Category Archives: Polar

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Polar ice loss speeds up by leaps and bounds

North and south, polar ice loss is happening faster than ever. Researchers now have a measure of the accelerating flow into the ocean.

LONDON, 22 January, 2019 – In the last few decades the speed of polar ice loss at both ends of the planet has begun to gallop away at rates which will have a marked effect on global sea levels.

Antarctica is now losing ice mass six times faster than it did 40 years ago. In the decade that began in 1979, the great white continent surrendered 40 billion tons of ice a year to raise global sea levels. By the decade 2009 to 2017, this mass loss had soared to 252 billion tons a year.

And in Greenland, the greatest concentration of terrestrial ice in the northern hemisphere has also accelerated its rate of ice loss fourfold in this century.

Satellite studies confirm that in 2003, around 102 billion tons of ice turned to flowing water or broke off into the ocean as floating bergs. By 2013, this figure had climbed to 393 billion tons a year.

“That’s just the tip of the iceberg, so to speak. As the Antarctic Ice Sheet continues to melt away, we expect multi-metre sea level rise from Antarctica in the coming centuries”

Scientists report in the Proceedings of the National Academy of Sciences that they studied high resolution aerial photographs, satellite radar readings and historic Landsat imagery to survey 18 south polar regions encompassing 176 basins and surrounding islands of Antarctica to take the most precise measurement of ice loss so far.

Most of the loss is attributed to the contact with ever-warmer ocean waters as they lap the ice shelves or eat away at grounded glaciers. Since 1979 it has contributed 14mm to global sea level rise. The researchers stress that their reading of the profit-and-loss accounts of polar ice is the longest study so far.

“That’s just the tip of the iceberg, so to speak,” said Eric Rignot, of the University of California Irvine. “As the Antarctic Ice Sheet continues to melt away, we expect multi-metre sea level rise from Antarctica in the coming centuries.” If all the ice on the continent were to melt, it would raise global sea levels by 57 metres.

Growing concern

For more than a decade scientists have been concerned with the rate of warming, the acceleration of glacial flow and the loss of shelf ice off West Antarctica. The latest study indicates that East Antarctica, home to a far greater volume of ice, is also losing mass.

Accelerating glacier movement across Greenland towards the sea has also concerned climate scientists worried about icemelt for years. The island’s bedrock bears a burden of ice sufficient to raise global sea levels by seven metres.

Researchers who have used data from the GRACE satellites – the acronym stands for Gravity Recovery and Climate Experiment – since 2002 also report in the same journal that the largest sustained loss of ice on Greenland came from the island’s southwest. They think that within two decades the region could become a major contributor to global sea level rise. But why the loss has accelerated is uncertain.

“Whichever this was, it couldn’t be explained by glaciers, because there aren’t many there,” said Michael Bevis of Ohio State University. “It had to be surface mass – the ice was melting inland from the coastline.”

Puzzling picture

Once again, warming atmosphere and ocean are linked to ice loss in the Arctic region, a change driven by global warming as a consequence of ever-higher ratios of greenhouse gases in the atmosphere, fed by ever-higher rates of combustion of fossil fuels.

Melting rates have been uneven: the unexplained acceleration between 2003 and 2013 was followed by an equally puzzling pause. Natural atmospheric cycles such as the North Atlantic Oscillation must be part of the explanation.

“These oscillations have been happening forever. So why only now are they causing this massive melt? It is because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained global warming,” Professor Bevis said.

“We are going to see faster and faster sea level rise for the foreseeable future. Once you hit that tipping point, the only question is: how severe does it get?” – Climate News Network

North and south, polar ice loss is happening faster than ever. Researchers now have a measure of the accelerating flow into the ocean.

LONDON, 22 January, 2019 – In the last few decades the speed of polar ice loss at both ends of the planet has begun to gallop away at rates which will have a marked effect on global sea levels.

Antarctica is now losing ice mass six times faster than it did 40 years ago. In the decade that began in 1979, the great white continent surrendered 40 billion tons of ice a year to raise global sea levels. By the decade 2009 to 2017, this mass loss had soared to 252 billion tons a year.

And in Greenland, the greatest concentration of terrestrial ice in the northern hemisphere has also accelerated its rate of ice loss fourfold in this century.

Satellite studies confirm that in 2003, around 102 billion tons of ice turned to flowing water or broke off into the ocean as floating bergs. By 2013, this figure had climbed to 393 billion tons a year.

“That’s just the tip of the iceberg, so to speak. As the Antarctic Ice Sheet continues to melt away, we expect multi-metre sea level rise from Antarctica in the coming centuries”

Scientists report in the Proceedings of the National Academy of Sciences that they studied high resolution aerial photographs, satellite radar readings and historic Landsat imagery to survey 18 south polar regions encompassing 176 basins and surrounding islands of Antarctica to take the most precise measurement of ice loss so far.

Most of the loss is attributed to the contact with ever-warmer ocean waters as they lap the ice shelves or eat away at grounded glaciers. Since 1979 it has contributed 14mm to global sea level rise. The researchers stress that their reading of the profit-and-loss accounts of polar ice is the longest study so far.

“That’s just the tip of the iceberg, so to speak,” said Eric Rignot, of the University of California Irvine. “As the Antarctic Ice Sheet continues to melt away, we expect multi-metre sea level rise from Antarctica in the coming centuries.” If all the ice on the continent were to melt, it would raise global sea levels by 57 metres.

Growing concern

For more than a decade scientists have been concerned with the rate of warming, the acceleration of glacial flow and the loss of shelf ice off West Antarctica. The latest study indicates that East Antarctica, home to a far greater volume of ice, is also losing mass.

Accelerating glacier movement across Greenland towards the sea has also concerned climate scientists worried about icemelt for years. The island’s bedrock bears a burden of ice sufficient to raise global sea levels by seven metres.

Researchers who have used data from the GRACE satellites – the acronym stands for Gravity Recovery and Climate Experiment – since 2002 also report in the same journal that the largest sustained loss of ice on Greenland came from the island’s southwest. They think that within two decades the region could become a major contributor to global sea level rise. But why the loss has accelerated is uncertain.

“Whichever this was, it couldn’t be explained by glaciers, because there aren’t many there,” said Michael Bevis of Ohio State University. “It had to be surface mass – the ice was melting inland from the coastline.”

Puzzling picture

Once again, warming atmosphere and ocean are linked to ice loss in the Arctic region, a change driven by global warming as a consequence of ever-higher ratios of greenhouse gases in the atmosphere, fed by ever-higher rates of combustion of fossil fuels.

Melting rates have been uneven: the unexplained acceleration between 2003 and 2013 was followed by an equally puzzling pause. Natural atmospheric cycles such as the North Atlantic Oscillation must be part of the explanation.

“These oscillations have been happening forever. So why only now are they causing this massive melt? It is because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained global warming,” Professor Bevis said.

“We are going to see faster and faster sea level rise for the foreseeable future. Once you hit that tipping point, the only question is: how severe does it get?” – Climate News Network

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Permafrost thaw unsettles the Arctic

Permafrost thaw and retreating Arctic ice don’t just imperil caribou and bears. People, too, may find the ground shifts beneath their feet.

LONDON, 1 January, 2019 − In just one human generation, citizens of the far north could find themselves on shifting soils as the region’s permafrost thaws. Roads will slump. Buildings will buckle. Pipelines will become at risk of fracture. And in 2050, around three fourths of the people of the permafrost could watch their infrastructure collapse, as what was once hard frozen ground turns into mud.

All this could happen even if the world keeps the promise it made in Paris in 2015 and limits global average warming to just 1.5°C above the level for most of pre-industrial history.

In the last century, the world has already warmed by 1°C on average: the Arctic region has warmed at a far faster rate. At present rates of warming, driven by the profligate use of fossil fuels that raise the levels of greenhouse gases in the atmosphere, the world is on course for an average warming of 3°C by 2100.

Researchers from Finland, Norway, Russia and the US report in the journal Nature Communications that they mapped, on a scale of a kilometre, the buildings, installations, roads and other infrastructure of the permafrost world: a region defined as that where the ground is frozen solid, summer and winter, for at least two consecutive years.

More than 4 million people live in this pan-Arctic landscape: at least 3.6 million of them, and 70% of their transportation and industrial infrastructure, are at risk.

Present reality

“These observations have led me to believe that global warming is not a ‘fake’ but the reality. And here, in Alaska, we are dealing already and will be dealing even more in the near future with this reality,” said Vladimir Romanovsky, of the University of Alaska’s geophysical institute, one of the authors.

Climate scientists and glaciologists have been warning about the rate of change in the Arctic for two decades: one estimate proposed that for every 1°C of warming, around 4 million square kilometres of permafrost − an area bigger than India − could thaw.

Locked in the frozen soil is an estimated 1,700 billion tonnes of carbon: this is about twice the mass of carbon in the atmosphere in the form of the greenhouse gas carbon dioxide. Its release could precipitate even more calamitous climate change. And the economic consequences – assessed at a potential cost of $43 trillion − could be ruinous.

The latest study found that climate change respected no borders: one third of all Arctic infrastructure and 45% of hydrocarbon extraction fields in the Russian Arctic were in high hazard regions: that is, once the soil thawed, the ground became unstable.

Around 470 kms of the Qinghai-Tibet Railway and 280 kms of the Obskaya-Bovanenkovo Railway, the most northerly in the world, lie across what could be thawing permafrost. The scientists identified more than 1,200 settlements in zones where the permafrost could thaw: around 40 of these had populations of 5,000 or more.

“These observations have led me to believe that global warming is not a ‘fake’ but the reality”

Pipelines, too, were endangered: 1,590 kms of the Eastern Siberia-Pacific Ocean oil pipeline, 1,260 kms of the gas pipelines in the Yamal-Nenets region − which supplies one-third of European Union imports − and 550 kms of the Trans-Alaska pipeline systems could be at “considerable risk”: that is, they were in areas where near-surface permafrost could thaw by 2050.

By then around one million people, 36,000 buildings, 13,000 kms of roads and 100 airports could have become high hazard environments. And with them, permafrost thaw could threaten to affect 45% of oil and gas fields in the Russian Arctic.

All forecasts arrive with considerable uncertainties, and the authors concede that they could be wrong. But, they warn, even if they are, their estimates of the infrastructure at risk would probably not be much smaller and could be substantially higher. Around 19 large settlements are in their highest hazard zone “but the number could be as large as 34,” they warn.

If nations acted on the Paris promises, they say, the levels of risk would start to stabilise after 2050. “In contrast, higher greenhouse gas levels would probably result in continued detrimental climate change impacts on the built environment and economic activity in the Arctic.” − Climate News Network

Permafrost thaw and retreating Arctic ice don’t just imperil caribou and bears. People, too, may find the ground shifts beneath their feet.

LONDON, 1 January, 2019 − In just one human generation, citizens of the far north could find themselves on shifting soils as the region’s permafrost thaws. Roads will slump. Buildings will buckle. Pipelines will become at risk of fracture. And in 2050, around three fourths of the people of the permafrost could watch their infrastructure collapse, as what was once hard frozen ground turns into mud.

All this could happen even if the world keeps the promise it made in Paris in 2015 and limits global average warming to just 1.5°C above the level for most of pre-industrial history.

In the last century, the world has already warmed by 1°C on average: the Arctic region has warmed at a far faster rate. At present rates of warming, driven by the profligate use of fossil fuels that raise the levels of greenhouse gases in the atmosphere, the world is on course for an average warming of 3°C by 2100.

Researchers from Finland, Norway, Russia and the US report in the journal Nature Communications that they mapped, on a scale of a kilometre, the buildings, installations, roads and other infrastructure of the permafrost world: a region defined as that where the ground is frozen solid, summer and winter, for at least two consecutive years.

More than 4 million people live in this pan-Arctic landscape: at least 3.6 million of them, and 70% of their transportation and industrial infrastructure, are at risk.

Present reality

“These observations have led me to believe that global warming is not a ‘fake’ but the reality. And here, in Alaska, we are dealing already and will be dealing even more in the near future with this reality,” said Vladimir Romanovsky, of the University of Alaska’s geophysical institute, one of the authors.

Climate scientists and glaciologists have been warning about the rate of change in the Arctic for two decades: one estimate proposed that for every 1°C of warming, around 4 million square kilometres of permafrost − an area bigger than India − could thaw.

Locked in the frozen soil is an estimated 1,700 billion tonnes of carbon: this is about twice the mass of carbon in the atmosphere in the form of the greenhouse gas carbon dioxide. Its release could precipitate even more calamitous climate change. And the economic consequences – assessed at a potential cost of $43 trillion − could be ruinous.

The latest study found that climate change respected no borders: one third of all Arctic infrastructure and 45% of hydrocarbon extraction fields in the Russian Arctic were in high hazard regions: that is, once the soil thawed, the ground became unstable.

Around 470 kms of the Qinghai-Tibet Railway and 280 kms of the Obskaya-Bovanenkovo Railway, the most northerly in the world, lie across what could be thawing permafrost. The scientists identified more than 1,200 settlements in zones where the permafrost could thaw: around 40 of these had populations of 5,000 or more.

“These observations have led me to believe that global warming is not a ‘fake’ but the reality”

Pipelines, too, were endangered: 1,590 kms of the Eastern Siberia-Pacific Ocean oil pipeline, 1,260 kms of the gas pipelines in the Yamal-Nenets region − which supplies one-third of European Union imports − and 550 kms of the Trans-Alaska pipeline systems could be at “considerable risk”: that is, they were in areas where near-surface permafrost could thaw by 2050.

By then around one million people, 36,000 buildings, 13,000 kms of roads and 100 airports could have become high hazard environments. And with them, permafrost thaw could threaten to affect 45% of oil and gas fields in the Russian Arctic.

All forecasts arrive with considerable uncertainties, and the authors concede that they could be wrong. But, they warn, even if they are, their estimates of the infrastructure at risk would probably not be much smaller and could be substantially higher. Around 19 large settlements are in their highest hazard zone “but the number could be as large as 34,” they warn.

If nations acted on the Paris promises, they say, the levels of risk would start to stabilise after 2050. “In contrast, higher greenhouse gas levels would probably result in continued detrimental climate change impacts on the built environment and economic activity in the Arctic.” − Climate News Network

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London’s melting ice shows world’s plight

How do you raise awareness of climate change? A novel approach in the UK this winter, shipped in from Greenland, is London’s melting ice.

LONDON, 18 December, 2018 – They stand on the bank of the river Thames, outside the world-famous Tate Modern art venue – London’s melting ice, 24 large blocks, some transparent, some opaque, all different shapes, all gently melting in the not so cold air. Another six stands of ice sit in a square in the heart of London’s financial district.

Ice Watch is the idea of Danish-Icelandic artist Olafur Eliasson and Minik Rosing, a Greenland geologist.

“These blocks tell their own story and I suggest you listen to what they have to say”, Eliasson tells London’s Evening Standard newspaper. “Their melting into the ocean is our world melting.”

The blocks on display in London – weighing a total of more than 100 tonnes – were collected from the cold waters of Nuup Kangerlua fjord near Nuuk, Greenland’s capital.

They had originally been part of Greenland’s ice sheet, which covers about 80% of the island and is the largest ice mass in the northern hemisphere. The blocks were transported to London in containers usually used for exports of frozen fish.

“You can’t live in a perennial state of shock. This is what Ice Watch is about”

Glaciologists say rising air and sea temperatures have caused the pace of melting of the ice sheet to go into overdrive in recent times. There are fears that if the sheet continues to melt at its present rate global sea levels could rise by several metres, flooding coastal cities and large tracts of land.

Visitors can touch the mini-icebergs in London and put their ears to the cold surfaces to listen to the crackling noises as the ice melts, with minuscule air pockets trapped within the blocks cracking open.

Dirt and other material trapped within the ice are evidence of life and changes in the atmosphere stretching back over thousands of years. “Smell, look – and witness the ecological changes our world is undergoing”, says Eliasson.

The artist says that while the facts about climate change and how great a threat it is to the world’s future are clear, people still need to be encouraged to take action.

“We need to communicate the facts of climate change to hearts as well as heads, to emotions as well as minds”, says Eliasson.

Fear is ineffective

“When it comes to people’s choices for or against taking climate action, we are inclined to stick to what we have, here and now, rather than make changes. Inducing fear does not seem an effective strategy.

“You can’t live in a perennial state of shock. This is what Ice Watch is about. I am hopeful that we can push for change. To do so, we have to make use of all the tools at hand, including art.”

Minik Rosing, who has undertaken extensive geological work on the Greenland ice sheet, says the melting of the area’s ice has raised global sea levels by 2.5 millimetres. “Earth is changing at an ever-increasing speed”, he says.

A similar Ice Watch installation has already been staged in Paris. Eliasson has long been involved in climate-related issues. Fifteen years ago his Weather Project exhibition was displayed at Tate Modern.

Ice Watch will be in place in London till December 20 – or until the ice melts completely. – Climate News Network

How do you raise awareness of climate change? A novel approach in the UK this winter, shipped in from Greenland, is London’s melting ice.

LONDON, 18 December, 2018 – They stand on the bank of the river Thames, outside the world-famous Tate Modern art venue – London’s melting ice, 24 large blocks, some transparent, some opaque, all different shapes, all gently melting in the not so cold air. Another six stands of ice sit in a square in the heart of London’s financial district.

Ice Watch is the idea of Danish-Icelandic artist Olafur Eliasson and Minik Rosing, a Greenland geologist.

“These blocks tell their own story and I suggest you listen to what they have to say”, Eliasson tells London’s Evening Standard newspaper. “Their melting into the ocean is our world melting.”

The blocks on display in London – weighing a total of more than 100 tonnes – were collected from the cold waters of Nuup Kangerlua fjord near Nuuk, Greenland’s capital.

They had originally been part of Greenland’s ice sheet, which covers about 80% of the island and is the largest ice mass in the northern hemisphere. The blocks were transported to London in containers usually used for exports of frozen fish.

“You can’t live in a perennial state of shock. This is what Ice Watch is about”

Glaciologists say rising air and sea temperatures have caused the pace of melting of the ice sheet to go into overdrive in recent times. There are fears that if the sheet continues to melt at its present rate global sea levels could rise by several metres, flooding coastal cities and large tracts of land.

Visitors can touch the mini-icebergs in London and put their ears to the cold surfaces to listen to the crackling noises as the ice melts, with minuscule air pockets trapped within the blocks cracking open.

Dirt and other material trapped within the ice are evidence of life and changes in the atmosphere stretching back over thousands of years. “Smell, look – and witness the ecological changes our world is undergoing”, says Eliasson.

The artist says that while the facts about climate change and how great a threat it is to the world’s future are clear, people still need to be encouraged to take action.

“We need to communicate the facts of climate change to hearts as well as heads, to emotions as well as minds”, says Eliasson.

Fear is ineffective

“When it comes to people’s choices for or against taking climate action, we are inclined to stick to what we have, here and now, rather than make changes. Inducing fear does not seem an effective strategy.

“You can’t live in a perennial state of shock. This is what Ice Watch is about. I am hopeful that we can push for change. To do so, we have to make use of all the tools at hand, including art.”

Minik Rosing, who has undertaken extensive geological work on the Greenland ice sheet, says the melting of the area’s ice has raised global sea levels by 2.5 millimetres. “Earth is changing at an ever-increasing speed”, he says.

A similar Ice Watch installation has already been staged in Paris. Eliasson has long been involved in climate-related issues. Fifteen years ago his Weather Project exhibition was displayed at Tate Modern.

Ice Watch will be in place in London till December 20 – or until the ice melts completely. – Climate News Network

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Greenland’s icecap melt picks up speed

Recent melting of Greenland’s icecap has been more intense than ever. And all the signs are that it could get worse.

LONDON, 13 December, 2018 – Greenland’s icecap – the largest single store of frozen freshwater in the northern hemisphere – is melting faster than ever, according to two separate studies using two different approaches.

Surface meltwater started flowing over the surface and percolating through the ice at a greater rate in the mid-19th century and accelerated dramatically during the 20th and the first decades of the 21st century, according to a new study of ice cores taken more than 2,000 metres above sea level.

And a 25-year record of European Space Agency satellite data confirms the alarming picture: the elevation of the Greenland ice sheet was changing in the mid-1990s, and the pace of thinning stepped up after 2003. Greenland’s bedrock carries enough ice to raise global sea levels by around seven metres.

“Melting of the Greenland Ice Sheet has gone into overdrive. As a result, Greenland melt is adding to sea level more than at any time in the last three and a half centuries, if not thousands of years,” said Luke Trusel, a glaciologist at Rowan University in the US.

“And increasing melt began around the same time as we started altering the atmosphere in the mid 1800s.”

“The melting and sea level rise we’ve observed will already be dwarfed by what may be expected in the future”

His co-author Sarah Das of the Woods Hole Oceanographic Institution said: “From a historical perspective, today’s melt rates are off the charts, and this study provides the evidence.”

Snow falls on the great icecaps of the two hemispheres, freezes, melts a little in the summer and freezes again, so that – like the rings of a tree – the accumulated precipitation tells a story of successive years of climate change. The two researchers and their colleagues report in Nature that ice cores taken from the icecap between 2003 and 2015 contained enough information for them to assess annual melting rates over several centuries.

They found a clear pattern of more intense melting nearer the present, and over the last 20 years the intensity increased by between 250% and 575%, compared to the 18th century. In the last century the entire planet has warmed by around 1°C as greenhouse gas levels in the atmosphere have risen, in response to ever greater use of fossil fuels.

The message for the future is ominous. “Rather than increasing steadily as climate warms, Greenland will melt increasingly more and more for every degree of warming,” said Dr Trusel. “The melting and sea level rise we’ve observed will already be dwarfed by what may be expected in the future as climate continues to warm.”

Greenland has served for decades as a climate laboratory: change almost imperceptible in lower latitudes can be measured almost on a yearly basis in the high fastnesses of the island, and the Nature study is only the latest twist in a story that is already alarming.

Dangers identified

Scientists long ago took the measure of change on the ice cap, in the glaciers and at the boundary with the Atlantic, and identified the dangers of accelerated warming in the Arctic.

They monitored unexpected increases in the flow of the island’s biggest glaciers, monitored the way the island’s bedrock rose in response to an increased loss of ice, and even identified those reaches of ice that had passed the point of no return.

The Nature scientists backed up their on-the-ground observations with measurements made by satellites. And in an entirely separate study, European researchers report in the journal Earth and Planetary Science Letters that, according to their readings too, the elevation of the icecap had begun to change in ways that enabled them to measure ice loss with the decades, and a recent speed-up.

“A pattern of thinning appears to dominate a large fraction of the ice sheet margins at the beginning of the millennium, with individual outlet glaciers exhibiting large thinning rates,” said Louise Sandberg Sørenson, of the Danish National Space Institute, who led the research.

“Over the full 25-year period, the general picture shows much larger volume losses are experienced in west, northwest and southeast basins of Greenland, compared to the more steady-state situations in the colder north.” – Climate News Network

Recent melting of Greenland’s icecap has been more intense than ever. And all the signs are that it could get worse.

LONDON, 13 December, 2018 – Greenland’s icecap – the largest single store of frozen freshwater in the northern hemisphere – is melting faster than ever, according to two separate studies using two different approaches.

Surface meltwater started flowing over the surface and percolating through the ice at a greater rate in the mid-19th century and accelerated dramatically during the 20th and the first decades of the 21st century, according to a new study of ice cores taken more than 2,000 metres above sea level.

And a 25-year record of European Space Agency satellite data confirms the alarming picture: the elevation of the Greenland ice sheet was changing in the mid-1990s, and the pace of thinning stepped up after 2003. Greenland’s bedrock carries enough ice to raise global sea levels by around seven metres.

“Melting of the Greenland Ice Sheet has gone into overdrive. As a result, Greenland melt is adding to sea level more than at any time in the last three and a half centuries, if not thousands of years,” said Luke Trusel, a glaciologist at Rowan University in the US.

“And increasing melt began around the same time as we started altering the atmosphere in the mid 1800s.”

“The melting and sea level rise we’ve observed will already be dwarfed by what may be expected in the future”

His co-author Sarah Das of the Woods Hole Oceanographic Institution said: “From a historical perspective, today’s melt rates are off the charts, and this study provides the evidence.”

Snow falls on the great icecaps of the two hemispheres, freezes, melts a little in the summer and freezes again, so that – like the rings of a tree – the accumulated precipitation tells a story of successive years of climate change. The two researchers and their colleagues report in Nature that ice cores taken from the icecap between 2003 and 2015 contained enough information for them to assess annual melting rates over several centuries.

They found a clear pattern of more intense melting nearer the present, and over the last 20 years the intensity increased by between 250% and 575%, compared to the 18th century. In the last century the entire planet has warmed by around 1°C as greenhouse gas levels in the atmosphere have risen, in response to ever greater use of fossil fuels.

The message for the future is ominous. “Rather than increasing steadily as climate warms, Greenland will melt increasingly more and more for every degree of warming,” said Dr Trusel. “The melting and sea level rise we’ve observed will already be dwarfed by what may be expected in the future as climate continues to warm.”

Greenland has served for decades as a climate laboratory: change almost imperceptible in lower latitudes can be measured almost on a yearly basis in the high fastnesses of the island, and the Nature study is only the latest twist in a story that is already alarming.

Dangers identified

Scientists long ago took the measure of change on the ice cap, in the glaciers and at the boundary with the Atlantic, and identified the dangers of accelerated warming in the Arctic.

They monitored unexpected increases in the flow of the island’s biggest glaciers, monitored the way the island’s bedrock rose in response to an increased loss of ice, and even identified those reaches of ice that had passed the point of no return.

The Nature scientists backed up their on-the-ground observations with measurements made by satellites. And in an entirely separate study, European researchers report in the journal Earth and Planetary Science Letters that, according to their readings too, the elevation of the icecap had begun to change in ways that enabled them to measure ice loss with the decades, and a recent speed-up.

“A pattern of thinning appears to dominate a large fraction of the ice sheet margins at the beginning of the millennium, with individual outlet glaciers exhibiting large thinning rates,” said Louise Sandberg Sørenson, of the Danish National Space Institute, who led the research.

“Over the full 25-year period, the general picture shows much larger volume losses are experienced in west, northwest and southeast basins of Greenland, compared to the more steady-state situations in the colder north.” – Climate News Network

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Arctic shorebirds face rising predation risk

Rapid warning means rapid change in the north. That’s bad news for the hardy Arctic shorebirds and delicate plants that once found safety there.

LONDON, 13 November, 2018 – Vulnerable baby birds are no longer safe in their nests. New research shows that nest predation – the theft of the eggs of migrant Arctic shorebirds such as plovers and sandpipers in the high latitudes of the northern hemisphere – has risen threefold in the last 70 years.

A second study suggests that the very thing that encourages Arctic plant growth – the rapid warming of the north polar regions – also means a loss of vital snow cover for the delicate plants in the high mountains that depend on snow for winter insulation. This is bad news for the snow buttercup, mountain sorrel and mossplant.

British, Czech, Russian and |Hungarian researchers report in the journal Science that they compared rates of nest robbery over two timespans, from 1944 to 1999 and from 2000 to 2015, around the world.

Altogether the study covered 38,191 nests in 237 populations of 111 species in 149 locations. Nest predation in the tropics was always higher – perhaps because there are more predators – and tropical bird species tend to counter offspring loss by living longer to generate more.

But, the researchers found, nest predation in temperate Europe, Asia and North America had doubled. And in the Arctic, nestling loss by shorebirds had risen threefold.

“The future changes in northern species populations may be abrupt, giving rise to ecological surprises that are hard to predict”

In fact, certain species have always flown far north to breed because until the Arctic began to warm rapidly, as a consequence of ever higher levels of the greenhouse gas carbon dioxide in the atmosphere, the Arctic provided a relatively safe space for ground-nesting birds.

The reason for ever greater nest losses? This has yet to be established. But the guess is that as change comes to the plants and animal life of the Arctic, either predator species have changed, or the loss of familiar prey has forced a change of diet on hunters.

Because snow cover in the high Arctic has changed the lemming population has crashed, and the carnivores that hunted lemmings may now have turned to birds’ nests.

“These findings are alarming. The Earth is a fragile planet with complex ecosystems, thus changes in predator-prey relationships can lead to cascading effects through the food web with detrimental consequences for many organisms thousands of kilometres away,” said Tamás Székely, a biologist at the University of Bath, UK, with research posts at Hungarian and Chinese universities.

Final blow

“Migration of shorebirds from the Arctic to the tropics is now one of the largest movements of biomass in the world. But with increased nest predation, the babies are no longer making the journeys with their parents. This could be the last nail in the coffin for critically-endangered species such as the spoon-billed sandpiper.”

And Vojtěch Kubelka, of Charles University in Prague, who led the research, said the Arctic was no longer a safe harbour for breeding birds. “On the contrary, the Arctic now represents an extensive ecological trap.”

Rapid warming of the north polar regions also means a more rapid invasion of plants from further south and a change in plant response.

Finnish scientists report in the journal Nature Climate Change that changes in snow cover on the high ground may be an even greater danger to Arctic biodiversity than rising temperatures.

Snow cover crucial

They looked at satellite data and computer-based models of probable change as humans burn ever more fossil fuels to drive global warming and climate change, and applied the results to 273 flowering plants, mosses and lichens at 1200 locations in the mountains of northern Scandinavia.

Snow that now lingers until late spring provides vital protection for fragile growths and prevents hardier southern species from colonising the same habitat. In brief, it limits the competition.

The great unknown remains snowfall: while climate scientists can be sure of likely future temperatures at any latitude, it is much harder to predict changes in precipitation. But if the snow cover is reduced, then local extinction rates could accelerate. Plants that once maintained a precarious hold in extreme conditions could vanish with the snows.

“Our findings show that the future changes in northern species populations may be abrupt, giving rise to ecological surprises that are hard to predict, such as fast eradications of populations in some places and the invasion of flexible species into new places”, said Risto Heikkinen from the Finnish Environment Institute. – Climate News Network

Rapid warning means rapid change in the north. That’s bad news for the hardy Arctic shorebirds and delicate plants that once found safety there.

LONDON, 13 November, 2018 – Vulnerable baby birds are no longer safe in their nests. New research shows that nest predation – the theft of the eggs of migrant Arctic shorebirds such as plovers and sandpipers in the high latitudes of the northern hemisphere – has risen threefold in the last 70 years.

A second study suggests that the very thing that encourages Arctic plant growth – the rapid warming of the north polar regions – also means a loss of vital snow cover for the delicate plants in the high mountains that depend on snow for winter insulation. This is bad news for the snow buttercup, mountain sorrel and mossplant.

British, Czech, Russian and |Hungarian researchers report in the journal Science that they compared rates of nest robbery over two timespans, from 1944 to 1999 and from 2000 to 2015, around the world.

Altogether the study covered 38,191 nests in 237 populations of 111 species in 149 locations. Nest predation in the tropics was always higher – perhaps because there are more predators – and tropical bird species tend to counter offspring loss by living longer to generate more.

But, the researchers found, nest predation in temperate Europe, Asia and North America had doubled. And in the Arctic, nestling loss by shorebirds had risen threefold.

“The future changes in northern species populations may be abrupt, giving rise to ecological surprises that are hard to predict”

In fact, certain species have always flown far north to breed because until the Arctic began to warm rapidly, as a consequence of ever higher levels of the greenhouse gas carbon dioxide in the atmosphere, the Arctic provided a relatively safe space for ground-nesting birds.

The reason for ever greater nest losses? This has yet to be established. But the guess is that as change comes to the plants and animal life of the Arctic, either predator species have changed, or the loss of familiar prey has forced a change of diet on hunters.

Because snow cover in the high Arctic has changed the lemming population has crashed, and the carnivores that hunted lemmings may now have turned to birds’ nests.

“These findings are alarming. The Earth is a fragile planet with complex ecosystems, thus changes in predator-prey relationships can lead to cascading effects through the food web with detrimental consequences for many organisms thousands of kilometres away,” said Tamás Székely, a biologist at the University of Bath, UK, with research posts at Hungarian and Chinese universities.

Final blow

“Migration of shorebirds from the Arctic to the tropics is now one of the largest movements of biomass in the world. But with increased nest predation, the babies are no longer making the journeys with their parents. This could be the last nail in the coffin for critically-endangered species such as the spoon-billed sandpiper.”

And Vojtěch Kubelka, of Charles University in Prague, who led the research, said the Arctic was no longer a safe harbour for breeding birds. “On the contrary, the Arctic now represents an extensive ecological trap.”

Rapid warming of the north polar regions also means a more rapid invasion of plants from further south and a change in plant response.

Finnish scientists report in the journal Nature Climate Change that changes in snow cover on the high ground may be an even greater danger to Arctic biodiversity than rising temperatures.

Snow cover crucial

They looked at satellite data and computer-based models of probable change as humans burn ever more fossil fuels to drive global warming and climate change, and applied the results to 273 flowering plants, mosses and lichens at 1200 locations in the mountains of northern Scandinavia.

Snow that now lingers until late spring provides vital protection for fragile growths and prevents hardier southern species from colonising the same habitat. In brief, it limits the competition.

The great unknown remains snowfall: while climate scientists can be sure of likely future temperatures at any latitude, it is much harder to predict changes in precipitation. But if the snow cover is reduced, then local extinction rates could accelerate. Plants that once maintained a precarious hold in extreme conditions could vanish with the snows.

“Our findings show that the future changes in northern species populations may be abrupt, giving rise to ecological surprises that are hard to predict, such as fast eradications of populations in some places and the invasion of flexible species into new places”, said Risto Heikkinen from the Finnish Environment Institute. – Climate News Network

*

High Arctic plant spurts raise climate concerns

Arctic
Arctic

Plants are getting taller in the Arctic high latitudes as warmer, moister soil prompts growth that could increase the release of greenhouse gases.

LONDON, 11 October, 2018 – The Arctic is becoming greener, warmer and leafier as small plants that once hugged the ground to trap snow and insulate their roots in the permafrost have started to gain in stature.

In the high latitudes, plants have begun to respond to climate change and warmer, moister soils by reaching for the sky.

It is estimated that, by 2100, the northernmost vegetation could have grown by up to 60% taller.

European scientists, backed by an international team of more than 120 biologists, report in Nature journal  that tundra plants are gaining in height, and that species from further south are advancing towards the Arctic Circle.

Close survey of growth

Their conclusion is based on more than 56,000 observations of tundra vegetation and a close survey of growth at 117 sites around the high latitudes in Alaska, Canada, Iceland, Scandinavia and Siberia.

“The increase in height we saw was not just in a few sites but nearly everywhere,” says Dr Anne Bjorkman, a researcher at Germany’s Senckenberg Biodiversity and Climate Research Centre. “If taller plants continue to spread at the current rate, the plant community height could increase by 20% to 60% by the end of the century.”

“Precipitation is likely to increase in the Arctic region, but that is just one factor that
affects soil moisture levels”

Her research colleague, Isla Myers-Smith, of the University of Edinburgh’s School of Geosciences, says: “While most climate change models have focused on increasing temperatures, our research has shown that soil moisture can play a much greater role in changing plant traits than we previously thought.

“We need to understand more about soil moisture in the Arctic. Precipitation is likely to increase in the Arctic region, but that is just one factor that affects soil moisture levels.”

The Arctic is one of the fastest-warming places on Earth. Sea ice has been in dramatic retreat and other research teams have repeatedly observed dramatic changes in the plants and animals that cling to life in the hemisphere’s harshest climate.

Ground reflectivity

What happens to tundra vegetation matters as a vast community of birds, insects and mammals survives on the annual growth in the brief northern summer.

Plants both respond to climate change and play a part in that change. They affect the reflectivity of the ground surface, and warm the soil in ways that could release ever more greenhouse gases.

Half of the planet’s stored carbon could be trapped in the permafrost, and any escapes could only accelerate global warming.

“This is the first time that a biome-scale study has been carried out to get to the root of the critical role that plants play in this rapidly-warming part of the planet,” Dr Myers-Smith says.

And Dr Bjorkman warns: “Shorter plants trap more snow, which insulates the underlying soil and prevents it from freezing as quickly in winter. An increase in taller plants could speed up the thawing of this frozen carbon bank, and lead to an increase in the release of greenhouse gases.” – Climate News Network

Plants are getting taller in the Arctic high latitudes as warmer, moister soil prompts growth that could increase the release of greenhouse gases.

LONDON, 11 October, 2018 – The Arctic is becoming greener, warmer and leafier as small plants that once hugged the ground to trap snow and insulate their roots in the permafrost have started to gain in stature.

In the high latitudes, plants have begun to respond to climate change and warmer, moister soils by reaching for the sky.

It is estimated that, by 2100, the northernmost vegetation could have grown by up to 60% taller.

European scientists, backed by an international team of more than 120 biologists, report in Nature journal  that tundra plants are gaining in height, and that species from further south are advancing towards the Arctic Circle.

Close survey of growth

Their conclusion is based on more than 56,000 observations of tundra vegetation and a close survey of growth at 117 sites around the high latitudes in Alaska, Canada, Iceland, Scandinavia and Siberia.

“The increase in height we saw was not just in a few sites but nearly everywhere,” says Dr Anne Bjorkman, a researcher at Germany’s Senckenberg Biodiversity and Climate Research Centre. “If taller plants continue to spread at the current rate, the plant community height could increase by 20% to 60% by the end of the century.”

“Precipitation is likely to increase in the Arctic region, but that is just one factor that
affects soil moisture levels”

Her research colleague, Isla Myers-Smith, of the University of Edinburgh’s School of Geosciences, says: “While most climate change models have focused on increasing temperatures, our research has shown that soil moisture can play a much greater role in changing plant traits than we previously thought.

“We need to understand more about soil moisture in the Arctic. Precipitation is likely to increase in the Arctic region, but that is just one factor that affects soil moisture levels.”

The Arctic is one of the fastest-warming places on Earth. Sea ice has been in dramatic retreat and other research teams have repeatedly observed dramatic changes in the plants and animals that cling to life in the hemisphere’s harshest climate.

Ground reflectivity

What happens to tundra vegetation matters as a vast community of birds, insects and mammals survives on the annual growth in the brief northern summer.

Plants both respond to climate change and play a part in that change. They affect the reflectivity of the ground surface, and warm the soil in ways that could release ever more greenhouse gases.

Half of the planet’s stored carbon could be trapped in the permafrost, and any escapes could only accelerate global warming.

“This is the first time that a biome-scale study has been carried out to get to the root of the critical role that plants play in this rapidly-warming part of the planet,” Dr Myers-Smith says.

And Dr Bjorkman warns: “Shorter plants trap more snow, which insulates the underlying soil and prevents it from freezing as quickly in winter. An increase in taller plants could speed up the thawing of this frozen carbon bank, and lead to an increase in the release of greenhouse gases.” – Climate News Network

*

Underwater walls might avert sea level rise

Could a vast underwater wall in front of an unstable glacier prevent dangerous sea level rise? Or should everyone just move further inland?

LONDON, 10 October, 2018 – Two climate scientists believe they have a long-term solution to dangerous sea level rise by targeting the most vulnerable glaciers, especially those that could trigger a massive collapse of the ice sheets behind them.

A submarine wall big enough and wide enough could halt the flow of increasingly warm ocean water below the front of each glacier. The combination of warmer air temperatures and warmer waters that accompany human-triggered climate change is dangerous: it could for instance accelerate the already alarming retreat of the Thwaites Glacier in West Antarctica, which alone shores up enough ice to raise global sea levels by up to 3 metres.

The scientists don’t propose an immediate start. But they do want to explore ways of halting sea level rise driven by global warming that could soon be costing the world $50 trillion a year in economic losses, that could submerge small island states and turn 1 million people a year into climate migrants.

“We are not advocating that glacial geoengineering be attempted any time soon”, they warn in the journal The Cryosphere.

Their simplest option – a series of pillars to shore up a targeted glacier and keep it “grounded” – would require engineering comparable in scale to the excavation of the Suez canal, would be undertaken in the world’s harshest environment, and would have just a one in three chance of success.

“In the long run we need plans to deal with the committed climate changes that are already in the pipeline, one of which may be an ice sheet collapse”

The researchers – John Moore, of Beijing Normal University in China, who also holds a post at the University of Lapland in Finland, and Michael Wolovick, of Princeton University in the US – have made this case before: they and others argued in March in Nature for what they call “managed collapse.”

In the latest study, they look at the challenge in greater detail. And they warn that even if targeted geoengineering of individual glaciers worked, it would only do so if humans stopped tipping ever more greenhouse gases into the atmosphere to fuel yet more global warming.

Nor do they argue that a submarine curtain wall to halt warming water across the front of the Thwaites glacier – up to 100 kms wide – is currently feasible. “But in the long run we need plans to deal with the committed climate changes that are already in the pipeline, one of which may be an ice sheet collapse.”

And one of these is the Thwaites Glacier in Antarctica: another is the Jakobshaven Isbrae in Greenland. Both could be cases of what the scientists call marine ice sheet instability: as a glacier retreats from its grounding line, the ice lifts off the bedrock and begins to float.

If the bedrock slopes down towards the centre of the ice sheet, and warmer ocean currents wash beneath it, then the ice starts to stretch and thin, and retreat further. At some point, it would become much easier for thawing ice to flow into the sea, and start what could become a runaway collapse. Engineers could devise a way of slowing or halting the process.

Huge impact

The scientists argue that even a rise of 0.6m to 1.2 metres by 2100 could cause up to $50 trillion in economic damage, and the resultant flooding could force up to 200 million to 500 million people out of their homes at least for a few days or weeks: around a million or so every year would never go back.

Climate scientists have been arguing about geoengineering solutions – the so-called technofix – to climate change for more than a decade. Global answers, such as blocking sunlight with stratospheric soot and sulphate aerosols, or whitening the polar ice to make it more reflective, remain contentious.

But the Cryosphere proposals are much more limited, and the immediate dangers of sea level rise are not contested. Ice sheet collapse in Antarctica, for instance, could raise sea levels by more than 3 metres and even by as much as 19 metres over the next two or three centuries.

The researchers’ calculations suggest that in theory an engineering solution that blocked even 50% of the warm water getting under a glacier could offer a 70% chance of delaying or stopping ice sheet collapse.

Left behind

Countries already spend on coastal protection: their solution would require international co-operation at the highest political level, and intensive scientific research.

“Managing sea level rise at the source has the advantage of benefiting the entire world, while a strategy that relies only on local coastal protection is more of an every-nation-for-itself approach that may leave many poor countries behind,” they write.

“Perhaps, after careful consideration, we may conclude that glacial geoengineering is unworkable and the right answer is to invest heavily in coastal protection and retreat inland where that is not practical or economical.

“However, we owe it to the 400 million people who live within 5m of sea level to at least consider the alternatives.” – Climate News Network

Could a vast underwater wall in front of an unstable glacier prevent dangerous sea level rise? Or should everyone just move further inland?

LONDON, 10 October, 2018 – Two climate scientists believe they have a long-term solution to dangerous sea level rise by targeting the most vulnerable glaciers, especially those that could trigger a massive collapse of the ice sheets behind them.

A submarine wall big enough and wide enough could halt the flow of increasingly warm ocean water below the front of each glacier. The combination of warmer air temperatures and warmer waters that accompany human-triggered climate change is dangerous: it could for instance accelerate the already alarming retreat of the Thwaites Glacier in West Antarctica, which alone shores up enough ice to raise global sea levels by up to 3 metres.

The scientists don’t propose an immediate start. But they do want to explore ways of halting sea level rise driven by global warming that could soon be costing the world $50 trillion a year in economic losses, that could submerge small island states and turn 1 million people a year into climate migrants.

“We are not advocating that glacial geoengineering be attempted any time soon”, they warn in the journal The Cryosphere.

Their simplest option – a series of pillars to shore up a targeted glacier and keep it “grounded” – would require engineering comparable in scale to the excavation of the Suez canal, would be undertaken in the world’s harshest environment, and would have just a one in three chance of success.

“In the long run we need plans to deal with the committed climate changes that are already in the pipeline, one of which may be an ice sheet collapse”

The researchers – John Moore, of Beijing Normal University in China, who also holds a post at the University of Lapland in Finland, and Michael Wolovick, of Princeton University in the US – have made this case before: they and others argued in March in Nature for what they call “managed collapse.”

In the latest study, they look at the challenge in greater detail. And they warn that even if targeted geoengineering of individual glaciers worked, it would only do so if humans stopped tipping ever more greenhouse gases into the atmosphere to fuel yet more global warming.

Nor do they argue that a submarine curtain wall to halt warming water across the front of the Thwaites glacier – up to 100 kms wide – is currently feasible. “But in the long run we need plans to deal with the committed climate changes that are already in the pipeline, one of which may be an ice sheet collapse.”

And one of these is the Thwaites Glacier in Antarctica: another is the Jakobshaven Isbrae in Greenland. Both could be cases of what the scientists call marine ice sheet instability: as a glacier retreats from its grounding line, the ice lifts off the bedrock and begins to float.

If the bedrock slopes down towards the centre of the ice sheet, and warmer ocean currents wash beneath it, then the ice starts to stretch and thin, and retreat further. At some point, it would become much easier for thawing ice to flow into the sea, and start what could become a runaway collapse. Engineers could devise a way of slowing or halting the process.

Huge impact

The scientists argue that even a rise of 0.6m to 1.2 metres by 2100 could cause up to $50 trillion in economic damage, and the resultant flooding could force up to 200 million to 500 million people out of their homes at least for a few days or weeks: around a million or so every year would never go back.

Climate scientists have been arguing about geoengineering solutions – the so-called technofix – to climate change for more than a decade. Global answers, such as blocking sunlight with stratospheric soot and sulphate aerosols, or whitening the polar ice to make it more reflective, remain contentious.

But the Cryosphere proposals are much more limited, and the immediate dangers of sea level rise are not contested. Ice sheet collapse in Antarctica, for instance, could raise sea levels by more than 3 metres and even by as much as 19 metres over the next two or three centuries.

The researchers’ calculations suggest that in theory an engineering solution that blocked even 50% of the warm water getting under a glacier could offer a 70% chance of delaying or stopping ice sheet collapse.

Left behind

Countries already spend on coastal protection: their solution would require international co-operation at the highest political level, and intensive scientific research.

“Managing sea level rise at the source has the advantage of benefiting the entire world, while a strategy that relies only on local coastal protection is more of an every-nation-for-itself approach that may leave many poor countries behind,” they write.

“Perhaps, after careful consideration, we may conclude that glacial geoengineering is unworkable and the right answer is to invest heavily in coastal protection and retreat inland where that is not practical or economical.

“However, we owe it to the 400 million people who live within 5m of sea level to at least consider the alternatives.” – Climate News Network

*

Frozen Arctic moves seawards in hectic melt

Once trapped in a Russian ice cap north of Siberia, the frozen Arctic is moving fast, racing in decades from metres to kilometres a year.

LONDON, 5 October, 2018 – Satellite images have revealed a dramatic change in Russia’s frozen Arctic. An ice cap that once crept almost imperceptibly across the barren rocks of October Revolution island, in the Kara Sea, is on the move.

All ice, even when permanently frozen to the bedrock, moves. From 1952 to 1985, the western edge of the Vavilov ice cap, 1,820 square kilometres in area and between 300 metres and 600 metres in thickness, shifted at about 12 metres a year. Between 1998 and 2011, it stepped up the pace to 75 metres a year. Between 2014 and 2015, the ice front had broken into tongues that moved at more than 1,000 metres a year.

And between 2015 and 2016 the leading edge had started racing into the Kara Sea at 5,000 metres a year. It is also thinning at the rate of a third of a metre a day, according to a new study in the journal Earth and Planetary Science Letters.

The high Arctic is the fastest-warming place on Earth, and researchers have for more than 30 years been measuring changes in the rate at which sea ice shrinks and Greenland glaciers flow.

Role as metaphor

“In a warming climate, glacier acceleration is becoming more and more common, but the rate of ice loss at Vavilov is extreme and unexpected,” said Michael Willis, a geologist at the University of California Boulder, who led the study by scientists from the US, UK and Russia.

Glaciers and icecaps such as Vavilov cover about 450,000 square kilometres of the planet’s surface and hold enough frozen water to raise global sea levels by 30 cms. They form on land in polar “deserts” in which the temperatures are below freezing and snow falls at no more than 25 cms a year.

In the Arctic summer the snow cover melts, and water trickles down through the ice; over the years, snowfall patterns shift and the ice cap shifts under gravitational tug. All glaciers flow, but so slowly that their pace has been incorporated into metaphor.

For the study authors, who used decades of satellite studies of the high Arctic to measure the change, the puzzle is one of geophysics: how could a fast-frozen mass of ice get to the stage where it can slide, as if lubricated, across a rocky surface above sea level?

“Glacier acceleration is becoming more and more common, but the rate of ice loss at Vavilov is extreme and unexpected”

“We’ve never seen anything like this before, this study has raised as many questions as it has answered,” said Dr Willis. “And we’re now working on modelling the whole situation to get a better handle on the physics involved.”

But for climate scientists concerned with the bigger picture, the study is another instance of potentially catastrophic climate change in the making. Once an ice cap starts to flow, the process is unlikely to stop.

And a second study in the same week from the other end of the globe shows that it doesn’t take much to start the ice flowing into the sea. It has confirmed that average global warming of no more than 2°C above historic levels, given long enough,  could melt much of the world’s largest ice sheet.

Planetary average temperatures have already risen by 1°C since the first industrial exploitation of coal, gas and oil only 200 years ago, and right now, although 195 nations vowed in Paris in 2015 to keep the rise to “well below” 2°C by 2100, the world seems headed for at least a 3°C rise later this century.

Future loss inevitable

British, Australian, New Zealand, Spanish and Japanese scientists report in Nature that they reconstructed the impact of change on the East Antarctic ice sheet during interglacials, those warm pauses during the last Ice Age.

For about 2,500 years, Antarctic air temperatures rose by about 2°C, the huge fastness of ice began to melt, and sea levels rose. The West Antarctic ice sheet, which has repeatedly shown signs of thawing, holds enough water to raise sea levels by up to 5 metres. The apparently stable East Antarctic sheet holds enough to lift global sea levels by 53 metres. During the interglacials of 400,000 years ago and 125,000 years ago, sea levels rose between 6 metres and 13 metres higher than they are today.

“What we have learned is that even modest warming of just two degrees, if sustained for a couple of thousand years, is enough to cause the East Antarctic ice sheet to retreat in some of its low-lying areas,” said David Wilson, of the UK’s Imperial College, who led the research.

“With current global temperatures already one degree higher than during pre-industrial times, future ice loss seems inevitable if we fail to reduce carbon emissions.” – Climate News Network

Once trapped in a Russian ice cap north of Siberia, the frozen Arctic is moving fast, racing in decades from metres to kilometres a year.

LONDON, 5 October, 2018 – Satellite images have revealed a dramatic change in Russia’s frozen Arctic. An ice cap that once crept almost imperceptibly across the barren rocks of October Revolution island, in the Kara Sea, is on the move.

All ice, even when permanently frozen to the bedrock, moves. From 1952 to 1985, the western edge of the Vavilov ice cap, 1,820 square kilometres in area and between 300 metres and 600 metres in thickness, shifted at about 12 metres a year. Between 1998 and 2011, it stepped up the pace to 75 metres a year. Between 2014 and 2015, the ice front had broken into tongues that moved at more than 1,000 metres a year.

And between 2015 and 2016 the leading edge had started racing into the Kara Sea at 5,000 metres a year. It is also thinning at the rate of a third of a metre a day, according to a new study in the journal Earth and Planetary Science Letters.

The high Arctic is the fastest-warming place on Earth, and researchers have for more than 30 years been measuring changes in the rate at which sea ice shrinks and Greenland glaciers flow.

Role as metaphor

“In a warming climate, glacier acceleration is becoming more and more common, but the rate of ice loss at Vavilov is extreme and unexpected,” said Michael Willis, a geologist at the University of California Boulder, who led the study by scientists from the US, UK and Russia.

Glaciers and icecaps such as Vavilov cover about 450,000 square kilometres of the planet’s surface and hold enough frozen water to raise global sea levels by 30 cms. They form on land in polar “deserts” in which the temperatures are below freezing and snow falls at no more than 25 cms a year.

In the Arctic summer the snow cover melts, and water trickles down through the ice; over the years, snowfall patterns shift and the ice cap shifts under gravitational tug. All glaciers flow, but so slowly that their pace has been incorporated into metaphor.

For the study authors, who used decades of satellite studies of the high Arctic to measure the change, the puzzle is one of geophysics: how could a fast-frozen mass of ice get to the stage where it can slide, as if lubricated, across a rocky surface above sea level?

“Glacier acceleration is becoming more and more common, but the rate of ice loss at Vavilov is extreme and unexpected”

“We’ve never seen anything like this before, this study has raised as many questions as it has answered,” said Dr Willis. “And we’re now working on modelling the whole situation to get a better handle on the physics involved.”

But for climate scientists concerned with the bigger picture, the study is another instance of potentially catastrophic climate change in the making. Once an ice cap starts to flow, the process is unlikely to stop.

And a second study in the same week from the other end of the globe shows that it doesn’t take much to start the ice flowing into the sea. It has confirmed that average global warming of no more than 2°C above historic levels, given long enough,  could melt much of the world’s largest ice sheet.

Planetary average temperatures have already risen by 1°C since the first industrial exploitation of coal, gas and oil only 200 years ago, and right now, although 195 nations vowed in Paris in 2015 to keep the rise to “well below” 2°C by 2100, the world seems headed for at least a 3°C rise later this century.

Future loss inevitable

British, Australian, New Zealand, Spanish and Japanese scientists report in Nature that they reconstructed the impact of change on the East Antarctic ice sheet during interglacials, those warm pauses during the last Ice Age.

For about 2,500 years, Antarctic air temperatures rose by about 2°C, the huge fastness of ice began to melt, and sea levels rose. The West Antarctic ice sheet, which has repeatedly shown signs of thawing, holds enough water to raise sea levels by up to 5 metres. The apparently stable East Antarctic sheet holds enough to lift global sea levels by 53 metres. During the interglacials of 400,000 years ago and 125,000 years ago, sea levels rose between 6 metres and 13 metres higher than they are today.

“What we have learned is that even modest warming of just two degrees, if sustained for a couple of thousand years, is enough to cause the East Antarctic ice sheet to retreat in some of its low-lying areas,” said David Wilson, of the UK’s Imperial College, who led the research.

“With current global temperatures already one degree higher than during pre-industrial times, future ice loss seems inevitable if we fail to reduce carbon emissions.” – Climate News Network

*

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