and Beijing’s 5.5 million cars, were found to be responsible for just 4%.

2 – Chinese helicopter reaches stranded Antarctic ship
After nine days stranded in the Antarctic ice, the rescue of the 52 passengers aboard the Russian exploration ship is afoot. A Chinese helicopter reached the scientists and journalists on board the ship today and will transfer them to an Australian Antarctic supply ship, the Aurora Australis, reports Reuters.

3 – North Dakota train fire adds to Keystone debate
A fire on a North Dakota train carrying oil has added fuel to the Keystone XL pipeline debate in the US, Bloomberg reports, raising questions about the safety of transporting oil across the country. More than 2000 residents were urged to evacuate after the flames, following a crash, spewed dangerous fumes across the area. Obama is expected to deliver his verdict on the controversial pipeline this year.

4 – Scottish government slashes its air miles
The Scottish government has saved around £2.9m and reduced its carbon emissions by 28%, after cutting flying in favour of video and web conferencing. Business Green quotes new figures from WWF Scotland confirming that the government took around 3000 fewer business flights per year between 2007 and 2012.

5 – Deep sea marine life to decline with climate change
A new study shows that climate change will have a significant impact on losses in deep sea marine life, reports Azo Clean Tech. The team of international scientists predict that life on the sea bed will decline by up to 38% in the North Atlantic and over 5% globally in the next century due to a reduction in the plants that live at the surface of the oceans.

The post Coal ‘largest contributor’ to Beijing’s deadly smog appeared first on Climate Home News.

Source: Flickr/Austronesian Expeditions

By Tim Radford

Ice is being lost over the West Antarctic ice sheet at a faster rate. 

The European Space Agency’s Cryosat – a satellite with a radar altimeter that can peer through the clouds and see in the dark – has confirmed  that 150 cubic kilometres of ice are drifting into the Southern Ocean each year: a much faster rate than the calculation for 2010.

After observations between 2005 and 2010, gathered by 10 different satellite missions, Antarctic scientists and oceanographers calculated that the melting of ice from the West Antarctic peninsula was causing global sea levels to rise by 0.28mm a year. The latest survey suggests this rate is 15% higher.

The figures were revealed at the autumn meeting of the American Geophysical Union in San Francisco. Most of the ice loss comes from glaciers flowing into the Amundsen Sea.

“We find that ice thinning continues to be most pronounced along fast-flowing ice streams of this sector and their tributaries, with thinning rates of between four to eight metres per year near the grounding lines – where the ice streams lift up off the land and begin to float out over the ocean – of the Pine Island, Thwaites and Smith glaciers,” said Malcolm McMillan of the University of Leeds in the UK.

Wide-ranging view

The increase could be due to faster thinning – or it could be down to more accurate measurement, because Cryosat has more advanced instruments and circles the planet in a near-polar orbit, to cross territory no other observers could hope to see.

Cryosat will be followed by another series of European satellites, to be launched from 2014 onwards. Each of these Sentinels – that is their name – will have synthetic aperture radar instruments that will monitor a 250 kilometre-wide strip of the globe with each orbit.

They will work in pairs and not just keep an eye on polar ice but will cover Europe and Canada as well every one to three days, and watch, too, the main shipping routes, whatever the weather.

This article was produced by the Climate News Network

The post West Antarctic ice loss has accelerated over past four years appeared first on Climate Home News.

(Pic: Liam Quinn)

By Tim Radford

Arctic fjords are poor places, low in marine life and muddied by glacial meltwater. In the southern ocean, where everything is upside down, it’s a different story.

Scientists from the University of Hawaii report that they found unexpected riches deep in the fjords of the Antarctic Peninsula.

The Peninsula is one of the fastest-warming places on the planet. On land, researchers have used 150 years of moss growth as a kind of archive of change, and recorded a warming of 0.56°C per decade since the 1960s.

But researchers who photographed the sea floor found an abundance of bristle worms, sea spiders, sea cucumbers, crustaceans, jellyfish and of krill, they report in the journal PLOS One.

This is precisely what they had not expected: on the evidence of the rapidly-warming Arctic waters, these Peninsula fjords should have been much less lively.

“There appears to be something special about these fjords that stimulates sea floor productivity”, says Laura Grange, of the UK National Oceanography Centre at the University of Southampton, who collaborated in the study.

Change on the way?

“Seafloor ecosystems at the bottom of fjords rely on detritus for food, so these Antarctic fjords must be getting some sort of enhanced food input, most likely from phytoplankton blooms, micro-algal debris or even from krill – their moulted carapaces or the dead bodies that sink to the bottom.”

Humpback whales forage in those waters, and their excrement, too, may fertilise life at the sea bottom. But although the fjords are rich in life, they may not stay that way.

The Antarctic Peninsula warming is at a much earlier stage than the Arctic warming, and so far the fjords show little disturbance from glacial melting. Icebergs drift out so sea without dropping much sediment, which keeps the waters clear, and permits phytoplankton and algae to bloom. As the climate warms, these conditions could change.

“The extraordinary ecosystems, which provide habitat and foraging areas for krill and baleen whales and are hotspots of seafloor diversity, are very likely to be negatively impacted by the very rapid warming occurring along the Antarctic Peninsula”, says Craig Smith of the University of Hawaii Mānoa.

The guess is that such marine communities play an important role in providing food for fish, penguins and whales.

“We urgently need to develop a better understanding of the structure, function and climate sensitivity of these fascinating and imperilled seafloor communities.”

This article was produced by the Climate News Network

The post Antarctic fjord life puzzles scientists appeared first on Climate Home News.

Source: Flickr/littlevanities

India: Holy smoke arising from Hindu funeral pyres, Muslim cemeteries and Buddhist temples are responsible for almost a quarter of the greenhouse gases blamed for global warming on the Indian subcontinent and the melting of the Himalayan glaciers, a new study has claimed. (Times of India)

Research: Global emissions of carbon dioxide may be showing the first signs of a “permanent slowdown” in the rate of increase. According to a new report, emissions in 2012 increased at less than half the average over the past decade. (BBC)

Antarctic: Talks to create the world’s two largest marine reserves in the Antarctic have broken down, with conservationists branding Russia a “repeat offender” for blocking an international agreement. (Guardian)

UK: Fracking for shale gas is safe as long as operations are well-regulated and well-run, the main public health watchdog for England said on Thursday, after reviewing evidence from the US on the controversial technology. (Guardian)

US: The White House is expected to take new steps on Friday to help society adapt to global warming, an acknowledgment that worldwide efforts to control emissions will be inadequate to head off big climatic shifts. White House aides said President Obama would sign an executive order on Friday morning directing federal agencies to make it easier for states and communities to build resilience against storms, droughts and other weather extremes. (NY Times)

UN: Investors and the panel overseeing the UN’s carbon market for developing countries have called on delegates at next month’s climate meeting in Warsaw to rescue the ailing scheme, which the UN estimates has provided $315 billion in funding to low-carbon projects to date. (Point Carbon)

Research: Areas of the Pacific are warming faster than at any time in the past 10,000 years, adding weight to theories that global warming may be ‘hiding’ in the world’s oceans. In a paper published in the journal Science, scientists at Columbia University’s Lamont-Doherty Earth Observatory and the Woods Hole Oceanographic Institution say water temperatures up to 2,200ft deep have increased by around 0.18°C since the 1950s. (RTCC)

Developing world: Total greenhouse gas emissions by China and other emerging nations since 1850 will surpass those of rich nations this decade, complicating UN talks about who is most to blame for global warming, a study showed on Thursday. (Reuters)

Canada: Suncor Energy Inc., Canada’s largest energy company by market value, will proceed with the C$13.5 billion ($12.9 billion) Fort Hills oil sands project as it seeks to increase production. (Bloomberg)

Africa: African nations are entitled to a fair share of financial and other assistance from the developed world to help them cope with climate change, but they should also take the initiative to green their own economies and use land more sustainably and productively, experts told a conference on climate change and development in Ethiopia this month. (Point Carbon)

Policy: Scientists could have a greater influence over climate change policy if more research showed how communities are already adapting to changes, rather than focusing solely on long-term projections, a scientist from the Center for International Forestry Research has said. (CIFOR)

The post Holy smoke blamed for melting Himalayan glaciers appeared first on Climate Home News.

Pic: Flickr / Austronesian Expeditions

By Sophie Yeo

The East Antarctic glaciers are more sensitive to climate change than previously thought, according to a new study, and could retreat dangerously as global temperatures increase.

Compared to the rapidly retreating glaciers in the northern hemisphere, the remote ice sheets in the Antarctic receive relatively little attention.

But using satellite imagery to record how the glaciers along the 5,400km coastline of the East Antarctic have changed since 1963, researchers from Durham University have shown that the glaciers are sensitive to periods of warming and cooling, and have been retreating and advancing as the temperatures rise and fall.

Scientists had previously assumed that glaciers in the cold and remote East Antarctica, which can be more than 4km thick, had so far been fairly immune to the effects of climate change, which last year caused the ice sheets in the Arctic to reach their lowest levels yet.

But the new research, published today in Nature, suggests that these glaciers are more vulnerable to periods of warming and cooling, which could have a serious effect on rising sea levels if the climate warms over the next 100 years in line with scientific forecasts. The entire East Antarctic ice sheet contains enough water to increase global sea levels by 50m.

Chris Stokes, a researcher in geography at Durham University, and one of the authors of the paper, told RTCC, “The issue with the east Antarctic ice sheet is that it’s so big and it’s located in such a cold environment that people have just generally assumed that there are no clear trends in the glaciers there – that even if there was a little bit of warming we wouldn’t expect to see a response.

“What our study showed was that it can actually get quite warm there, and when it gets warm the glaciers shrink and when it cools down the glaciers advance or grow. This is the first study to show the sensitivity of the east Antarctic ice sheet to variations in climate.”

Advance and retreat

The observations showed that, during the 1970s and 80s, when temperatures were rising, most of the glaciers retreated, while during the 1990s, temperatures decreased and the glaciers correspondingly advanced.

During the 2000s, a combination of increase and decrease in temperatures meant that there was an even mix of retreat and advance.

For the moment, Stokes said, the overall volume of the ice sheets remains in equilibrium – the warmer periods which cause the glaciers to melt cause a corresponding increase in rain and snowfall, which compensate for the melting that the team observed around the margins of the ice sheet.

But the importance of the research is that it highlights that this balance should not be taken for granted over the next two centuries, and that the sensitivity of the ice sheets is a factor that must now be given more consideration when looking at the impacts of climate change.

Stokes said, “The difficulty is working out whether the additional snowfall will be enough to compensate for any additional shrinkage of the ice around the margins of the ice sheet.

“What our study shows is we need to start looking at the ice sheet in a lot more detail. We shouldn’t be complacent, we should just assume that it’s always going to be in balance.”

The post Antarctic glaciers sensitive to climate change, research shows appeared first on Climate Home News.

The rate of ice melt at the north and south poles could have severe ramifications for many of the world’s coastal cities

By Tim Radford

Here is a non-conclusion: after nine years of close observation, researchers still cannot be sure whether the planet is losing its ice caps at an accelerating rate.

That is because the run of data from one satellite is still not long enough to answer the big question: are Greenland and Antarctica melting because of global warming, or just blowing hot before blowing cold again in some long-term natural cycle?

The question is a serious one.

If the loss of ice that seems to be happening now is really going to accelerate, then by 2100, mean sea level will rise 43 centimetres higher than the original notional prediction, and hundreds  of millions of people who live on estuaries, deltas, coral atolls and great city river basins face serious losses.

Bert Wouters, a glaciologist at the University of Bristol in the UK and the University of Colorado at Boulder, Colorado, in the US, and colleagues report in Nature Geoscience that their most up-to-date and consistent measuring system, a satellite called Grace, needs to run for a lot longer before there can be a clear answer.

Grace stands for Gravity Recovery and Climate Experiment and it measures changes in mass in the landscape over which it flies, and the biggest variations in mass come from the changes in ice cover.

The main targets of the study are the ice sheets of Greenland and Antarctica because these amount to more than 99% of the planet’s snow and ice, and were these to melt completely, sea levels would rise by 63 metres, with calamitous consequences.

Shared caution

To be sure of detecting an accelerating mass loss of give or take 10 billion tonnes a year per year, the experiment needs at least 10 years for Antarctica and perhaps 20 years for Greenland.

But the results so far are ominous. “It has become apparent that ice sheets are losing substantial amounts of ice – about 300 billion tonnes each year – and the rate at which these losses occur is increasing. Compared to the first few years of the Grace mission, the ice sheets’ contribution to sea level rise has almost doubled in recent years,” said Dr Wouters.

But he is talking, of course, of a consistent finding from one experiment: other research has shown that the melting so far is real enough. The question is: could this just be the consequence of some natural rhythm so far unidentified?

Dr Wouters’ caution is echoed through the glaciological community. “Although ice is lost beyond any doubt, the period is not long enough to state that ice loss is accelerating,” said Wolfgang Rack of the University of Canterbury in New Zealand.

“This is because of the natural variability of the credit process, snowfall, and the debit process, melting, and iceberg calving, which both control the ice sheet balance.”

The article was produced by the Climate News Network

The post Scientists uncertain over rate of polar ice loss appeared first on Climate Home News.

Antarctic clams (Laternula elliptica) play a vital role in the ocean ecosystem, drawing down carbon into sea-bed sediments and circulating ocean nutrients.

Now a new study has found that the reproductive capacity of this long-lived and abundant species – existing in the cold, oxygen-rich waters of the Antarctic – could be seriously affected by rising ocean temperatures.

The study, by scientists at the British Antarctic Survey (BAS) and from the University of Kiel and the Alfred Wegener Institute in Germany and published in the journal Global Change Biology, found that young clams examined – averaging three years old – tended to try to move and bury themselves deeper when they sensed warmer ocean temperatures or reduced oxygen levels.

But more mature clams – of around 18 years old – stayed put. This, say scientists, is important as it is the older clams, not the younger ones, which reproduce. If they don’t adapt, their existence could be threatened.

“The polar regions are the Earth’s early warning system and Antarctica is a great natural laboratory to study future global change,” says Dr Melody Clark of the BAS, the lead author of the study.

Changes in clam behaviour are sending a warning signal as ocean temperatures rise (Source: Flickr/Liam Quinn)

“These small and rather uncharismatic animals can tell us a lot about age and survival in a changing world – they are one of the ‘engines of the ocean’.

“We know that they are extremely sensitive to their environment. Our study suggests that the numbers of clams that will survive a changing climate will reduce.”

Antarctic clams, which can live up to 36 years, have evolved in stable temperatures over the centuries. But scientists say sea surface temperatures around the Antarctic Peninsula have risen by 1°C over the last 50 years.

Age reduces mobility

As with humans, the muscle mass of clams decreases with age, making them more sedentary. The study, which follows on from earlier research, confirmed that it is these older, reproductively active clams which will suffer most from rising water temperatures.

The study involved divers collecting both young and older clams from the the seabed off King George Island and adjacent to a BAS research station on the Antarctic Peninsula.

The clams were then placed in aquarium tanks simulating different environmental conditions, with reactions to variations in oxygen and nitrogen levels monitored. Older clams showed little sign of movement in warmer waters with less oxygen while younger clams tended to be more active.

“We are trying to correlate long term predictions for clam populations,” Dr Clark told the Climate News Network. “What is interesting with clams is that their shells show their age more or less exactly and we are therefore able to monitor their behaviour at different stages of the life cycle, in differing conditions.”

Doris Abele of the Alfred Wegener Institute says the study shows the physiological flexibility of young clams diminishes as they get older.

“However, the species has evolved in such a way that the fittest animals, that can tolerate life in an extreme environment, survive to reproduce into old age. Climatic change, affecting primarily the older clams, may interfere with this evolutionary strategy, with unpredictable consequences for ecosystems all around Antarctica.”

This story was produced by the Climate News Network

The post Antarctic clam libido sends climate warning signal appeared first on Climate Home News.

The findings explain a series of sudden collapses of ice shelves in the last 20 years, which scientists studying them had not expected.

Researchers say the melting that is now occurring could lead to further dramatic events, making the loss of large quantities of ice on the Peninsula more likely, and adding to sea level rise.

The results are significant because in the last two decades scientists have been divided on whether the Antarctic would gain mass through extra snow falling and so reduce sea level rise, or would lose ice because of higher sea and air temperatures and so multiply the effect.

The new data come from a 1,000-year Antarctic Peninsula climate reconstruction published in the journal Nature Geoscience.

Antarctic ice melt is significant as it increases the chances of sea level rise (Pic: NASA)

In 2008 a UK-French team drilled a 364-metre ice core from James Ross Island, near the northern tip of the Peninsula, with the idea of measuring past temperatures in the area. What surprised them was that the core also gave an unexpected insight into ice melt in the region over that period.

Layers in the ice core showed periods when summer snow on the ice cap thawed and then refroze.  By measuring the thickness of these melt layers the scientists were able to examine how the history of melting compared with changes in temperature at the ice core site over the last thousand years.

In the last 600 years the temperature has increased by 1.6C, but only in the last 50 years has it reached a level at which summer melting has increased dramatically.

Lead author Dr Nerilie Abram of the Australian National University and the British Antarctic Survey (BAS) said: “We found that the coolest conditions on the Antarctic Peninsula and the lowest amount of summer melt occurred around 600 years ago.

“At that time temperatures were around 1.6°C lower than those recorded in the late 20th century and the amount of annual snowfall that melted and refroze was about 0.5%. Today, we see almost ten times as much (5%) of the annual snowfall melting each year.

“…even small changes in temperature can result in large increases in the amount of melting…”

“Summer melting at the ice core site today is now at a level that is higher than at any other time over the last 1,000 years.  And whilst temperatures at this site increased gradually in phases over many hundreds of years, most of the intensification of melting has happened since the mid-20th century.”

Dr Robert Mulvaney from the BAS led the ice core drilling expedition and co-authored the paper.  He said: “Having a record of previous melt intensity for the Peninsula is particularly important because of the glacier retreat and ice shelf loss we are now seeing in the area.

“Summer ice melt is a key process that is thought to have weakened ice shelves along the Antarctic Peninsula leading to a succession of dramatic collapses, as well as speeding up glacier ice loss across the region over the last 50 years.”

The changes in the Peninsula do not necessarily apply to other parts of Antarctica, for example the West Antarctic Ice sheet, where melting is occurring and there is potentially an even greater risk of large-scale sea level rise.

It is not yet clear that the levels of recent ice melt and glacier loss in West Antarctica are exceptional or are caused by human-driven climate changes.

However, Dr Abram said: “This new ice core record shows that even small changes in temperature can result in large increases in the amount of melting in places where summer temperatures are near to 0°C, such as along the Antarctic Peninsula, and this has important implications for ice instability and sea level rise in a warming climate.”

This story was produced by the Climate News Network

The post Antarctic summer ice melt accelerating – report appeared first on Climate Home News.

The Arctic may be shrinking as the world warms but Antarctic sea ice is expanding. Blame global warming for that, too, say Dutch scientists.

The paradox is that increasing temperatures have set in motion a chain of events in the southern seas that have the opposite effect. Engineers call this negative feedback. So do Richard Bintanja and colleagues of the Royal Netherlands Meteorological Institute.

They report in Nature Geoscience that as the Antarctic ice shelves melt, the resulting cool fresh water has actually served to insulate the offshore sea ice from the warming ocean beneath the floating floes. So, as a consequence, in 2010 southern ocean sea ice reached a record extent.

The Arctic Ocean is mostly just that: ocean, which is getting warmer, and the northernmost parts of the globe have been warming at twice the global average rate.

Not everyone is convinced with this theory – some suggest changes in the wind patterns might deliver blasts of colder air to Antarctica’s seas

So the north polar sea ice has been steadily thinning in depth and shrinking in area for more than 30 years. Ice reflects sunlight and keeps itself cold. Dark seas absorb sunlight and continue to get warmer.

As the Arctic ice shrinks, the feedback becomes positive. So the expectation is that sometime this century, in late summer, the Arctic ocean will for a few weeks be ice-free.

Conclusive?

But Antarctica is an enormous, high continental landmass covered almost entirely by a huge depth of ice and snow, and it keeps itself cold very effectively.

The oceans as a whole are warming – but in Antarctica, this warming has a counter-intuitive effect: thanks to the melt water, the total area of reflective sea ice is stable, or getting larger.

So although warm water is reaching the continental shelves, and creating some melting, the overall effect is to deliver a cold freshwater layer to the top hundred metres or so of the surrounding ocean. Fresh water freezes more quickly, so sea ice builds up quickly in the autumn and early winter.

“Our analyses indicate that the overall sea-ice trend is dominated by increased ice-shelf melt”, the Dutch scientists report.  “We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise.”

That should be good news: there is enough ice on the southern continent to completely inundate most of the world’s great estuarine and sea level cities.  But the conclusions are tentative and not everybody is likely to agree.

Is this an effect that will last? The interaction of ocean and atmosphere is a complicated one, with a number of factors at work that influence the growth of sea ice. In the UK, Martin Siegert of the University of Bristol suspects that the process just described may not be significant in the long run.

Paul Holland of the British Antarctic Survey calls the freshwater concept “plausible” but thinks there are also plausible alternative explanations for the increase in sea ice around Antarctica, among them changes in the wind patterns that might deliver blasts of colder air to the surrounding seas.

Galloping change

And Andrew Russell of Brunel University agrees: he sees both wind pattern changes and ice shelf melting resulting in increased sea ice “which perhaps isn’t what you’d expect but is consistent with our best description of climate change.”

Meanwhile, scientists at the American Museum of Natural History have more bad news for polar bears and other creatures adapted to the frozen Arctic. It will get warmer, and greener.

Rising temperatures in the next few decades will lead to a “massive” increase in vegetation in the lands bordering the Arctic, with as much as 50% more tree cover.

Three weeks ago, an international team reported in Nature Climate Change that vegetation conditions had advanced hundreds of miles north in the last few decades.

Now a consortium of researchers from the New York museum, Woods Hole research centre, Cornell University and the University of York in the UK report in the same journal that the growth will continue.

They used climate models to simulate future conditions and they believe that positive feedback will guarantee the advance of mosses, dwarf shrubs, sedges, grasses and even trees towards the pole.

As the ice and snow give way to green foliage, the rate of warming will step up.

“These impacts would extend far beyond the Arctic region,” said Richard Pearson of the American Natural History Museum. “For example some species of birds seasonally migrate from lower latitudes and rely on finding particular polar habitats, such as open space for ground nesting.”

This story was produced by the Climate News Network

The post Global warming extends Antarctic sea ice appeared first on Climate Home News.

It reveals the ‘summer melt’ season has grown over the last 60 years – one weather station reports the season has doubled since 1948.

“We found a significant increase in the length of the melting season at most of the stations with the longest temperature records,” said Dr Nick Barrand who carried out the research while working for the British Antarctic Survey.

The additional melting has been caused by a strengthening of local westerly winds causing the warmer air above the ocean to be swept up and over the mountainous peninsula.

The Antarctic Peninsula has warmed three times more than the global average (Source: Flickr/LiamQuinn)

The meltwater makes a contribution to rising sea levels but is has secondary effects too.

Melting and refreezing water widens cracks in the ice that can accelerate its break up. In the case of floating ice shelves, their collapse can accelerate the advance of glaciers, which can surge forward when ice ahead of them breaks away.

The Peninsula, which curls north towards South America, has warmed by 3°C since 1950, three times the global average.

Funded by the European Union’s ice2sea programme, Barrand used satellite data to map the melting and matched it with the records of 30 weather stations. They found a strong correlation with a regional climate model, RACMO2.

“We found that the model was very good at reproducing the pattern and timing of the melt, and changes in melting between years. This increases confidence in the use of climate models to predict future changes to snow and ice cover in the Antarctic Peninsula,” said Dr Barrand who now works for the University of Birmingham.

North and South

Arctic sea ice has also witnessed increases in summer melting. Last September it shrank to record low levels.

The two polar regions are very different with the South Pole dominated by the Antarctic continent while the Arctic is a mix of land and sea.

Sea ice in the Arctic reflects much solar radiation back into the atmosphere. Less ice means the sea absorbs more energy, which in turn melts more ice.

Claims that gains in Antarctic sea ice balance out losses in the Arctic have been rejected by polar experts.

The post Summer melt increasing on the Antarctic Peninsula appeared first on Climate Home News.

The Antarctic ozone hole has changed how the seas around the Antarctic mix, scientists say, threatening their ability to absorb atmospheric carbon dioxide and potentially speeding up global warming.

The discovery is important because the Antarctic accounts for about 40% of the total carbon absorbed by the world’s seas.

Writing in the journal Science, Darryn W. Waugh, an earth scientist at Johns Hopkins University, and his team show that both the sub-tropical waters in the southern oceans and the upwelling circumpolar waters closer to the Antarctic landmass have changed, in a way they say is consistent with the changes in the westerly winds around Antarctica.

These have grown stronger and moved poleward over the past few decades as the ozone layer has thinned. The new study finds evidence that those shifting winds are speeding circulation patterns in polar waters, with the currents closer to the land pushing more deep water up to the ocean surface.

The scientists’ worry is that the increasing upwelling of that water, hundreds of years old and naturally rich in carbon dioxide, is reducing the amount of manmade carbon absorbed by sub-polar waters.

“This may sound entirely academic, but believe me, it’s not,” said Waugh. “This matters because the southern oceans play an important role in the uptake of heat and carbon dioxide, so any changes in southern ocean circulation have the potential to change the global climate.”

The Southern Ocean ‘carbon sink’ is credited with absorbing vast quantities of Co2

The team used measurements taken from the early 1990s to the mid-to-late 2000s of the amount of a chemical, chlorofluorocarbon-12 (CFC-12), in the southern oceans.

CFC-12 was first produced commercially in the 1930s and was widely used in aerosols, refrigeration systems and air conditioning. It was finally phased out by the Montreal Protocol on Substances that Deplete the Ozone Layer.

Because they knew that concentrations of CFCs at the surface increased in tandem with those in the atmosphere, the scientists were able to surmise that the higher the concentration of CFC-12 deeper in the ocean, the more recently those waters had been at the surface, and they worked out how fast the mixing had happened.

They believe north-south circulation in the deep ocean has been speeding up, sending water from the ocean surface near the pole to intermediate depths (500-1,000 metres down) more quickly.

At the same time, the currents closer to Antarctica’s shores appear to be pushing more old, deep water up to the surface.

If surface waters are already rich in carbon, “that would mean more of the carbon we’re producing would stay in the atmosphere, and that would contribute more to climate change,” Waugh says.

Michael Meredith, a British Antarctic Survey oceanographer, said the new research drove home the importance of the Southern Ocean carbon sink. “It’s doing us a very big favour, if you like, by taking carbon from the atmosphere and slowing the rate of atmospheric climate change,” he said.

He believes the question now is what will happen as the ozone layer slowly heals and human activities pump out increasing amounts of greenhouse gases. The ozone hole is expected, on present trends, to have recovered by mid-century.

This article was produced by the Climate News Network

The post Ozone hole affecting Antarctic’s ability to absorb carbon dioxide appeared first on Climate Home News.

2012 will go down as the year when we all became experts in sea ice.

Records were smashed in the North and South Poles. Arctic sea ice shrunk to its lowest seasonal minimum since satellite records began, the strongest indication yet that climate change is warming the planet, according to scientists.

The melt in the Arctic could mean more sunlight is absorbed by the waters that reflect less heat than the ice. Scientists have also warned that methane deposits on the ocean floors could melt, evaporate and enter the atmosphere. Arctic sea ice melt has also been linked to severe winter weather in the US and Northern Europe.

The National Snow and Ice Data Center (NSIDC) in Colorado has put together two animations observing conditions in the Arctic and Antarctic. Both are below, starting with the North Pole.

On the other side of the world, another record was broken, as winter sea ice extent in Antarctica reached a record high.

The NSIDC say the extent increase in the Antarctic could be as response to changes in circulation patterns in the Southern Hemisphere, as well as cooling winds and snowfall.

Trying to compare the sea ice in the two regions can be very problematic. Here’s why.

Related Articles

Is the Arctic’s loss Antarctica’s gain?

Arctic ice hits record low

Arctic ice loss equivalent to 20 years of man-made CO2, says polar scientist

Arctic spill would create inaccessible ‘oil sandwich’ in ice impossible to clean, says UK polar expert

The post VIDEO: A record-breaking year for the Arctic & Antarctic appeared first on Climate Home News.

There has never been a better time to be a polar expert.

The focus is on the two poles like never before, especially after reports this week that sea-ice at the Arctic had reached a record low.

But as websites and news agencies pumped out this alarming headline, others called for calm. Arctic loss was being matched by Antarctic gain they said – this was actually a question of ice redistribution rather than ice loss.

Minimum and maximum sea ice cover for the Arctic and Antarctic (Picture: National Snow and Ice Data Center, University of Colorado, Boulder)

Take the Real Science blog, where Steven Goddard argues that cooling in the Southern Hemisphere could be balancing the warming the North: “Antarctic ice is nearing an all-time record high, and is above average everywhere”, he writes.

It’s a compelling theory, and one that has gained traction on Twitter and blogs, but much less so in the world of polar science.

We checked in with some experts to check up on this claim – and it’s fair to say they seem less convinced.

“The sea ice extent change in the Arctic and the Antarctic do not cancel each other out,” Professor John Turner from the British Antarctic Survey told me.

Yes, the Antarctic sea ice has seen an increase he said. According to NASA, it has increased by about 1% per decade since satellite records begun.

But Turner and NASA both say that the areas of sea ice increases in the Antarctic vary significantly.

“Across the Southern Ocean the greatest increase in sea ice extent has been in the Ross Sea, with smaller increases around the coast of East Antarctica and in the North East Weddell Sea,” Turner said. “There has been a marked decrease in ice extent just to the west of the Antarctic Peninsula.”

For its part, NASA says: “In short, Antarctic sea ice shows a small positive trend, but large scale variation make the trend very noisy.”

But is does seem odd that in what we understand is a warming world, ice anywhere can be increasing. But again, scientists say we should not be surprised.

“Antarctic sea ice hasn’t seen these big reductions we’ve seen in the Arctic,” Mark Serreze, director of the US-based National Snow and Ice Data Center told the LiveScience website, adding that they had expected the Antarctic to be more robust to the changing climate.

Why?

Turner explains that there are a number of reasons why this might be.

“One possibility is that it is a result of the ozone hole, which is believed to have caused a small cooling at the coastal stations around East Antarctica,” he said. “But it could also be a result of natural variability of the climate system.

“We don’t have the data to allow us to determine how sea ice extent would vary if forcing factors such as stratospheric ozone, greenhouse gases and aerosols were all kept fixed.”

Some explain the difference in melt levels by observing that the Arctic is ocean surrounded by land, while the Antarctic is land surrounded by ocean.

Serreze says the Arctic responds much more directly to changes in air and sea-surface temperatures than the Antarctic – which in turn is governed more by wind and ocean currents.

Another theory, published in a 2010 edition of the Proceedings of the National Academy of Sciences‘ journal argued that ocean warming in the 20th Century has boosted precipitation over the Antarctic region – which has fallen as snow.

This snow made the top layers of the ocean less salty and less dense, preventing warm currents in the deep ocean rising and melting ice.

What does the future hold?

Turner says that if the world maintains its warming trends, there is an inevitability around the Antarctic losing sea ice.

“By the end of the century, if greenhouse gas concentrations double, we expect that there will be one third less Antarctic sea ice,” said Turner.

As greenhouse gases continue to warm the atmosphere and the oceans of Antarctica, some scientists expect the precipitation in the region to turn from snow to rain, rapidly melting snow and ice.

Experts warn us we should beware playing the Arctic and Antarctic against each other. The environments are not directly comparable.

In Antarctica, sea ice grows extensively during the winter, and melts rapidly in the summer. This is very different to the Arctic, where sea ice lasts all year round – with relative increases in winter and decreases in summer. The Antarctic is often referred to as one-year, or ‘young’ ice, whereas Arctic sea ice is built up over many years.

In effect there is a feedback system in operation. As sea ice melts, the exposed darker water beneath absorbs more sunlight, heating the water. In the Arctic, where levels of sea ice are falling, more ocean is revealed, and more sunlight absorbed.

In the Antarctic, the sea ice virtually disappears each summer (December to February). So unlike the Arctic, the amount of ocean revealed to the sun does not increase year on year, and therefore the process does not have a pronounced affect on the Earth’s temperature. If the ice were to start disappearing in the winter that would be a different story.

The Antarctic ice sheet

The really significant question in the Antarctic concerns the extent of land ice.

It it the potential melting of this that raises alarm around the world – because unlike sea ice, it would contribute to sea-level rises.

Increasingly attention is being turned towards the stability of the Antarctic’s ice sheets. UN climate chief Christiana Figueres visited the continent earlier in 2012, and explorer Ranulph Fiennes is planning an expedition in 2013 which will supply more data from Antarctica’s bleak interior.

That’s for another day – but if you’re interested NASA gathered data from Antarctica earlier this year – you can read about the results on their website and check the accompanying info-graphic below.

NASA: Average yearly change in mass, in centimeters of water, during 2003-2010, as measured by NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites, for just Greenland and Antarctica and their peripheral glaciers and ice caps.

Related Articles:

Arctic ice hits record low

Arctic ice loss equivalent to 20 years of man-made CO2, says polar scientist

Rapid warming in the Antarctic could destabilise thousand year old ice shelves, say scientists

The post Is the Arctic’s loss Antarctica’s gain? appeared first on Climate Home News.

– The day’s top climate change stories as chosen by RTCC
– Tweet @RTCCnewswire and use #RTCCLive hashtag
– Send your thoughts to ts@rtcc.org
– Updated from 0900-1700 BST (GMT+1) 

Latest news – Thursday 26 July

1735 Olympic Torch passes the RTCC offices on Regent Street in the centre of London. Cue pandamonium as hundreds people sprint from their offices to catch a glimpse of the Olympic flame

Here’s the lucky torchbearer – a man called Mario – waiting to have his moment of glory. We won’t even mention all the emissions from that torch, the six buses and legion of police outriders that this procession must have emitted!

1700 Coal production increased by 6.6% globally in 2011, reported the IEA. That is the twelfth consecutive year of growth.

1600 A study reveals less than a fifth of US companies have strategies to address climate change

Peru is set to get its first validated project under the REDD carbon offset project. The project will use revenue generated from the sale of carbon credits to prevent illegal deforestation on over 290,000 hectares of Peruvian rainforest.

1500 The USA has opened its first commercial, grid-connected tidal energy project off the coast of the north-eastern state of Maine.

1400 An art installation running all this week at London’s Russell square – ahead of the London 2012 Olympics – aims to highlight the importance of urban forests, both for a city’s environment and its residents social well-being.

1300 The UK Department for Energy and Climate have released their energy stats. Onshore wind and solar PV are both on the up and there has been little change on the country’s coal use.

1230 US Congressman Randy Forbes has said Barack Obama has let the Chinese “get their body in the door” of the North American energy market by blocking the KeystoneXL pipeline. The project will connect Canadian tar sands oil to refineries in Texas, but Forbes says delays have left Canada looking to the east for customers.

1030 Climate change is viewed as an increasingly real and serious risk by global business, according to a new report. The ‘Global Investor Survey on Climate Change’, conducted by the consultancy firm Mercer, interviewed 42 asset owners and 51 asset managers who were involved with funds with a combined value of over $12 Trillion. Over half of the owners interviewed had embarked on climate change risk assessmens, while a quarter had changed their investment strategy based on those findings.

1000 The carbon footprint of the entire London Olympic Games could be wiped out if steelmaker ArcelorMittal – an official supporter of the event – cancelled just 3% of its excess carbon emission permits, according to green groups.

Ask @ArcelorMittal to make #London2012 carbon neutral by cancelling <3% of spare 123M carbon credits,received for free! bit.ly/MI85lu

— sandbag.org.uk (@sandbagorguk) July 26, 2012

0900 At least 70% of the decline in sea ice around the Arctic could be due to human-induced climate change, according to a new study.

The research used several computer based simulations on how the climate around the Arctic may have fluctuated without the input of greenhouse gas emissions, found the human impact could even be as high as 95%.

A dramatic gash that has been compared in size to the Grand Canyon has been discovered hidden beneath Antarctica’s ice sheet. Named the Ferrigno Rift – after the glacier that fills it – its existence could ‘profoundly affect ice loss’ warn the researchers who found it.

Strong expansion of nuclear power as a carbon-free energy is expected to continue in Asia despite the Fukushima accident in Japan, according to a report from the UN nuclear body and the Organisation for Economic Cooperation and Development (OECD).

Shell’s plans to drill exploratory wells in remote Arctic water off Alaska are being further hampered by its failure to secure the regulatory approvals needed.

The company, which had hoped to use this year’s brief, ice-free season to drill the wells, had already faced three-week delays to their work because of lingering sea ice.

Top Tweets

Reaction from new that Centrica – owners of British Gas – saw a 15% rise in profits in the first half of the year…

Less than day after Osborne hands half a billion quid of our money to Centrica and gas lobby, Centrica announce they’re making record profit

— Joss Garman (@jossgarman) July 26, 2012

More on yesterday’s story on the “extreme melt” in Greenland…

Piece by me on the Greenland melt. Scientist says last time CO2 reached this level, there was no ice sheet. bit.ly/OYJPtu #climate

— Ben Cubby (@bencubby) July 25, 2012

This is what climate change looks like. #SaveTheArcticj.mp/ARCT1Ctwitter.com/ecotist/status…

— Lisa Vickers (@ecotist) July 26, 2012

Photo of the day

Loss of Arctic sea ice ‘70% man-made’ bit.ly/QHl23l Just Because You Cant See It… twitter.com/_CatInAHat/sta…

— JLW (@_CatInAHat) July 26, 2012

The post Climate Live: Research finds 70% of Arctic ice loss is due to man-made climate change and OECD report says nuclear expansion to continue in Asia appeared first on Climate Home News.

Source: IUCN Photo Library
Photographer: B. Riche & G. Davila

The effects of climate change on ice-dependant seals could be devastating.

Harp seals, for example, require a stable ice platform to give birth and nurse their pups. The failure of ice to form or its early disappearance in recent years has meant many seals have been unable to find suitable spots for birthing.

Many seals are forced to give birth in the water and the pups often die.

A study from Duke University in the US in January this year found that the seal’s breeding grounds had shrunk by about 6% per decade over the last 30 years.

Another study in March this year warned that newborn Fur seal pups could also be at risk. It found young pups were increasingly using energy to keep warm in windier and wetter conditions in the Antarctic – leaving less for their development.

The IUCN (International Union for Conservation of Nature) is the world’s oldest and largest global environmental organisation aimed at finding solutions to the most pressing environment and development challenges.

The post Photo of the week #26 – The threat of climate change on seal pups appeared first on Climate Home News.

Desertification is a threat to communities around the world but positive action is taking place to combat it (© UN Photo)

Global action to combat desertification, Antarctic sea-ice being lost from below and women’s role in the green economy; it has been a busy week for climate change news.

RTCC summarises five of the biggest ideas on climate change, energy and clean development that emerged this week…

1) There is positive action being taken on desertification all around the world

This week is Desertification Week at RTCC and it has been a week filled with positive messages. We started with a call from Luc Gnacadja chief of the UNCCD to correct the image we have of desertification as an “unstoppable monster slowly consuming the world’s fertile lands”.

He said there are great examples from the world of positive work being done to combat desertification and this week we have heard such stories from across the globe from Africa to China to Turkey and Iran.

2) Warm oceans are a dominant cause of Antarctic ice melt

New laser images from NASA show that warm oceans thawing ice shelves from below has become a dominant cause of ice loss in Antarctica – showing that the ice melt in the region is not only due to the warming atmosphere.

Organisation aim to find more sustainable sources for biofuels (© Vilseskogen/Flickr)

The researchers believe this new information will take them a step closer to being able to reliably predict potential sea-level rises from ice melt in the Antarctic.

3) There could still be hope for sustainable biofuels

Following renewed criticism over biofuels – and their potential to exacerbate food security threat and human rights abuses – the EU has confirmed its commitment to sourcing 10% of transport fuels from renewable sources by 2020.

But as the debate around biofuels shows no signs of slowing down, some organisations are making strides in their attempts to find a more sustainable solution to the problem. While they still have some way to go, they believe they have learnt from past mistakes and are making positive progress.

4) The US could have its first climate change migrants

It appears climate change migration it not a problem isolated to countries in the developing world. While we have heard a lot in recent months about island communities’ plans for relocation and estimates of climate induced movements across Asia and Africa, this week it was the turn of the USA.

The Yup’ik Eskimo village from Newtok, Alaska could have gained the title as America’s first climate change refugees this week as they plan an ambitious relocation nine miles south of the town’s present site, as melting permafrost has literally shifted the ground beneath them.

Twenty-three energy Ministers met this week at the Clean Energy Ministerial in London.

5) India’s electric fans, frozen peas and women hold key to green economy

This week saw the Clean Energy Ministerial in London, where ministers, along with the UN Secretary-General’s Sustainable Energy for All initiative, gave their support for a number of measures to promote energy efficiency and the empowerment of women.

These included programmes targeting super-efficient fans in India, energy efficiency standards for TVs and fridges, and a US-led project to empower women in the clean energy sector.

The post A week in climate change: five things we learnt appeared first on Climate Home News.