Tag Archives: Greenland

North Pole may be clear water by mid-century

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

Within 30 years, there could be clear blue water over the North Pole – not good news for most of the planet.

LONDON, 25 April, 2020 – Within three decades, the North Pole could be free of sea ice in the late summer. The latest and most advanced climate simulations, tested by 21 research institutes from around the world, predict that if humans go on emitting ever-greater volumes of carbon dioxide from fossil fuel combustion and other actions, then before 2050, for the first time in human history, there could be no ice over the North Pole.

And a team of research scientists aboard a ship intent on spending a year observing the drift of sea ice across the Arctic Ocean has been warned that they may have to finish early: the ice supposed to hold the ship fast could melt too soon.

The loss of sea ice promises devastating consequences for the rich life in the most northern waters. The ice reflects sunlight back into space and keeps the Arctic cool. It also provides space for seals on which to haul out, and hunting grounds for blubber-hungry polar bears.

And although human inaction in the climate emergency makes the loss of polar ice ever more probable, so much greenhouse gas has already built up in the planetary atmosphere that it could happen anyway.

Taken aback

“If we reduce global emissions rapidly and substantially, and thus keep our warming below 2°C relative to pre-industrial levels, sea ice will nevertheless likely disappear occasionally in summer even before 2050,” said Dirk Notz, of the University of Hamburg in Germany, who led the study. “This really surprised us.”

Climate scientists first warned of the accelerating loss of Arctic sea ice two decades ago, and have repeatedly re-examined the climate predictions, each time with much the same outcome.

The loss of ice promises new trade routes between Atlantic and Pacific Oceans, but the cost of a warming Arctic could have catastrophic economic consequences.

The pattern of the northern hemisphere climate is driven by the temperature difference between the Arctic and the tropics, and rapid polar warming both disturbs temperate climate regimes and brings ever higher sea levels, with accelerating ice loss from Greenland, which right now bears enough ice to raise global sea levels by more than seven metres.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today”

Dr Notz and his co-authors report in the journal Geophysical Research Letters that they used the very latest climate model developed for the Intergovernmental Panel on Climate Change and tested it on a range of 40 possible climate outcomes.

In most simulations, the Arctic sea ice was reduced to less than a million square kilometres – polar researchers call this “practically sea-ice free” – in the month of September for the first time before 2050. Even if human fossil fuel use was sharply reduced, the ocean could be free of ice some years; if not, the pole could become open water most years.

And a second study, in the journal The Cryosphere, offers a measure of the sea ice loss even now. More than a century ago, the great explorer Fridtjof Nansen sailed his ship the Fram into the polar ice, became fast, and travelled with the floe across the Arctic Ocean.

His became the first scientific observation of a phenomenon called the trans-Polar drift, which takes algae, sediments and nutrients – and increasingly, plastic pollution – across the Arctic from Siberia to Canada and Greenland.

Melted out

In October a team of international researchers boarded a vessel called Polarstern with the intention of measuring the ice movement in the modern Arctic in more detail. They had planned for a year fast in the ice. Their project even has a name: Mosaic, or Multidisciplinary drifting Observatory for the Study of Arctic Climate.

But climate simulations by the US scientists reveal that in every sense, the project is on thin ice and could end prematurely. The flow of ice could be faster, and carry the ship further, than expected: nearly one in five of the simulations also predicted that the ship could melt out of the ice in less than a year.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today,” said one of the authors, Marika Holland of the US National Center for Atmospheric Research.

“Now there is thinner ice, which moves more quickly, and there is less snow cover. It is a totally different ice regime.” – Climate News Network

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

Within 30 years, there could be clear blue water over the North Pole – not good news for most of the planet.

LONDON, 25 April, 2020 – Within three decades, the North Pole could be free of sea ice in the late summer. The latest and most advanced climate simulations, tested by 21 research institutes from around the world, predict that if humans go on emitting ever-greater volumes of carbon dioxide from fossil fuel combustion and other actions, then before 2050, for the first time in human history, there could be no ice over the North Pole.

And a team of research scientists aboard a ship intent on spending a year observing the drift of sea ice across the Arctic Ocean has been warned that they may have to finish early: the ice supposed to hold the ship fast could melt too soon.

The loss of sea ice promises devastating consequences for the rich life in the most northern waters. The ice reflects sunlight back into space and keeps the Arctic cool. It also provides space for seals on which to haul out, and hunting grounds for blubber-hungry polar bears.

And although human inaction in the climate emergency makes the loss of polar ice ever more probable, so much greenhouse gas has already built up in the planetary atmosphere that it could happen anyway.

Taken aback

“If we reduce global emissions rapidly and substantially, and thus keep our warming below 2°C relative to pre-industrial levels, sea ice will nevertheless likely disappear occasionally in summer even before 2050,” said Dirk Notz, of the University of Hamburg in Germany, who led the study. “This really surprised us.”

Climate scientists first warned of the accelerating loss of Arctic sea ice two decades ago, and have repeatedly re-examined the climate predictions, each time with much the same outcome.

The loss of ice promises new trade routes between Atlantic and Pacific Oceans, but the cost of a warming Arctic could have catastrophic economic consequences.

The pattern of the northern hemisphere climate is driven by the temperature difference between the Arctic and the tropics, and rapid polar warming both disturbs temperate climate regimes and brings ever higher sea levels, with accelerating ice loss from Greenland, which right now bears enough ice to raise global sea levels by more than seven metres.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today”

Dr Notz and his co-authors report in the journal Geophysical Research Letters that they used the very latest climate model developed for the Intergovernmental Panel on Climate Change and tested it on a range of 40 possible climate outcomes.

In most simulations, the Arctic sea ice was reduced to less than a million square kilometres – polar researchers call this “practically sea-ice free” – in the month of September for the first time before 2050. Even if human fossil fuel use was sharply reduced, the ocean could be free of ice some years; if not, the pole could become open water most years.

And a second study, in the journal The Cryosphere, offers a measure of the sea ice loss even now. More than a century ago, the great explorer Fridtjof Nansen sailed his ship the Fram into the polar ice, became fast, and travelled with the floe across the Arctic Ocean.

His became the first scientific observation of a phenomenon called the trans-Polar drift, which takes algae, sediments and nutrients – and increasingly, plastic pollution – across the Arctic from Siberia to Canada and Greenland.

Melted out

In October a team of international researchers boarded a vessel called Polarstern with the intention of measuring the ice movement in the modern Arctic in more detail. They had planned for a year fast in the ice. Their project even has a name: Mosaic, or Multidisciplinary drifting Observatory for the Study of Arctic Climate.

But climate simulations by the US scientists reveal that in every sense, the project is on thin ice and could end prematurely. The flow of ice could be faster, and carry the ship further, than expected: nearly one in five of the simulations also predicted that the ship could melt out of the ice in less than a year.

“The changes in the Arctic system are so incredibly rapid that even our satellite observations from 15 years ago are unlike the Arctic today,” said one of the authors, Marika Holland of the US National Center for Atmospheric Research.

“Now there is thinner ice, which moves more quickly, and there is less snow cover. It is a totally different ice regime.” – Climate News Network

Cloudless skies hasten Greenland’s ice loss

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

The bad news about Greenland’s ice loss has just got even worse. Blame it on mischief by blue skies all day long.

LONDON, 22 April, 2020 – Greenland’s ice loss reached record levels in 2019, and scientists think they’ve identified the culprit: the good weather which normally brings the snow-bearing clouds to the High Arctic.

The huge island, the biggest bank of ice in the northern hemisphere, has been losing ice at an ever-increasing rate in a rapidly warming world. Last year it shed more ice than ever, and this time because the skies were unusually clear.

There is enough ice on Greenland to raise global sea levels by more than seven metres. A recent study established that in the years between 1992 and 2018, rates of polar ice loss have risen six-fold, and so much water has flowed off the Greenland ice surface that sea levels have risen by more than 10mm everywhere.

Now a new study by US and Belgian scientists in the journal The Cryosphere confirms that 2019 was even worse. Because of good weather and cloudless skies, only enough snow fell to deposit 50 billion tonnes of ice into the island’s profit-and-loss ice account. The average annual deposit between 1981 and 2010 was about 375bn tonnes.

But glaciers still flowed towards the sea at an ever-increasing rate, summer snow melt continued to flow off the ice sheet, and icebergs continued to calve, so on balance the island lost 600 billion tonnes of ice: enough to raise global sea levels by 1.5mm. This is the biggest overall loss of ice since records in Greenland began in 1948.

“These atmospheric conditions are becoming more and more frequent over the past few decades. It is very likely that this is due to the waviness of the jet stream”

The cause: unusual spells of high atmospheric pressure over the island for unusually long periods of time. That stopped the formation of clouds, and that meant less precipitation, in the form of snow. Snow reflects solar radiation more effectively than ice, so the surface absorbed more heat and melting also accelerated.

The pattern of warm moist clouds trapped over northern Greenland by the heat that would normally radiate off the ice, instead of releasing snow, also emitted their own heat, to make things worse. The worst year for surface melting remains 2012, but the summer of 2019 was a good second.

The implication is that things could get worse, and losses of Greenland ice could accelerate.

“These atmospheric conditions are becoming more and more frequent over the past few decades,” said Marco Tedesco, of the Lamont-Doherty Earth Observatory at the University of Columbia in the US, the lead author.

“It is very likely that this is due to the waviness of the jet stream, which we think is related to, among other things, the disappearance of snow cover in Siberia, the disappearance of sea ice, and the difference in the rate at which temperature is increasing in the Arctic versus the mid-latitudes.” – Climate News Network

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

The bad news about Greenland’s ice loss has just got even worse. Blame it on mischief by blue skies all day long.

LONDON, 22 April, 2020 – Greenland’s ice loss reached record levels in 2019, and scientists think they’ve identified the culprit: the good weather which normally brings the snow-bearing clouds to the High Arctic.

The huge island, the biggest bank of ice in the northern hemisphere, has been losing ice at an ever-increasing rate in a rapidly warming world. Last year it shed more ice than ever, and this time because the skies were unusually clear.

There is enough ice on Greenland to raise global sea levels by more than seven metres. A recent study established that in the years between 1992 and 2018, rates of polar ice loss have risen six-fold, and so much water has flowed off the Greenland ice surface that sea levels have risen by more than 10mm everywhere.

Now a new study by US and Belgian scientists in the journal The Cryosphere confirms that 2019 was even worse. Because of good weather and cloudless skies, only enough snow fell to deposit 50 billion tonnes of ice into the island’s profit-and-loss ice account. The average annual deposit between 1981 and 2010 was about 375bn tonnes.

But glaciers still flowed towards the sea at an ever-increasing rate, summer snow melt continued to flow off the ice sheet, and icebergs continued to calve, so on balance the island lost 600 billion tonnes of ice: enough to raise global sea levels by 1.5mm. This is the biggest overall loss of ice since records in Greenland began in 1948.

“These atmospheric conditions are becoming more and more frequent over the past few decades. It is very likely that this is due to the waviness of the jet stream”

The cause: unusual spells of high atmospheric pressure over the island for unusually long periods of time. That stopped the formation of clouds, and that meant less precipitation, in the form of snow. Snow reflects solar radiation more effectively than ice, so the surface absorbed more heat and melting also accelerated.

The pattern of warm moist clouds trapped over northern Greenland by the heat that would normally radiate off the ice, instead of releasing snow, also emitted their own heat, to make things worse. The worst year for surface melting remains 2012, but the summer of 2019 was a good second.

The implication is that things could get worse, and losses of Greenland ice could accelerate.

“These atmospheric conditions are becoming more and more frequent over the past few decades,” said Marco Tedesco, of the Lamont-Doherty Earth Observatory at the University of Columbia in the US, the lead author.

“It is very likely that this is due to the waviness of the jet stream, which we think is related to, among other things, the disappearance of snow cover in Siberia, the disappearance of sea ice, and the difference in the rate at which temperature is increasing in the Arctic versus the mid-latitudes.” – Climate News Network

Northern Europe’s warm water flow may falter

Global heating can stop the flow of Europe’s warm water from the tropics. Happening often during the Ice Ages, it could soon recur.

LONDON, 1 April, 2020 – Oceanographers have confirmed once again that global heating could slow or shut down the flow of currents such as the Gulf Stream, ending northern Europe’s warm water supply with an unexpected and prolonged cold snap.

This time the confidence is based neither on ocean measurements made now, nor complex computer simulations of the future. There is fresh evidence from the sea floor that such an ocean shutdown happened many times in the last half a million years of Ice Ages.

The Gulf Stream is part of a much larger flow of water called the Atlantic Meridional Overturning Circulation, an ocean recycling system that both nourishes marine life and moderates the climate in two hemispheres.

For the last 10,000 years of human history, tropical water has flowed north from the Caribbean and equatorial regions and washed the shores of Europe as far north as Norway, bringing equatorial heat to soften the impact of European winters.

A former UK chief scientist once calculated that the Gulf Stream delivered the warmth of 27,000 power stations and kept Britain about 5°C warmer than its citizens had any right to expect, given the latitude at which they lived.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions”

But as that stretch of the Gulf Stream known to oceanographers as the North Atlantic drift current reaches the Greenland Sea it becomes increasingly colder and saltier and thus more dense, and sinks to the ocean floor, loaded with dissolved atmospheric carbon dioxide and oxygen, to become a southward flow called the North Atlantic Deepwater formation.

And it also mingles with fresh water melting each summer from the Greenland ice sheet. But as the rate of Arctic melting accelerates, more fresh water will plunge into the same sea, with an increasing probability that it will disrupt the ocean cycle, turn off the flow of warm tropical water, and plunge Europe into a prolonged cold spell.

In its most dramatic form, this hypothesis was the basis for a 2004 Hollywood disaster movie called The Day After Tomorrow. Climate scientists are fairly sure that such an event would not mean the sudden advance of glacial ice over much of Europe and North America. But they have repeatedly identified evidence that the flow of the northward current is beginning to weaken.

And the journal Science now carries additional evidence that the ocean circulation was repeatedly interrupted for periods of a century or more during the warm spells or interglacials that have happened during the last 450,000 years.

Shells’ signatures

The signature of ocean change is there in the tiny sea shells from marine creatures called foraminifera that rain down onto the ocean floor to form annual layers of silent testimony to past climates.

When the mix of carbon isotope ratios preserved in them is high, that is a sign that the Atlantic circulation was once vigorous. When it is low, then this overturning circulation is feeble, or has stopped altogether.

The signal from the deep ocean is that when they happen, these disruptions seem to happen very swiftly, and to linger for 100 years or more. And, the scientists say, these interruptions in the flow of the ocean – and with it, the transport of heat from the tropics – happen more easily than previously appreciated, and they occurred in past climate conditions similar to those the world may soon face.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions,” said Yair Rosenthal of Rutgers University in the US, one of the authors.

“Although the disruptions in circulation and possible coolings may be relatively short-lived – lasting maybe a century or more – the consequences might be large.” – Climate News Network

Global heating can stop the flow of Europe’s warm water from the tropics. Happening often during the Ice Ages, it could soon recur.

LONDON, 1 April, 2020 – Oceanographers have confirmed once again that global heating could slow or shut down the flow of currents such as the Gulf Stream, ending northern Europe’s warm water supply with an unexpected and prolonged cold snap.

This time the confidence is based neither on ocean measurements made now, nor complex computer simulations of the future. There is fresh evidence from the sea floor that such an ocean shutdown happened many times in the last half a million years of Ice Ages.

The Gulf Stream is part of a much larger flow of water called the Atlantic Meridional Overturning Circulation, an ocean recycling system that both nourishes marine life and moderates the climate in two hemispheres.

For the last 10,000 years of human history, tropical water has flowed north from the Caribbean and equatorial regions and washed the shores of Europe as far north as Norway, bringing equatorial heat to soften the impact of European winters.

A former UK chief scientist once calculated that the Gulf Stream delivered the warmth of 27,000 power stations and kept Britain about 5°C warmer than its citizens had any right to expect, given the latitude at which they lived.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions”

But as that stretch of the Gulf Stream known to oceanographers as the North Atlantic drift current reaches the Greenland Sea it becomes increasingly colder and saltier and thus more dense, and sinks to the ocean floor, loaded with dissolved atmospheric carbon dioxide and oxygen, to become a southward flow called the North Atlantic Deepwater formation.

And it also mingles with fresh water melting each summer from the Greenland ice sheet. But as the rate of Arctic melting accelerates, more fresh water will plunge into the same sea, with an increasing probability that it will disrupt the ocean cycle, turn off the flow of warm tropical water, and plunge Europe into a prolonged cold spell.

In its most dramatic form, this hypothesis was the basis for a 2004 Hollywood disaster movie called The Day After Tomorrow. Climate scientists are fairly sure that such an event would not mean the sudden advance of glacial ice over much of Europe and North America. But they have repeatedly identified evidence that the flow of the northward current is beginning to weaken.

And the journal Science now carries additional evidence that the ocean circulation was repeatedly interrupted for periods of a century or more during the warm spells or interglacials that have happened during the last 450,000 years.

Shells’ signatures

The signature of ocean change is there in the tiny sea shells from marine creatures called foraminifera that rain down onto the ocean floor to form annual layers of silent testimony to past climates.

When the mix of carbon isotope ratios preserved in them is high, that is a sign that the Atlantic circulation was once vigorous. When it is low, then this overturning circulation is feeble, or has stopped altogether.

The signal from the deep ocean is that when they happen, these disruptions seem to happen very swiftly, and to linger for 100 years or more. And, the scientists say, these interruptions in the flow of the ocean – and with it, the transport of heat from the tropics – happen more easily than previously appreciated, and they occurred in past climate conditions similar to those the world may soon face.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions,” said Yair Rosenthal of Rutgers University in the US, one of the authors.

“Although the disruptions in circulation and possible coolings may be relatively short-lived – lasting maybe a century or more – the consequences might be large.” – Climate News Network

Polar ice melt raises sea level dangers

polar ice

Greenland’s polar ice is now melting far faster than 30 years ago, Antarctic ice is retreating at an accelerating rate, and sea levels are creeping up.

LONDON, 19 March, 2020 – Greenland and Antarctica, the two greatest stores of frozen water on the planet, are now losing polar ice at a rate at least six times faster than they were at the close of the last century.

The fact that polar ice is melting ever faster has been clear for a decade, but the latest research is authoritative.

To establish the rate of loss, 89 polar scientists from 50 of the world’s great research institutions looked at data from 26 separate surveys between 1992 and 2018, along with information from 11 different satellite missions.

Gloomiest forecasts

And the finding is in line with the worst-case scenarios considered by the Intergovernmental Panel on Climate Change (IPCC). If this rate of increase continues, sea levels at the close of this century will be at least 17 centimetres higher than the gloomiest official forecasts so far.

Between 1992 and 2017, the global sea level rose by 17.8 millimetres, as 6.4 trillion tonnes of polar ice turned to water and trickled into the oceans – 10.6 mm from Greenland and 7.2 mm from Antarctica.

In the last decade of the last century, the northern and southern icecaps dwindled at the rate of 81 billion tonnes a year. In the last decade, this had risen to 475 billion tonnes a year. This means that a third of all sea level rise is now caused by the loss of polar ice.

The most recent assessment by the IPCC is that, by 2100, sea levels will have risen by 53 cms, putting 360 million people who live at sea level at some risk.

“This would mean 400 million people at risk of annual coastal flooding by 2100”

But the latest finding from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) scientists is that seas will rise even higher, and even more people will have to move.

“Every centimetre of sea level rise leads to coastal flooding and coastal erosion, disrupting people’s lives around the planet,” said Andrew Shepherd, professor of Earth observation at the University of Leeds, UK, as he and colleagues published their findings of Greenland losses in Nature journal.

“If Antarctica and Greenland continue to track the worst-case climate warning scenario, they will cause an extra 17 cms of sea level rise by the end of the century.

“This would mean 400 million people at risk of annual coastal flooding by 2100. These are not unlikely events with small impacts; they are already under way and will be devastating for coastal communities.”

Global picture

Professor Shepherd and his IMBIE colleagues established almost two years ago that Antarctica was losing ice at an ever-accelerating rate, but the Greenland survey completes the global picture.

And it remains a picture in which the Arctic seems to be warming at an accelerating rate and sea levels seem to be rising ever faster.

This is not just because the polar ice caps are melting, but also because, almost everywhere, mountain glaciers are in retreat, and the oceans are expanding as sea temperatures rise in response to the steady warming of the planetary atmosphere. – Climate News Network

Greenland’s polar ice is now melting far faster than 30 years ago, Antarctic ice is retreating at an accelerating rate, and sea levels are creeping up.

LONDON, 19 March, 2020 – Greenland and Antarctica, the two greatest stores of frozen water on the planet, are now losing polar ice at a rate at least six times faster than they were at the close of the last century.

The fact that polar ice is melting ever faster has been clear for a decade, but the latest research is authoritative.

To establish the rate of loss, 89 polar scientists from 50 of the world’s great research institutions looked at data from 26 separate surveys between 1992 and 2018, along with information from 11 different satellite missions.

Gloomiest forecasts

And the finding is in line with the worst-case scenarios considered by the Intergovernmental Panel on Climate Change (IPCC). If this rate of increase continues, sea levels at the close of this century will be at least 17 centimetres higher than the gloomiest official forecasts so far.

Between 1992 and 2017, the global sea level rose by 17.8 millimetres, as 6.4 trillion tonnes of polar ice turned to water and trickled into the oceans – 10.6 mm from Greenland and 7.2 mm from Antarctica.

In the last decade of the last century, the northern and southern icecaps dwindled at the rate of 81 billion tonnes a year. In the last decade, this had risen to 475 billion tonnes a year. This means that a third of all sea level rise is now caused by the loss of polar ice.

The most recent assessment by the IPCC is that, by 2100, sea levels will have risen by 53 cms, putting 360 million people who live at sea level at some risk.

“This would mean 400 million people at risk of annual coastal flooding by 2100”

But the latest finding from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) scientists is that seas will rise even higher, and even more people will have to move.

“Every centimetre of sea level rise leads to coastal flooding and coastal erosion, disrupting people’s lives around the planet,” said Andrew Shepherd, professor of Earth observation at the University of Leeds, UK, as he and colleagues published their findings of Greenland losses in Nature journal.

“If Antarctica and Greenland continue to track the worst-case climate warning scenario, they will cause an extra 17 cms of sea level rise by the end of the century.

“This would mean 400 million people at risk of annual coastal flooding by 2100. These are not unlikely events with small impacts; they are already under way and will be devastating for coastal communities.”

Global picture

Professor Shepherd and his IMBIE colleagues established almost two years ago that Antarctica was losing ice at an ever-accelerating rate, but the Greenland survey completes the global picture.

And it remains a picture in which the Arctic seems to be warming at an accelerating rate and sea levels seem to be rising ever faster.

This is not just because the polar ice caps are melting, but also because, almost everywhere, mountain glaciers are in retreat, and the oceans are expanding as sea temperatures rise in response to the steady warming of the planetary atmosphere. – 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

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

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

Most Greenlanders feel effects of climate change

The climate crisis is part of daily life near the North Pole for most Greenlanders, with 75% saying they have felt it themselves.

LONDON, 20 September, 2019 − Most Greenlanders, those who live in the High Arctic, need no persuading that the climate emergency is real enough: three-quarters of them say they’ve experienced it.

Amid a flurry of scientific reports and dispatches by journalists, the world should know by now about the speed of the ice melt going on in the Arctic and the grave consequences it’s likely to have for the rest of the planet.

What is often less well-known is how people in this vast region feel about the dramatic way that climate change is altering their environment and way of life.

A recently published report on Greenland by the Denmark-based Kraks Fond Institute for Urban Economic Research, the University of Copenhagen and others attempts to provide an answer.

Not surprisingly, given the record high temperatures of recent years in Greenland and elsewhere in the Arctic, almost all those surveyed – 92% – believe climate change is happening, with more than half attributing such developments to human activities.

Future generations

A substantial majority – 76% – say they have personally experienced the effects of climate change; a large segment of those surveyed say the warming they’re witnessing will harm people in present and future generations and adversely impact plant and animal species – especially dogs used for sledging.

More than 640 residents of Greenland – 1.5% of the population of what is the world’s biggest island – participated in the report. Questioned on the level of anxiety they feel about the changes happening around them, those surveyed said they were most concerned about increasingly unpredictable weather patterns, the loss and thinning of sea ice, and the melting of permafrost.

Greenland, along with many other areas of the Arctic, has a particularly high incidence of mental health problems, along with alcohol, drug and other dependence issues.

Suicide rates, especially among the young, are well above those in other regions. In Arctic parts of northern Canada the incidence of suicide among the Inuit and other indigenous people is three times the national average.

“Those surveyed said they were most concerned about increasingly unpredictable weather patterns, the loss and thinning of sea ice, and the melting of permafrost”

A lack of jobs and low levels of education are said to be contributing to what is being described as a suicide crisis across the Arctic. Changing settlement patterns, community displacement due to climate change and a high incidence of TB and other diseases are also believed to be factors.

Various initiatives are now under way in an effort to tackle the problem.

Fishing is Greenland’s biggest industry, while hunting is a traditional activity, with much of the local diet dependent on seal meat and other wild food. Thinning ice means that hunting expeditions by sled are often dangerous.

A majority questioned in the survey said climate change will harm hunting, while about half say fishing will also be affected by warming temperatures.

Environment a priority

Overall more than 40% of residents thought climate change a bad thing, while only 11% said it was beneficial, with 46% still undecided on whether it would be good or bad.

Despite high unemployment rates in Greenland, a majority of those surveyed said they wanted to protect the environment, even if it was at the expense of jobs and economic growth.

Last month President Trump surprised the world by suggesting that the US would be interested in buying Greenland – he said the island was important for US security and had considerable economic potential.

Greenland is an autonomous territory ultimately ruled by Denmark. Copenhagen described Trump’s proposal as absurd. Native Greenlanders seemed equally dismissive of the idea. − Climate News Network

The climate crisis is part of daily life near the North Pole for most Greenlanders, with 75% saying they have felt it themselves.

LONDON, 20 September, 2019 − Most Greenlanders, those who live in the High Arctic, need no persuading that the climate emergency is real enough: three-quarters of them say they’ve experienced it.

Amid a flurry of scientific reports and dispatches by journalists, the world should know by now about the speed of the ice melt going on in the Arctic and the grave consequences it’s likely to have for the rest of the planet.

What is often less well-known is how people in this vast region feel about the dramatic way that climate change is altering their environment and way of life.

A recently published report on Greenland by the Denmark-based Kraks Fond Institute for Urban Economic Research, the University of Copenhagen and others attempts to provide an answer.

Not surprisingly, given the record high temperatures of recent years in Greenland and elsewhere in the Arctic, almost all those surveyed – 92% – believe climate change is happening, with more than half attributing such developments to human activities.

Future generations

A substantial majority – 76% – say they have personally experienced the effects of climate change; a large segment of those surveyed say the warming they’re witnessing will harm people in present and future generations and adversely impact plant and animal species – especially dogs used for sledging.

More than 640 residents of Greenland – 1.5% of the population of what is the world’s biggest island – participated in the report. Questioned on the level of anxiety they feel about the changes happening around them, those surveyed said they were most concerned about increasingly unpredictable weather patterns, the loss and thinning of sea ice, and the melting of permafrost.

Greenland, along with many other areas of the Arctic, has a particularly high incidence of mental health problems, along with alcohol, drug and other dependence issues.

Suicide rates, especially among the young, are well above those in other regions. In Arctic parts of northern Canada the incidence of suicide among the Inuit and other indigenous people is three times the national average.

“Those surveyed said they were most concerned about increasingly unpredictable weather patterns, the loss and thinning of sea ice, and the melting of permafrost”

A lack of jobs and low levels of education are said to be contributing to what is being described as a suicide crisis across the Arctic. Changing settlement patterns, community displacement due to climate change and a high incidence of TB and other diseases are also believed to be factors.

Various initiatives are now under way in an effort to tackle the problem.

Fishing is Greenland’s biggest industry, while hunting is a traditional activity, with much of the local diet dependent on seal meat and other wild food. Thinning ice means that hunting expeditions by sled are often dangerous.

A majority questioned in the survey said climate change will harm hunting, while about half say fishing will also be affected by warming temperatures.

Environment a priority

Overall more than 40% of residents thought climate change a bad thing, while only 11% said it was beneficial, with 46% still undecided on whether it would be good or bad.

Despite high unemployment rates in Greenland, a majority of those surveyed said they wanted to protect the environment, even if it was at the expense of jobs and economic growth.

Last month President Trump surprised the world by suggesting that the US would be interested in buying Greenland – he said the island was important for US security and had considerable economic potential.

Greenland is an autonomous territory ultimately ruled by Denmark. Copenhagen described Trump’s proposal as absurd. Native Greenlanders seemed equally dismissive of the idea. − Climate News Network

Ice-free Greenland possible in 1,000 years

Look far enough ahead and in a millennium an ice-free Greenland is a possibility, scientists say. Sea levels too will be a lot higher by then.

LONDON, 25 June, 2019 − US scientists have just established that the long-term future may bring an ice-free Greenland, if melting continues at the current rate. By the year 3,000 it could simply be green, with rocky outcrops. Greenland’s icy mountains will have vanished.

By the end of this century, the island – the largest body of ice in the northern hemisphere, and home to 8% of the world’s fresh water in frozen form – will have lost 4.5% of its ice cover, and sea levels will have risen by up to 33cm.

And if melting continues, and the world goes on burning fossil fuels under climate science’s notorious “business as usual scenario”, then within another thousand years the entire cover will have run into the sea, which by then will have risen – just because of melting in Greenland – by more than seven metres, to wash away cities such as Miami, Los Angeles, Copenhagen, Shanghai and New Orleans.

“How Greenland will look in the future – in a couple of hundred years or in 1,000 years – whether there will be Greenland, or at least a Greenland similar to today, it’s up to us”, said Andy Aschwanden, of the University of Fairbanks, Alaska geophysical institute.

He and colleagues from the US and Denmark report in the journal Science Advances that they used new radar data that gave a picture of the thickness of the ice and the bedrock beneath it to estimate the total mass of ice.

“We project that Greenland will very likely become ice-free within a millennium without substantial reduction in greenhouse gas emissions”

They then selected three possible climate outcomes, depending on national and political responses to the climate emergency, considered the rates at which glaciers had begun to flow, the levels of summer and even winter ice melt, and the warming of the oceans, and ran 500 computer simulations to form a picture of the future.

Researchers have been warning for years that the rate of ice loss in Greenland is accelerating. Ice is being lost from the ice sheet surface, in some places at such speed that the bedrock beneath, once crushed by the weight of ice, is beginning to rise.

The great frozen rivers that carry ice to the sea to form summer icebergs are themselves gathering pace: one of these in 2014 was recorded as having quadrupled in speed, to move at almost 50 metres a day.

Research in polar regions is always difficult, and conclusions are necessarily tentative. On-the-ground studies are limited in summer and all but impossible in winter. The dynamic of ice loss changes, depending on conditions both in the atmosphere and the surrounding ocean.

Greenhouse gas increase

But the Fairbanks study is consistent with a huge body of other research. And the same computer simulations confirm that what happens depends ultimately on whether the world continues to heat up as a consequence of the profligate consumption of fossil fuels that increase the ratio of greenhouse gases in the atmosphere.

If carbon dioxide emissions are sharply reduced, the scientists say, the picture changes. Instead, the island could lose only up to a quarter of its ice cover by the end of this millennium, with a corresponding sea level rise of up to 1.88 metres.

Another, less hopeful scenario foresees a loss of up to 57% and sea level rise of up to 4.17 metres. In the worst case, the range of possible ice loss is from 72% to the lot, with the oceans higher by up to 7.28 metres, all of it from the existing ice mass of Greenland.

“We project that Greenland will very likely become ice-free within a millennium without substantial reduction in greenhouse gas emissions”, the researchers conclude. − Climate News Network

Look far enough ahead and in a millennium an ice-free Greenland is a possibility, scientists say. Sea levels too will be a lot higher by then.

LONDON, 25 June, 2019 − US scientists have just established that the long-term future may bring an ice-free Greenland, if melting continues at the current rate. By the year 3,000 it could simply be green, with rocky outcrops. Greenland’s icy mountains will have vanished.

By the end of this century, the island – the largest body of ice in the northern hemisphere, and home to 8% of the world’s fresh water in frozen form – will have lost 4.5% of its ice cover, and sea levels will have risen by up to 33cm.

And if melting continues, and the world goes on burning fossil fuels under climate science’s notorious “business as usual scenario”, then within another thousand years the entire cover will have run into the sea, which by then will have risen – just because of melting in Greenland – by more than seven metres, to wash away cities such as Miami, Los Angeles, Copenhagen, Shanghai and New Orleans.

“How Greenland will look in the future – in a couple of hundred years or in 1,000 years – whether there will be Greenland, or at least a Greenland similar to today, it’s up to us”, said Andy Aschwanden, of the University of Fairbanks, Alaska geophysical institute.

He and colleagues from the US and Denmark report in the journal Science Advances that they used new radar data that gave a picture of the thickness of the ice and the bedrock beneath it to estimate the total mass of ice.

“We project that Greenland will very likely become ice-free within a millennium without substantial reduction in greenhouse gas emissions”

They then selected three possible climate outcomes, depending on national and political responses to the climate emergency, considered the rates at which glaciers had begun to flow, the levels of summer and even winter ice melt, and the warming of the oceans, and ran 500 computer simulations to form a picture of the future.

Researchers have been warning for years that the rate of ice loss in Greenland is accelerating. Ice is being lost from the ice sheet surface, in some places at such speed that the bedrock beneath, once crushed by the weight of ice, is beginning to rise.

The great frozen rivers that carry ice to the sea to form summer icebergs are themselves gathering pace: one of these in 2014 was recorded as having quadrupled in speed, to move at almost 50 metres a day.

Research in polar regions is always difficult, and conclusions are necessarily tentative. On-the-ground studies are limited in summer and all but impossible in winter. The dynamic of ice loss changes, depending on conditions both in the atmosphere and the surrounding ocean.

Greenhouse gas increase

But the Fairbanks study is consistent with a huge body of other research. And the same computer simulations confirm that what happens depends ultimately on whether the world continues to heat up as a consequence of the profligate consumption of fossil fuels that increase the ratio of greenhouse gases in the atmosphere.

If carbon dioxide emissions are sharply reduced, the scientists say, the picture changes. Instead, the island could lose only up to a quarter of its ice cover by the end of this millennium, with a corresponding sea level rise of up to 1.88 metres.

Another, less hopeful scenario foresees a loss of up to 57% and sea level rise of up to 4.17 metres. In the worst case, the range of possible ice loss is from 72% to the lot, with the oceans higher by up to 7.28 metres, all of it from the existing ice mass of Greenland.

“We project that Greenland will very likely become ice-free within a millennium without substantial reduction in greenhouse gas emissions”, the researchers conclude. − Climate News Network