Tag Archives: Arctic

Ice-free Arctic Ocean allowed ancient carbon leaks

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

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

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

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

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

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

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

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

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

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

Permafrost in jeopardy

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Permafrost in jeopardy

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

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

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

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

Russia moves to exploit Arctic riches

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

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

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

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

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

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

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

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

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

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

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

Tax-free incentive

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

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

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

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

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

American anxiety

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Tax-free incentive

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

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

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

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

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

American anxiety

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

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

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

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

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

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

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

Arctic’s oldest ice shows signs of change

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

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

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

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

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

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

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

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

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

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

No monolith

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

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

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

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

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

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

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

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

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

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

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

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

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

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

No monolith

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

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

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

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

Global climate treaty is not working

Three out of four nations have yet to start to honour the global climate treaty. The world waits, the seas go on rising – and greenhouse gases too.

LONDON, 13 November, 2019 – Three nations in every four that vowed in the global climate treaty, the Paris Agreement, to contain global heating to “well below” 2°C by the century’s end have failed to deliver pledges that will reduce emissions by even 40% by 2030.

In Paris in 2015, a total of 195 nations agreed that action was vital. Since then only 36 countries have taken steps to meet the targets they agreed, according to a new study by the Universal Ecological Fund. And one nation has announced that it will withdraw altogether from the agreement.

“The comprehensive examination found that with few exceptions, the pledges of the rich, middle income and poor countries are insufficient to address climate change,” said Sir Robert Watson, once chair of the Intergovernmental Panel on Climate Change, which was present at the Paris meeting, and co-author of the study. “Simply, the pledges are far too little, too late.

“Even if all climate pledges, which are voluntary, are fully implemented, they will cover less than half of what is needed to limit the acceleration of climate change in the next decade.”

“The more carbon we release now the more sea level rise we are locking in for the future”

What happens now will affect the planetary climate and its ocean systems for much longer than that for at least the next two centuries. Researchers report in the Proceedings of the National Academy of Sciences that they looked at the impact to come even if all nations were to honour all the pledges made in Paris.

They agree that the global emissions of greenhouse gases since Paris and by 2030 would alone be enough to raise global sea levels by 20 cms: half of that from China, the US, the EU, India and Russia, the top five emitters. But they add a much more ominous long-term warning

“Our results show that what we do today will have a huge effect in 2300. 20 cms is very significant; it is basically as much sea-level rise as we’ve observed over the entire 20th century. To cause that with only 15 years of emissions is quite staggering”, said Alexander Nauels, of Climate Analytics, who led the study.

“The true consequences of our emissions on sea level rise unfold over centuries, due to the slow pace at which the ocean, polar ice sheets and glaciers respond to global warming. The more carbon we release now the more sea level rise we are locking in for the future.”

And as if to add force to the need for drastic action, a new US and German study has warned that even if nations honour their pledges by 2030, sea levels around the world will go on rising, and stay at higher levels for thousands of years.

Leaking permafrost

As the polar ice retreats, and rising tides batter the shores of the Arctic Ocean, vast volumes of carbon dioxide so far imprisoned  in the permafrost of the polar coasts – 34% of all the world’s coastlines  – could escape to accelerate further warming and of course yet greater sea level rise.

Climate scientists have been wrestling for decades with what they call the carbon budget – the accounting of all the ways in which carbon dioxide gets into the atmosphere and out of it again – and missed another potentially dangerous source of the greenhouse gas.

As glaciers retreat and the frozen coasts and soils thaw, this could begin to seep into the atmosphere. Laboratory experiments suggest it will seep even faster as sea levels rise and waves grow more powerful. For every gram, dry weight, of eroded permafrost, more than 4 grams of carbon dioxide would escape into the atmosphere.

“Carbon budgets and climate simulations have so far missed coastal erosion in their equations even though it might be a substantial source of carbon dioxide,” says George Tanski of Vrije Universiteit Amsterdam, the lead author.

“Our research found that the erosion of permafrost coastlines can lead to the rapid release of significant quantities of CO2, which can be expected to increase as coastal erosion accelerates, temperatures increase, sea ice diminishes and stronger storms batter Arctic coasts.”

Early warning

That the Paris Agreement was backed up by pledges that might fail to contain global warning to an ideal target of 1.5°C was clear from the start, and scientists who looked at the promises made at the time warned that unless they were increased, they committed the world to a warming of at least 3°C above the long term average for most of human history.

The latest study from the Universal Ecological Fund now finds that not only are the pledges not enough; some are not being honoured. China and India pledged to reduce the intensity of their emissions relative to gross domestic product, but since their economies continue to grow, so will their emissions.

China already contributes more than 26% of all global emissions, India 7%. The US, which contributes 13% of all greenhouse emissions, is to quit the Paris Agreement in 2020, and has in any case reversed much of its climate legislation. Russia, which contributes 4.6% of all atmospheric carbon dioxide, has submitted no pledges.

Europe’s 28 nations, and seven others, have promised to reduce emissions by 40% by 2040. Of the remaining 152 nations, responsible for more than 36% of all emissions, 127 have submitted conditional plans, but rely upon technical assistance and funding from the wealthy nations to execute these. But the US and Australia have stopped making contributions to such funding.

Almost 70% of emissions are from fossil fuels: successful action would require the closure of 2,400 coal-fired power stations. In fact, 250 new coal-fired power stations are now under construction. The message is that governments are doing too little, too slowly, leaving horrendous future consequences. – Climate News Network

Three out of four nations have yet to start to honour the global climate treaty. The world waits, the seas go on rising – and greenhouse gases too.

LONDON, 13 November, 2019 – Three nations in every four that vowed in the global climate treaty, the Paris Agreement, to contain global heating to “well below” 2°C by the century’s end have failed to deliver pledges that will reduce emissions by even 40% by 2030.

In Paris in 2015, a total of 195 nations agreed that action was vital. Since then only 36 countries have taken steps to meet the targets they agreed, according to a new study by the Universal Ecological Fund. And one nation has announced that it will withdraw altogether from the agreement.

“The comprehensive examination found that with few exceptions, the pledges of the rich, middle income and poor countries are insufficient to address climate change,” said Sir Robert Watson, once chair of the Intergovernmental Panel on Climate Change, which was present at the Paris meeting, and co-author of the study. “Simply, the pledges are far too little, too late.

“Even if all climate pledges, which are voluntary, are fully implemented, they will cover less than half of what is needed to limit the acceleration of climate change in the next decade.”

“The more carbon we release now the more sea level rise we are locking in for the future”

What happens now will affect the planetary climate and its ocean systems for much longer than that for at least the next two centuries. Researchers report in the Proceedings of the National Academy of Sciences that they looked at the impact to come even if all nations were to honour all the pledges made in Paris.

They agree that the global emissions of greenhouse gases since Paris and by 2030 would alone be enough to raise global sea levels by 20 cms: half of that from China, the US, the EU, India and Russia, the top five emitters. But they add a much more ominous long-term warning

“Our results show that what we do today will have a huge effect in 2300. 20 cms is very significant; it is basically as much sea-level rise as we’ve observed over the entire 20th century. To cause that with only 15 years of emissions is quite staggering”, said Alexander Nauels, of Climate Analytics, who led the study.

“The true consequences of our emissions on sea level rise unfold over centuries, due to the slow pace at which the ocean, polar ice sheets and glaciers respond to global warming. The more carbon we release now the more sea level rise we are locking in for the future.”

And as if to add force to the need for drastic action, a new US and German study has warned that even if nations honour their pledges by 2030, sea levels around the world will go on rising, and stay at higher levels for thousands of years.

Leaking permafrost

As the polar ice retreats, and rising tides batter the shores of the Arctic Ocean, vast volumes of carbon dioxide so far imprisoned  in the permafrost of the polar coasts – 34% of all the world’s coastlines  – could escape to accelerate further warming and of course yet greater sea level rise.

Climate scientists have been wrestling for decades with what they call the carbon budget – the accounting of all the ways in which carbon dioxide gets into the atmosphere and out of it again – and missed another potentially dangerous source of the greenhouse gas.

As glaciers retreat and the frozen coasts and soils thaw, this could begin to seep into the atmosphere. Laboratory experiments suggest it will seep even faster as sea levels rise and waves grow more powerful. For every gram, dry weight, of eroded permafrost, more than 4 grams of carbon dioxide would escape into the atmosphere.

“Carbon budgets and climate simulations have so far missed coastal erosion in their equations even though it might be a substantial source of carbon dioxide,” says George Tanski of Vrije Universiteit Amsterdam, the lead author.

“Our research found that the erosion of permafrost coastlines can lead to the rapid release of significant quantities of CO2, which can be expected to increase as coastal erosion accelerates, temperatures increase, sea ice diminishes and stronger storms batter Arctic coasts.”

Early warning

That the Paris Agreement was backed up by pledges that might fail to contain global warning to an ideal target of 1.5°C was clear from the start, and scientists who looked at the promises made at the time warned that unless they were increased, they committed the world to a warming of at least 3°C above the long term average for most of human history.

The latest study from the Universal Ecological Fund now finds that not only are the pledges not enough; some are not being honoured. China and India pledged to reduce the intensity of their emissions relative to gross domestic product, but since their economies continue to grow, so will their emissions.

China already contributes more than 26% of all global emissions, India 7%. The US, which contributes 13% of all greenhouse emissions, is to quit the Paris Agreement in 2020, and has in any case reversed much of its climate legislation. Russia, which contributes 4.6% of all atmospheric carbon dioxide, has submitted no pledges.

Europe’s 28 nations, and seven others, have promised to reduce emissions by 40% by 2040. Of the remaining 152 nations, responsible for more than 36% of all emissions, 127 have submitted conditional plans, but rely upon technical assistance and funding from the wealthy nations to execute these. But the US and Australia have stopped making contributions to such funding.

Almost 70% of emissions are from fossil fuels: successful action would require the closure of 2,400 coal-fired power stations. In fact, 250 new coal-fired power stations are now under construction. The message is that governments are doing too little, too slowly, leaving horrendous future consequences. – Climate News Network