Category Archives: Polar

Ice-free Arctic Ocean allowed ancient carbon leaks

As the world warms, more greenhouse gas will enter the atmosphere. Researchers now think an ice-free Arctic Ocean explains how and why.

LONDON, 10 January, 2020 – Deep in a cave in Siberia, Israeli, Russian and British scientists have identified evidence of periodic losses of carbon from the permafrost. And the unexpected link is not simply with peak periods of bygone global warming, but with an ice-free Arctic Ocean.

The escape into the atmosphere of prodigious volumes of methane and carbon dioxide from the thawing soils is in step not with average planetary temperature rise, but with long periods when the Arctic Ocean is free of ice every summer.

Fact one: about one quarter of land in the northern hemisphere is now, and has been for much of the last half million years, permanently frozen, and with it about twice as much atmospheric carbon – in the form of peat and preserved vegetation – as there exists freely in the planetary atmosphere.

Fact two: in the most recent decades, sea ice has been both thinning and dwindling rapidly, and the polar ocean could by 2050 become almost entirely ice-free in the summer months.

“This discovery about the behaviour of the permafrost suggests that the expected loss of Arctic sea ice will accelerate melting of the permafrost presently found across much of Siberia”

And this twist in the tale of a rapidly-warming Arctic is preserved in stalagmite formations in a cave deep beneath the rim of the Arctic Circle in Siberia.

The chronology of stalagmite and stalactite development can be established precisely by the pattern of uranium and lead isotope deposits in formations, built up imperceptibly by the steady drip of water from, and through, the soils far above.

That is, the speleothems – a geologist’s catch-all word for both stalactite and stalagmite – form fastest when the permafrost has thawed. And unexpectedly, the periods of thaw did not match the peaks of interglacial warming during the last 1.35 million years. They did however coincide with periods when the Arctic was ice-free in the summer.

“This discovery about the behaviour of the permafrost suggests that the expected loss of Arctic sea ice in the future will accelerate melting of the permafrost presently found across much of Siberia,” said Gideon Henderson of the University of Oxford, and one of the authors of a new study in the journal Nature.

Permafrost in jeopardy

The argument goes like this: if there is no sea ice then more heat and moisture is delivered from the ocean to the atmosphere, with warmer air flowing over Siberia, and therefore more autumn snowfall.

A blanket of snow insulates the soil beneath from the extreme winter cold, so ground temperatures go up, to unsettle the permafrost and start a thaw that leads to accelerated plant decay and ever-increasing escape of carbon dioxide and methane that would otherwise have been frozen into the permafrost.

So the stalagmites endure as evidence of these warmer soils and survive as a direct link to periods of ice-free ocean.

“If these processes continue during modern climate change, future loss of summer Arctic sea ice will accelerate the thawing of Siberian permafrost,” the scientists say. – Climate News Network

As the world warms, more greenhouse gas will enter the atmosphere. Researchers now think an ice-free Arctic Ocean explains how and why.

LONDON, 10 January, 2020 – Deep in a cave in Siberia, Israeli, Russian and British scientists have identified evidence of periodic losses of carbon from the permafrost. And the unexpected link is not simply with peak periods of bygone global warming, but with an ice-free Arctic Ocean.

The escape into the atmosphere of prodigious volumes of methane and carbon dioxide from the thawing soils is in step not with average planetary temperature rise, but with long periods when the Arctic Ocean is free of ice every summer.

Fact one: about one quarter of land in the northern hemisphere is now, and has been for much of the last half million years, permanently frozen, and with it about twice as much atmospheric carbon – in the form of peat and preserved vegetation – as there exists freely in the planetary atmosphere.

Fact two: in the most recent decades, sea ice has been both thinning and dwindling rapidly, and the polar ocean could by 2050 become almost entirely ice-free in the summer months.

“This discovery about the behaviour of the permafrost suggests that the expected loss of Arctic sea ice will accelerate melting of the permafrost presently found across much of Siberia”

And this twist in the tale of a rapidly-warming Arctic is preserved in stalagmite formations in a cave deep beneath the rim of the Arctic Circle in Siberia.

The chronology of stalagmite and stalactite development can be established precisely by the pattern of uranium and lead isotope deposits in formations, built up imperceptibly by the steady drip of water from, and through, the soils far above.

That is, the speleothems – a geologist’s catch-all word for both stalactite and stalagmite – form fastest when the permafrost has thawed. And unexpectedly, the periods of thaw did not match the peaks of interglacial warming during the last 1.35 million years. They did however coincide with periods when the Arctic was ice-free in the summer.

“This discovery about the behaviour of the permafrost suggests that the expected loss of Arctic sea ice in the future will accelerate melting of the permafrost presently found across much of Siberia,” said Gideon Henderson of the University of Oxford, and one of the authors of a new study in the journal Nature.

Permafrost in jeopardy

The argument goes like this: if there is no sea ice then more heat and moisture is delivered from the ocean to the atmosphere, with warmer air flowing over Siberia, and therefore more autumn snowfall.

A blanket of snow insulates the soil beneath from the extreme winter cold, so ground temperatures go up, to unsettle the permafrost and start a thaw that leads to accelerated plant decay and ever-increasing escape of carbon dioxide and methane that would otherwise have been frozen into the permafrost.

So the stalagmites endure as evidence of these warmer soils and survive as a direct link to periods of ice-free ocean.

“If these processes continue during modern climate change, future loss of summer Arctic sea ice will accelerate the thawing of Siberian permafrost,” the scientists say. – Climate News Network

Russia moves to exploit Arctic riches

As the polar sea ice vanishes faster, Russia unveils plans to exploit Arctic riches: fossil fuel deposits, minerals and new shipping routes.

LONDON, 7 January, 2020 − The Russian government has published ambitious plans to exploit the Arctic riches off its northern coast, opening up the polar region to exploitation with a fleet of 40 ships, new roads and railways and four enlarged airports.

The plans, posted in Russian on the official government website on 30 December and signed off by prime minister Dmitry Medvedev, have been translated and reported by the independent Barents Observer newspaper, based in Norway.

The scale of the plans will alarm other Arctic nations, particularly Canada, the United States, Norway and Finland, which all have coastlines on the increasingly ice-free Arctic Ocean.

None of these has the powerful nuclear-propelled ships required to compete with Russia’s existing fleet, let alone the new ones it intends to build.

Although the Russian plans will not be completed until 2035, because the scale of shipbuilding alone is enormous, work has already begun and many of the preparations are going forward this year with a regional geological survey being conducted to pinpoint the riches to be exploited.

“In the 21st century, there will be a maritime ‘gold rush’ to the upper latitudes once conditions permit”

The Barents Observer reports that the plan builds on decrees issued by President Putin from May 2018, and a request to boost annual shipments on the Northern Sea Route across the top of Siberia to 80 million tons by 2024.

Although Rosatom, the giant state-controlled nuclear company, is leading the push to exploit the Arctic, and has already led the way with a floating nuclear power station to help provide power, there are a host of other leading Russian companies involved.

The fact that they are mostly involved in fossil fuel extraction and mineral mining will send a shiver down the spine of all those who believe that the Arctic should be left alone – and that exploiting its potential riches will ensure the destruction of much of the planet through climate change.

The Russians, on the other hand, see the Arctic as their own backyard and climate change as a way of gaining both economic and financial advantage, because Siberia will become much warmer.

Tax-free incentive

Enterprises involved include oil and gas companies Novatek, Gazprom Neft, Rosneft and the Independent Oil Company. In addition there are mineral and ore developers like Nornickel, VostokCoal, Baimskaya, KAZ Minerals, Vostok Engineering and Severnaya Zvezda.

The plans involve around 40 new vessels, several of them huge nuclear ice-breakers, designed to keep shipping lanes open in all circumstances. New railway lines, roads and bridges will be built in northern Siberia, with four airports upgraded to bring in supplies and people. Both companies and people will be encouraged by a special tax-free status for the region.

Exactly what is there to be exploited is not yet known. However, the Maritime Executive website has this to say: “What is generally understood is that there are vast resources to be harnessed. It is estimated that 30% of the world’s untapped hydrocarbons can be found in the Arctic, including a full 25% of proven hydrocarbon reserves.

“Much nickel, platinum, palladium, lead, diamonds, and other rare Earth metals are there as well. In the 21st century, there will be a maritime ‘gold rush’ to the upper latitudes once conditions permit.”

By coincidence the US Congressional Research Service put out an updated research paper on the Arctic on 20 December, discussing the tensions in the region.

American anxiety

Even before the latest Russian announcement there was concern in Washington that an Arctic takeover was planned. The document quotes US Secretary of State Michael Pompeo: “We’re concerned about Russia’s claim over the international waters of the Northern Sea Route, including its newly announced plans to connect it with China’s Maritime Silk Road.

“In the Northern Sea Route, Moscow already illegally demands other nations request permission to pass, requires Russian maritime pilots to be aboard foreign ships, and threatens to use military force to sink any that fail to comply with its demands.

“Just because the Arctic is a place of wilderness does not mean it should become a place of lawlessness. It need not be the case. And we stand ready to ensure that it does not become so.”

As the ice in the region melts, it is clear that the tensions will continue to grow. − Climate News Network

As the polar sea ice vanishes faster, Russia unveils plans to exploit Arctic riches: fossil fuel deposits, minerals and new shipping routes.

LONDON, 7 January, 2020 − The Russian government has published ambitious plans to exploit the Arctic riches off its northern coast, opening up the polar region to exploitation with a fleet of 40 ships, new roads and railways and four enlarged airports.

The plans, posted in Russian on the official government website on 30 December and signed off by prime minister Dmitry Medvedev, have been translated and reported by the independent Barents Observer newspaper, based in Norway.

The scale of the plans will alarm other Arctic nations, particularly Canada, the United States, Norway and Finland, which all have coastlines on the increasingly ice-free Arctic Ocean.

None of these has the powerful nuclear-propelled ships required to compete with Russia’s existing fleet, let alone the new ones it intends to build.

Although the Russian plans will not be completed until 2035, because the scale of shipbuilding alone is enormous, work has already begun and many of the preparations are going forward this year with a regional geological survey being conducted to pinpoint the riches to be exploited.

“In the 21st century, there will be a maritime ‘gold rush’ to the upper latitudes once conditions permit”

The Barents Observer reports that the plan builds on decrees issued by President Putin from May 2018, and a request to boost annual shipments on the Northern Sea Route across the top of Siberia to 80 million tons by 2024.

Although Rosatom, the giant state-controlled nuclear company, is leading the push to exploit the Arctic, and has already led the way with a floating nuclear power station to help provide power, there are a host of other leading Russian companies involved.

The fact that they are mostly involved in fossil fuel extraction and mineral mining will send a shiver down the spine of all those who believe that the Arctic should be left alone – and that exploiting its potential riches will ensure the destruction of much of the planet through climate change.

The Russians, on the other hand, see the Arctic as their own backyard and climate change as a way of gaining both economic and financial advantage, because Siberia will become much warmer.

Tax-free incentive

Enterprises involved include oil and gas companies Novatek, Gazprom Neft, Rosneft and the Independent Oil Company. In addition there are mineral and ore developers like Nornickel, VostokCoal, Baimskaya, KAZ Minerals, Vostok Engineering and Severnaya Zvezda.

The plans involve around 40 new vessels, several of them huge nuclear ice-breakers, designed to keep shipping lanes open in all circumstances. New railway lines, roads and bridges will be built in northern Siberia, with four airports upgraded to bring in supplies and people. Both companies and people will be encouraged by a special tax-free status for the region.

Exactly what is there to be exploited is not yet known. However, the Maritime Executive website has this to say: “What is generally understood is that there are vast resources to be harnessed. It is estimated that 30% of the world’s untapped hydrocarbons can be found in the Arctic, including a full 25% of proven hydrocarbon reserves.

“Much nickel, platinum, palladium, lead, diamonds, and other rare Earth metals are there as well. In the 21st century, there will be a maritime ‘gold rush’ to the upper latitudes once conditions permit.”

By coincidence the US Congressional Research Service put out an updated research paper on the Arctic on 20 December, discussing the tensions in the region.

American anxiety

Even before the latest Russian announcement there was concern in Washington that an Arctic takeover was planned. The document quotes US Secretary of State Michael Pompeo: “We’re concerned about Russia’s claim over the international waters of the Northern Sea Route, including its newly announced plans to connect it with China’s Maritime Silk Road.

“In the Northern Sea Route, Moscow already illegally demands other nations request permission to pass, requires Russian maritime pilots to be aboard foreign ships, and threatens to use military force to sink any that fail to comply with its demands.

“Just because the Arctic is a place of wilderness does not mean it should become a place of lawlessness. It need not be the case. And we stand ready to ensure that it does not become so.”

As the ice in the region melts, it is clear that the tensions will continue to grow. − Climate News Network

Little time left to arrest Greenland’s melting

Humans may still have time to stop Greenland’s melting, preventing Arctic ice sheet collapse and devastating sea level rise. But the time left may be short.

LONDON, 30 December, 2019 – It’s still possible, but it’s far from certain: stopping Greenland’s melting can be done, but it must be done soon.

Norwegian and US scientists have taken a close look at the ice age history of Greenland and come to a grim conclusion. All it takes to set the island’s ice cap melting away is a mean sea surface temperature higher than seven degrees Celsius. And the present mean sea surface temperature is already 7.7°C.

Greenland is the northern hemisphere’s single richest store of frozen water: the island’s bedrock holds enough to raise global sea levels by seven metres and drown or wash away the world’s coastal communities, including the great cities of New York and Miami, Shanghai and Kolkata, Amsterdam and London.

And the pattern of geological evidence – outlined in the Proceedings of the National Academy of Sciences – combined with climate models suggests that any sustained temperature rise could trigger an irreversible melt of the entire southern Greenland ice sheet.

The scientists suggest that the threshold for this calamity could be between 0.8°C above the post-Ice Age norm, and 3.2°C.

“The critical temperature threshold for past Greenland ice sheet decay will likely be surpassed this century”

In fact, because of profligate use of fossil fuels and the release of greenhouse gases into the atmosphere, the planet has already warmed by around 1°C above the level for most of human history, and warming of at least 3.2°C by the end of this century now seems almost certain.

Researchers publish their conclusions with the intention that they should be examined, tested, challenged and perhaps overturned. But widespread alarm at the rate of melt and mass loss in Greenland has been consistent and increasing with the years.

Researchers have repeatedly established that melting each summer is increasing the rate at which glaciers flow and deliver ice to increasingly warmer northern seas, and that this rate of melting has itself begun to accelerate.

So Nil Irvali of the University of Bergen and colleagues took a closer look at the story told by microfossils within cores from the ice and the ocean floor during four interglacial periods over the last 450,000 years.

During those warm spells ocean levels rose dramatically, and in two episodes Greenland’s vanishing ice could have contributed more than five metres in one case, and up to seven metres of sea level rise in the other.

Triggers identified

And in all four of those interglacials, conditions reached temperatures higher than they are right now.

Concern about the stability of the Greenland icecap is no surprise: the Arctic is already warming faster than anywhere else on the planet, thanks to profligate use of fossil fuels and the destruction of the rainforests, and researchers worldwide have begun to identify triggers that feed back into further warming: rain, for instance, in winter; the loss of cloud cover in summer; and the deposits of soot from polar wildfires that darken the snows and enhance the absorption of the sun’s rays.

Years ago, the phrase “at a glacial pace” ceased to be a valid cliché: US scientists clocked one river of ice moving at a rate of 46 metres a day.

So the new study simply confirms fears that already are widespread. What remains to be settled is the point at which the decline of the ice sheet becomes irreversible, the Bergen scientists say. As the ocean warms, this feeds back into the process of melting and triggers longer-term feedbacks.

“The exact point at which these feedbacks are triggered remains equivocal,” say Dr Irvali and her co-authors. “Notably, the critical temperature threshold for past Greenland ice sheet decay will likely be surpassed this century. The duration for which this threshold is exceeded will determine Greenland’s fate.” – Climate News Network

Humans may still have time to stop Greenland’s melting, preventing Arctic ice sheet collapse and devastating sea level rise. But the time left may be short.

LONDON, 30 December, 2019 – It’s still possible, but it’s far from certain: stopping Greenland’s melting can be done, but it must be done soon.

Norwegian and US scientists have taken a close look at the ice age history of Greenland and come to a grim conclusion. All it takes to set the island’s ice cap melting away is a mean sea surface temperature higher than seven degrees Celsius. And the present mean sea surface temperature is already 7.7°C.

Greenland is the northern hemisphere’s single richest store of frozen water: the island’s bedrock holds enough to raise global sea levels by seven metres and drown or wash away the world’s coastal communities, including the great cities of New York and Miami, Shanghai and Kolkata, Amsterdam and London.

And the pattern of geological evidence – outlined in the Proceedings of the National Academy of Sciences – combined with climate models suggests that any sustained temperature rise could trigger an irreversible melt of the entire southern Greenland ice sheet.

The scientists suggest that the threshold for this calamity could be between 0.8°C above the post-Ice Age norm, and 3.2°C.

“The critical temperature threshold for past Greenland ice sheet decay will likely be surpassed this century”

In fact, because of profligate use of fossil fuels and the release of greenhouse gases into the atmosphere, the planet has already warmed by around 1°C above the level for most of human history, and warming of at least 3.2°C by the end of this century now seems almost certain.

Researchers publish their conclusions with the intention that they should be examined, tested, challenged and perhaps overturned. But widespread alarm at the rate of melt and mass loss in Greenland has been consistent and increasing with the years.

Researchers have repeatedly established that melting each summer is increasing the rate at which glaciers flow and deliver ice to increasingly warmer northern seas, and that this rate of melting has itself begun to accelerate.

So Nil Irvali of the University of Bergen and colleagues took a closer look at the story told by microfossils within cores from the ice and the ocean floor during four interglacial periods over the last 450,000 years.

During those warm spells ocean levels rose dramatically, and in two episodes Greenland’s vanishing ice could have contributed more than five metres in one case, and up to seven metres of sea level rise in the other.

Triggers identified

And in all four of those interglacials, conditions reached temperatures higher than they are right now.

Concern about the stability of the Greenland icecap is no surprise: the Arctic is already warming faster than anywhere else on the planet, thanks to profligate use of fossil fuels and the destruction of the rainforests, and researchers worldwide have begun to identify triggers that feed back into further warming: rain, for instance, in winter; the loss of cloud cover in summer; and the deposits of soot from polar wildfires that darken the snows and enhance the absorption of the sun’s rays.

Years ago, the phrase “at a glacial pace” ceased to be a valid cliché: US scientists clocked one river of ice moving at a rate of 46 metres a day.

So the new study simply confirms fears that already are widespread. What remains to be settled is the point at which the decline of the ice sheet becomes irreversible, the Bergen scientists say. As the ocean warms, this feeds back into the process of melting and triggers longer-term feedbacks.

“The exact point at which these feedbacks are triggered remains equivocal,” say Dr Irvali and her co-authors. “Notably, the critical temperature threshold for past Greenland ice sheet decay will likely be surpassed this century. The duration for which this threshold is exceeded will determine Greenland’s fate.” – Climate News Network

Heat the Arctic to cool the Earth, scientists say

If we seriously want to tackle the climate crisis, here’s a drastic idea: we could heat the Arctic to cool the planet.

LONDON, 19 December, 2019 − With politicians failing to cut greenhouse gas emissions far and fast enough, the only hope may be to find a different way to cool the planet. One group of researchers has put forward an idea so different that critics may regard it as outlandish: heat the Arctic.

To heat the Arctic so much that the sea ice disappears even in the winter sounds like a weird idea. But the researchers believe it would have the beneficial effect of cooling the planet down.

They argue that with the Arctic ice already expected to disappear during the summer months within the next 30 years, and large increases in temperature and changes in the polar climate already certain, we should turn this radical shift to our advantage.

Their point is that since, at the current rate of progress, politicians seem unlikely to cut greenhouse gas emissions enough to prevent drastic temperature rise, humankind must find other ways to cool the Earth if it is to survive.

“Climate change is a major issue and all options should be considered when dealing with it”

Heating the planet in order to cool it is certainly counter-intuitive. But, whether or not the scheme could ever work, it shows the ingenuity and enterprise now being poured into stabilising global temperatures close to their historic level.

It also, of course, shows how horribly late we have left it to rein in the climate crisis, when wise and determined action 30 years ago could have achieved so much.

The idea proposed is, in principle, simple enough: to ensure that the warm currents of the Gulf Stream, known by science as the North Atlantic Oscillation (NAO) continue northwards across the Arctic Circle the whole year round. This would release massive amounts of heat from the ocean into the atmosphere and beyond that into space, so cooling the sea and ultimately the Earth.

“The Arctic Ocean ice cover works as a strong insulator, impeding the heat from the ocean below to warm up the atmosphere above. If this ice layer were however removed, the atmosphere would increase in temperature by around 20°C during the winter.

More heat escapes

“This increase in temperature would in turn increase the heat irradiated into space, thus cooling down the oceans,” explains the lead author of the study which details the proposal, published in the journal SN Applied Sciences. He is Julian Hunt, a postdoctoral research scholar at IIASA, the International Institute for Applied Systems Analysis.

The problem that needs to be overcome is that very cold and only mildly salty water currently floats on the surface of the Arctic Ocean, freezing in the winter and capturing the warmth of the water in the ocean depths.

The authors say the main factor helping to maintain the Arctic sea ice cover is the fact that the top 100 metres of the ocean is less saline than the Atlantic, preventing the Atlantic from flowing above the cold Arctic waters. Increasing the salinity of the Arctic Ocean’s surface, they say, would let the warmer and less salty North Atlantic current flow over it, warming the atmosphere considerably and releasing the ocean heat trapped under the ice.

They suggest three ways to keep fresh water out of the Arctic. The first would divert the big rivers of North America and Siberia southwards to prevent them draining into the polar ocean. The second would place submerged obstructions in front of the rapidly melting Greenland glaciers, to slow the speed of the ice sheets’ melting, while the third would use a solar- and wind-powered icebreaker to pump cold, near-fresh water deeper into the ocean to mix with the saltier water below, allowing the warmer currents to sweep in from the south.

Unknown consequences

Dr Hunt and his colleagues say there could be terrific benefits. Shipping could navigate the ice-free Arctic Ocean all year round, cutting journey times between Asia, Europe and North America. The need for heating homes in the northern hemisphere during the winter would be drastically reduced, because their plan would raise air temperatures by as much as 20°C.

But the massive interference with natural systems in the Arctic would also have its downside. The rapid year-round rise in temperature would dramatically increase the melting of Greenland and therefore of sea level rise the world over. The effect on the northern hemisphere climate, particularly much increased rainfall with a warmer sea and atmosphere, is impossible to predict.

But Dr Hunt says that while there are clearly huge risks, the world is already heading for uncharted waters, so humans must do something drastic. “Although it is important to mitigate the impacts from climate change with the reduction in CO2 emissions, we should also think of ways to adapt the world to the new climate conditions to avoid uncontrollable, unpredictable and destructive climate change resulting in socio-economic and environmental collapse.

“Climate change is a major issue and all options should be considered when dealing with it.” − Climate News Network

If we seriously want to tackle the climate crisis, here’s a drastic idea: we could heat the Arctic to cool the planet.

LONDON, 19 December, 2019 − With politicians failing to cut greenhouse gas emissions far and fast enough, the only hope may be to find a different way to cool the planet. One group of researchers has put forward an idea so different that critics may regard it as outlandish: heat the Arctic.

To heat the Arctic so much that the sea ice disappears even in the winter sounds like a weird idea. But the researchers believe it would have the beneficial effect of cooling the planet down.

They argue that with the Arctic ice already expected to disappear during the summer months within the next 30 years, and large increases in temperature and changes in the polar climate already certain, we should turn this radical shift to our advantage.

Their point is that since, at the current rate of progress, politicians seem unlikely to cut greenhouse gas emissions enough to prevent drastic temperature rise, humankind must find other ways to cool the Earth if it is to survive.

“Climate change is a major issue and all options should be considered when dealing with it”

Heating the planet in order to cool it is certainly counter-intuitive. But, whether or not the scheme could ever work, it shows the ingenuity and enterprise now being poured into stabilising global temperatures close to their historic level.

It also, of course, shows how horribly late we have left it to rein in the climate crisis, when wise and determined action 30 years ago could have achieved so much.

The idea proposed is, in principle, simple enough: to ensure that the warm currents of the Gulf Stream, known by science as the North Atlantic Oscillation (NAO) continue northwards across the Arctic Circle the whole year round. This would release massive amounts of heat from the ocean into the atmosphere and beyond that into space, so cooling the sea and ultimately the Earth.

“The Arctic Ocean ice cover works as a strong insulator, impeding the heat from the ocean below to warm up the atmosphere above. If this ice layer were however removed, the atmosphere would increase in temperature by around 20°C during the winter.

More heat escapes

“This increase in temperature would in turn increase the heat irradiated into space, thus cooling down the oceans,” explains the lead author of the study which details the proposal, published in the journal SN Applied Sciences. He is Julian Hunt, a postdoctoral research scholar at IIASA, the International Institute for Applied Systems Analysis.

The problem that needs to be overcome is that very cold and only mildly salty water currently floats on the surface of the Arctic Ocean, freezing in the winter and capturing the warmth of the water in the ocean depths.

The authors say the main factor helping to maintain the Arctic sea ice cover is the fact that the top 100 metres of the ocean is less saline than the Atlantic, preventing the Atlantic from flowing above the cold Arctic waters. Increasing the salinity of the Arctic Ocean’s surface, they say, would let the warmer and less salty North Atlantic current flow over it, warming the atmosphere considerably and releasing the ocean heat trapped under the ice.

They suggest three ways to keep fresh water out of the Arctic. The first would divert the big rivers of North America and Siberia southwards to prevent them draining into the polar ocean. The second would place submerged obstructions in front of the rapidly melting Greenland glaciers, to slow the speed of the ice sheets’ melting, while the third would use a solar- and wind-powered icebreaker to pump cold, near-fresh water deeper into the ocean to mix with the saltier water below, allowing the warmer currents to sweep in from the south.

Unknown consequences

Dr Hunt and his colleagues say there could be terrific benefits. Shipping could navigate the ice-free Arctic Ocean all year round, cutting journey times between Asia, Europe and North America. The need for heating homes in the northern hemisphere during the winter would be drastically reduced, because their plan would raise air temperatures by as much as 20°C.

But the massive interference with natural systems in the Arctic would also have its downside. The rapid year-round rise in temperature would dramatically increase the melting of Greenland and therefore of sea level rise the world over. The effect on the northern hemisphere climate, particularly much increased rainfall with a warmer sea and atmosphere, is impossible to predict.

But Dr Hunt says that while there are clearly huge risks, the world is already heading for uncharted waters, so humans must do something drastic. “Although it is important to mitigate the impacts from climate change with the reduction in CO2 emissions, we should also think of ways to adapt the world to the new climate conditions to avoid uncontrollable, unpredictable and destructive climate change resulting in socio-economic and environmental collapse.

“Climate change is a major issue and all options should be considered when dealing with it.” − Climate News Network

Racing ice loss strips Greenland of mass

Greenland is shrinking, losing ice seven times faster than a generation ago. Scientists have taken a new and ominous measure of polar loss.

LONDON, 11 December, 2019 – Greenland – the largest body of frozen water in the northern hemisphere – is now losing ice seven times faster than it did during the last decade of the 20th century.

From 1990 to 1999, the Greenland ice sheet spilled an average of 33 billion tonnes of ice into the oceans every year. In the last decade the rate of loss has accelerated to an average of 254 billion tonnes a year.

Altogether, the Greenland ice cap has surrendered 3.8 trillion tonnes of ice since 1992. This alone is enough to raise global sea levels by 10.6 millimetres.

Glaciers and icecaps are in retreat in two hemispheres, and on every continent, as a consequence of profligate human combustion of fossil fuels, to drive up greenhouse gas levels in the atmosphere, and accelerate global heating.

Devastating

“As a rule of thumb, for every centimetre rise in global sea level another six million people are exposed to coastal flooding around the planet”, said Andrew Shepherd of the University of Leeds in the UK.

“On current trends, Greenland ice melting will cause 100 million people to be flooded each year by the end of the century, so 400 million in total due to all sea level rise. These are not unlikely events of small impacts; they are happening and will be devastating for coastal communities.”

Professor Shepherd is one of 96 polar scientists from 50 international organisations in a partnership known by the cumbrous name IMBIE, which stands for Ice Sheet Mass Balance Intercomparison Exercise. They made this assessment, based on data from 11 satellite missions and 26 separate surveys between 1992 and 2018, and published their conclusions in the journal Nature.

Greenland is not just the largest ice mass in the Arctic, it is probably the polar landscape studied for the longest time, and the most intensively.
Researchers have monitored the rate of summer melt, tried to match increases with other phenomena – for instance the darkening of snow by sub-Arctic wildfires – and tried to explore the mechanisms by which volumes of water that might in the past have frozen again each winter now accelerate glacier melt and escape into the ocean.

No surprise

The icecap is so big that – were it all to melt, which would take centuries – it would raise sea levels by as much as seven metres.

The news of a dramatic increase in rates of melting is not a surprise, and certainly not to the people who live in Greenland.

In 2013, the Intergovernmental Panel on Climate Change warned that global sea levels would rise by 60 cms by 2100. What matters about the latest survey is that it confirms the worst fears of many climate scientists and suggests that sea level rise is heading for the high end of the 2013 projections.

That is, by the end of this century, seas could have risen by nearer 70 cms. Around 100 million people already live at levels below the highest tides: the numbers increasingly at risk may be much higher.

The same study also explores the rates of change. Although the warmest years ever recorded have happened in the last century, as fossil fuel emissions and rainforest losses have continued to increase, the impact of global heating has been uneven.

“Our project is a great example of the importance of international collaboration to tackle problems that are global in scale”

The greatest loss of Greenland ice in any one year was in 2011, when the island lost 335 billion tonnes. Nor does the survey include all the data from 2019, and researchers could yet find that this summer’s ice loss has set new records.

Greenland’s loss of ice has been mirrored by continued loss of sea ice during successive Arctic summers, and since the world’s seasonal weather patterns have – for most of human history – been driven by the temperature difference between tropics and poles, the continued loss of ice will almost certainly impose worldwide costs in harvest losses, freak storms, droughts, wildfires and of course coastal flooding.

And ultimately, the study is a test of computer simulations of change in the northern hemisphere. Climate models have consistently predicted polar ice loss and sea level rise. But the latest study is a confirmation that such loss is real, and beyond argument.

“While computer simulation allows us to make projections from climate change scenarios, the satellite measurements provide prima facie, rather irrefutable evidence,” said Erik Ivins of Nasa’s Jet Propulsion Laboratory in California, and a co-author.

“Our project is a great example of the importance of international collaboration to tackle problems that are global in scale.” – Climate News Network

Greenland is shrinking, losing ice seven times faster than a generation ago. Scientists have taken a new and ominous measure of polar loss.

LONDON, 11 December, 2019 – Greenland – the largest body of frozen water in the northern hemisphere – is now losing ice seven times faster than it did during the last decade of the 20th century.

From 1990 to 1999, the Greenland ice sheet spilled an average of 33 billion tonnes of ice into the oceans every year. In the last decade the rate of loss has accelerated to an average of 254 billion tonnes a year.

Altogether, the Greenland ice cap has surrendered 3.8 trillion tonnes of ice since 1992. This alone is enough to raise global sea levels by 10.6 millimetres.

Glaciers and icecaps are in retreat in two hemispheres, and on every continent, as a consequence of profligate human combustion of fossil fuels, to drive up greenhouse gas levels in the atmosphere, and accelerate global heating.

Devastating

“As a rule of thumb, for every centimetre rise in global sea level another six million people are exposed to coastal flooding around the planet”, said Andrew Shepherd of the University of Leeds in the UK.

“On current trends, Greenland ice melting will cause 100 million people to be flooded each year by the end of the century, so 400 million in total due to all sea level rise. These are not unlikely events of small impacts; they are happening and will be devastating for coastal communities.”

Professor Shepherd is one of 96 polar scientists from 50 international organisations in a partnership known by the cumbrous name IMBIE, which stands for Ice Sheet Mass Balance Intercomparison Exercise. They made this assessment, based on data from 11 satellite missions and 26 separate surveys between 1992 and 2018, and published their conclusions in the journal Nature.

Greenland is not just the largest ice mass in the Arctic, it is probably the polar landscape studied for the longest time, and the most intensively.
Researchers have monitored the rate of summer melt, tried to match increases with other phenomena – for instance the darkening of snow by sub-Arctic wildfires – and tried to explore the mechanisms by which volumes of water that might in the past have frozen again each winter now accelerate glacier melt and escape into the ocean.

No surprise

The icecap is so big that – were it all to melt, which would take centuries – it would raise sea levels by as much as seven metres.

The news of a dramatic increase in rates of melting is not a surprise, and certainly not to the people who live in Greenland.

In 2013, the Intergovernmental Panel on Climate Change warned that global sea levels would rise by 60 cms by 2100. What matters about the latest survey is that it confirms the worst fears of many climate scientists and suggests that sea level rise is heading for the high end of the 2013 projections.

That is, by the end of this century, seas could have risen by nearer 70 cms. Around 100 million people already live at levels below the highest tides: the numbers increasingly at risk may be much higher.

The same study also explores the rates of change. Although the warmest years ever recorded have happened in the last century, as fossil fuel emissions and rainforest losses have continued to increase, the impact of global heating has been uneven.

“Our project is a great example of the importance of international collaboration to tackle problems that are global in scale”

The greatest loss of Greenland ice in any one year was in 2011, when the island lost 335 billion tonnes. Nor does the survey include all the data from 2019, and researchers could yet find that this summer’s ice loss has set new records.

Greenland’s loss of ice has been mirrored by continued loss of sea ice during successive Arctic summers, and since the world’s seasonal weather patterns have – for most of human history – been driven by the temperature difference between tropics and poles, the continued loss of ice will almost certainly impose worldwide costs in harvest losses, freak storms, droughts, wildfires and of course coastal flooding.

And ultimately, the study is a test of computer simulations of change in the northern hemisphere. Climate models have consistently predicted polar ice loss and sea level rise. But the latest study is a confirmation that such loss is real, and beyond argument.

“While computer simulation allows us to make projections from climate change scenarios, the satellite measurements provide prima facie, rather irrefutable evidence,” said Erik Ivins of Nasa’s Jet Propulsion Laboratory in California, and a co-author.

“Our project is a great example of the importance of international collaboration to tackle problems that are global in scale.” – Climate News Network

Greenland ice melt feeds glacier instability

In a runaway effect, the Greenland ice melt lets surface water gurgle down to the bedrock – and at unexpected speeds.

LONDON, 6 December, 2019 – British scientists have caught a huge ice sheet in the act of draining away, with significant effects on its surroundings: they have seen what happens to the water created by the Greenland ice melt.

For the first time – and with help from drones – researchers have witnessed water flowing at a million cubic metres an hour from the surface of ice sheets through caverns in the ice and down to the glacial bedrock.

The study does not change the big picture of increasingly rapid melt as greenhouse gases build up in the atmosphere, and ever more of the northern hemisphere’s biggest ice cap flows downhill to raise global sea levels.

But it does throw light on the mechanisms by which glaciers turn to sea water, and it does suggest that many estimates of melt rate so far might prove to be under-estimates.

Greenland is the planet’s second largest ice sheet and the biggest single contributor to global sea level rise. Researchers have been alarmed for years about the increasing rate of summer melt and the accelerating speed of what had once been imperceptible glacial flows.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere, but the overall effect is in fact very significant”

And researchers from the universities of Cambridge, Aberystwyth and Lancaster have now been able to put a measure on water surface loss.

They report in the Proceedings of the National Academy of Sciences that they used custom-built aerial drones and complex computer modelling to work out how fractures form below vast lakes of meltwater that collect on the surface of the Store Glacier on the island’s northwestern sheet.

They watched splits form in the glacial ice, to suddenly open up an escape route for the supraglacial pool. As they watched, such fractures became caverns called moulins, down which in one case five million cubic metres of water – think of 2,000 Olympic swimming pools – flowed in just five hours.

The ice of the glacier is typically a kilometre thick, so the scientists may have observed the planet’s longest waterfall. And as the ice drained away to the bottom of the ice sheet, it may have served as a lubricant to speed up glacier flow over the bedrock.

The ice sheet lifted by half a metre, presumably in response to the sub-surface flood, and four kilometres downstream glacial speed picked up from a speed of two metres to more than five metres a day.

Daily billion-tonne loss

“It’s possible we’ve under-estimated the effects of these glaciers on the overall instability of the Greenland ice sheet. It’s a rare thing to observe these fast-draining lakes – we were lucky to be in the right place at the right time,” said Tom Chudley, of the Scott Polar Research Institute in Cambridge, one of the authors.

Until now, scientists have been able to estimate glacial flow and surface melt only by satellite studies – which reveal little of the detail – or direct on-the-ground measurement under conditions that are difficult even in good weather.

But even with these constraints researchers have been able to calculate the shrinkage of the Greenland ice sheet at the rate of a billion tonnes a day, as temperatures rise in response to ever-increasing use of fossil fuels around the globe.

The next step is to deploy drilling equipment for a closer look at how the water gets below the glacier to reach the bedrock, and calculate how the ice sheet may change not just over hours but over the coming decades as well.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere,” said Poul Christofferson, who led the project, “but the overall effect is in fact very significant.” – Climate News Network

In a runaway effect, the Greenland ice melt lets surface water gurgle down to the bedrock – and at unexpected speeds.

LONDON, 6 December, 2019 – British scientists have caught a huge ice sheet in the act of draining away, with significant effects on its surroundings: they have seen what happens to the water created by the Greenland ice melt.

For the first time – and with help from drones – researchers have witnessed water flowing at a million cubic metres an hour from the surface of ice sheets through caverns in the ice and down to the glacial bedrock.

The study does not change the big picture of increasingly rapid melt as greenhouse gases build up in the atmosphere, and ever more of the northern hemisphere’s biggest ice cap flows downhill to raise global sea levels.

But it does throw light on the mechanisms by which glaciers turn to sea water, and it does suggest that many estimates of melt rate so far might prove to be under-estimates.

Greenland is the planet’s second largest ice sheet and the biggest single contributor to global sea level rise. Researchers have been alarmed for years about the increasing rate of summer melt and the accelerating speed of what had once been imperceptible glacial flows.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere, but the overall effect is in fact very significant”

And researchers from the universities of Cambridge, Aberystwyth and Lancaster have now been able to put a measure on water surface loss.

They report in the Proceedings of the National Academy of Sciences that they used custom-built aerial drones and complex computer modelling to work out how fractures form below vast lakes of meltwater that collect on the surface of the Store Glacier on the island’s northwestern sheet.

They watched splits form in the glacial ice, to suddenly open up an escape route for the supraglacial pool. As they watched, such fractures became caverns called moulins, down which in one case five million cubic metres of water – think of 2,000 Olympic swimming pools – flowed in just five hours.

The ice of the glacier is typically a kilometre thick, so the scientists may have observed the planet’s longest waterfall. And as the ice drained away to the bottom of the ice sheet, it may have served as a lubricant to speed up glacier flow over the bedrock.

The ice sheet lifted by half a metre, presumably in response to the sub-surface flood, and four kilometres downstream glacial speed picked up from a speed of two metres to more than five metres a day.

Daily billion-tonne loss

“It’s possible we’ve under-estimated the effects of these glaciers on the overall instability of the Greenland ice sheet. It’s a rare thing to observe these fast-draining lakes – we were lucky to be in the right place at the right time,” said Tom Chudley, of the Scott Polar Research Institute in Cambridge, one of the authors.

Until now, scientists have been able to estimate glacial flow and surface melt only by satellite studies – which reveal little of the detail – or direct on-the-ground measurement under conditions that are difficult even in good weather.

But even with these constraints researchers have been able to calculate the shrinkage of the Greenland ice sheet at the rate of a billion tonnes a day, as temperatures rise in response to ever-increasing use of fossil fuels around the globe.

The next step is to deploy drilling equipment for a closer look at how the water gets below the glacier to reach the bedrock, and calculate how the ice sheet may change not just over hours but over the coming decades as well.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere,” said Poul Christofferson, who led the project, “but the overall effect is in fact very significant.” – Climate News Network

Arctic’s oldest ice shows signs of change

There’s change afoot even where scientists least expect it, among the Arctic’s oldest ice. If it goes, so does the wildlife.

LONDON, 21 November, 2019 – Stretches of the Arctic’s oldest ice, and its thickest – the last refuge ice that should survive even when the Arctic Ocean technically becomes ice-free in summers later this century – are now disappearing twice as fast as the rest of the Arctic icecap.

Although the north polar ice is vulnerable to global heating, and has been thinning and retreating at an accelerating rate for the last 40 summers, researchers have always expected some winter ice to survive: they define an “ice-free Arctic Ocean” as one with less than 1 million square kilometres of surviving ice pack.

But this supposedly ancient remnant of the polar winters, concentrated north of Greenland and the Canadian polar archipelago, is showing signs of change.

Researchers do not explicitly finger climate change driven by ever-greater human use of fossil fuels as the direct agent of this change: this is an area of polar ice difficult to observe and explore, is little known, and may always have been subject to change.

“This area will be a refuge where species can survive and hopefully expand their regions once the ice starts returning”

But scientists know why it is important. From submarine algae to polar bears, an entire Arctic ecosystem is dependent on the ice sheet. As the ice disappears, so will the seals, and their predators too.

Conservation-minded governments that want to establish protected areas need to know where protection will work best. “Eventually, the Last Ice Area will be the region that will repopulate the Arctic with wildlife,” said Kent Moore of the University of Toronto in Canada. “This area will be a refuge where species can survive and hopefully expand their regions once the ice starts returning.”

Dr Moore and his colleagues report in the journal Geophysical Research Letters that they used computer models and satellite observation data to build up a picture of what they call “spatiotemporal variability” in their Last Ice Area.

They found two distinct places where ice thickness fluctuated by up to 1.2 metres from year to year. In some patches, the ice was thinning by the decade: a loss of 1.5 metres since the late 1970s.

No monolith

Most north polar ice is youthful: seldom more than four years old. The Last Ice Area is certainly more than five years old, and has been measured at a thickness of four metres. It is not a static region: ice moves with the ocean beneath it.

And even the levels of melting are affected by natural cyclic ocean shifts as well as higher temperatures fuelled by greenhouse gas build-up in the atmosphere.

The race is on to understand the forces at work in what might be – one day – the only surviving ice in the polar summer.

“We can’t treat the Last Ice Area as a monolithic area of ice which is going to last a long time,” said Dr Moore. “There’s actually lots of regional variability.” – Climate News Network

There’s change afoot even where scientists least expect it, among the Arctic’s oldest ice. If it goes, so does the wildlife.

LONDON, 21 November, 2019 – Stretches of the Arctic’s oldest ice, and its thickest – the last refuge ice that should survive even when the Arctic Ocean technically becomes ice-free in summers later this century – are now disappearing twice as fast as the rest of the Arctic icecap.

Although the north polar ice is vulnerable to global heating, and has been thinning and retreating at an accelerating rate for the last 40 summers, researchers have always expected some winter ice to survive: they define an “ice-free Arctic Ocean” as one with less than 1 million square kilometres of surviving ice pack.

But this supposedly ancient remnant of the polar winters, concentrated north of Greenland and the Canadian polar archipelago, is showing signs of change.

Researchers do not explicitly finger climate change driven by ever-greater human use of fossil fuels as the direct agent of this change: this is an area of polar ice difficult to observe and explore, is little known, and may always have been subject to change.

“This area will be a refuge where species can survive and hopefully expand their regions once the ice starts returning”

But scientists know why it is important. From submarine algae to polar bears, an entire Arctic ecosystem is dependent on the ice sheet. As the ice disappears, so will the seals, and their predators too.

Conservation-minded governments that want to establish protected areas need to know where protection will work best. “Eventually, the Last Ice Area will be the region that will repopulate the Arctic with wildlife,” said Kent Moore of the University of Toronto in Canada. “This area will be a refuge where species can survive and hopefully expand their regions once the ice starts returning.”

Dr Moore and his colleagues report in the journal Geophysical Research Letters that they used computer models and satellite observation data to build up a picture of what they call “spatiotemporal variability” in their Last Ice Area.

They found two distinct places where ice thickness fluctuated by up to 1.2 metres from year to year. In some patches, the ice was thinning by the decade: a loss of 1.5 metres since the late 1970s.

No monolith

Most north polar ice is youthful: seldom more than four years old. The Last Ice Area is certainly more than five years old, and has been measured at a thickness of four metres. It is not a static region: ice moves with the ocean beneath it.

And even the levels of melting are affected by natural cyclic ocean shifts as well as higher temperatures fuelled by greenhouse gas build-up in the atmosphere.

The race is on to understand the forces at work in what might be – one day – the only surviving ice in the polar summer.

“We can’t treat the Last Ice Area as a monolithic area of ice which is going to last a long time,” said Dr Moore. “There’s actually lots of regional variability.” – Climate News Network

‘Upside-down rivers’ speed polar ice loss

polar ice

Researchers move closer to understanding the invisible dynamics that drive the loss of polar ice shelves – but what it means for global warming is still uncertain.

LONDON, October 16, 2019 – Scientists in the US believe they have now identified the machinery that drives the break-up of great chunks of polar ice shelves. What they call “upside down rivers” of warm, less dense, less saline water, tens of miles long and miles wide, find weaknesses in the massive ice shelves.

And because global temperature rise is causing polar currents to get warmer, the effect could be to accelerate the collapse of great tracts of ice shelf, and allow glacial flow to speed up – resulting in rising sea levels.

Call it subversion: these unexpected channels of water rise from underneath to concentrate their effect on fracture zones that form as land-bound glaciers flow slowly onto the marine surface.

“Warm water circulation is attacking the undersides of these ice shelves at their weakest points,” says Earth scientist Karen Alley, who did her research at the University of Colorado in Boulder, but is now at the College of Wooster in Ohio, US. “These effects matter. Exactly how much, we don’t yet know. But we need to.”

Frozen sheets

The research could explain the persistent appearance, at roughly the same place every year, of polynyas. These are great pools of open sea water in the ice shelves, and scientists have been puzzling for decades about the mechanisms that make them possible.

About 80% of Antarctica is bounded by frozen sheets of sea ice, many of them anchored by bumps and chasms on the sea floor, and this is what slows the flow of ice from high ground to ocean.

But satellite studies have long exposed crevasses in this ice, formed at what scientists call “shear margins” – weak points in flowing ice.

Once part of the floating shelf, these fracture zones are more vulnerable to plumes of more buoyant – that is, less saline and warmer – water that flow as “basal channels” to create long wrinkles or sags in the shelf.

Dr Alley and her colleagues report in Science Advances journal that they pieced together this picture of polar dynamism far below the surface by combing satellite data to expose patterns of surface change made possible only by some consistent erosion by warmer current.

Climate – winds, rainfall, heat and drought patterns – is driven by the temperature gradient. Large-scale weather systems happen because the poles are cold and the tropics are hot, and this difference powers the stratospheric jet stream and the most profound ocean flow.

So climate scientists are intensely interested in change in both Greenland and the Antarctic.

“Now we’re seeing a new process, where warm water cuts into the ice shelf from below”

Other teams have already established that ice shelves are melting ever faster in the coldest places on the planet, that this melting is happening ever faster, that the ice is being attacked from below, and that this can only accelerate sea-level rise in a world subject to global heating driven by human use of fossil fuels that deposit huge volumes of greenhouse gases in the atmosphere.

The latest study focused on Antarctica, but the findings could also be applied to Greenland, which has the greatest reserve of Arctic ice, and where ice loss is accelerating even faster.

Report co-author Ted Scambos, senior research scientist in the Earth Science and Observation Centre at the University of Colorado at Boulder, says: “Now we’re seeing a new process, where warm water cuts into the ice shelf from below.

“Like scoring a plate of glass, the trough renders the shelf weak and, in a few decades, it’s gone, freeing the ice sheet to ride out faster into the ocean.” – Climate News Network

Researchers move closer to understanding the invisible dynamics that drive the loss of polar ice shelves – but what it means for global warming is still uncertain.

LONDON, October 16, 2019 – Scientists in the US believe they have now identified the machinery that drives the break-up of great chunks of polar ice shelves. What they call “upside down rivers” of warm, less dense, less saline water, tens of miles long and miles wide, find weaknesses in the massive ice shelves.

And because global temperature rise is causing polar currents to get warmer, the effect could be to accelerate the collapse of great tracts of ice shelf, and allow glacial flow to speed up – resulting in rising sea levels.

Call it subversion: these unexpected channels of water rise from underneath to concentrate their effect on fracture zones that form as land-bound glaciers flow slowly onto the marine surface.

“Warm water circulation is attacking the undersides of these ice shelves at their weakest points,” says Earth scientist Karen Alley, who did her research at the University of Colorado in Boulder, but is now at the College of Wooster in Ohio, US. “These effects matter. Exactly how much, we don’t yet know. But we need to.”

Frozen sheets

The research could explain the persistent appearance, at roughly the same place every year, of polynyas. These are great pools of open sea water in the ice shelves, and scientists have been puzzling for decades about the mechanisms that make them possible.

About 80% of Antarctica is bounded by frozen sheets of sea ice, many of them anchored by bumps and chasms on the sea floor, and this is what slows the flow of ice from high ground to ocean.

But satellite studies have long exposed crevasses in this ice, formed at what scientists call “shear margins” – weak points in flowing ice.

Once part of the floating shelf, these fracture zones are more vulnerable to plumes of more buoyant – that is, less saline and warmer – water that flow as “basal channels” to create long wrinkles or sags in the shelf.

Dr Alley and her colleagues report in Science Advances journal that they pieced together this picture of polar dynamism far below the surface by combing satellite data to expose patterns of surface change made possible only by some consistent erosion by warmer current.

Climate – winds, rainfall, heat and drought patterns – is driven by the temperature gradient. Large-scale weather systems happen because the poles are cold and the tropics are hot, and this difference powers the stratospheric jet stream and the most profound ocean flow.

So climate scientists are intensely interested in change in both Greenland and the Antarctic.

“Now we’re seeing a new process, where warm water cuts into the ice shelf from below”

Other teams have already established that ice shelves are melting ever faster in the coldest places on the planet, that this melting is happening ever faster, that the ice is being attacked from below, and that this can only accelerate sea-level rise in a world subject to global heating driven by human use of fossil fuels that deposit huge volumes of greenhouse gases in the atmosphere.

The latest study focused on Antarctica, but the findings could also be applied to Greenland, which has the greatest reserve of Arctic ice, and where ice loss is accelerating even faster.

Report co-author Ted Scambos, senior research scientist in the Earth Science and Observation Centre at the University of Colorado at Boulder, says: “Now we’re seeing a new process, where warm water cuts into the ice shelf from below.

“Like scoring a plate of glass, the trough renders the shelf weak and, in a few decades, it’s gone, freeing the ice sheet to ride out faster into the ocean.” – Climate News Network

Penguins in peril as winds change and heat rises

New weather patterns in the warming Antarctic are leaving thousands of penguins in peril, prompting calls for them to be specially protected.

LONDON, 10 October, 2019 – A species that has come to symbolise Antarctica’s wealth of wildlife now faces mortal danger: climate change is putting emperor penguins in peril.

British scientists say the continent is warming with unparalleled speed, meaning the birds may soon have almost nowhere to breed. Some researchers think the number of emperors could be cut by more than half by 2100.

Philip Trathan, head of conservation biology at the British Antarctic Survey in Cambridge, says: “The current rate of warming in parts of the Antarctic is greater than anything in the recent glaciological record.

“Though emperor penguins have experienced periods of warming and cooling over their evolutionary history, the current rates of warming are unprecedented.

“Currently, we have no idea how the emperors will adjust to the loss of their primary breeding habitat – sea ice. They are not agile, and climbing ashore across steep coastal land forms will be difficult.

Numbers fluctuate

“For breeding, they depend upon sea ice, and in a warming world there is a high probability that this will decrease. Without it, they will have little or no breeding habitat.”

It is not the first time scientists have sounded the alarm for the emperors. This time, though, they are urging potentially far-reaching action.

In a study published in the journal Biological Conservation, an international team of researchers, led by Dr Trathan, recommends new steps to protect and conserve the penguins (Aptenodytes forsteri).

Satellite images in 2012 suggested there were almost 600,000 of the birds in the Antarctic, roughly double the number estimated in 1992. The researchers involved in this latest report reviewed over 150 studies on the species and its environment as well as its behaviour and character in relation to its breeding biology.

“Some colonies of emperor penguins may not survive the coming decades, so we must work to give as much protection as we can to the species”

Current climate change projections indicate that rising temperatures and changing wind patterns will damage the sea ice on which the emperors breed, with some studies showing populations likely to fall by more than 50% over this century.

Before breeding, both males and females must build their body reserves so that females can lay their single egg, and for males to fast while undertaking the entire egg incubation during the Antarctic winter.

Emperors are unique amongst birds because they breed on seasonal Antarctic sea ice which they need while incubating their eggs and raising their chicks.

They also need stable sea ice after they have completed breeding, during the time when they undergo their annual moult. They cannot enter the water then as their feathers are no longer waterproof, leaving them unable to enter the sea.

So the researchers are recommending that the IUCN status for the species be raised from “near-threatened” to “vulnerable” on the IUCN Red List.  They say improvements in climate change forecasting of impacts on Antarctic wildlife would help, and recommend that the emperors should be listed by the Antarctic Treaty as a specially protected species.

Wider appeal

Better protection will let scientists coordinate research into the penguins’ resilience to a range of different threats and stressors.

Dr Peter Fretwell, remote sensing specialist at BAS and a co-author of the study, says: “Some colonies of emperor penguins may not survive the coming decades, so we must work to give as much protection as we can to the species to give them the best chance.”

The UK was one of the countries which notified the Antarctic Treaty Consultative Meeting at its 2019 meeting in July that emperor penguins were threatened by the loss of their breeding habitat and that further protection was needed.

A similar paper has also been submitted to this year’s Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which meets in the Tasmanian capital, Hobart, later this month. – Climate News Network 

New weather patterns in the warming Antarctic are leaving thousands of penguins in peril, prompting calls for them to be specially protected.

LONDON, 10 October, 2019 – A species that has come to symbolise Antarctica’s wealth of wildlife now faces mortal danger: climate change is putting emperor penguins in peril.

British scientists say the continent is warming with unparalleled speed, meaning the birds may soon have almost nowhere to breed. Some researchers think the number of emperors could be cut by more than half by 2100.

Philip Trathan, head of conservation biology at the British Antarctic Survey in Cambridge, says: “The current rate of warming in parts of the Antarctic is greater than anything in the recent glaciological record.

“Though emperor penguins have experienced periods of warming and cooling over their evolutionary history, the current rates of warming are unprecedented.

“Currently, we have no idea how the emperors will adjust to the loss of their primary breeding habitat – sea ice. They are not agile, and climbing ashore across steep coastal land forms will be difficult.

Numbers fluctuate

“For breeding, they depend upon sea ice, and in a warming world there is a high probability that this will decrease. Without it, they will have little or no breeding habitat.”

It is not the first time scientists have sounded the alarm for the emperors. This time, though, they are urging potentially far-reaching action.

In a study published in the journal Biological Conservation, an international team of researchers, led by Dr Trathan, recommends new steps to protect and conserve the penguins (Aptenodytes forsteri).

Satellite images in 2012 suggested there were almost 600,000 of the birds in the Antarctic, roughly double the number estimated in 1992. The researchers involved in this latest report reviewed over 150 studies on the species and its environment as well as its behaviour and character in relation to its breeding biology.

“Some colonies of emperor penguins may not survive the coming decades, so we must work to give as much protection as we can to the species”

Current climate change projections indicate that rising temperatures and changing wind patterns will damage the sea ice on which the emperors breed, with some studies showing populations likely to fall by more than 50% over this century.

Before breeding, both males and females must build their body reserves so that females can lay their single egg, and for males to fast while undertaking the entire egg incubation during the Antarctic winter.

Emperors are unique amongst birds because they breed on seasonal Antarctic sea ice which they need while incubating their eggs and raising their chicks.

They also need stable sea ice after they have completed breeding, during the time when they undergo their annual moult. They cannot enter the water then as their feathers are no longer waterproof, leaving them unable to enter the sea.

So the researchers are recommending that the IUCN status for the species be raised from “near-threatened” to “vulnerable” on the IUCN Red List.  They say improvements in climate change forecasting of impacts on Antarctic wildlife would help, and recommend that the emperors should be listed by the Antarctic Treaty as a specially protected species.

Wider appeal

Better protection will let scientists coordinate research into the penguins’ resilience to a range of different threats and stressors.

Dr Peter Fretwell, remote sensing specialist at BAS and a co-author of the study, says: “Some colonies of emperor penguins may not survive the coming decades, so we must work to give as much protection as we can to the species to give them the best chance.”

The UK was one of the countries which notified the Antarctic Treaty Consultative Meeting at its 2019 meeting in July that emperor penguins were threatened by the loss of their breeding habitat and that further protection was needed.

A similar paper has also been submitted to this year’s Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which meets in the Tasmanian capital, Hobart, later this month. – Climate News Network 

Extreme sea level events ‘will hit once a year by 2050’

This story originally appeared in The Guardian. It is republished here as part of the Climate News Network’s partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Extreme sea level events that used to occur once a century will strike every year on many coasts by 2050, no matter whether climate heating emissions are curbed or not, according to a landmark report by the world’s scientists.

25 September, 2019 − The stark assessment of the climate crisis in the world’s oceans and ice caps concludes that many serious impacts are already inevitable, from more intense storms to melting permafrost and dwindling marine life.

But far worse impacts will hit without urgent action to cut fossil fuel emissions, including eventual sea level rise of more than 4 metres in the worst case, an outcome that would redraw the map of the world and harm billions of people.

The report from the Intergovernmental Panel on Climate Change (IPCC), and approved by its 193 member nations, says that “all people on Earth depend directly or indirectly on the ocean” and ice caps and glaciers to regulate the climate and provide water and oxygen. But it finds unprecedented and dangerous changes being driven by global heating.

Sea level rise is accelerating as losses from Greenland and Antarctica increase, and the ocean is getting hotter, more acidic and less oxygenated. All these trends will continue to the end of the century, the IPCC report said.

Half the world’s megacities, and almost 2 billion people, live on coasts. Even if heating is restricted to just 2C, scientists expect the impact of sea level rise to cause several trillion dollars of damage a year, and result in many millions of migrants.

“The future for low-lying coastal communities looks extremely bleak,” said Prof Jonathan Bamber at Bristol University in the UK, who is not one of the report’s authors. “But the consequences will be felt by all of us. There is plenty to be concerned about for the future of humanity and social order from the headlines in this report.”

The new IPCC projections of likely sea level rise by 2100 are higher than those it made in 2014, due to unexpectedly fast melting in Antarctica. Without cuts in carbon emissions, the ocean is expected to rise between 61cm and 110cm, about 10cm more than the earlier estimate. A 10cm rise means 10 million additional people exposed to flooding, research shows.

The IPCC considers the likely range of sea level rise but not the worst-case scenario. Recent expert analysis led by Bamber concluded that up to 238cm of sea level rise remains possible by 2100, drowning many megacities around the world. “This cannot be ruled out,” said Zita Sebesvari at the United Nations University, a lead author of the IPCC report.

Even if huge cuts in emissions begin immediately, between 29cm and 59cm of sea level rise is already inevitable because the ice caps and glaciers melt slowly. Sea level will rise for centuries without action, Sebesvari warned. “The dramatic thing about sea level rise is if we accept 1 metre happening by 2100, we accept we will get about 4 metres by 2300. That is simply not an option we can risk.”

Extreme sea level impacts will be felt in many places very soon and well before 2050, Sebesvari said. The IPCC report states: “Extreme sea level events that [occur] once per century in the recent past are projected to occur at least once per year at many locations by 2050 in all scenarios.”

The heating oceans are causing more intense tropical storms to batter coasts, the IPCC report found, with stronger winds and greater deluges of rain. For example, Hurricane Harvey’s unprecedented deluge, which caused catastrophic flooding, was made three times more likely by climate change.

Ocean heating also harms kelp forests and other important ecosystems, with the marine heatwaves that sear through them like underwater wildfires having doubled in frequency in the last 40 years. They are projected to increase by at least 20 times by 2100, the IPCC reported.

Extreme El Niño events, which see heatwaves in some regions and floods in others, are projected to occur twice as often this century whether emissions are cut or not, the report said. Coral reefs, vital nurseries for marine life, will suffer major losses and local extinctions. Across the ocean, heat, acidification and lower oxygen is set to cut fisheries by a quarter and all marine life by 15% if emissions are not slashed.

The IPCC report also records the large reduction in Arctic ice. This loss exacerbates global heating, because the exposed darker ocean absorbs more heat from the sun than highly reflective ice. On Monday, scientists announced that the Arctic sea ice in 2019 shrank to its second lowest extent in the 41-year satellite record.

The world’s high mountain glaciers, upon which almost 2 billion people rely for water, are also melting fast, the IPCC found, while landslides are expected to increase. A third of the great Himalayan range is already doomed, with two-thirds projected to vanish if emissions are not cut.

One of the most worrying alarms sounded by the IPCC report is about melting tundra and increasing wildfires in northern latitudes: “Widespread permafrost thaw is projected for this century and beyond.” A quarter is already near certain to melt, it said, and 70% or more would go if emissions are not curbed. In the latter case, hundreds of billions of tonnes of carbon dioxide and methane could be released, supercharging the climate emergency.

“That risks taking us beyond the point where climate change could be easily constrained,” said Richard Black, at the UK’s Energy and Climate Intelligence Unit. “Nevertheless, the IPCC’s 2018 report concluded that governments can shrink emissions quickly enough to keep global warming to 1.5C if they choose. None can claim to be unaware of both the dangers of untrammelled climate change nor the feasibility of preventing it.”

Anne Hidalgo, the mayor of Paris and chair of the C40 Cities climate coalition, said the IPCC report was shocking. “Around 1.9 billion people and over half of the world’s megacities are all in grave danger if we don’t act immediately. Several cities, home to hundreds of thousands of people, are already disappearing underwater. This is what the climate crisis looks like now.”

Taehyun Park, of Greenpeace East Asia, said: “The science is both chilling and compelling. The impacts on our oceans are on a much larger scale and happening way faster than predicted. It will require unprecedented political action to prevent the most severe consequences to our planet.”

As well as cutting fossil fuel emissions, preparing for the inevitable impacts is also vital, said Sebesvari, especially in poorer nations that lack the funds to build sea walls, move settlements or restore protective coastal marshes.

“Action is needed now to secure the coast for our children and coming generations,” she said. The pressure now being exerted by the global school strikes for climate was important, she said. “I have very strong motivation. I have two kids and we are really being tested by our kids on our actions.”

* * * * * * *

Damian Carrington is The Guardian’s environment editor.

This story originally appeared in The Guardian. It is republished here as part of the Climate News Network’s partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Extreme sea level events that used to occur once a century will strike every year on many coasts by 2050, no matter whether climate heating emissions are curbed or not, according to a landmark report by the world’s scientists.

25 September, 2019 − The stark assessment of the climate crisis in the world’s oceans and ice caps concludes that many serious impacts are already inevitable, from more intense storms to melting permafrost and dwindling marine life.

But far worse impacts will hit without urgent action to cut fossil fuel emissions, including eventual sea level rise of more than 4 metres in the worst case, an outcome that would redraw the map of the world and harm billions of people.

The report from the Intergovernmental Panel on Climate Change (IPCC), and approved by its 193 member nations, says that “all people on Earth depend directly or indirectly on the ocean” and ice caps and glaciers to regulate the climate and provide water and oxygen. But it finds unprecedented and dangerous changes being driven by global heating.

Sea level rise is accelerating as losses from Greenland and Antarctica increase, and the ocean is getting hotter, more acidic and less oxygenated. All these trends will continue to the end of the century, the IPCC report said.

Half the world’s megacities, and almost 2 billion people, live on coasts. Even if heating is restricted to just 2C, scientists expect the impact of sea level rise to cause several trillion dollars of damage a year, and result in many millions of migrants.

“The future for low-lying coastal communities looks extremely bleak,” said Prof Jonathan Bamber at Bristol University in the UK, who is not one of the report’s authors. “But the consequences will be felt by all of us. There is plenty to be concerned about for the future of humanity and social order from the headlines in this report.”

The new IPCC projections of likely sea level rise by 2100 are higher than those it made in 2014, due to unexpectedly fast melting in Antarctica. Without cuts in carbon emissions, the ocean is expected to rise between 61cm and 110cm, about 10cm more than the earlier estimate. A 10cm rise means 10 million additional people exposed to flooding, research shows.

The IPCC considers the likely range of sea level rise but not the worst-case scenario. Recent expert analysis led by Bamber concluded that up to 238cm of sea level rise remains possible by 2100, drowning many megacities around the world. “This cannot be ruled out,” said Zita Sebesvari at the United Nations University, a lead author of the IPCC report.

Even if huge cuts in emissions begin immediately, between 29cm and 59cm of sea level rise is already inevitable because the ice caps and glaciers melt slowly. Sea level will rise for centuries without action, Sebesvari warned. “The dramatic thing about sea level rise is if we accept 1 metre happening by 2100, we accept we will get about 4 metres by 2300. That is simply not an option we can risk.”

Extreme sea level impacts will be felt in many places very soon and well before 2050, Sebesvari said. The IPCC report states: “Extreme sea level events that [occur] once per century in the recent past are projected to occur at least once per year at many locations by 2050 in all scenarios.”

The heating oceans are causing more intense tropical storms to batter coasts, the IPCC report found, with stronger winds and greater deluges of rain. For example, Hurricane Harvey’s unprecedented deluge, which caused catastrophic flooding, was made three times more likely by climate change.

Ocean heating also harms kelp forests and other important ecosystems, with the marine heatwaves that sear through them like underwater wildfires having doubled in frequency in the last 40 years. They are projected to increase by at least 20 times by 2100, the IPCC reported.

Extreme El Niño events, which see heatwaves in some regions and floods in others, are projected to occur twice as often this century whether emissions are cut or not, the report said. Coral reefs, vital nurseries for marine life, will suffer major losses and local extinctions. Across the ocean, heat, acidification and lower oxygen is set to cut fisheries by a quarter and all marine life by 15% if emissions are not slashed.

The IPCC report also records the large reduction in Arctic ice. This loss exacerbates global heating, because the exposed darker ocean absorbs more heat from the sun than highly reflective ice. On Monday, scientists announced that the Arctic sea ice in 2019 shrank to its second lowest extent in the 41-year satellite record.

The world’s high mountain glaciers, upon which almost 2 billion people rely for water, are also melting fast, the IPCC found, while landslides are expected to increase. A third of the great Himalayan range is already doomed, with two-thirds projected to vanish if emissions are not cut.

One of the most worrying alarms sounded by the IPCC report is about melting tundra and increasing wildfires in northern latitudes: “Widespread permafrost thaw is projected for this century and beyond.” A quarter is already near certain to melt, it said, and 70% or more would go if emissions are not curbed. In the latter case, hundreds of billions of tonnes of carbon dioxide and methane could be released, supercharging the climate emergency.

“That risks taking us beyond the point where climate change could be easily constrained,” said Richard Black, at the UK’s Energy and Climate Intelligence Unit. “Nevertheless, the IPCC’s 2018 report concluded that governments can shrink emissions quickly enough to keep global warming to 1.5C if they choose. None can claim to be unaware of both the dangers of untrammelled climate change nor the feasibility of preventing it.”

Anne Hidalgo, the mayor of Paris and chair of the C40 Cities climate coalition, said the IPCC report was shocking. “Around 1.9 billion people and over half of the world’s megacities are all in grave danger if we don’t act immediately. Several cities, home to hundreds of thousands of people, are already disappearing underwater. This is what the climate crisis looks like now.”

Taehyun Park, of Greenpeace East Asia, said: “The science is both chilling and compelling. The impacts on our oceans are on a much larger scale and happening way faster than predicted. It will require unprecedented political action to prevent the most severe consequences to our planet.”

As well as cutting fossil fuel emissions, preparing for the inevitable impacts is also vital, said Sebesvari, especially in poorer nations that lack the funds to build sea walls, move settlements or restore protective coastal marshes.

“Action is needed now to secure the coast for our children and coming generations,” she said. The pressure now being exerted by the global school strikes for climate was important, she said. “I have very strong motivation. I have two kids and we are really being tested by our kids on our actions.”

* * * * * * *

Damian Carrington is The Guardian’s environment editor.