Category Archives: Polar

Pacific climate wobble speeds Arctic ice melt

Thanks to a natural sea temperature cycle, a Pacific climate wobble, the Arctic Ocean could be ice-free in the summer in a decade or two.

LONDON, 6 March, 2019 – Sunlit skies and bright blue water could come earlier to the Arctic – much earlier, thanks to a distant Pacific climate wobble.

Scientists now think that the Arctic Ocean could be effectively ice-free within the next 20 years, opening it to sea lanes across the polar waters between Europe, the US and east Asia.

Climate researchers have repeatedly warned, in the last two decades, that because of global warming the ice sheet that masks the Arctic Ocean has been thinning and could in effect vanish altogether in summertime by 2050.

New research has brought forward the prediction date. And this time the effective agency is not just global warming driven by profligate combustion of fossil fuels worldwide, but a natural cyclic phenomenon known to oceanographers as the interdecadal Pacific oscillation, or IPO.

“The trajectory is towards becoming ice-free in the summer …  there’s more chance of it being on the earlier end of that window than the later end”

Over a cycle of between one to three decades, the average ocean temperatures of the north Pacific shift up or down by about 0.5°C.

And a new study in the journal Geophysical Research Letters pinpoints the state of the present cycle: the Pacific ended its cold phase and started to warm up about five years ago.

James Screen of the University of Exeter, UK, and a colleague used computer modelling to merge the continuous upward rise in global average temperatures as a consequence of the build-up of greenhouse gases in the atmosphere with the pattern of predicted natural change in ocean surface temperatures to identify the moment when the summer ice will have melted.

The phrase “ice-free” is not a simple one, because some sea ice always remains, but oceanographers and glaciologists have their own definition: it happens when the area of summer sea ice falls below a million square kilometres.

Dramatic change likely

And this is now likely to happen some time between 2030 and 2050. Any argument is not about if, but when. The Arctic is just about the fastest-warming region of the planet, and in 2016 polar sea ice in both hemispheres  reached a record low: an area of ice the size of Mexico was lost.

Temperatures in the Arctic were recorded as up to 20°C above the average for some of the winter months. The long-term consequences are unpredictable, but since both ocean current and air movement are driven by the difference between equatorial and polar temperatures, dramatic climate change is likely to follow.

“The trajectory is towards becoming ice-free in the summer, but there is uncertainty as to when that is going to occur,” Dr Screen said.

“You can hedge your bets. The shift in the IPO means there’s more chance of it being on the earlier end of that window than the later end.” – Climate News Network

Thanks to a natural sea temperature cycle, a Pacific climate wobble, the Arctic Ocean could be ice-free in the summer in a decade or two.

LONDON, 6 March, 2019 – Sunlit skies and bright blue water could come earlier to the Arctic – much earlier, thanks to a distant Pacific climate wobble.

Scientists now think that the Arctic Ocean could be effectively ice-free within the next 20 years, opening it to sea lanes across the polar waters between Europe, the US and east Asia.

Climate researchers have repeatedly warned, in the last two decades, that because of global warming the ice sheet that masks the Arctic Ocean has been thinning and could in effect vanish altogether in summertime by 2050.

New research has brought forward the prediction date. And this time the effective agency is not just global warming driven by profligate combustion of fossil fuels worldwide, but a natural cyclic phenomenon known to oceanographers as the interdecadal Pacific oscillation, or IPO.

“The trajectory is towards becoming ice-free in the summer …  there’s more chance of it being on the earlier end of that window than the later end”

Over a cycle of between one to three decades, the average ocean temperatures of the north Pacific shift up or down by about 0.5°C.

And a new study in the journal Geophysical Research Letters pinpoints the state of the present cycle: the Pacific ended its cold phase and started to warm up about five years ago.

James Screen of the University of Exeter, UK, and a colleague used computer modelling to merge the continuous upward rise in global average temperatures as a consequence of the build-up of greenhouse gases in the atmosphere with the pattern of predicted natural change in ocean surface temperatures to identify the moment when the summer ice will have melted.

The phrase “ice-free” is not a simple one, because some sea ice always remains, but oceanographers and glaciologists have their own definition: it happens when the area of summer sea ice falls below a million square kilometres.

Dramatic change likely

And this is now likely to happen some time between 2030 and 2050. Any argument is not about if, but when. The Arctic is just about the fastest-warming region of the planet, and in 2016 polar sea ice in both hemispheres  reached a record low: an area of ice the size of Mexico was lost.

Temperatures in the Arctic were recorded as up to 20°C above the average for some of the winter months. The long-term consequences are unpredictable, but since both ocean current and air movement are driven by the difference between equatorial and polar temperatures, dramatic climate change is likely to follow.

“The trajectory is towards becoming ice-free in the summer, but there is uncertainty as to when that is going to occur,” Dr Screen said.

“You can hedge your bets. The shift in the IPO means there’s more chance of it being on the earlier end of that window than the later end.” – Climate News Network

Melting polar ice sheets will alter weather

Sea level rise and melting polar ice sheets may not cause a climate catastrophe, but they will certainly change weather patterns unpredictably.

LONDON, 15 February, 2019 – The global weather is about to get worse. The melting polar ice sheets will mean rainfall and windstorms could become more violent, and hot spells and ice storms could become more extreme.

This is because the ice sheets of Greenland and Antarctica are melting, to affect what were once stable ocean currents and airflow patterns around the globe.

Planetary surface temperatures could rise by 3°C or even 4°C by the end of the century. Global sea levels will rise in ways that would “enhance global temperature variability”, but this might not be as high as earlier studies have predicted. That is because the ice cliffs of Antarctica might not be so much at risk of disastrous collapse that would set the glaciers accelerating to the sea.

The latest revision of evidence from the melting ice sheets in two hemispheres – and there is plenty of evidence that melting is happening at ever greater rates – is based on two studies of what could happen to the world’s greatest reservoirs of frozen freshwater if nations pursue current policies, fossil fuel combustion continues to increase, and global average temperatures creep up to unprecedented levels.

“Even if we do include ice-cliff instability … the most likely contribution to sea level rise would be less than half a metre by 2100”

“Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic ice sheets to enter Earth’s oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world,” said Nick Golledge, a south polar researcher at Victoria University, in New Zealand.

He and colleagues from Canada, the US, Germany and the UK report in Nature that they matched satellite observations of what is happening to the ice sheets with detailed simulations of the complex effects of melting over time, and according to the human response so far to warnings of climate change.

In Paris in 2015, leaders from 195 nations vowed to contain global warming to “well below” an average rise of 2°C by 2100. But promises have yet to become concerted and coherent action, and researchers warn that on present policies, a 3°C rise seems inevitable.

Sea levels have already risen by about 14 cms in the last century: the worst scenarios have proposed a devastating rise of 130 cms by 2100. The fastest increase in the rise of sea levels is likely to happen between 2065 and 2075.

Gulf Stream weakens

As warmer melt water gets into the North Atlantic, that major ocean current the Gulf Stream is likely to be weakened. Air temperatures are likely to rise over eastern Canada, central America and the high Arctic. Northwestern Europe – scientists have been warning of this for years – will become cooler.

In the Antarctic, a lens of warm fresh water will form over the surface, allowing uprising warm ocean water to spread and cause what could be further Antarctic melting.

But how bad this could be is re-examined in a second, companion paper in Nature. Tamsin Edwards, now at King’s College London, Dr Golledge and others took a fresh look at an old scare: that the vast cliffs of ice – some of them 100 metres above sea level – around the Antarctic could become unstable and collapse, accelerating the retreat of the ice behind them.

They used geophysical techniques to analyse dramatic episodes of ice loss that must have happened 3 million years ago and 125,000 years ago, and they went back to the present patterns of melt. These losses, in their calculations, did not cause unstoppable ice loss in the past, and may not affect the future much either.

Instability less important

“We’ve shown that ice-cliff instability doesn’t appear to be an essential mechanism in reproducing past sea level changes and so this suggests ‘the jury’s still out’ when it comes to including it in future predictions,” said Dr Edwards.

“Even if we do include ice-cliff instability, our more thorough assessment shows the most likely contribution to sea level rise would be less than half a metre by 2100.”

At worst, there is a one in 20 chance that enough of Antarctica’s glacial burden will melt to raise sea levels by 39 cms. More likely, both studies conclude, under high levels of greenhouse gas concentrations, south polar ice will only melt to raise sea levels worldwide by about 15 cms. – Climate News Network

Sea level rise and melting polar ice sheets may not cause a climate catastrophe, but they will certainly change weather patterns unpredictably.

LONDON, 15 February, 2019 – The global weather is about to get worse. The melting polar ice sheets will mean rainfall and windstorms could become more violent, and hot spells and ice storms could become more extreme.

This is because the ice sheets of Greenland and Antarctica are melting, to affect what were once stable ocean currents and airflow patterns around the globe.

Planetary surface temperatures could rise by 3°C or even 4°C by the end of the century. Global sea levels will rise in ways that would “enhance global temperature variability”, but this might not be as high as earlier studies have predicted. That is because the ice cliffs of Antarctica might not be so much at risk of disastrous collapse that would set the glaciers accelerating to the sea.

The latest revision of evidence from the melting ice sheets in two hemispheres – and there is plenty of evidence that melting is happening at ever greater rates – is based on two studies of what could happen to the world’s greatest reservoirs of frozen freshwater if nations pursue current policies, fossil fuel combustion continues to increase, and global average temperatures creep up to unprecedented levels.

“Even if we do include ice-cliff instability … the most likely contribution to sea level rise would be less than half a metre by 2100”

“Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic ice sheets to enter Earth’s oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world,” said Nick Golledge, a south polar researcher at Victoria University, in New Zealand.

He and colleagues from Canada, the US, Germany and the UK report in Nature that they matched satellite observations of what is happening to the ice sheets with detailed simulations of the complex effects of melting over time, and according to the human response so far to warnings of climate change.

In Paris in 2015, leaders from 195 nations vowed to contain global warming to “well below” an average rise of 2°C by 2100. But promises have yet to become concerted and coherent action, and researchers warn that on present policies, a 3°C rise seems inevitable.

Sea levels have already risen by about 14 cms in the last century: the worst scenarios have proposed a devastating rise of 130 cms by 2100. The fastest increase in the rise of sea levels is likely to happen between 2065 and 2075.

Gulf Stream weakens

As warmer melt water gets into the North Atlantic, that major ocean current the Gulf Stream is likely to be weakened. Air temperatures are likely to rise over eastern Canada, central America and the high Arctic. Northwestern Europe – scientists have been warning of this for years – will become cooler.

In the Antarctic, a lens of warm fresh water will form over the surface, allowing uprising warm ocean water to spread and cause what could be further Antarctic melting.

But how bad this could be is re-examined in a second, companion paper in Nature. Tamsin Edwards, now at King’s College London, Dr Golledge and others took a fresh look at an old scare: that the vast cliffs of ice – some of them 100 metres above sea level – around the Antarctic could become unstable and collapse, accelerating the retreat of the ice behind them.

They used geophysical techniques to analyse dramatic episodes of ice loss that must have happened 3 million years ago and 125,000 years ago, and they went back to the present patterns of melt. These losses, in their calculations, did not cause unstoppable ice loss in the past, and may not affect the future much either.

Instability less important

“We’ve shown that ice-cliff instability doesn’t appear to be an essential mechanism in reproducing past sea level changes and so this suggests ‘the jury’s still out’ when it comes to including it in future predictions,” said Dr Edwards.

“Even if we do include ice-cliff instability, our more thorough assessment shows the most likely contribution to sea level rise would be less than half a metre by 2100.”

At worst, there is a one in 20 chance that enough of Antarctica’s glacial burden will melt to raise sea levels by 39 cms. More likely, both studies conclude, under high levels of greenhouse gas concentrations, south polar ice will only melt to raise sea levels worldwide by about 15 cms. – Climate News Network

Permafrost thaws as global warming sets in

Global warming is at work far below the surface, at depths seemingly insulated from the greenhouse effect. This is bad news for the permafrost.

LONDON, 29 January, 2019 – Even in the coldest places – 10 metres below the surface of the polar wastes – global warming has begun to work. A new study of the frozen soils in both hemispheres shows that between 2007 and 2016, they warmed by an average of 0.3°C.

This remained true within the Arctic and Antarctic zones, in the highest mountain regions of Europe and Asia, and even in the Siberian tundra, where the temperatures at depth rose by almost a whole degree.

New research into the permafrost, defined as territory where soil has been frozen for at least two consecutive years, suggests that much of it may not be permanently frozen for much longer.

Climate scientists have repeatedly warned that along with the tilth, clays and sediments the icy structures store vast amounts of carbon in the form of yet-to-be-decomposed plant material.

So the thawing permafrost could surrender even more warming agents in the form of greenhouse gases, and accelerate global warming even further.

“The permafrost isn’t simply warming on a local and regional scale, but worldwide and at virtually the same pace as climate warming”

Researchers based in Potsdam, Germany report in the journal Nature Communications that they and colleagues in the Global Terrestrial Network for Permafrost monitored and measured soil temperatures in boreholes at 154 locations; more than 120 of them over a 10-year cycle. In a dozen locations the temperatures actually fell, and at 40 locations there was virtually no change.

The most dramatic warming was in the Arctic, where soils that were more than 90% permafrost increased temperatures by 0.3°C, and the Siberian north, where temperatures rose by 0.9°C or more. Air temperatures over those regions had risen by an average of 0.6°C in the same decade. In those Arctic regions with less than 90% permafrost, the frozen ground had warmed by 0.2°C.

“In these regions there is more and more snowfall, which insulates the permafrost in two ways, following the igloo principle,” said Boris Biskaborn of the Alfred Wegener Institute, at the Helmholtz Centre for Polar and Marine Research, who led the study.

“In winter snow protects the soil from extreme cold, which on average produces a warming effect. In spring it reflects the sunlight, and prevents the soils from being exposed to too much warmth, at least until the snow has completely melted away.”

Widespread impact

The scientists also report that soil temperature rises were recorded in the Alps of Europe, the mountain ranges of Scandinavia, and in the Himalayas.

Other scientists have already this year identified potential disaster for many settlements in the Arctic regions: the once-hard-frozen topsoils are in danger of thawing, and since these support industrial buildings, oil and gas pipelines, road surfaces, and even whole towns, the danger of severe damage to infrastructure is growing.

And, the researchers warn, even if the world sticks to its promise, made by 195 nations in Paris in 2015, and contains global warming to no more than 2°C over pre-industrial levels by 2100, there is still a likelihood that the permafrost will disappear over a large area, to surrender more greenhouse gases, and trigger more warming.

“All this data tells us that the permafrost isn’t simply warming on a local and regional scale, but worldwide and at virtually the same pace as climate warming, which is producing a substantial warming of the air and increased snow thickness, especially in the Arctic,” said Guido Grosse, who heads permafrost research in Potsdam. “These two factors produce a warming of the once permanently frozen ground.” – Climate News Network

Global warming is at work far below the surface, at depths seemingly insulated from the greenhouse effect. This is bad news for the permafrost.

LONDON, 29 January, 2019 – Even in the coldest places – 10 metres below the surface of the polar wastes – global warming has begun to work. A new study of the frozen soils in both hemispheres shows that between 2007 and 2016, they warmed by an average of 0.3°C.

This remained true within the Arctic and Antarctic zones, in the highest mountain regions of Europe and Asia, and even in the Siberian tundra, where the temperatures at depth rose by almost a whole degree.

New research into the permafrost, defined as territory where soil has been frozen for at least two consecutive years, suggests that much of it may not be permanently frozen for much longer.

Climate scientists have repeatedly warned that along with the tilth, clays and sediments the icy structures store vast amounts of carbon in the form of yet-to-be-decomposed plant material.

So the thawing permafrost could surrender even more warming agents in the form of greenhouse gases, and accelerate global warming even further.

“The permafrost isn’t simply warming on a local and regional scale, but worldwide and at virtually the same pace as climate warming”

Researchers based in Potsdam, Germany report in the journal Nature Communications that they and colleagues in the Global Terrestrial Network for Permafrost monitored and measured soil temperatures in boreholes at 154 locations; more than 120 of them over a 10-year cycle. In a dozen locations the temperatures actually fell, and at 40 locations there was virtually no change.

The most dramatic warming was in the Arctic, where soils that were more than 90% permafrost increased temperatures by 0.3°C, and the Siberian north, where temperatures rose by 0.9°C or more. Air temperatures over those regions had risen by an average of 0.6°C in the same decade. In those Arctic regions with less than 90% permafrost, the frozen ground had warmed by 0.2°C.

“In these regions there is more and more snowfall, which insulates the permafrost in two ways, following the igloo principle,” said Boris Biskaborn of the Alfred Wegener Institute, at the Helmholtz Centre for Polar and Marine Research, who led the study.

“In winter snow protects the soil from extreme cold, which on average produces a warming effect. In spring it reflects the sunlight, and prevents the soils from being exposed to too much warmth, at least until the snow has completely melted away.”

Widespread impact

The scientists also report that soil temperature rises were recorded in the Alps of Europe, the mountain ranges of Scandinavia, and in the Himalayas.

Other scientists have already this year identified potential disaster for many settlements in the Arctic regions: the once-hard-frozen topsoils are in danger of thawing, and since these support industrial buildings, oil and gas pipelines, road surfaces, and even whole towns, the danger of severe damage to infrastructure is growing.

And, the researchers warn, even if the world sticks to its promise, made by 195 nations in Paris in 2015, and contains global warming to no more than 2°C over pre-industrial levels by 2100, there is still a likelihood that the permafrost will disappear over a large area, to surrender more greenhouse gases, and trigger more warming.

“All this data tells us that the permafrost isn’t simply warming on a local and regional scale, but worldwide and at virtually the same pace as climate warming, which is producing a substantial warming of the air and increased snow thickness, especially in the Arctic,” said Guido Grosse, who heads permafrost research in Potsdam. “These two factors produce a warming of the once permanently frozen ground.” – Climate News Network

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

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

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

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

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

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