Tag Archives: Ice melt

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

Atlantic current could falter before 2100

The Atlantic current won’t come to a full stop the day after tomorrow. But it could face a temporary halt later this century.

LONDON, 3 January, 2020 − European scientists think they have settled one of the more alarming questions of the climate crisis: the potential collapse of the Atlantic current, the Gulf Stream that delivers heat from the tropics to the Arctic.

The answer is clear. Total collapse is not likely for another 1000 years. But there is roughly a one in six chance in the next century that the flow of the north Atlantic current may temporarily halt or falter because of climate change.

That is because faster melting of the Greenland ice cap, and more freshwater in the Arctic Ocean, could trigger a slowdown in what scientists like to call the Atlantic meridional overturning circulation.

And a team of US researchers has separately highlighted one of the potential mechanisms of ocean change: for every 1°C rise in average global temperature, there will be roughly six days fewer on which many of the world’s rivers are frozen, which will mean more freshwater in the northern seas.

The findings are based in the first case on sophisticated use of computer simulations, and in the second on the careful study of 400,000 satellite images collected over more than 30 years.

“The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette”

Researchers from the universities of Groningen and Utrecht say, in the journal Scientific Reports, that they modelled the likelihood and impact of small changes in the flow of freshwater into the ocean at high latitudes.

The Atlantic current – sometimes called the Gulf Stream – is a massive flow of warm, salty water from the tropics to the Arctic that keeps  northwestern Europe much warmer than, for example, the same latitudes of North America.

As the water flows north, it cools and becomes more dense, and begins to sink below the fresh meltwater of the summer Arctic: the cold, dense, salty water then flows along the sea bed southwards, and this one dramatic global oceanic conveyor belt ultimately delivers nutrients and dissolved oxygen to the Southern Ocean. It also stores dissolved carbon dioxide, distributes heat and moderates high latitude weather.

But in the past 150 years the flow has been weakening, and there have been fears that the circulation could halt entirely, with unforeseeable consequences. This notional failure became the trigger for a 2004 disaster movie called The Day After Tomorrow. Something so sudden and catastrophic as the Hollywood version was never going to happen – but there have been repeated fears that the weakening could continue, and tip the planet’s climate into a new and potentially dangerous state.

The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette, in which a player spins a six-chambered revolver with one bullet in it, and points it at his or her head.

River ice lost

Their model simulated small changes in the delivery of freshwater. This is likely to accelerate however, according to research in the journal Nature. Researchers combed through 407,880 satellite pictures taken between 1984 and 2018, to find that 56% of rivers were affected by winter freezing, which masked altogether 87,000 square kilometres of water surface.

Freezing is important to both humans and wild things: frozen rivers traditionally have provided good surfaces for ground transport in the high latitudes. The act of freezing also regulates greenhouse gas emissions that would otherwise escape from the rivers. Ice-jams during the spring melt can trigger flooding, which – though damaging to human settlements – spreads fresh water, nutrients and sediments around the flood plains.

But these benefits are at risk. The researchers found that river and lake surfaces were freezing ever later, as global temperatures crept up, and that the world had lost 2.5% of its river ice in the last 30 years.

If the world’s nations stick to the agreement reached in Paris in 2015 and contain global heating to just 2°C above the average for most of human history, then by the end of the century the world could see a reduction of another 16 days in the length of ice cover, compared with the present, they calculate.

If they achieve the Paris ideal of no more than 1.5°C, this extra ice-free period could be reduced to just over seven days. Right now, global average temperatures are already 1°C above the historic average, and the planet is on course for a warming by the end of the century of more than 3°C. − Climate News Network

The Atlantic current won’t come to a full stop the day after tomorrow. But it could face a temporary halt later this century.

LONDON, 3 January, 2020 − European scientists think they have settled one of the more alarming questions of the climate crisis: the potential collapse of the Atlantic current, the Gulf Stream that delivers heat from the tropics to the Arctic.

The answer is clear. Total collapse is not likely for another 1000 years. But there is roughly a one in six chance in the next century that the flow of the north Atlantic current may temporarily halt or falter because of climate change.

That is because faster melting of the Greenland ice cap, and more freshwater in the Arctic Ocean, could trigger a slowdown in what scientists like to call the Atlantic meridional overturning circulation.

And a team of US researchers has separately highlighted one of the potential mechanisms of ocean change: for every 1°C rise in average global temperature, there will be roughly six days fewer on which many of the world’s rivers are frozen, which will mean more freshwater in the northern seas.

The findings are based in the first case on sophisticated use of computer simulations, and in the second on the careful study of 400,000 satellite images collected over more than 30 years.

“The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette”

Researchers from the universities of Groningen and Utrecht say, in the journal Scientific Reports, that they modelled the likelihood and impact of small changes in the flow of freshwater into the ocean at high latitudes.

The Atlantic current – sometimes called the Gulf Stream – is a massive flow of warm, salty water from the tropics to the Arctic that keeps  northwestern Europe much warmer than, for example, the same latitudes of North America.

As the water flows north, it cools and becomes more dense, and begins to sink below the fresh meltwater of the summer Arctic: the cold, dense, salty water then flows along the sea bed southwards, and this one dramatic global oceanic conveyor belt ultimately delivers nutrients and dissolved oxygen to the Southern Ocean. It also stores dissolved carbon dioxide, distributes heat and moderates high latitude weather.

But in the past 150 years the flow has been weakening, and there have been fears that the circulation could halt entirely, with unforeseeable consequences. This notional failure became the trigger for a 2004 disaster movie called The Day After Tomorrow. Something so sudden and catastrophic as the Hollywood version was never going to happen – but there have been repeated fears that the weakening could continue, and tip the planet’s climate into a new and potentially dangerous state.

The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette, in which a player spins a six-chambered revolver with one bullet in it, and points it at his or her head.

River ice lost

Their model simulated small changes in the delivery of freshwater. This is likely to accelerate however, according to research in the journal Nature. Researchers combed through 407,880 satellite pictures taken between 1984 and 2018, to find that 56% of rivers were affected by winter freezing, which masked altogether 87,000 square kilometres of water surface.

Freezing is important to both humans and wild things: frozen rivers traditionally have provided good surfaces for ground transport in the high latitudes. The act of freezing also regulates greenhouse gas emissions that would otherwise escape from the rivers. Ice-jams during the spring melt can trigger flooding, which – though damaging to human settlements – spreads fresh water, nutrients and sediments around the flood plains.

But these benefits are at risk. The researchers found that river and lake surfaces were freezing ever later, as global temperatures crept up, and that the world had lost 2.5% of its river ice in the last 30 years.

If the world’s nations stick to the agreement reached in Paris in 2015 and contain global heating to just 2°C above the average for most of human history, then by the end of the century the world could see a reduction of another 16 days in the length of ice cover, compared with the present, they calculate.

If they achieve the Paris ideal of no more than 1.5°C, this extra ice-free period could be reduced to just over seven days. Right now, global average temperatures are already 1°C above the historic average, and the planet is on course for a warming by the end of the century of more than 3°C. − 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

Glacial melt creates Andes time bomb

The speed of glacial melt in parts of Latin America is threatening water supplies – and life and limb in cities downstream.

LONDON, 16 December, 2019 – Rising regional temperatures in the Andes and the warming of waters in the Pacific Ocean, off Latin America’s west coast, are driving the mountains’ glacial melt to alarming new speeds.

Long-term water supplies to many millions of people are under threat. Capital cities like Lima in Peru and La Paz in Bolivia, largely dependent on water from glacier melt flows, face an uncertain future.

The prospects for agriculture – a mainstay of the economies of countries in the region – will be imperilled as land dries up.

There is another, potentially lethal consequence of the melting of the Andes’ glaciers. In 1941, large chunks of ice breaking off a glacier and falling into Lake Palcacocha, more than 4,500 metres up in the Cordillera Blanca mountain range in the Peruvian Andes, are said to have triggered what’s known as a glacial lake outburst flood (GLOF).

“As temperatures in the region continue to rise, the danger level increases”

The sudden influx of ice caused the lake to burst, its waters racing down a canyon to burst another glacial lake below and then on to flood the city of Huarez, more than 20 kilometres away. It’s estimated that more than 4,000 people – about a third of the city’s population at the time – were killed.

Rising temperatures caused by climate change in mountain ranges around the world are leading to an ever-increasing number of GLOF incidents. Mountainous countries like Peru and Nepal, in the Himalayas, are particularly vulnerable to the sudden flooding caused when glacial lakes burst.

In the aftermath of the 1941 flood, a dam was built on Lake Palcacocha: at first the lake slowly refilled, but in recent years the process accelerated due to increased temperatures and more glacial melt.

Flexible pipes have been used to siphon waters off from the lake but experts say it’s only a matter of time before Lake Palcacocha again bursts its banks. The dam, they say, will be swept away. The consequences would be devastating as a wave up to 30 metres tall is unleashed.

Increased population

The city of Huarez has become a big tourist destination and its population has grown to more than 120,000. Large numbers of farmers have moved onto lands below Lake Palcacocha. Mine workers are also active in the area, searching for valuable minerals in ground uncovered by the melting of the glaciers.

Various safety measures are being installed. After years of wrangling and bureaucratic delays, a flood early warning system is about to be activated in the area.

Installation of the system has also been subject to sabotage by local farmers who say that the introduction of the technology has somehow interfered with natural weather patterns.

Monitoring systems have improved – with often daily glacial avalanches being recorded. Inaigem, the national research institute on glaciers and mountain ecosystems, provides a live video of Lake Palcacocha water flows. But as temperatures in the region continue to rise, the danger level increases. – Climate News Network

The speed of glacial melt in parts of Latin America is threatening water supplies – and life and limb in cities downstream.

LONDON, 16 December, 2019 – Rising regional temperatures in the Andes and the warming of waters in the Pacific Ocean, off Latin America’s west coast, are driving the mountains’ glacial melt to alarming new speeds.

Long-term water supplies to many millions of people are under threat. Capital cities like Lima in Peru and La Paz in Bolivia, largely dependent on water from glacier melt flows, face an uncertain future.

The prospects for agriculture – a mainstay of the economies of countries in the region – will be imperilled as land dries up.

There is another, potentially lethal consequence of the melting of the Andes’ glaciers. In 1941, large chunks of ice breaking off a glacier and falling into Lake Palcacocha, more than 4,500 metres up in the Cordillera Blanca mountain range in the Peruvian Andes, are said to have triggered what’s known as a glacial lake outburst flood (GLOF).

“As temperatures in the region continue to rise, the danger level increases”

The sudden influx of ice caused the lake to burst, its waters racing down a canyon to burst another glacial lake below and then on to flood the city of Huarez, more than 20 kilometres away. It’s estimated that more than 4,000 people – about a third of the city’s population at the time – were killed.

Rising temperatures caused by climate change in mountain ranges around the world are leading to an ever-increasing number of GLOF incidents. Mountainous countries like Peru and Nepal, in the Himalayas, are particularly vulnerable to the sudden flooding caused when glacial lakes burst.

In the aftermath of the 1941 flood, a dam was built on Lake Palcacocha: at first the lake slowly refilled, but in recent years the process accelerated due to increased temperatures and more glacial melt.

Flexible pipes have been used to siphon waters off from the lake but experts say it’s only a matter of time before Lake Palcacocha again bursts its banks. The dam, they say, will be swept away. The consequences would be devastating as a wave up to 30 metres tall is unleashed.

Increased population

The city of Huarez has become a big tourist destination and its population has grown to more than 120,000. Large numbers of farmers have moved onto lands below Lake Palcacocha. Mine workers are also active in the area, searching for valuable minerals in ground uncovered by the melting of the glaciers.

Various safety measures are being installed. After years of wrangling and bureaucratic delays, a flood early warning system is about to be activated in the area.

Installation of the system has also been subject to sabotage by local farmers who say that the introduction of the technology has somehow interfered with natural weather patterns.

Monitoring systems have improved – with often daily glacial avalanches being recorded. Inaigem, the national research institute on glaciers and mountain ecosystems, provides a live video of Lake Palcacocha water flows. But as temperatures in the region continue to rise, the danger level increases. – 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

New water for old as glaciers vanish

Voids left as glaciers vanish could be used to store spring snowmelt and rainfall to save the valleys below from summer droughts.

LONDON, 4 December, 2019 – Building dams in high mountains to store water as glaciers vanish could produce much-needed hydropower as well as saving people in the valleys below from summer droughts.

Following an earlier study of their own crisis of retreating glaciers in the Alps, Swiss glaciologists have carried out a worldwide study of 185,000 retreating rivers of ice to assess whether the empty valleys they leave behind could usefully be turned into holding dams.

The issue is urgent, because even with an average climate change scenario about three-quarters of the storage potential of these valleys could become ice-free by 2050 – and all of them by the end of the century.

The retreating ice – apart from spelling the end for some magnificent natural monuments – will dramatically affect the water cycle, leaving large river systems with seriously low flows, and some perhaps drying up altogether in the summer. This would have serious consequences for hydro-electricity production, agriculture and even drinking water for cities downstream.

Although water shortage is a potential problem in many high mountain regions, it is already affecting cities like Peru’s capital, Lima, which lies below the Andes. It also has the potential to cause serious problems in India, Pakistan and China, all of them reliant on summer run-off from the Himalayas.

“This theoretical total potential corresponds to about one third of current hydropower production worldwide. But, in reality, only part of it would be realisable”

The idea of the dams would be to capture the water from winter rainfall and spring snowmelt and retain it for gradual release during the summer – so, at least partly, replicating the current summer glacier melt.

ETH Zurich (the Swiss Federal Institute of Technology) and the Swiss Federal Institute for Forest, Snow and Landscape Research report, in a study published in the journal Nature, that the scheme could be viable in many countries.

The team calculated that theoretically the storage potential of these glacier valleys was 875 cubic kilometres of water, providing enormous hydropower potential.

Daniel Farinotti, professor of glaciology at ETH Zurich, who led the team, said: “This theoretical total potential corresponds to about one third of current hydropower production worldwide. But in reality, only part of it would be realisable.”

Since it was neither realistic nor desirable to build a dam in each of the thousands of the valleys vacated by glaciers, the researchers carried out a suitability assessment for all sites.

Significant addition

They identified around 40% of the theoretical total as “potentially” suitable, equalling a storage volume of 355 cubic km and a hydropower potential of 533 TWh per year. The latter corresponds to around 13% of current global hydropower production, or nine times Switzerland’s annual electricity demand.

“Even this potentially suitable storage volume would be sufficient to store about half of the annual runoff from the studied glacierised basins,” Professor Farinotti said.

The results show that basins which have lost their glaciers could contribute significantly to energy supply and water storage in a number of countries, particularly in the high mountain countries of Asia.

Among those with the largest potentials are Tajikistan, where the calculated hydropower potential could account for up to 80% of current electricity consumption, Chile (40%) and Pakistan (35%).

In Canada, Iceland, Bolivia and Norway, the potential equals 10–25% of their current electricity consumption. For Switzerland, the study shows a potential of 10%. – Climate News Network

Voids left as glaciers vanish could be used to store spring snowmelt and rainfall to save the valleys below from summer droughts.

LONDON, 4 December, 2019 – Building dams in high mountains to store water as glaciers vanish could produce much-needed hydropower as well as saving people in the valleys below from summer droughts.

Following an earlier study of their own crisis of retreating glaciers in the Alps, Swiss glaciologists have carried out a worldwide study of 185,000 retreating rivers of ice to assess whether the empty valleys they leave behind could usefully be turned into holding dams.

The issue is urgent, because even with an average climate change scenario about three-quarters of the storage potential of these valleys could become ice-free by 2050 – and all of them by the end of the century.

The retreating ice – apart from spelling the end for some magnificent natural monuments – will dramatically affect the water cycle, leaving large river systems with seriously low flows, and some perhaps drying up altogether in the summer. This would have serious consequences for hydro-electricity production, agriculture and even drinking water for cities downstream.

Although water shortage is a potential problem in many high mountain regions, it is already affecting cities like Peru’s capital, Lima, which lies below the Andes. It also has the potential to cause serious problems in India, Pakistan and China, all of them reliant on summer run-off from the Himalayas.

“This theoretical total potential corresponds to about one third of current hydropower production worldwide. But, in reality, only part of it would be realisable”

The idea of the dams would be to capture the water from winter rainfall and spring snowmelt and retain it for gradual release during the summer – so, at least partly, replicating the current summer glacier melt.

ETH Zurich (the Swiss Federal Institute of Technology) and the Swiss Federal Institute for Forest, Snow and Landscape Research report, in a study published in the journal Nature, that the scheme could be viable in many countries.

The team calculated that theoretically the storage potential of these glacier valleys was 875 cubic kilometres of water, providing enormous hydropower potential.

Daniel Farinotti, professor of glaciology at ETH Zurich, who led the team, said: “This theoretical total potential corresponds to about one third of current hydropower production worldwide. But in reality, only part of it would be realisable.”

Since it was neither realistic nor desirable to build a dam in each of the thousands of the valleys vacated by glaciers, the researchers carried out a suitability assessment for all sites.

Significant addition

They identified around 40% of the theoretical total as “potentially” suitable, equalling a storage volume of 355 cubic km and a hydropower potential of 533 TWh per year. The latter corresponds to around 13% of current global hydropower production, or nine times Switzerland’s annual electricity demand.

“Even this potentially suitable storage volume would be sufficient to store about half of the annual runoff from the studied glacierised basins,” Professor Farinotti said.

The results show that basins which have lost their glaciers could contribute significantly to energy supply and water storage in a number of countries, particularly in the high mountain countries of Asia.

Among those with the largest potentials are Tajikistan, where the calculated hydropower potential could account for up to 80% of current electricity consumption, Chile (40%) and Pakistan (35%).

In Canada, Iceland, Bolivia and Norway, the potential equals 10–25% of their current electricity consumption. For Switzerland, the study shows a potential of 10%. – Climate News Network

Earth nears irreversible tipping points

Changes afoot now in at least nine areas could drastically alter the Earth’s climate. There’s no time left to act on these tipping points.

LONDON, 28 November, 2019 – On the eve of a global climate summit in Madrid, seven distinguished climate scientists have issued an urgent warning of approaching planetary tipping points: within a few years, they say, humankind could enter a state of potentially catastrophic climate change on a new “hothouse” Earth.

They warn that dramatic changes to planetary stability may already be happening in nine vulnerable ecosystems. As these changes happen, they could reinforce each other and at the same time amplify planetary temperature rise, commit the oceans to inexorable sea level rise of around 10 metres, and threaten the existence of human civilisations.

Their warning is issued in a commentary in the journal Nature. Their conclusions are not – and perhaps cannot be – confirmed by direct evidence or the consensus of other scientists. They present an opinion, not a set of facts that can be scrutinised and challenged or endorsed by their peers.

And the seven researchers recognise that although such changes are happening at speed, some of the consequences of those changes will follow more slowly. Their point is that the risks of irreversible change are too great not to act – and to act now.

Happening now

But the fact that they have chosen to issue such an alarm at all is a measure of the concern raised by the rapid retreat of the Arctic ice, the steady loss of the Greenland ice cap, the damage to the boreal forests, the thaw of the polar permafrost, the slowing of a great ocean current, the loss of tropical corals and the collapse of ice sheets in East and West Antarctica.

Each of these happenings – and many more – was identified more than a decade ago as a potential “tipping point”: an irreversible change that would amplify global heating and trigger a cascade of other climate changes.

“Now we see evidence that over half of them have been activated,” said Tim Lenton of the University of Exeter, UK. “The growing threat of rapid, irreversible changes means it is no longer responsible to wait and see.”

“The stability and resilience of our planet is in peril. International action – not just words – must reflect this”

The idea of a climate tipping point – a threshold beyond which dramatic climate change would be irreversible – is an old one. Two decades ago the Intergovernmental Panel on Climate Change examined the idea and proposed that, were the planet to warm by 5°C above the long-term average for most of human history, then it could tip into a new climate regime.

But in the last few decades, carbon dioxide concentrations in the atmosphere have gone from around 280 parts per million to more than 400 ppm, and global average temperatures have risen by more than 1°C. And the rate of change, driven by profligate use of fossil fuels that deposit greenhouse gases into the atmosphere, has been alarming.

“It is not only human pressures on Earth that continue rising to unprecedented levels. It is also that, as science advances, we must admit that we have underestimated the risks of unleashing irreversible changes, where the planet self-amplifies global warming. This is what we are seeing already at 1°C global warming,” said Johan Rockström, who directs the Potsdam Institute for Climate Impact Research in Germany, and who is another signatory.

“Scientifically, this provides strong evidence for declaring a state of planetary emergency, to unleash world action that accelerates the path towards a world that can continue evolving on a stable planet.”

Inadequate pledges

In 2015, at a climate summit in Paris, 195 nations promised to contain planetary heating to “well below” 2°C, and ideally to 1.5°C, by 2100. But the Nature signatories point at that even if the pledges those nations made are implemented – a “big if”, they warn – then they will ensure only that the world is committed to at least 3°C warming.

The scientists believe there is still time to act – but their dangerous tipping points are now dangerously close.

The arguments go like this. In West Antarctica, ice may already be retreating beyond the “grounding line” where ice, ocean and bedrock meet. If so, then the rest of the West Antarctic ice sheet could collapse, and sea levels could rise by three metres.

New evidence suggests the East Antarctic ice sheet could be similarly unstable, and precipitate further sea level rise of up to four metres. Hundreds of millions are already at risk from coastal flooding.

Timescale controlled

The Greenland ice sheet is melting at an accelerating rate, and once past a critical threshold could lose enough water to raise sea levels by seven metres. Even a 1.5°C warming might condemn Greenland to irreversible melting – and on present form the world could warm by 1.5°C by 2030.

“Thus we might have already committed future generations to living with sea level rises of around 10m over thousands of years. But the timescale is still under our control,” the authors warn.

They also warn that a “staggering 99% of tropical corals” could be lost if the planet heats by even 2°C – at a profound cost to both marine sea life and human economies.

They say 17% of the Amazon rainforest has been lost since 1970: a loss of somewhere between 20% and 40% could tip the entire rainforest into a destabilised state, increasingly at risk from drought and fire.

Risks multiply

In the boreal forests of northern Asia, Europe and Canada, insect outbreaks, fire and dieback could turn some regions into sources of more carbon, rather than sinks that soak up the extra carbon dioxide.

Permafrost thaw could release ever-greater volumes of stored methane, a greenhouse gas 30 times more potent, over a century, than carbon dioxide, and so on. The dangers multiply, and each one amplifies planetary heating.

“If damaging tipping cascades can occur and a global tipping point cannot be ruled out, then this is an existential threat to civilisation,” the authors warn.

“The stability and resilience of our planet is in peril. International action – not just words – must reflect this.” – Climate News Network

Changes afoot now in at least nine areas could drastically alter the Earth’s climate. There’s no time left to act on these tipping points.

LONDON, 28 November, 2019 – On the eve of a global climate summit in Madrid, seven distinguished climate scientists have issued an urgent warning of approaching planetary tipping points: within a few years, they say, humankind could enter a state of potentially catastrophic climate change on a new “hothouse” Earth.

They warn that dramatic changes to planetary stability may already be happening in nine vulnerable ecosystems. As these changes happen, they could reinforce each other and at the same time amplify planetary temperature rise, commit the oceans to inexorable sea level rise of around 10 metres, and threaten the existence of human civilisations.

Their warning is issued in a commentary in the journal Nature. Their conclusions are not – and perhaps cannot be – confirmed by direct evidence or the consensus of other scientists. They present an opinion, not a set of facts that can be scrutinised and challenged or endorsed by their peers.

And the seven researchers recognise that although such changes are happening at speed, some of the consequences of those changes will follow more slowly. Their point is that the risks of irreversible change are too great not to act – and to act now.

Happening now

But the fact that they have chosen to issue such an alarm at all is a measure of the concern raised by the rapid retreat of the Arctic ice, the steady loss of the Greenland ice cap, the damage to the boreal forests, the thaw of the polar permafrost, the slowing of a great ocean current, the loss of tropical corals and the collapse of ice sheets in East and West Antarctica.

Each of these happenings – and many more – was identified more than a decade ago as a potential “tipping point”: an irreversible change that would amplify global heating and trigger a cascade of other climate changes.

“Now we see evidence that over half of them have been activated,” said Tim Lenton of the University of Exeter, UK. “The growing threat of rapid, irreversible changes means it is no longer responsible to wait and see.”

“The stability and resilience of our planet is in peril. International action – not just words – must reflect this”

The idea of a climate tipping point – a threshold beyond which dramatic climate change would be irreversible – is an old one. Two decades ago the Intergovernmental Panel on Climate Change examined the idea and proposed that, were the planet to warm by 5°C above the long-term average for most of human history, then it could tip into a new climate regime.

But in the last few decades, carbon dioxide concentrations in the atmosphere have gone from around 280 parts per million to more than 400 ppm, and global average temperatures have risen by more than 1°C. And the rate of change, driven by profligate use of fossil fuels that deposit greenhouse gases into the atmosphere, has been alarming.

“It is not only human pressures on Earth that continue rising to unprecedented levels. It is also that, as science advances, we must admit that we have underestimated the risks of unleashing irreversible changes, where the planet self-amplifies global warming. This is what we are seeing already at 1°C global warming,” said Johan Rockström, who directs the Potsdam Institute for Climate Impact Research in Germany, and who is another signatory.

“Scientifically, this provides strong evidence for declaring a state of planetary emergency, to unleash world action that accelerates the path towards a world that can continue evolving on a stable planet.”

Inadequate pledges

In 2015, at a climate summit in Paris, 195 nations promised to contain planetary heating to “well below” 2°C, and ideally to 1.5°C, by 2100. But the Nature signatories point at that even if the pledges those nations made are implemented – a “big if”, they warn – then they will ensure only that the world is committed to at least 3°C warming.

The scientists believe there is still time to act – but their dangerous tipping points are now dangerously close.

The arguments go like this. In West Antarctica, ice may already be retreating beyond the “grounding line” where ice, ocean and bedrock meet. If so, then the rest of the West Antarctic ice sheet could collapse, and sea levels could rise by three metres.

New evidence suggests the East Antarctic ice sheet could be similarly unstable, and precipitate further sea level rise of up to four metres. Hundreds of millions are already at risk from coastal flooding.

Timescale controlled

The Greenland ice sheet is melting at an accelerating rate, and once past a critical threshold could lose enough water to raise sea levels by seven metres. Even a 1.5°C warming might condemn Greenland to irreversible melting – and on present form the world could warm by 1.5°C by 2030.

“Thus we might have already committed future generations to living with sea level rises of around 10m over thousands of years. But the timescale is still under our control,” the authors warn.

They also warn that a “staggering 99% of tropical corals” could be lost if the planet heats by even 2°C – at a profound cost to both marine sea life and human economies.

They say 17% of the Amazon rainforest has been lost since 1970: a loss of somewhere between 20% and 40% could tip the entire rainforest into a destabilised state, increasingly at risk from drought and fire.

Risks multiply

In the boreal forests of northern Asia, Europe and Canada, insect outbreaks, fire and dieback could turn some regions into sources of more carbon, rather than sinks that soak up the extra carbon dioxide.

Permafrost thaw could release ever-greater volumes of stored methane, a greenhouse gas 30 times more potent, over a century, than carbon dioxide, and so on. The dangers multiply, and each one amplifies planetary heating.

“If damaging tipping cascades can occur and a global tipping point cannot be ruled out, then this is an existential threat to civilisation,” the authors warn.

“The stability and resilience of our planet is in peril. International action – not just words – must reflect this.” – Climate News Network

Iceland put people first to save melting economy

Faced in 2008 with a melting economy, Iceland acted fast to avoid total collapse. Icelanders’ own needs were its priority.

LONDON, 27 November, 2019 − What can you do if you’re a smallish island in the North Atlantic with a lot of snow and a melting economy? Quite a lot, it turns out, if you’re prepared to put local people’s needs first.

Iceland was hailed recently for erecting a memorial plaque to one of its most striking features, Okjökull, which shrank so drastically because of climate breakdown that it lost its status as a glacier. It was the first in Iceland to do so, and is now known, fittingly, by a diminutive, as Ok.

Barely 10 years ago, when the country was in the grip of a different crisis, the pace of its far from glacial response showed how quickly rapid changes of government policy can turn a crisis around.

Iceland was at the heart of the global financial crisis in late 2008 and was nearly destroyed by it; 97% of its banking sector collapsed in just three days. its three largest banks − Glitnir, Kaupthing and Landsbankinn − had accumulated a debt of $85 billion (£66bn), equivalent to 10 times the country’s national income (GDP), or 20 times the national budget.

These losses amounted to $330,000 for every man, woman and child on the island, whose stock market then collapsed, with huge numbers of businesses going bankrupt. Iceland approached the International Monetary Fund (IMF) for emergency aid − the first western country to do so since 1976 − and obtained a loan of $2.1bn (£1.4bn).

“It is possible that the Icelandic way of governing also played a part. Was their natural reflex to protect the many, rather than the few?”

So how did it manage to survive? First, it allowed a default on the $85bn in debt accumulated by the banks. A new national mood set in, creating lasting conditions for change and the desire for new economic approaches.

Other countries had largely let banks off the hook, but in 2015 Iceland’s Supreme Court upheld convictions against bankers at the heart of the crisis. Finance is now so sensitive that when the Prime Minister was caught up in revelations from the release of the so-called Panama Papers, he was forced from office.

The debts are now largely paid off, but most multinational businesses have left Iceland, for fear of the capital controls. A huge expansion in tourism has rescued the nation’s economy, though average wages are now much lower.

The government protected Icelanders’ bank deposits and forgave debts for a quarter of the population. As Bloomberg News reported in 2012, “Iceland’s approach to dealing with the meltdown has put the needs of its population ahead of the markets at every turn.”

The Rapid Transition Alliance (RTA), a global initiative which aims to learn from rapid change to address urgent environmental problems, believes Iceland’s way of extricating itself quickly from the global crisis has lessons for other countries, some of which are still paying a heavy price for the events of 2008 and the way they reacted.

Contrary to the conventional wisdom that individual countries cannot independently follow radically different economic policy and control capital flows, says the RTA, Iceland shows they can, and quickly;

Radical change can usher in a virtuous circle, by becoming a habit: once you’ve started, new opportunities may open up for yet more change;

And, perhaps most surprisingly of all, the Alliance says, it is possible to put people before the demands of financial markets and still run a successful economy. Citizen engagement and economic reform can go hand in hand.

Iceland’s economy had thrived on speculative finance but, after the meltdown, rather than making the public pay for the crisis, as the Nobel economist Paul Krugman points out, Iceland “let the banks go bust and actually expanded its social safety net”. Instead of placating financial markets, it introduced temporary controls on the movement of capital to give itself room to manoeuvre.

Following this, a “pots and pans” revolution kick-started a process that led to a new citizen-drafted constitution, which succeeded in engaging half the electorate.

The constitutional exercise proposed a new approach to the ownership of natural resources for the public good, which has had a lasting effect on the country’s choices: all its electricity and heat today comes from renewable sources, and transparency has become a central part of Icelandic public life.

The RTA thinks there were several key factors that enabled such rapid and fundamental change: the extent to which the economic system was irreparably damaged; the decision by the government to respond to the people’s demands and not to those of the banks; and the decision to punish those at fault and start anew.

It concludes: “It is possible that the Icelandic way of governing also played a part, because they have a longstanding history of deeply embedded democracy and a culture that discourages hierarchy. Was their natural reflex to protect the many, rather than the few?” − Climate News Network

* * * * *

The Rapid Transition Alliance is coordinated by the New Weather Institute, the STEPS Centre at the Institute of  Development Studies, and the School of Global Studies at the University of Sussex, UK. The Climate News Network is partnering with and supported by the Rapid Transition Alliance, and will be reporting regularly on its work. If you would like to see more stories of evidence-based hope for rapid transition, please sign up here.

Do you know a story of rapid transition? If so, we’d like to hear from you. Please send us a brief outline on info@climatenewsnetwork.net. Thank you.

Faced in 2008 with a melting economy, Iceland acted fast to avoid total collapse. Icelanders’ own needs were its priority.

LONDON, 27 November, 2019 − What can you do if you’re a smallish island in the North Atlantic with a lot of snow and a melting economy? Quite a lot, it turns out, if you’re prepared to put local people’s needs first.

Iceland was hailed recently for erecting a memorial plaque to one of its most striking features, Okjökull, which shrank so drastically because of climate breakdown that it lost its status as a glacier. It was the first in Iceland to do so, and is now known, fittingly, by a diminutive, as Ok.

Barely 10 years ago, when the country was in the grip of a different crisis, the pace of its far from glacial response showed how quickly rapid changes of government policy can turn a crisis around.

Iceland was at the heart of the global financial crisis in late 2008 and was nearly destroyed by it; 97% of its banking sector collapsed in just three days. its three largest banks − Glitnir, Kaupthing and Landsbankinn − had accumulated a debt of $85 billion (£66bn), equivalent to 10 times the country’s national income (GDP), or 20 times the national budget.

These losses amounted to $330,000 for every man, woman and child on the island, whose stock market then collapsed, with huge numbers of businesses going bankrupt. Iceland approached the International Monetary Fund (IMF) for emergency aid − the first western country to do so since 1976 − and obtained a loan of $2.1bn (£1.4bn).

“It is possible that the Icelandic way of governing also played a part. Was their natural reflex to protect the many, rather than the few?”

So how did it manage to survive? First, it allowed a default on the $85bn in debt accumulated by the banks. A new national mood set in, creating lasting conditions for change and the desire for new economic approaches.

Other countries had largely let banks off the hook, but in 2015 Iceland’s Supreme Court upheld convictions against bankers at the heart of the crisis. Finance is now so sensitive that when the Prime Minister was caught up in revelations from the release of the so-called Panama Papers, he was forced from office.

The debts are now largely paid off, but most multinational businesses have left Iceland, for fear of the capital controls. A huge expansion in tourism has rescued the nation’s economy, though average wages are now much lower.

The government protected Icelanders’ bank deposits and forgave debts for a quarter of the population. As Bloomberg News reported in 2012, “Iceland’s approach to dealing with the meltdown has put the needs of its population ahead of the markets at every turn.”

The Rapid Transition Alliance (RTA), a global initiative which aims to learn from rapid change to address urgent environmental problems, believes Iceland’s way of extricating itself quickly from the global crisis has lessons for other countries, some of which are still paying a heavy price for the events of 2008 and the way they reacted.

Contrary to the conventional wisdom that individual countries cannot independently follow radically different economic policy and control capital flows, says the RTA, Iceland shows they can, and quickly;

Radical change can usher in a virtuous circle, by becoming a habit: once you’ve started, new opportunities may open up for yet more change;

And, perhaps most surprisingly of all, the Alliance says, it is possible to put people before the demands of financial markets and still run a successful economy. Citizen engagement and economic reform can go hand in hand.

Iceland’s economy had thrived on speculative finance but, after the meltdown, rather than making the public pay for the crisis, as the Nobel economist Paul Krugman points out, Iceland “let the banks go bust and actually expanded its social safety net”. Instead of placating financial markets, it introduced temporary controls on the movement of capital to give itself room to manoeuvre.

Following this, a “pots and pans” revolution kick-started a process that led to a new citizen-drafted constitution, which succeeded in engaging half the electorate.

The constitutional exercise proposed a new approach to the ownership of natural resources for the public good, which has had a lasting effect on the country’s choices: all its electricity and heat today comes from renewable sources, and transparency has become a central part of Icelandic public life.

The RTA thinks there were several key factors that enabled such rapid and fundamental change: the extent to which the economic system was irreparably damaged; the decision by the government to respond to the people’s demands and not to those of the banks; and the decision to punish those at fault and start anew.

It concludes: “It is possible that the Icelandic way of governing also played a part, because they have a longstanding history of deeply embedded democracy and a culture that discourages hierarchy. Was their natural reflex to protect the many, rather than the few?” − Climate News Network

* * * * *

The Rapid Transition Alliance is coordinated by the New Weather Institute, the STEPS Centre at the Institute of  Development Studies, and the School of Global Studies at the University of Sussex, UK. The Climate News Network is partnering with and supported by the Rapid Transition Alliance, and will be reporting regularly on its work. If you would like to see more stories of evidence-based hope for rapid transition, please sign up here.

Do you know a story of rapid transition? If so, we’d like to hear from you. Please send us a brief outline on info@climatenewsnetwork.net. Thank you.