Category Archives: Polar

Arctic thaw imperils climate goals

Promises to slow climate change have yet to be implemented. And even if they are, they may not be enough, because of the Arctic thaw.

LONDON, 26 September, 2018 – Austrian researchers have bad news for those nations alarmed about climate change: the Arctic thaw means the chances that the world will exceed the global warming limit set by international agreement are high – and getting ever higher with every tiny shift in the planetary thermometer.

Warming in the Arctic is the fastest on the planet – and any warming will release ever more methane and other forms of stored carbon from the thawing permafrost.

Methane is a greenhouse gas far more potent than carbon dioxide. And as it seeps into the atmosphere, the chances that the world will overshoot its promise to contain planetary warming to “well below” 2°C increase.

This target was agreed by 195 nations at a summit in Paris in 2015. The promise implicit in this historic decision was that the world would by 2100 be no hotter than 1.5°C above historic levels.

Global average temperatures have already risen by about 1°C in the last century, thanks to unconstrained combustion of fossil fuels that deposit ancient stored carbon back into the atmosphere in the form of ever more carbon dioxide.

“Getting back to lower levels after an overshoot will be extremely difficult … we may never get back to safer levels of warming”

But, says an international team led by Thomas Gasser of the International Institute for Applied Systems Analysis in Austria, there are prodigious amounts of carbon stored in the world’s once permanently frozen soils. As these are released, the chances are that global warming will accelerate.

“Permafrost carbon release from previously frozen organic matter is caused by global warming, and will certainly diminish the budget of CO2 we can emit while staying below a certain level of global warming,” Dr Gasser said.

“It is also an irreversible process over the course of a few centuries, and may therefore be considered a ‘tipping’ element of the Earth’s carbon-climate system that puts the linear approximation of the emission budget framework to the test.”

The message behind the formal language of a paper in the journal Nature Geoscience is simple: the world has less time to act than the presidents and prime ministers who signed the Paris Declaration may think.

But this is no surprise. Right from the start, leading climate scientists were warning that the planet could already be much nearer its optimum target than anybody suspected.

Other researchers have repeatedly stressed the need for urgency, and the inadequacy of any of the prepared responses.

Feedback concern

Concern about the permafrost, too, is not new: polar researchers have been arguing for years that any thaw will increase the atmospheric carbon burden, which will in turn accelerate further warning, with potentially catastrophic consequences.

It is one thing to slow the rate of global warming by drastically reducing fossil fuel emissions and restoring the world’s forests so as to arrive at a limit; quite another thing to overshoot the limit and then try to reduce the planetary temperature, the latest study suggests. There is no simple correlation between burning coal or oil and the planetary temperatures that follow.

“Overshooting is a risky strategy and getting back to lower levels after an overshoot will be extremely difficult. However, since we are officially on an overshooting trajectory, we have to prepare ourselves for the possibility that we may never get back to safer levels of warming,” Dr Gasser said.

“Policymakers should understand that there is no elementary proportionality between cumulative CO2 emissions due to human activity and global temperature, as previously believed, and that overshooting may have serious consequences.” – Climate News Network


 

Promises to slow climate change have yet to be implemented. And even if they are, they may not be enough, because of the Arctic thaw.

LONDON, 26 September, 2018 – Austrian researchers have bad news for those nations alarmed about climate change: the Arctic thaw means the chances that the world will exceed the global warming limit set by international agreement are high – and getting ever higher with every tiny shift in the planetary thermometer.

Warming in the Arctic is the fastest on the planet – and any warming will release ever more methane and other forms of stored carbon from the thawing permafrost.

Methane is a greenhouse gas far more potent than carbon dioxide. And as it seeps into the atmosphere, the chances that the world will overshoot its promise to contain planetary warming to “well below” 2°C increase.

This target was agreed by 195 nations at a summit in Paris in 2015. The promise implicit in this historic decision was that the world would by 2100 be no hotter than 1.5°C above historic levels.

Global average temperatures have already risen by about 1°C in the last century, thanks to unconstrained combustion of fossil fuels that deposit ancient stored carbon back into the atmosphere in the form of ever more carbon dioxide.

“Getting back to lower levels after an overshoot will be extremely difficult … we may never get back to safer levels of warming”

But, says an international team led by Thomas Gasser of the International Institute for Applied Systems Analysis in Austria, there are prodigious amounts of carbon stored in the world’s once permanently frozen soils. As these are released, the chances are that global warming will accelerate.

“Permafrost carbon release from previously frozen organic matter is caused by global warming, and will certainly diminish the budget of CO2 we can emit while staying below a certain level of global warming,” Dr Gasser said.

“It is also an irreversible process over the course of a few centuries, and may therefore be considered a ‘tipping’ element of the Earth’s carbon-climate system that puts the linear approximation of the emission budget framework to the test.”

The message behind the formal language of a paper in the journal Nature Geoscience is simple: the world has less time to act than the presidents and prime ministers who signed the Paris Declaration may think.

But this is no surprise. Right from the start, leading climate scientists were warning that the planet could already be much nearer its optimum target than anybody suspected.

Other researchers have repeatedly stressed the need for urgency, and the inadequacy of any of the prepared responses.

Feedback concern

Concern about the permafrost, too, is not new: polar researchers have been arguing for years that any thaw will increase the atmospheric carbon burden, which will in turn accelerate further warning, with potentially catastrophic consequences.

It is one thing to slow the rate of global warming by drastically reducing fossil fuel emissions and restoring the world’s forests so as to arrive at a limit; quite another thing to overshoot the limit and then try to reduce the planetary temperature, the latest study suggests. There is no simple correlation between burning coal or oil and the planetary temperatures that follow.

“Overshooting is a risky strategy and getting back to lower levels after an overshoot will be extremely difficult. However, since we are officially on an overshooting trajectory, we have to prepare ourselves for the possibility that we may never get back to safer levels of warming,” Dr Gasser said.

“Policymakers should understand that there is no elementary proportionality between cumulative CO2 emissions due to human activity and global temperature, as previously believed, and that overshooting may have serious consequences.” – Climate News Network


 

Nature may explain North Atlantic circulation

Ocean circulation distributes the planet’s heat. If the North Atlantic circulation slows, is it because of global warming, or a natural cycle?

LONDON, 26 July, 2018 – The world can breathe again. Europe can relax: the glaciers will not return. The North Atlantic circulation may resume its former pace and the Gulf Stream slowdown could be coming to an end.

But that may not be entirely good news. Global warming could also be about to accelerate, according to new research into one of oceanography’s most enigmatic phenomena, the North Atlantic Meridional Overturning Circulation.

New studies of all the data so far by an ocean scientist and a mathematician say that what affects North Atlantic circulation may not be driven by man-made climate change. The ocean may be responding to a very long-term natural climate cycle.

At the heart of the puzzle is a simple fact. The flow of warm water from the tropical Atlantic right up to the coast of northern Norway has a dramatic impact on western Europe’s climate. This means that the United Kingdom, France, and other nations are conspicuously warmer than they might be if latitude was the only factor.

“We do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic”

A former UK chief scientist once calculated that the Gulf Stream contributed 27,000 times the warmth generated by all the UK’s power stations. But theorists argued that as the Arctic region warmed, the rate of flow could diminish, and paradoxically throw Europe into a new little Ice Age. A 2004 Hollywood disaster movie called The Day After Tomorrow followed this logic, with Britain frozen and glaciers cascading south into the US.

In fact, no such calamitous and sudden return of the intense and lethal cold could happen, but researchers have since then consistently observed a pattern of slowing in the North Atlantic circulation, linked such slowdowns to global warming
driven by profligate use of fossil fuels that enrich the levels of greenhouse gases in the atmosphere, and repeatedly warned that the consequences could be costly or even devastating.

But a new study of the data available exposes other possibilities. In the first place, climate scientists have direct measurements of the circulation strength only from 2004, and the decline measured since then has been 10 times more than anyone expected. Perhaps the slowdown could be just part of a regular, rhythmic cycle that happens independently of anything humans have done to trigger global warming, researchers say in the journal Nature.

“Many have focused on the fact that it’s declining very rapidly, and that if the trend continues it will go past a tipping point, bringing a catastrophe such as an ice age,” said Ka-Kit Tung, a mathematician at the University of Washington in the US.

Already over

“It turns out that none of that is going to happen in the near future. The fast response may instead be part of a natural cycle and there are signs that the decline is already ending.”

The Atlantic Meridional Overturning Circulation takes warm surface water northward. The dense salty water sinks into the Labrador and Nordic Seas and returns at depth all the way to the Southern Ocean, to rise again. The puzzle is what happens next.

As the current sinks in the far north, it carries heat away from the surface. But the same transport of heat causes the northern glaciers to recede, and melt, diluting the saline water and making it less likely to sink. So the circulation slows.

The reasoning that follows is that, in a slow phase, the North Atlantic becomes cooler, the ice melt slows, the fresh meltwater sources begin to dry up and the heavier, saltier water plunges more urgently, and the whole circulation speeds up again.

Disagreement

And if this happens in a natural cycle – and not all climate scientists and oceanographers will agree – it is one that lasts for many decades: 60 to 70 years. But oceanographers don’t have the more than 60 to 70 years of measurements needed to confirm this pattern.

“We have about one cycle of observations at depth, so we do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic,” said Professor Tung.

“The good news is that the indicators show that this slowdown of the Atlantic overturning circulation is ending, and so we shouldn’t be alarmed that this current will collapse any time soon.

“The bad news is that surface temperatures are likely to start rising more quickly in the coming decades.” – Climate News Network

Ocean circulation distributes the planet’s heat. If the North Atlantic circulation slows, is it because of global warming, or a natural cycle?

LONDON, 26 July, 2018 – The world can breathe again. Europe can relax: the glaciers will not return. The North Atlantic circulation may resume its former pace and the Gulf Stream slowdown could be coming to an end.

But that may not be entirely good news. Global warming could also be about to accelerate, according to new research into one of oceanography’s most enigmatic phenomena, the North Atlantic Meridional Overturning Circulation.

New studies of all the data so far by an ocean scientist and a mathematician say that what affects North Atlantic circulation may not be driven by man-made climate change. The ocean may be responding to a very long-term natural climate cycle.

At the heart of the puzzle is a simple fact. The flow of warm water from the tropical Atlantic right up to the coast of northern Norway has a dramatic impact on western Europe’s climate. This means that the United Kingdom, France, and other nations are conspicuously warmer than they might be if latitude was the only factor.

“We do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic”

A former UK chief scientist once calculated that the Gulf Stream contributed 27,000 times the warmth generated by all the UK’s power stations. But theorists argued that as the Arctic region warmed, the rate of flow could diminish, and paradoxically throw Europe into a new little Ice Age. A 2004 Hollywood disaster movie called The Day After Tomorrow followed this logic, with Britain frozen and glaciers cascading south into the US.

In fact, no such calamitous and sudden return of the intense and lethal cold could happen, but researchers have since then consistently observed a pattern of slowing in the North Atlantic circulation, linked such slowdowns to global warming
driven by profligate use of fossil fuels that enrich the levels of greenhouse gases in the atmosphere, and repeatedly warned that the consequences could be costly or even devastating.

But a new study of the data available exposes other possibilities. In the first place, climate scientists have direct measurements of the circulation strength only from 2004, and the decline measured since then has been 10 times more than anyone expected. Perhaps the slowdown could be just part of a regular, rhythmic cycle that happens independently of anything humans have done to trigger global warming, researchers say in the journal Nature.

“Many have focused on the fact that it’s declining very rapidly, and that if the trend continues it will go past a tipping point, bringing a catastrophe such as an ice age,” said Ka-Kit Tung, a mathematician at the University of Washington in the US.

Already over

“It turns out that none of that is going to happen in the near future. The fast response may instead be part of a natural cycle and there are signs that the decline is already ending.”

The Atlantic Meridional Overturning Circulation takes warm surface water northward. The dense salty water sinks into the Labrador and Nordic Seas and returns at depth all the way to the Southern Ocean, to rise again. The puzzle is what happens next.

As the current sinks in the far north, it carries heat away from the surface. But the same transport of heat causes the northern glaciers to recede, and melt, diluting the saline water and making it less likely to sink. So the circulation slows.

The reasoning that follows is that, in a slow phase, the North Atlantic becomes cooler, the ice melt slows, the fresh meltwater sources begin to dry up and the heavier, saltier water plunges more urgently, and the whole circulation speeds up again.

Disagreement

And if this happens in a natural cycle – and not all climate scientists and oceanographers will agree – it is one that lasts for many decades: 60 to 70 years. But oceanographers don’t have the more than 60 to 70 years of measurements needed to confirm this pattern.

“We have about one cycle of observations at depth, so we do not know if it is periodic, but based on the surface phenomena we think it’s very likely it is episodic,” said Professor Tung.

“The good news is that the indicators show that this slowdown of the Atlantic overturning circulation is ending, and so we shouldn’t be alarmed that this current will collapse any time soon.

“The bad news is that surface temperatures are likely to start rising more quickly in the coming decades.” – Climate News Network

Alien seaweed arrives in Antarctica

For more than a century, scientists believed that only humans could cross the hostile oceans to reach Antarctica. Some strands of alien seaweed tell another story.

LONDON, 19 July, 2018 – A foreign invader, a species of alien seaweed, has managed to cross the oceans to reach the frozen Antarctic shores. So scientists may have to give up a cherished belief: that Antarctica is inviolate.

For a century, researchers have assumed that the mix of ocean currents, distance and temperature have kept the Great White Continent shielded from invasion by Pacific or Atlantic flotsam.

But the discovery of strands of kelp on an Antarctic beach – seaweed that may have drifted for considerable periods and a distance of 20,000 kms before becoming stranded far from home – brings an end to that belief. And the discovery suggests that global warming could bring serious changes to Antarctic ecosystems.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected”

“This finding shows us that living plants and animals can reach Antarctica across the ocean, with temperate and sub-Antarctic marine species probably bombarding Antarctic coastlines all the time,” said Ceridwen Fraser, of the Australian National University.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research now suggests these differences are almost entirely due to environmental extremes, not isolation.”

Dr Fraser and her colleagues report in the journal Nature Climate Change that strands of southern bull kelp, Durvillaea antarctica, found by a Chilean scientist, must have floated 20,000 km from the Kerguelen Islands and South Georgia. The kelp was encrusted with barnacles, evidence of a long time adrift.

In fact, researchers believe, it may be evidence of the longest episode of “biological rafting” ever confirmed. The word raft is significant: such floating platforms could provide shelter and transport for other biological invaders.

Plastic next?

Until now, the assumption has been that the pattern of surface currents and westerly winds tends to drive drifting material northwards from Antarctica. The discovery suggests that if kelp can get there, so can floating driftwood, or plastic debris, or any other unwelcome visitor.

The researchers think large waves driven by Southern Ocean storms may have steered the kelp rafts over what had been considered a natural ocean barrier. Global warming has begun to change conditions in Antarctica, and the continent – considered the last great tract of terrain unmarked by human colonisation – could become increasingly vulnerable to change.

“This is an unequivocal demonstration that marine species from the north can reach Antarctica. To get there the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable,” Dr Fraser said.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected.” – Climate News Network

For more than a century, scientists believed that only humans could cross the hostile oceans to reach Antarctica. Some strands of alien seaweed tell another story.

LONDON, 19 July, 2018 – A foreign invader, a species of alien seaweed, has managed to cross the oceans to reach the frozen Antarctic shores. So scientists may have to give up a cherished belief: that Antarctica is inviolate.

For a century, researchers have assumed that the mix of ocean currents, distance and temperature have kept the Great White Continent shielded from invasion by Pacific or Atlantic flotsam.

But the discovery of strands of kelp on an Antarctic beach – seaweed that may have drifted for considerable periods and a distance of 20,000 kms before becoming stranded far from home – brings an end to that belief. And the discovery suggests that global warming could bring serious changes to Antarctic ecosystems.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected”

“This finding shows us that living plants and animals can reach Antarctica across the ocean, with temperate and sub-Antarctic marine species probably bombarding Antarctic coastlines all the time,” said Ceridwen Fraser, of the Australian National University.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research now suggests these differences are almost entirely due to environmental extremes, not isolation.”

Dr Fraser and her colleagues report in the journal Nature Climate Change that strands of southern bull kelp, Durvillaea antarctica, found by a Chilean scientist, must have floated 20,000 km from the Kerguelen Islands and South Georgia. The kelp was encrusted with barnacles, evidence of a long time adrift.

In fact, researchers believe, it may be evidence of the longest episode of “biological rafting” ever confirmed. The word raft is significant: such floating platforms could provide shelter and transport for other biological invaders.

Plastic next?

Until now, the assumption has been that the pattern of surface currents and westerly winds tends to drive drifting material northwards from Antarctica. The discovery suggests that if kelp can get there, so can floating driftwood, or plastic debris, or any other unwelcome visitor.

The researchers think large waves driven by Southern Ocean storms may have steered the kelp rafts over what had been considered a natural ocean barrier. Global warming has begun to change conditions in Antarctica, and the continent – considered the last great tract of terrain unmarked by human colonisation – could become increasingly vulnerable to change.

“This is an unequivocal demonstration that marine species from the north can reach Antarctica. To get there the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable,” Dr Fraser said.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected.” – Climate News Network

Arctic permafrost set for faster carbon leak

Researchers now know more about the intricate mechanisms of change in the thawing Arctic permafrost. And what they know is ominous.

LONDON, 18 July, 2018 – The Arctic permafrost – a frozen store of at least half the planet’s organic carbon – could be about to release more carbon in the form of greenhouse gases than it absorbs in the growing season.

A 42-year study of atmospheric carbon dioxide over the north slope of Alaska reveals that the “cycling time” – that is, the time a quantity of carbon is locked away in the frozen subsurface of the tundra regions – has been reduced by more than 13% over four decades.

This means that in response to global warming, the world’s greatest single store of ancient sunshine in the form of peat and other preserved vegetation is about to surrender yet more carbon dioxide and methane, and accelerate the process.

And a second study delivers better understanding of the mechanisms that will get to work as the permafrost thaws.

All decay from foliage and wood is achieved by soil microbes – and researchers have now taken more than 200 samples from a stretch of once-frozen bog and fen in northern Sweden to identify the genomic mix of fungi, bacteria and archaeo-bacteria ready and waiting to turn old vegetation back into atmospheric carbon.

“Large amounts of carbon sequestered in perennially frozen permafrost are becoming available for microbial degradation”

The first study is published in the journal Science Advances: Korean, US and Chinese scientists went to the data archives of the US National Oceanic and Atmospheric Administration to analyse the variations in carbon dioxide over Barrow, Alaska between 1974 and 2015.

Levels vary naturally from season to season as plants flower, bloom and die back in the brief polar summer. But over the 42-year span of the study, the scientists also found a pattern of change.

Respiration during the early cold season was, under the warming of the last four decades, beginning to outpace the take-up of carbon during the growing season, as the tundra dwindled, and the boreal woodlands began to march northwards.

And, they warn, by 2100 this potentially means an increase in atmospheric concentrations of greenhouse gases, an increase of from 50 billion tonnes of carbon to 200 billion tonnes.

More accurate prediction

Swedish and US researchers, led by Australian microbiologists, report in the journal Nature that they used new software to identify the DNA of 1,500 microbe samples, all new to science, and all little cogs in the complex machinery of decay, found in the thawed, partially thawed, and frozen first three metres of northern Swedish permafrost.

With luck and patience, the extra understanding of the biochemistry of change in the permafrost should lead to more accurate predictions of global warming.

“As global temperatures rise, large amounts of carbon sequestered in perennially frozen permafrost are becoming available for microbial degradation,” said Ben Woodcroft, of the Australian Centre for Ecogenomics at the University of Queensland, who led the research.

“Until now, accurate prediction of greenhouse gas emissions produced from thawing permafrost has been limited by our understanding of permafrost microbial communities and their carbon metabolisms.” – Climate News Network

Researchers now know more about the intricate mechanisms of change in the thawing Arctic permafrost. And what they know is ominous.

LONDON, 18 July, 2018 – The Arctic permafrost – a frozen store of at least half the planet’s organic carbon – could be about to release more carbon in the form of greenhouse gases than it absorbs in the growing season.

A 42-year study of atmospheric carbon dioxide over the north slope of Alaska reveals that the “cycling time” – that is, the time a quantity of carbon is locked away in the frozen subsurface of the tundra regions – has been reduced by more than 13% over four decades.

This means that in response to global warming, the world’s greatest single store of ancient sunshine in the form of peat and other preserved vegetation is about to surrender yet more carbon dioxide and methane, and accelerate the process.

And a second study delivers better understanding of the mechanisms that will get to work as the permafrost thaws.

All decay from foliage and wood is achieved by soil microbes – and researchers have now taken more than 200 samples from a stretch of once-frozen bog and fen in northern Sweden to identify the genomic mix of fungi, bacteria and archaeo-bacteria ready and waiting to turn old vegetation back into atmospheric carbon.

“Large amounts of carbon sequestered in perennially frozen permafrost are becoming available for microbial degradation”

The first study is published in the journal Science Advances: Korean, US and Chinese scientists went to the data archives of the US National Oceanic and Atmospheric Administration to analyse the variations in carbon dioxide over Barrow, Alaska between 1974 and 2015.

Levels vary naturally from season to season as plants flower, bloom and die back in the brief polar summer. But over the 42-year span of the study, the scientists also found a pattern of change.

Respiration during the early cold season was, under the warming of the last four decades, beginning to outpace the take-up of carbon during the growing season, as the tundra dwindled, and the boreal woodlands began to march northwards.

And, they warn, by 2100 this potentially means an increase in atmospheric concentrations of greenhouse gases, an increase of from 50 billion tonnes of carbon to 200 billion tonnes.

More accurate prediction

Swedish and US researchers, led by Australian microbiologists, report in the journal Nature that they used new software to identify the DNA of 1,500 microbe samples, all new to science, and all little cogs in the complex machinery of decay, found in the thawed, partially thawed, and frozen first three metres of northern Swedish permafrost.

With luck and patience, the extra understanding of the biochemistry of change in the permafrost should lead to more accurate predictions of global warming.

“As global temperatures rise, large amounts of carbon sequestered in perennially frozen permafrost are becoming available for microbial degradation,” said Ben Woodcroft, of the Australian Centre for Ecogenomics at the University of Queensland, who led the research.

“Until now, accurate prediction of greenhouse gas emissions produced from thawing permafrost has been limited by our understanding of permafrost microbial communities and their carbon metabolisms.” – Climate News Network

West Antarctica’s rocks’ rise may slow ice melt

The southern continent is changing fast. West Antarctica’s rocks are on the rise, something which could slow the rate of ice melt.

LONDON, 26 June, 2018 – Its ice sheet may be melting, but West Antarctica’s rocks are on the way up. In a dramatic demonstration of geology’s in-depth response to surface change, the submerged bedrock of that part of the southern continent is springing upwards at 41mm a year.

And as it does so, it may slow the rate of inexorable ice melt, as the western part of the continent sheds ice in response to global warming driven by profligate human combustion of fossil fuels.

But for the moment the finding is yet another surprising demonstration of what geophysicists call isostatic response: as mass is shifted from the surface of the continent – and that region of Antarctica has lost three trillion metric tons of ice in the last 25 years – the semi-liquid rocks of the Earth’s mantle, deep below the continental crust, flow below the lightening burden to liftthe crustal rocks higher.

This rate of rise is unexpectedly rapid. As more ice melts, the process is likely to accelerate. A century from now, that stretch of Antarctic peninsula could have risen by 8 metres.

“To keep global sea levels from rising more than a few feet this century and beyond, we must still limit greenhouse gas concentrations in the atmosphere”

“When the ice melts and gets thinner, the Earth readjusts, and rises immediately by a few millimetres, which depends on the ice lost,” said Valentina Barletta, of the Technical University of Denmark, who led the research.

“But the earth also acts a bit like a very hard memory-foam mattress. And it slowly keeps readjusting for several thousand years after the melting. In Scandinavia the bedrock is still rising about 10 millimetres per year because of the last ice age.”

Dr Barletta and US colleagues report in the journal Science that they gathered data from six global positioning satellite stations fixed to the exposed rock around a stretch of West Antarctica called the Amundsen Sea embayment.

They coupled that with seismic studies of the crustal bedrock and then ran an immense number of computer simulations to settle on the most likely explanation – that deep beneath that point of the southern continent, the Earth’s mantle was relatively hotter and more fluid, and could respond to changes in mass more swiftly.

Polar perplexities

At the heart of such research is the puzzle of southern polar dynamics: the complex interplay of ocean, atmosphere, precipitation and topography that keeps Antarctica the coldest, driest, iciest place on the planet: it may be technically a desert, but its continental crust carries almost two thirds of the world’s freshwater in frozen form. If it all melted, global sea levels would rise by 70 metres.

But such is the weight of ice that some parts of the continent are depressed below sea level. In West Antarctica the surrounding sea ice is so thick it is anchored to submerged bedrock, to provide a buffer that slows the rate of glacial flow from inland.

Right now, the West Antarctic Ice Sheet is spilling into the oceans the equivalent of a quarter of all the planet’s melting ice. If all of West Antarctica were to melt, global sea levels would rise by three metres.

And the fear is that, as the oceans and atmosphere warm in response to ever-rising levels of greenhouse gases in the atmosphere, winds and currents could loosen the great shelves of sea ice and send them floating north, at which point the glacial flow from the high ground of the continent to the sea would accelerate.

Stability explained

So the latest discovery helps explain the wider puzzle of why Antarctica’s ice has been relatively stable over long geological periods: as the ice melts, the bedrock rises, and the ice shelves are more likely to stay anchored to the mainland, at least at that particular “pinning point” above a hotter, more fluid mantle.

There is another factor at work: the gravitational pull of the ice itself, which raises sea level near the great mass of ancient polar ice. As the ice melts, the gravitational tug diminishes, and the sea levels subside.

“The lowering of the sea level, the rising of the pinning points and the decrease of the inland slope due to the uplift of the bedrock are all feedbacks that can stabilise the ice sheet,” said Terry Wilson, of Ohio State University, and one of the authors. “Under many realistic climate models, this should be enough to stabilise the ice sheet.”

But as planetary average temperatures rise, so does the hazard. Rick Aster, of Colorado State University, and another of the authors, warned: “To keep global sea levels from rising more than a few feet this century and beyond, we must still limit greenhouse gas concentrations in the atmosphere, which can only occur through international cooperation and innovation.” – Climate News Network

The southern continent is changing fast. West Antarctica’s rocks are on the rise, something which could slow the rate of ice melt.

LONDON, 26 June, 2018 – Its ice sheet may be melting, but West Antarctica’s rocks are on the way up. In a dramatic demonstration of geology’s in-depth response to surface change, the submerged bedrock of that part of the southern continent is springing upwards at 41mm a year.

And as it does so, it may slow the rate of inexorable ice melt, as the western part of the continent sheds ice in response to global warming driven by profligate human combustion of fossil fuels.

But for the moment the finding is yet another surprising demonstration of what geophysicists call isostatic response: as mass is shifted from the surface of the continent – and that region of Antarctica has lost three trillion metric tons of ice in the last 25 years – the semi-liquid rocks of the Earth’s mantle, deep below the continental crust, flow below the lightening burden to liftthe crustal rocks higher.

This rate of rise is unexpectedly rapid. As more ice melts, the process is likely to accelerate. A century from now, that stretch of Antarctic peninsula could have risen by 8 metres.

“To keep global sea levels from rising more than a few feet this century and beyond, we must still limit greenhouse gas concentrations in the atmosphere”

“When the ice melts and gets thinner, the Earth readjusts, and rises immediately by a few millimetres, which depends on the ice lost,” said Valentina Barletta, of the Technical University of Denmark, who led the research.

“But the earth also acts a bit like a very hard memory-foam mattress. And it slowly keeps readjusting for several thousand years after the melting. In Scandinavia the bedrock is still rising about 10 millimetres per year because of the last ice age.”

Dr Barletta and US colleagues report in the journal Science that they gathered data from six global positioning satellite stations fixed to the exposed rock around a stretch of West Antarctica called the Amundsen Sea embayment.

They coupled that with seismic studies of the crustal bedrock and then ran an immense number of computer simulations to settle on the most likely explanation – that deep beneath that point of the southern continent, the Earth’s mantle was relatively hotter and more fluid, and could respond to changes in mass more swiftly.

Polar perplexities

At the heart of such research is the puzzle of southern polar dynamics: the complex interplay of ocean, atmosphere, precipitation and topography that keeps Antarctica the coldest, driest, iciest place on the planet: it may be technically a desert, but its continental crust carries almost two thirds of the world’s freshwater in frozen form. If it all melted, global sea levels would rise by 70 metres.

But such is the weight of ice that some parts of the continent are depressed below sea level. In West Antarctica the surrounding sea ice is so thick it is anchored to submerged bedrock, to provide a buffer that slows the rate of glacial flow from inland.

Right now, the West Antarctic Ice Sheet is spilling into the oceans the equivalent of a quarter of all the planet’s melting ice. If all of West Antarctica were to melt, global sea levels would rise by three metres.

And the fear is that, as the oceans and atmosphere warm in response to ever-rising levels of greenhouse gases in the atmosphere, winds and currents could loosen the great shelves of sea ice and send them floating north, at which point the glacial flow from the high ground of the continent to the sea would accelerate.

Stability explained

So the latest discovery helps explain the wider puzzle of why Antarctica’s ice has been relatively stable over long geological periods: as the ice melts, the bedrock rises, and the ice shelves are more likely to stay anchored to the mainland, at least at that particular “pinning point” above a hotter, more fluid mantle.

There is another factor at work: the gravitational pull of the ice itself, which raises sea level near the great mass of ancient polar ice. As the ice melts, the gravitational tug diminishes, and the sea levels subside.

“The lowering of the sea level, the rising of the pinning points and the decrease of the inland slope due to the uplift of the bedrock are all feedbacks that can stabilise the ice sheet,” said Terry Wilson, of Ohio State University, and one of the authors. “Under many realistic climate models, this should be enough to stabilise the ice sheet.”

But as planetary average temperatures rise, so does the hazard. Rick Aster, of Colorado State University, and another of the authors, warned: “To keep global sea levels from rising more than a few feet this century and beyond, we must still limit greenhouse gas concentrations in the atmosphere, which can only occur through international cooperation and innovation.” – Climate News Network

Antarctic buffer damage spurs ice break-up

The Antarctic buffer which has for millennia sheltered the continent’s huge inland ice sheet is being battered by seaborne wave action.

LONDON, 21 June, 2018 – The vast southern ice sheet, despite the Antarctic buffer which has protected it for so long, is now being threatened by ocean swells chipping away at the continent’s coastal edge, says a new study by US scientists published in the journal Nature.

For millennia the southern ice sheet has had this protective buffer of sea ice ringing its coastal shelves. But now the swells from the north are flexing them and can weaken their stabilising seaward edge. Regular inundation by summer meltwater as the edge breaks away can also contribute to rapid ice shelf disintegration.

Ice shelves, with their ring of sea ice, are thick plates of ice fed by tributary glaciers, floating seaward extensions of the massive grounded inland ice sheet. They slow the flow of ice from the sheet, so rapidly disintegrating shelves have implications for sea level rise.

“Sea ice here acts like the bumpers on a car – with the bumpers in place, the car can take a shock and not be damaged. Take them off, and every hit adds up,” said Ted Scambos, study co-author and senior research scientist at the National Snow and Ice Data Center at the University of Colorado Boulder.

Since 1995, three large ice shelves on the Antarctic Peninsula – Larsen A, Larsen B and Wilkins – have suddenly and dramatically disintegrated.
Occurring over a few weeks, or sometimes even only a few days, these break-ups mark an unprecedented departure from the more typical and natural recurring calving of larger icebergs every decade or so.

Trigger found

Until recently researchers had thought intense surface melting caused by a warming climate and ice fracturing were the sole culprits. But the new findings suggest that loss of sea ice and the calving of the seaward edge into narrow sliver-like icebergs are the trigger that sets off a rapid ice shelf disintegration.

“Our study breaks new ground in how it implicates sea ice change in sea level rise,” said Rob Massom, the study’s lead author and a senior research scientist at the Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre.

“It introduces ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer as the straw that breaks the camel’s back.”

He and his colleagues analysed disintegrations on three ice shelves that had been stable for centuries or even millennia: Larsen A in 1995, Larsen B in 2002, and Wilkins in 2008 and 2009.

They confirmed that atmospheric warming led to increased meltwater on the surfaces of the shelves. Pooled meltwater then percolated downward through crevasses, setting off a hydrofracturing process that weakened the ice.

“Ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer [is] the straw that breaks the camel’s back”

Earlier studies have identified the central role that ice shelves play in making sea level rise more likely and the accelerating pace of Antarctic melting.

But, crucially, what the NSIDC analysis reveals is a previously little-recognised link to sea ice: all three disintegrations happened when there was little or no sea ice cover along the shelf edge. Without that protective buffer, the shelves became exposed to waves which flexed the already fractured ice.

“What we’ve found is that increased flexing of the outer parts of ice shelves by waves sets the ice up for destruction. Even though the movement is tiny, over time the shelf is weakened,” Scambos said.

In each case, ocean swells began affecting the ice shelf edge. As the shelves flexed, existing fractures along the seaward edge chipped off as long, thin, sliver-shaped icebergs, not the larger tabular icebergs more typical of Antarctic ice shelf calvings. The remaining ice shelf was then ripe for runaway collapse.

“Other ice shelves can survive for centuries if they don’t have surface meltwater – or if the water can run off easily,” Scambos said. “But with meltwater ponding and a legacy of weakening from sea ice loss, you can destroy a shelf in just a few weeks.”

Pressure off

Because ice shelves are already floating in the ocean and displacing their volume, like ice cubes in a glass of water, their disintegration does not contribute directly to sea level rise.

But they do provide a backpressure that moderates glacier flow speed. Once they’re gone, so is the backpressure, allowing the glaciers to flow more rapidly into the ocean and ultimately contribute to sea level rise.

“This represents an important pathway towards reducing current large uncertainty in predictions of the response of the Antarctic cryosphere to climate change and its contribution to sea level rise,” Dr Massom said.

The Antarctic ice sheet contains enough ice to raise sea level by approximately 57 metres (187 feet), about half the length of a soccer pitch. Worldwide, more than 100 million people currently live within 1m of mean sea level. – Climate News Network

The Antarctic buffer which has for millennia sheltered the continent’s huge inland ice sheet is being battered by seaborne wave action.

LONDON, 21 June, 2018 – The vast southern ice sheet, despite the Antarctic buffer which has protected it for so long, is now being threatened by ocean swells chipping away at the continent’s coastal edge, says a new study by US scientists published in the journal Nature.

For millennia the southern ice sheet has had this protective buffer of sea ice ringing its coastal shelves. But now the swells from the north are flexing them and can weaken their stabilising seaward edge. Regular inundation by summer meltwater as the edge breaks away can also contribute to rapid ice shelf disintegration.

Ice shelves, with their ring of sea ice, are thick plates of ice fed by tributary glaciers, floating seaward extensions of the massive grounded inland ice sheet. They slow the flow of ice from the sheet, so rapidly disintegrating shelves have implications for sea level rise.

“Sea ice here acts like the bumpers on a car – with the bumpers in place, the car can take a shock and not be damaged. Take them off, and every hit adds up,” said Ted Scambos, study co-author and senior research scientist at the National Snow and Ice Data Center at the University of Colorado Boulder.

Since 1995, three large ice shelves on the Antarctic Peninsula – Larsen A, Larsen B and Wilkins – have suddenly and dramatically disintegrated.
Occurring over a few weeks, or sometimes even only a few days, these break-ups mark an unprecedented departure from the more typical and natural recurring calving of larger icebergs every decade or so.

Trigger found

Until recently researchers had thought intense surface melting caused by a warming climate and ice fracturing were the sole culprits. But the new findings suggest that loss of sea ice and the calving of the seaward edge into narrow sliver-like icebergs are the trigger that sets off a rapid ice shelf disintegration.

“Our study breaks new ground in how it implicates sea ice change in sea level rise,” said Rob Massom, the study’s lead author and a senior research scientist at the Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre.

“It introduces ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer as the straw that breaks the camel’s back.”

He and his colleagues analysed disintegrations on three ice shelves that had been stable for centuries or even millennia: Larsen A in 1995, Larsen B in 2002, and Wilkins in 2008 and 2009.

They confirmed that atmospheric warming led to increased meltwater on the surfaces of the shelves. Pooled meltwater then percolated downward through crevasses, setting off a hydrofracturing process that weakened the ice.

“Ocean wave-induced breakage of the outer margins of ice shelves following loss of a protective sea ice buffer [is] the straw that breaks the camel’s back”

Earlier studies have identified the central role that ice shelves play in making sea level rise more likely and the accelerating pace of Antarctic melting.

But, crucially, what the NSIDC analysis reveals is a previously little-recognised link to sea ice: all three disintegrations happened when there was little or no sea ice cover along the shelf edge. Without that protective buffer, the shelves became exposed to waves which flexed the already fractured ice.

“What we’ve found is that increased flexing of the outer parts of ice shelves by waves sets the ice up for destruction. Even though the movement is tiny, over time the shelf is weakened,” Scambos said.

In each case, ocean swells began affecting the ice shelf edge. As the shelves flexed, existing fractures along the seaward edge chipped off as long, thin, sliver-shaped icebergs, not the larger tabular icebergs more typical of Antarctic ice shelf calvings. The remaining ice shelf was then ripe for runaway collapse.

“Other ice shelves can survive for centuries if they don’t have surface meltwater – or if the water can run off easily,” Scambos said. “But with meltwater ponding and a legacy of weakening from sea ice loss, you can destroy a shelf in just a few weeks.”

Pressure off

Because ice shelves are already floating in the ocean and displacing their volume, like ice cubes in a glass of water, their disintegration does not contribute directly to sea level rise.

But they do provide a backpressure that moderates glacier flow speed. Once they’re gone, so is the backpressure, allowing the glaciers to flow more rapidly into the ocean and ultimately contribute to sea level rise.

“This represents an important pathway towards reducing current large uncertainty in predictions of the response of the Antarctic cryosphere to climate change and its contribution to sea level rise,” Dr Massom said.

The Antarctic ice sheet contains enough ice to raise sea level by approximately 57 metres (187 feet), about half the length of a soccer pitch. Worldwide, more than 100 million people currently live within 1m of mean sea level. – Climate News Network

Antarctica’s melting is accelerating faster

Scientists have just completed the most detailed mass observation of the southern continent so far. The news is ominous: Antarctica’s melting is speeding up.

LONDON, 14 June, 2018 – The speed of Antarctica’s melting has begun to gather pace. Between 1992 and 2017, the rate of loss of ice from West Antarctica has risen threefold, from 59 billion metric tons per year to 159bn. The West Antarctic peninsula, one of the fastest warming places on Earth, has seen ice loss soar from 7bn to 33bn tonnes a year in that timespan, as ice shelves have collapsed.

Altogether, in those 25 years, Antarctica has lost more than a trillion tonnes of ice. Since the southern continent is the biggest store of freshwater on the planet – if it all melted, the sea levels would rise by 58 metres – the news is ominous. It means that melting in Antarctica alone has raised global sea levels by 8mm, as global average temperatures rise, in response to ever-higher levels of carbon dioxide in the atmosphere.

And if the world’s economies go on burning the fossil fuels that have driven rising levels of greenhouse gases, then by 2070 global sea levels will rise even faster – by a metre, with one fourth of that from Antarctic meltwater – and ever more ice will be lost from the Southern Ocean.

This in turn will drive big changes in the marine ecosystems of the Antarctic and for the first time permit invasive pests to colonise what was once a pristine, unspoiled landscape.

“If we aren’t already alert to the dangers posed by climate change, this should be an enormous wake-up call”

But such an outcome is not inevitable. “The future of Antarctica is tied to that of the rest of the planet and human society,” said Steve Rintoul, of the Centre for Southern Hemisphere Oceans Research in Hobart, Tasmania, and one of the research team.

Actions can be taken now that will slow the rate of environmental change, increase the resilience of Antarctica, and reduce the risk that we commit to irreversible changes with widespread impact.”

A series of research papers in the journal Nature tells a story of ice loss and global concern. A team of 84 scientists from 44 international organisations have amalgamated 24 satellite surveys of change in the farthest south with greater precision that any other study so far.

“According to our analysis, there has been a steep increase in ice losses from Antarctica during the last decade, and the continent is causing sea levels to rise faster today than at any time in the past 25 years,” said Andrew Shepherd of the University of Leeds, UK, who led the assessment. “This has to be a concern for the governments we trust to protect our coastal cities and communities.”

None of this is a surprise: what is new about the latest research is the confidence with which the researchers speak. Human exploration of Antarctica began little more than a century ago, and systematic scientific observation began only in the mid-20th century.

Diminishing argument

Antarctic ice has retreated and advanced and retreated again many times over the millennia: there has always been argument about how much of the change is because of natural cycles, how much because of human-induced climate change. In the last few years, the contribution of warmer oceans and warmer atmosphere has begun to become obvious.

Researchers have warned that warmer seas make faster melting inevitable and that by 2050 the rate of loss could double.

Using both direct observation and remote sensing, they have watched fresh water running off the polar surface in the summer and recorded the first signs of invasive plants on rocks that were once all but barren.

And now data from satellites launched by the European Space Agency, Japan, Canada, NASA, Italy and Germany has been combined into something known as the Ice Sheet Mass Balance Inter-comparison Exercise, or IMBIE for short. And it has settled one of the great uncertainties.

Continent-wide picture

While the western Antarctica ice sheet has been steadily melting, there has been evidence that East Antarctica itself was stable, or even growing. The latest study settles an old argument: the combined evidence suggests that East Antarctica is more or less stable, gaining if anything 5bn tonnes a year on average, perhaps because of greater snowfall.

Overall, though, the continent is losing the mass of its ice, and if the world continues to warm, this loss can only accelerate.

“Unfortunately, we appear to be on a pathway to substantial ice-sheet loss in the decades ahead, with longer-term consequences for enhanced sea-level rise; something that has been predicted in models for some time.

“If we aren’t already alert to the dangers posed by climate change, this should be an enormous wake-up call,” said Martin Siegert, of the Grantham Institute at Imperial College London, and one of the authors.

“Antarctica is being affected by global warming, and unless we curtail our CO2 emissions within the next decade, and have a zero carbon economy within a few decades, we will be locked into substantial global changes, including those in Antarctica and the Southern Ocean.” – Climate News Network

Scientists have just completed the most detailed mass observation of the southern continent so far. The news is ominous: Antarctica’s melting is speeding up.

LONDON, 14 June, 2018 – The speed of Antarctica’s melting has begun to gather pace. Between 1992 and 2017, the rate of loss of ice from West Antarctica has risen threefold, from 59 billion metric tons per year to 159bn. The West Antarctic peninsula, one of the fastest warming places on Earth, has seen ice loss soar from 7bn to 33bn tonnes a year in that timespan, as ice shelves have collapsed.

Altogether, in those 25 years, Antarctica has lost more than a trillion tonnes of ice. Since the southern continent is the biggest store of freshwater on the planet – if it all melted, the sea levels would rise by 58 metres – the news is ominous. It means that melting in Antarctica alone has raised global sea levels by 8mm, as global average temperatures rise, in response to ever-higher levels of carbon dioxide in the atmosphere.

And if the world’s economies go on burning the fossil fuels that have driven rising levels of greenhouse gases, then by 2070 global sea levels will rise even faster – by a metre, with one fourth of that from Antarctic meltwater – and ever more ice will be lost from the Southern Ocean.

This in turn will drive big changes in the marine ecosystems of the Antarctic and for the first time permit invasive pests to colonise what was once a pristine, unspoiled landscape.

“If we aren’t already alert to the dangers posed by climate change, this should be an enormous wake-up call”

But such an outcome is not inevitable. “The future of Antarctica is tied to that of the rest of the planet and human society,” said Steve Rintoul, of the Centre for Southern Hemisphere Oceans Research in Hobart, Tasmania, and one of the research team.

Actions can be taken now that will slow the rate of environmental change, increase the resilience of Antarctica, and reduce the risk that we commit to irreversible changes with widespread impact.”

A series of research papers in the journal Nature tells a story of ice loss and global concern. A team of 84 scientists from 44 international organisations have amalgamated 24 satellite surveys of change in the farthest south with greater precision that any other study so far.

“According to our analysis, there has been a steep increase in ice losses from Antarctica during the last decade, and the continent is causing sea levels to rise faster today than at any time in the past 25 years,” said Andrew Shepherd of the University of Leeds, UK, who led the assessment. “This has to be a concern for the governments we trust to protect our coastal cities and communities.”

None of this is a surprise: what is new about the latest research is the confidence with which the researchers speak. Human exploration of Antarctica began little more than a century ago, and systematic scientific observation began only in the mid-20th century.

Diminishing argument

Antarctic ice has retreated and advanced and retreated again many times over the millennia: there has always been argument about how much of the change is because of natural cycles, how much because of human-induced climate change. In the last few years, the contribution of warmer oceans and warmer atmosphere has begun to become obvious.

Researchers have warned that warmer seas make faster melting inevitable and that by 2050 the rate of loss could double.

Using both direct observation and remote sensing, they have watched fresh water running off the polar surface in the summer and recorded the first signs of invasive plants on rocks that were once all but barren.

And now data from satellites launched by the European Space Agency, Japan, Canada, NASA, Italy and Germany has been combined into something known as the Ice Sheet Mass Balance Inter-comparison Exercise, or IMBIE for short. And it has settled one of the great uncertainties.

Continent-wide picture

While the western Antarctica ice sheet has been steadily melting, there has been evidence that East Antarctica itself was stable, or even growing. The latest study settles an old argument: the combined evidence suggests that East Antarctica is more or less stable, gaining if anything 5bn tonnes a year on average, perhaps because of greater snowfall.

Overall, though, the continent is losing the mass of its ice, and if the world continues to warm, this loss can only accelerate.

“Unfortunately, we appear to be on a pathway to substantial ice-sheet loss in the decades ahead, with longer-term consequences for enhanced sea-level rise; something that has been predicted in models for some time.

“If we aren’t already alert to the dangers posed by climate change, this should be an enormous wake-up call,” said Martin Siegert, of the Grantham Institute at Imperial College London, and one of the authors.

“Antarctica is being affected by global warming, and unless we curtail our CO2 emissions within the next decade, and have a zero carbon economy within a few decades, we will be locked into substantial global changes, including those in Antarctica and the Southern Ocean.” – Climate News Network

UK and US scientists tackle Antarctic glacier

British and American scientists are joining forces to research the melting of an Antarctic glacier in what they are calling a race against time. 

CAMBRIDGE, UK, 30 April, 2018 – An international team of scientists is mounting an ambitious research programme to find how soon a vast Antarctic glacier may collapse, with implications for sea levels worldwide.

The Thwaites Glacier in West Antarctica could significantly affect global sea levels. It already drains an area roughly the size of Britain or the US state of Florida, accounting for around 4% of global sea-level rise, an amount that has doubled since the mid-1990s. Its collapse would destabilise other parts of the ice sheet.

If – or more likely when – Thwaites and its neighbour, the Pine Island glacier, ultimately lose all their ice, one estimate suggests that could raise global sea levels by about 3.4m, enough to affect every coastal city on Earth.

Fastest-moving

Satellites have shown for more than a decade that the Thwaites region is an area of massive change and rapid ice loss as the global climate warms in response to rising greenhouse gas emissions from humans’ profligate use of fossil fuels. The two glaciers are among the fastest-moving in the Antarctic.

One of the scientists involved in the research is David Vaughan, director of science at the Cambridge-based British Antarctic Survey (BAS). He says he and his colleagues are involved in “a race against time”.

Professor Vaughan told the Climate News Network: “Understanding sea level rise is the front line of climate change, and sea level rise doesn’t happen overnight. [What’s happening to Thwaites] is not an emergency this year, but I’m very glad we’re doing the research this decade, because we can’t wait too long.”

Understanding collapse

As part of a new £20 million (roughly US$27.5m) research collaboration, the UK Natural Environment Research Council and the US National Science Foundation are about to send a team of scientists to Antarctica to gather the data needed to understand when the collapse of the Thwaites glacier could begin – in centuries, or in the next few decades.

NERC and NSF are jointly funding eight large-scale projects that will bring together leading polar scientists in the International Thwaites Glacier Collaboration (ITGC), the largest joint project undertaken by the two nations in Antarctica for more than 70 years. The ITGC involves around 100 scientists from leading research institutes in both countries with researchers from South Korea, Germany, Sweden, New Zealand and Finland.

There are signs that the process of Thwaites’ collapse has already begun. Antarctica’s glaciers add to sea-level rise when they lose more ice to the ocean than they gain from snowfall. To fully understand the causes of changes in ice flow requires research on the ice itself, the nearby ocean, and the Antarctic climate.

“Sea level rise doesn’t happen overnight. [It’s] not an emergency this year, but I’m very glad we’re doing the research this decade, because we can’t wait too long”

The Collaboration will use drills that can make access holes 1,500 metres into the ice with jets of hot water, as well as other state-of-the-art techniques and equipment, such as autonomous submarines like the Autosub Long Range, the first of whose fleet is named Boaty McBoatface.

While NERC is funding the UK’s share of the project, it is being co-ordinated by BAS, whose total annual budget is around £50m. The agency co-ordinating the US share is the National Snow & Ice Data Center.

As well as the cost of the research itself, the physical problems of mounting a scientific campaign in one of the most remote places in Antarctica could cost as much again in logistical support. The nearest permanently occupied research station to the Thwaites glacier is more than 1,600km away, so even getting the scientists to where they need to be will be demanding.

Collaboration welcome

Researchers on the ice will rely on aircraft support from UK and US research stations, but oceanographers and geophysicists will approach the glacier from the sea in British and American research icebreakers.

The UK’s science minister, Sam Gyimah, said: “Rising sea levels are a globally important issue which cannot be tackled by one country alone. The Thwaites glacier already contributes to rising sea levels, and understanding its likely collapse in the coming century is vitally important.”

The five-year programme begins in October this year and continues to 2023. Its data will be archived and freely shared when it ends. – Climate News Network

British and American scientists are joining forces to research the melting of an Antarctic glacier in what they are calling a race against time. 

CAMBRIDGE, UK, 30 April, 2018 – An international team of scientists is mounting an ambitious research programme to find how soon a vast Antarctic glacier may collapse, with implications for sea levels worldwide.

The Thwaites Glacier in West Antarctica could significantly affect global sea levels. It already drains an area roughly the size of Britain or the US state of Florida, accounting for around 4% of global sea-level rise, an amount that has doubled since the mid-1990s. Its collapse would destabilise other parts of the ice sheet.

If – or more likely when – Thwaites and its neighbour, the Pine Island glacier, ultimately lose all their ice, one estimate suggests that could raise global sea levels by about 3.4m, enough to affect every coastal city on Earth.

Fastest-moving

Satellites have shown for more than a decade that the Thwaites region is an area of massive change and rapid ice loss as the global climate warms in response to rising greenhouse gas emissions from humans’ profligate use of fossil fuels. The two glaciers are among the fastest-moving in the Antarctic.

One of the scientists involved in the research is David Vaughan, director of science at the Cambridge-based British Antarctic Survey (BAS). He says he and his colleagues are involved in “a race against time”.

Professor Vaughan told the Climate News Network: “Understanding sea level rise is the front line of climate change, and sea level rise doesn’t happen overnight. [What’s happening to Thwaites] is not an emergency this year, but I’m very glad we’re doing the research this decade, because we can’t wait too long.”

Understanding collapse

As part of a new £20 million (roughly US$27.5m) research collaboration, the UK Natural Environment Research Council and the US National Science Foundation are about to send a team of scientists to Antarctica to gather the data needed to understand when the collapse of the Thwaites glacier could begin – in centuries, or in the next few decades.

NERC and NSF are jointly funding eight large-scale projects that will bring together leading polar scientists in the International Thwaites Glacier Collaboration (ITGC), the largest joint project undertaken by the two nations in Antarctica for more than 70 years. The ITGC involves around 100 scientists from leading research institutes in both countries with researchers from South Korea, Germany, Sweden, New Zealand and Finland.

There are signs that the process of Thwaites’ collapse has already begun. Antarctica’s glaciers add to sea-level rise when they lose more ice to the ocean than they gain from snowfall. To fully understand the causes of changes in ice flow requires research on the ice itself, the nearby ocean, and the Antarctic climate.

“Sea level rise doesn’t happen overnight. [It’s] not an emergency this year, but I’m very glad we’re doing the research this decade, because we can’t wait too long”

The Collaboration will use drills that can make access holes 1,500 metres into the ice with jets of hot water, as well as other state-of-the-art techniques and equipment, such as autonomous submarines like the Autosub Long Range, the first of whose fleet is named Boaty McBoatface.

While NERC is funding the UK’s share of the project, it is being co-ordinated by BAS, whose total annual budget is around £50m. The agency co-ordinating the US share is the National Snow & Ice Data Center.

As well as the cost of the research itself, the physical problems of mounting a scientific campaign in one of the most remote places in Antarctica could cost as much again in logistical support. The nearest permanently occupied research station to the Thwaites glacier is more than 1,600km away, so even getting the scientists to where they need to be will be demanding.

Collaboration welcome

Researchers on the ice will rely on aircraft support from UK and US research stations, but oceanographers and geophysicists will approach the glacier from the sea in British and American research icebreakers.

The UK’s science minister, Sam Gyimah, said: “Rising sea levels are a globally important issue which cannot be tackled by one country alone. The Thwaites glacier already contributes to rising sea levels, and understanding its likely collapse in the coming century is vitally important.”

The five-year programme begins in October this year and continues to 2023. Its data will be archived and freely shared when it ends. – Climate News Network

Plastic particles now infest the Arctic

Tiny plastic particles have been found in every sample collected of Arctic sea ice. But the ice can only hold these indestructible pollutants for so long.

LONDON, 27 April, 2018 – Plastic particles have colonised one of the last  once-pristine oceans. German scientists sampled sea ice from five locations within the Arctic Circle and counted up to 12,000 microscopic particles per litre of ice.

They have even been able to identify the sources and piece together the journey to the icy fastness. Some tiny lumps of plastic detritus have made their way north from what has become known as the Great Pacific Garbage Patch, a swirling assembly of an estimated 80,000 tons of plastic floating in the ocean across a stretch of water bigger than France.

Other fragments, that began as paint and nylon, date from the invasion of increasingly ice-free Arctic summer waters by more freight ships, and more fishing vessels, the scientists report in the journal Nature Communications.

“During our work, we realised that more than half of the microplastic particles trapped in the ice were less than a twentieth of a millimetre wide, which means they could easily be ingested by Arctic micro-organisms like ciliates, but also by copepods,” said Ilka Peeken, a biologist with the Alfred Wegener Institute.

“Microplastics are now ubiquitous within the surface waters of the world’s oceans.  Nowhere is immune”

“No one can say for certain how harmful these tiny plastic particles are for marine life, or ultimately also for human beings.”

The researchers gathered their samples during three expeditions to the Arctic aboard the icebreaker Polarstern in the spring of 2014 and the summer of 2015, following an ice movement called the Transpolar Drift from Siberia as far as the Fram Strait where warm Atlantic water enters the polar ocean. The Transpolar Drift was first identified by the Norwegian explorer Fridtjof Nansen aboard the Fram, late in the 19th century.

Microplastic particles are defined as 5mm or smaller, and many are measured in millionths of a metre. These are formed by the deterioration of larger pieces of plastic dumped into landfills in billions of tonnes, or released into the waterways and thus into the ocean.

Man-made synthetic polymers are effectively indestructible, and now represent a major source of marine pollution and a constant hazard to wildlife.

More than two-thirds of the particles measured 50 millionths of a metre or smaller. Some were as small as 11 micrometres – one sixth of the diameter of a human hair.

Multiple sources

The researchers identified 17 different types of plastic in the sea ice: from paints, nylon, polyester, cellulose acetate – used in cigarette filters – and the packaging materials polyethylene and polypropylene.

The guess is that the plastics endure in the sea ice for between two and 11 years before melting from their icy packaging in the Fram Strait, to begin sinking in deeper waters. One study recently found 6,500 bits of microplastic per kilogram sampled from the sea floor.

“This is an important finding because it means that they were always present in the water under the ice as it was growing, and drifting, within the Arctic Ocean,” said Jeremy Wilkinson, a sea ice physicist with the British Antarctic Survey, commenting on the study.

“Sea ice grows from the freezing of seawater directly onto the bottom of the ice (i.e. it grows vertically downwards), thus it was incorporating microplastic particles as it grew. It suggests that microplastics are now ubiquitous within the surface waters of the world’s oceans.  Nowhere is immune.” – Climate News Network

Tiny plastic particles have been found in every sample collected of Arctic sea ice. But the ice can only hold these indestructible pollutants for so long.

LONDON, 27 April, 2018 – Plastic particles have colonised one of the last  once-pristine oceans. German scientists sampled sea ice from five locations within the Arctic Circle and counted up to 12,000 microscopic particles per litre of ice.

They have even been able to identify the sources and piece together the journey to the icy fastness. Some tiny lumps of plastic detritus have made their way north from what has become known as the Great Pacific Garbage Patch, a swirling assembly of an estimated 80,000 tons of plastic floating in the ocean across a stretch of water bigger than France.

Other fragments, that began as paint and nylon, date from the invasion of increasingly ice-free Arctic summer waters by more freight ships, and more fishing vessels, the scientists report in the journal Nature Communications.

“During our work, we realised that more than half of the microplastic particles trapped in the ice were less than a twentieth of a millimetre wide, which means they could easily be ingested by Arctic micro-organisms like ciliates, but also by copepods,” said Ilka Peeken, a biologist with the Alfred Wegener Institute.

“Microplastics are now ubiquitous within the surface waters of the world’s oceans.  Nowhere is immune”

“No one can say for certain how harmful these tiny plastic particles are for marine life, or ultimately also for human beings.”

The researchers gathered their samples during three expeditions to the Arctic aboard the icebreaker Polarstern in the spring of 2014 and the summer of 2015, following an ice movement called the Transpolar Drift from Siberia as far as the Fram Strait where warm Atlantic water enters the polar ocean. The Transpolar Drift was first identified by the Norwegian explorer Fridtjof Nansen aboard the Fram, late in the 19th century.

Microplastic particles are defined as 5mm or smaller, and many are measured in millionths of a metre. These are formed by the deterioration of larger pieces of plastic dumped into landfills in billions of tonnes, or released into the waterways and thus into the ocean.

Man-made synthetic polymers are effectively indestructible, and now represent a major source of marine pollution and a constant hazard to wildlife.

More than two-thirds of the particles measured 50 millionths of a metre or smaller. Some were as small as 11 micrometres – one sixth of the diameter of a human hair.

Multiple sources

The researchers identified 17 different types of plastic in the sea ice: from paints, nylon, polyester, cellulose acetate – used in cigarette filters – and the packaging materials polyethylene and polypropylene.

The guess is that the plastics endure in the sea ice for between two and 11 years before melting from their icy packaging in the Fram Strait, to begin sinking in deeper waters. One study recently found 6,500 bits of microplastic per kilogram sampled from the sea floor.

“This is an important finding because it means that they were always present in the water under the ice as it was growing, and drifting, within the Arctic Ocean,” said Jeremy Wilkinson, a sea ice physicist with the British Antarctic Survey, commenting on the study.

“Sea ice grows from the freezing of seawater directly onto the bottom of the ice (i.e. it grows vertically downwards), thus it was incorporating microplastic particles as it grew. It suggests that microplastics are now ubiquitous within the surface waters of the world’s oceans.  Nowhere is immune.” – Climate News Network

High Arctic species respond to climate warming

The northern ocean is abuzz with life, but the composition of those high Arctic species is changing as the world gets warmer.

LONDON, 23 April, 2018 – Global warming is beginning to change the high Arctic species which make up the region’s most numerous occupants. Scientists who have been collecting spiders, mites, ticks, bugs, bees, wasps, ants, moths and springtails in the northeast of Greenland report that the arthropod population is starting to respond to the changing seasons.

Arthropods make up the largest variety of animals on the planet: this is a phylum of jointy-legged things with exoskeletons that includes spiders as well as flies, bees and butterflies as well as mites. In the tundra, the mass of arthropods is greater than that of birds or mammals.

Danish and US scientists report in the Royal Society journal Open Science that between 1996 and 2014, researchers collected 593,788 specimens of different arthropod groups around the Zackenberg research station and noted the way the species composition of a population changed with time and with the pattern of summer rainfall.

In this region, the winter temperatures fall to minus 30°C and average annual temperature is minus 9°C. The ground is more or less permanently frozen. But in the brief Arctic summer, temperatures can soar to between 3°C and 7°C and the Arctic fens, heaths and arid zones effervesce with life.

”We often don’t pay much attention to these small animals, but there could be real consequences to their changing abundances”

Compared with the past, the population is changing. There are more herbivores and creatures that parasitise other animals, but the detritivores – the creatures that consume carrion, excrement and decomposing plants – seem to be on the way down, with, the scientists say, potential implications for key ecosystem processes such as decomposition, nutrient cycling and primary productivity.

Change varied according to habitat: the changes in the composition of the community of arthropods were up to five times more extreme in the drier ecosystems. The implication of such research is that study of shorter-lived, tinier creatures may provide more information about adaptation and loss in the rapidly warming Arctic than, for instance, study of seals and polar bears.

And the insects do respond, even to subtle change: researchers four years ago noted that around 80 species of moth inside Finland’s Arctic seemed to be coping with warmer summers.

“Twenty years may not be long enough to detect changes in abundances of longer-lived species, like some mammals, but because of their short life spans, it’s a pretty long time for arthropods. Still, the fact that we can detect changes over 20 years in some of these animal groups at such a coarse taxonomic resolution is remarkable,” said Amanda Koltz, of Washington University in St Louis, who led the study.

“We often don’t pay much attention to these small animals, but there could be real consequences to their changing abundances.” – Climate News Network

The northern ocean is abuzz with life, but the composition of those high Arctic species is changing as the world gets warmer.

LONDON, 23 April, 2018 – Global warming is beginning to change the high Arctic species which make up the region’s most numerous occupants. Scientists who have been collecting spiders, mites, ticks, bugs, bees, wasps, ants, moths and springtails in the northeast of Greenland report that the arthropod population is starting to respond to the changing seasons.

Arthropods make up the largest variety of animals on the planet: this is a phylum of jointy-legged things with exoskeletons that includes spiders as well as flies, bees and butterflies as well as mites. In the tundra, the mass of arthropods is greater than that of birds or mammals.

Danish and US scientists report in the Royal Society journal Open Science that between 1996 and 2014, researchers collected 593,788 specimens of different arthropod groups around the Zackenberg research station and noted the way the species composition of a population changed with time and with the pattern of summer rainfall.

In this region, the winter temperatures fall to minus 30°C and average annual temperature is minus 9°C. The ground is more or less permanently frozen. But in the brief Arctic summer, temperatures can soar to between 3°C and 7°C and the Arctic fens, heaths and arid zones effervesce with life.

”We often don’t pay much attention to these small animals, but there could be real consequences to their changing abundances”

Compared with the past, the population is changing. There are more herbivores and creatures that parasitise other animals, but the detritivores – the creatures that consume carrion, excrement and decomposing plants – seem to be on the way down, with, the scientists say, potential implications for key ecosystem processes such as decomposition, nutrient cycling and primary productivity.

Change varied according to habitat: the changes in the composition of the community of arthropods were up to five times more extreme in the drier ecosystems. The implication of such research is that study of shorter-lived, tinier creatures may provide more information about adaptation and loss in the rapidly warming Arctic than, for instance, study of seals and polar bears.

And the insects do respond, even to subtle change: researchers four years ago noted that around 80 species of moth inside Finland’s Arctic seemed to be coping with warmer summers.

“Twenty years may not be long enough to detect changes in abundances of longer-lived species, like some mammals, but because of their short life spans, it’s a pretty long time for arthropods. Still, the fact that we can detect changes over 20 years in some of these animal groups at such a coarse taxonomic resolution is remarkable,” said Amanda Koltz, of Washington University in St Louis, who led the study.

“We often don’t pay much attention to these small animals, but there could be real consequences to their changing abundances.” – Climate News Network