Tag Archives: Arctic

Arctic’s coldest sea ice is vulnerable to melting

Every year an ice floe as big as Austria simply vanishes. That’s climate change, as the Arctic’s coldest sea ice risks melting.

LONDON, 6 July, 2021 − The frozen world is dwindling fast. New research suggests that the cryosphere − the area of the planet covered by snow and ice − is dwindling by around 87,000 square kilometres every year. This is an area bigger than Austria, almost as big as Hungary, or Jordan. Even the Arctic’s coldest sea ice is threatened.

A second, separate study warns that what glacier scientists call the Last Ice Refuge − the tract of Arctic Ocean that will stay frozen when the rest of it becomes open water during some summers in the next decades − is itself at risk: the coldest and most secure reaches of sea ice just north of Greenland and Canada could be vulnerable to summer melt.

That the polar regions and the high-altitude frozen rivers and lakes are at risk is not news: climate scientists have been warning for decades of accelerating melt in Antarctica, ever-higher losses of ice mass from Greenland, and a loss of northern polar sea ice so comprehensive that by 2050, much of the Arctic Ocean could be clear blue water most summers.

The cryosphere matters: it is a reservoir of two-thirds of the planet’s fresh water. Its gleaming white surface acts as planetary insulation: most of the sunlight that falls upon it is reflected back into space. As the ice thins and retreats, the exposed darker ocean below it warms up, to accelerate global heating and trigger yet more ice loss.

“In years when you replenish the ice cover in this region with older, thicker ice, that doesn’t seem to help as much as you might expect”

Scientists from Lanzhou University in China report in the journal Earth’s Future that they tried to look at the picture of change on a planetary scale. The cryosphere has always expanded and shrunk with the seasons in both hemispheres. Scientists calculated the daily extent of all the world’s snow and ice cover and then averaged it to get yearly estimates.

The Arctic is perhaps the fastest-warming zone on the planet and the northern hemisphere cover has been losing 102,000 sq kms a year, every year. This is an area bigger than Iceland, or Eritrea. The southern hemisphere ice however has been expanding by about 14,000 sq kms a year − think of the Bahamas − to offset a little of the loss.

The researchers also found that much of the cryosphere was now frozen for shorter periods: the day of first freezing now happens about 3.6 days later than it did in 1979, and the ice thaws 5.7 days earlier than it did 40 years ago.

But until now, one stretch of Arctic sea ice had shown no particular signs of change. When glaciologists repeatedly warned that the Arctic could be ice-free in summer by mid-century, they meant that the region would be down to its last million sq km of ice floe. This would be the last stronghold of the frozen world: the last place where seals, walruses and polar bears could find the surfaces they needed for survival.

Essential Refuge

But researchers aboard the German icebreaker Polarstern observed that the ice cover of the Wandel Sea off Greenland and Canada in the summer of 2020 was at a record low. This was a surprise, because at the beginning of the season it had been as dense as ever.

Permanent ice is a matter of life and death to the Arctic’s apex mammal predators: seals haul out onto the ice, to become potential prey for polar bears. Walruses use the ice as a platform for foraging. As the summer sea ice thins and shrinks a little more every year over the rest of the Arctic, the Last Ice Refuge becomes ever more important for their survival as species. The big question is: were the weather conditions unusual, or was this a sign of global heating?

“During the winter and spring of 2020 you had patches of older, thicker ice that had drifted into there, but there was enough thinner, newer ice that melted to expose open ocean,” said Axel Schweiger of the University of Washington in the US, who led the research.

“That began a cycle of absorbing heat energy to melt more ice, in spite of the fact that there was some thick ice. So in years when you replenish the ice cover in this region with older, thicker ice, that doesn’t seem to help as much as you might expect.” − Climate News Network

Every year an ice floe as big as Austria simply vanishes. That’s climate change, as the Arctic’s coldest sea ice risks melting.

LONDON, 6 July, 2021 − The frozen world is dwindling fast. New research suggests that the cryosphere − the area of the planet covered by snow and ice − is dwindling by around 87,000 square kilometres every year. This is an area bigger than Austria, almost as big as Hungary, or Jordan. Even the Arctic’s coldest sea ice is threatened.

A second, separate study warns that what glacier scientists call the Last Ice Refuge − the tract of Arctic Ocean that will stay frozen when the rest of it becomes open water during some summers in the next decades − is itself at risk: the coldest and most secure reaches of sea ice just north of Greenland and Canada could be vulnerable to summer melt.

That the polar regions and the high-altitude frozen rivers and lakes are at risk is not news: climate scientists have been warning for decades of accelerating melt in Antarctica, ever-higher losses of ice mass from Greenland, and a loss of northern polar sea ice so comprehensive that by 2050, much of the Arctic Ocean could be clear blue water most summers.

The cryosphere matters: it is a reservoir of two-thirds of the planet’s fresh water. Its gleaming white surface acts as planetary insulation: most of the sunlight that falls upon it is reflected back into space. As the ice thins and retreats, the exposed darker ocean below it warms up, to accelerate global heating and trigger yet more ice loss.

“In years when you replenish the ice cover in this region with older, thicker ice, that doesn’t seem to help as much as you might expect”

Scientists from Lanzhou University in China report in the journal Earth’s Future that they tried to look at the picture of change on a planetary scale. The cryosphere has always expanded and shrunk with the seasons in both hemispheres. Scientists calculated the daily extent of all the world’s snow and ice cover and then averaged it to get yearly estimates.

The Arctic is perhaps the fastest-warming zone on the planet and the northern hemisphere cover has been losing 102,000 sq kms a year, every year. This is an area bigger than Iceland, or Eritrea. The southern hemisphere ice however has been expanding by about 14,000 sq kms a year − think of the Bahamas − to offset a little of the loss.

The researchers also found that much of the cryosphere was now frozen for shorter periods: the day of first freezing now happens about 3.6 days later than it did in 1979, and the ice thaws 5.7 days earlier than it did 40 years ago.

But until now, one stretch of Arctic sea ice had shown no particular signs of change. When glaciologists repeatedly warned that the Arctic could be ice-free in summer by mid-century, they meant that the region would be down to its last million sq km of ice floe. This would be the last stronghold of the frozen world: the last place where seals, walruses and polar bears could find the surfaces they needed for survival.

Essential Refuge

But researchers aboard the German icebreaker Polarstern observed that the ice cover of the Wandel Sea off Greenland and Canada in the summer of 2020 was at a record low. This was a surprise, because at the beginning of the season it had been as dense as ever.

Permanent ice is a matter of life and death to the Arctic’s apex mammal predators: seals haul out onto the ice, to become potential prey for polar bears. Walruses use the ice as a platform for foraging. As the summer sea ice thins and shrinks a little more every year over the rest of the Arctic, the Last Ice Refuge becomes ever more important for their survival as species. The big question is: were the weather conditions unusual, or was this a sign of global heating?

“During the winter and spring of 2020 you had patches of older, thicker ice that had drifted into there, but there was enough thinner, newer ice that melted to expose open ocean,” said Axel Schweiger of the University of Washington in the US, who led the research.

“That began a cycle of absorbing heat energy to melt more ice, in spite of the fact that there was some thick ice. So in years when you replenish the ice cover in this region with older, thicker ice, that doesn’t seem to help as much as you might expect.” − Climate News Network

Let nature restore itself on its own for best results

Don’t meddle: let nature restore itself on its own. Old forest will spread over nearby farmland. It’s cheap, and often best.

LONDON, 22 June, 2021 − British scientists have just confirmed something that might have seemed obvious: to regenerate the natural world, the best way is often to let nature restore itself on its own.

That is: left to its own devices, and with help only from wild birds and mammals, bare agricultural land turned into dense native woodland in little more than half a human lifetime.

Nobody needed to plant trees and shield them with plastic tubing; nobody had to patrol the protected zone or fence it against rabbits and deer, or attempt to choose the ideal species for the terrain. It all happened anyway, with the help of the wind, the wild things and a species of crow called a jay.

The research offers lessons for governments that have committed to restoring natural forest as part of the arsenal against global heating and climate change: it need not cost much.

Fast work

“Biodiversity-rich woodland that is resilient to drought and reduces disease risk can be created without any input from us,” said Richard Broughton, of the UK’s Centre for Ecology and Hydrology.

“Our study provides essential evidence that passive rewilding has the potential to expand native woodland habitat at no cost and within relatively short timescales.”

He and his colleagues tell the story in the Public Library of Science journal PLOS One. They simply monitored the progress of two farmland fields over two periods of 24 and 59 years respectively: one had been abandoned in 1996, the other in 1961. Significantly, both fields − of 2.1 hectares and 3.9 hectares, and labelled New Wilderness and Old Wilderness − were close by a patch of ancient woodland.

This was the Monks Wood national nature reserve in Cambridgeshire, a tract of wildwood in eastern England that has been studied in fine detail for many decades and documented since 1279 AD.

“Passive rewilding has the potential to expand native woodland habitat at no cost and within relatively short timescales”

Of the two abandoned neighbouring fields, one had been grazing land, the other laid down to barley. Brambles and thornbushes colonised the neglected fields, to provide cover for seeds, nuts and acorns spread by wild mammals and birds.

After 23 years, 86% of the grassland had turned into shrub and sapling that had reached an average height of 2.9 metres, with a density of 132 trees per hectare: 57% of these were the oak Quercus robur. The Old Wilderness, after 53 years, had 100% cover averaging 13.1 metres in height, with a density of 390 trees per hectare, 52% of them oak.

Climate scientists have been urging the protection and restoration of natural ecosystems for four decades. Conservation scientists, alarmed at the potential rapid rise in rates of species extinction along with the damage to natural habitats, have been urging the same thing for even longer.

Both have made a case for restoring the wilderness: the debate has been about the best ways to make this happen. More trees should mean more carbon absorbed from the atmosphere. But more climate change might make such restoration, through for instance deliberate plantation, increasingly problematic.

Reheating the Arctic

So the next question is: could Nature restore itself? Rewilding is still at the experimental stage: a process backed by in some cases deliberate re-introductions, for instance of beavers and other wild species in Europe. There is even an argument that in the fastest-warming zone of the planet, the Arctic, the reintroduction of large herbivores could help slow climate change and contain global heating driven by ever-higher ratios of atmospheric greenhouse gases.

The clear message of the latest study is that − at least if natural forest rich in wild birds and mammals is close by − then nature can be left to do what nature does best. There were no costs of planting, there was no risk of disease introduction from nursery-grown saplings, and no need for plastic tubes to protect the tender young tree trunks from predators.

Blackthorn and hawthorn helped screen the young trees from hares, rabbits and deer. Seeds were dispersed by helpful wild agents, among them squirrels and wood mice and a bird commonly regarded as a pest, the jay, Garrulus glandarius.

“The huge benefits that jays provide in natural colonisation by dispersing tree seeds, especially acorns, help create more woodland habitat for all wildlife and far outweigh any impact of predation,” Dr Broughton said. − Climate News Network

Don’t meddle: let nature restore itself on its own. Old forest will spread over nearby farmland. It’s cheap, and often best.

LONDON, 22 June, 2021 − British scientists have just confirmed something that might have seemed obvious: to regenerate the natural world, the best way is often to let nature restore itself on its own.

That is: left to its own devices, and with help only from wild birds and mammals, bare agricultural land turned into dense native woodland in little more than half a human lifetime.

Nobody needed to plant trees and shield them with plastic tubing; nobody had to patrol the protected zone or fence it against rabbits and deer, or attempt to choose the ideal species for the terrain. It all happened anyway, with the help of the wind, the wild things and a species of crow called a jay.

The research offers lessons for governments that have committed to restoring natural forest as part of the arsenal against global heating and climate change: it need not cost much.

Fast work

“Biodiversity-rich woodland that is resilient to drought and reduces disease risk can be created without any input from us,” said Richard Broughton, of the UK’s Centre for Ecology and Hydrology.

“Our study provides essential evidence that passive rewilding has the potential to expand native woodland habitat at no cost and within relatively short timescales.”

He and his colleagues tell the story in the Public Library of Science journal PLOS One. They simply monitored the progress of two farmland fields over two periods of 24 and 59 years respectively: one had been abandoned in 1996, the other in 1961. Significantly, both fields − of 2.1 hectares and 3.9 hectares, and labelled New Wilderness and Old Wilderness − were close by a patch of ancient woodland.

This was the Monks Wood national nature reserve in Cambridgeshire, a tract of wildwood in eastern England that has been studied in fine detail for many decades and documented since 1279 AD.

“Passive rewilding has the potential to expand native woodland habitat at no cost and within relatively short timescales”

Of the two abandoned neighbouring fields, one had been grazing land, the other laid down to barley. Brambles and thornbushes colonised the neglected fields, to provide cover for seeds, nuts and acorns spread by wild mammals and birds.

After 23 years, 86% of the grassland had turned into shrub and sapling that had reached an average height of 2.9 metres, with a density of 132 trees per hectare: 57% of these were the oak Quercus robur. The Old Wilderness, after 53 years, had 100% cover averaging 13.1 metres in height, with a density of 390 trees per hectare, 52% of them oak.

Climate scientists have been urging the protection and restoration of natural ecosystems for four decades. Conservation scientists, alarmed at the potential rapid rise in rates of species extinction along with the damage to natural habitats, have been urging the same thing for even longer.

Both have made a case for restoring the wilderness: the debate has been about the best ways to make this happen. More trees should mean more carbon absorbed from the atmosphere. But more climate change might make such restoration, through for instance deliberate plantation, increasingly problematic.

Reheating the Arctic

So the next question is: could Nature restore itself? Rewilding is still at the experimental stage: a process backed by in some cases deliberate re-introductions, for instance of beavers and other wild species in Europe. There is even an argument that in the fastest-warming zone of the planet, the Arctic, the reintroduction of large herbivores could help slow climate change and contain global heating driven by ever-higher ratios of atmospheric greenhouse gases.

The clear message of the latest study is that − at least if natural forest rich in wild birds and mammals is close by − then nature can be left to do what nature does best. There were no costs of planting, there was no risk of disease introduction from nursery-grown saplings, and no need for plastic tubes to protect the tender young tree trunks from predators.

Blackthorn and hawthorn helped screen the young trees from hares, rabbits and deer. Seeds were dispersed by helpful wild agents, among them squirrels and wood mice and a bird commonly regarded as a pest, the jay, Garrulus glandarius.

“The huge benefits that jays provide in natural colonisation by dispersing tree seeds, especially acorns, help create more woodland habitat for all wildlife and far outweigh any impact of predation,” Dr Broughton said. − Climate News Network

Polar concerns rise as ice now melts ever faster

An Antarctic glacier gathers pace. In the north, the Arctic ice thins faster. Racing climate heat is feeding polar concerns.

LONDON, 15 June, 2021 − An Antarctic glacier has begun to move more quickly towards the open ocean, as the shelf of sea ice that once held it back starts to collapse. The water in that one glacier is enough to raise global sea levels by half a metre. And that’s not all that’s raising polar concerns across the scientific world.

At the other end of the Earth global heating is accelerating the loss of Arctic ice. A new study reports that the thinning of sea ice in three separate coastal regions could now be happening twice as fast.

Both findings are linked to the inexorable rise in global average temperatures as the profligate use of fossil fuels heightens the ratio of greenhouse gases in the planet’s atmosphere.

Antarctic scientists have been worrying about warming in Antarctica for years. And they have been anxiously watching the Pine Island glacier in West Antarctica for decades.

Glaciers move at the proverbial glacial pace towards the sea, to be held in check, in the polar oceans, by vast shelves of sea ice. Between 2017 and 2020 the ice shelves have undergone a series of collapses and lost one fifth of their area, possibly because the glacier has been accelerating.

“The thickness of the sea ice is a sensitive indicator of the health of the Arctic”

“We may not have the luxury of waiting for slow changes on Pine Island; things could actually go much quicker than expected,” said Ian Joughin, of the University of Washington in the US.

“The processes we’d been studying in this region were leading to an irreversible collapse, but at a fairly measured pace. Things could be much more abrupt if we lose the rest of that ice shelf.”

He and his colleagues report in the journal Science Advances that the Pine Island glacier has already become Antarctica’s biggest contributor to sea level rise. The pace of flow remained fairly steady from 2009 to 2017, but they found that data from Europe’s Copernicus Sentinel satellite system showed an acceleration of 12% in the past three years.

The Pine Island glacier contains roughly 180 trillion tonnes of ice, enough to raise global sea levels by 0.5 metres. Researchers had calculated that it might take a century or more for slowly-warming polar waters to thin the ice shelves to the point where they could no longer stem the glacier flow. But it now seems that the big player in the shelf ice collapse is the glacier itself, as the flow rate increases.

“The loss of Pine Island’s ice shelf now looks possibly like it could occur in the next decade or two, as opposed to the melt-driven sub-surface change playing out over more than 100 or more years,” said Pierre Dutrieux of the British Antarctic Survey, a co-author. “So it’s a potentially much more rapid and abrupt change.”

Snow fall dwindles

Abrupt change, too, may be on the way in the Arctic Ocean. British researchers used a new computer simulation to explore measurements from Europe’s CryoSat-2 satellite. The scientists report in the journal The Cryosphere that the thinning of ice in the Laptev and Kara Seas north of Siberia, and the Chukchi Sea between Siberia and Alaska, has stepped up by 70%, 98% and 110% respectively.

Sea ice diminishes each summer and forms again each winter; each successive summer reveals an ever-greater loss, as the ice itself thins and the area covered by ice dwindles.

Calculations of ice thickness have always allowed for the falls of fresh winter snow. But since the formation of sea ice has been later every year, there has been less time for the snow to accumulate. Such things make a difference.

“The thickness of the sea ice is a sensitive indicator of the health of the Arctic,” said Robbie Mallett, of University College London.

“It is important as thicker ice acts as an insulating blanket, stopping the ocean from warming up the atmosphere in winter, and protecting the ocean from sunshine in summer. Thinner ice is also less likely to survive the summer melt.” − Climate News Network

An Antarctic glacier gathers pace. In the north, the Arctic ice thins faster. Racing climate heat is feeding polar concerns.

LONDON, 15 June, 2021 − An Antarctic glacier has begun to move more quickly towards the open ocean, as the shelf of sea ice that once held it back starts to collapse. The water in that one glacier is enough to raise global sea levels by half a metre. And that’s not all that’s raising polar concerns across the scientific world.

At the other end of the Earth global heating is accelerating the loss of Arctic ice. A new study reports that the thinning of sea ice in three separate coastal regions could now be happening twice as fast.

Both findings are linked to the inexorable rise in global average temperatures as the profligate use of fossil fuels heightens the ratio of greenhouse gases in the planet’s atmosphere.

Antarctic scientists have been worrying about warming in Antarctica for years. And they have been anxiously watching the Pine Island glacier in West Antarctica for decades.

Glaciers move at the proverbial glacial pace towards the sea, to be held in check, in the polar oceans, by vast shelves of sea ice. Between 2017 and 2020 the ice shelves have undergone a series of collapses and lost one fifth of their area, possibly because the glacier has been accelerating.

“The thickness of the sea ice is a sensitive indicator of the health of the Arctic”

“We may not have the luxury of waiting for slow changes on Pine Island; things could actually go much quicker than expected,” said Ian Joughin, of the University of Washington in the US.

“The processes we’d been studying in this region were leading to an irreversible collapse, but at a fairly measured pace. Things could be much more abrupt if we lose the rest of that ice shelf.”

He and his colleagues report in the journal Science Advances that the Pine Island glacier has already become Antarctica’s biggest contributor to sea level rise. The pace of flow remained fairly steady from 2009 to 2017, but they found that data from Europe’s Copernicus Sentinel satellite system showed an acceleration of 12% in the past three years.

The Pine Island glacier contains roughly 180 trillion tonnes of ice, enough to raise global sea levels by 0.5 metres. Researchers had calculated that it might take a century or more for slowly-warming polar waters to thin the ice shelves to the point where they could no longer stem the glacier flow. But it now seems that the big player in the shelf ice collapse is the glacier itself, as the flow rate increases.

“The loss of Pine Island’s ice shelf now looks possibly like it could occur in the next decade or two, as opposed to the melt-driven sub-surface change playing out over more than 100 or more years,” said Pierre Dutrieux of the British Antarctic Survey, a co-author. “So it’s a potentially much more rapid and abrupt change.”

Snow fall dwindles

Abrupt change, too, may be on the way in the Arctic Ocean. British researchers used a new computer simulation to explore measurements from Europe’s CryoSat-2 satellite. The scientists report in the journal The Cryosphere that the thinning of ice in the Laptev and Kara Seas north of Siberia, and the Chukchi Sea between Siberia and Alaska, has stepped up by 70%, 98% and 110% respectively.

Sea ice diminishes each summer and forms again each winter; each successive summer reveals an ever-greater loss, as the ice itself thins and the area covered by ice dwindles.

Calculations of ice thickness have always allowed for the falls of fresh winter snow. But since the formation of sea ice has been later every year, there has been less time for the snow to accumulate. Such things make a difference.

“The thickness of the sea ice is a sensitive indicator of the health of the Arctic,” said Robbie Mallett, of University College London.

“It is important as thicker ice acts as an insulating blanket, stopping the ocean from warming up the atmosphere in winter, and protecting the ocean from sunshine in summer. Thinner ice is also less likely to survive the summer melt.” − Climate News Network

Pathway to global climate catastrophe is clear

Global climate catastrophe could be nearer than we think. New research suggests how it could happen.

LONDON, 8 June, 2021 − Here is a set of circumstances that could trigger global climate catastrophe. The Greenland ice sheet could begin a process of irreversible melting.

As it does, greater quantities of fresh water would flood into the Arctic Ocean, to further slow the already slowing Atlantic meridional overturning circulation, that great flow of water sometimes called the Gulf Stream that  distributes warmth from the tropics.

But as the Atlantic flow weakens, so rises the probability of increased and sustained drought and dieback in the Amazon rainforest: the entire region could begin to tip inexorably into savannah.

And the Southern Ocean would begin to warm: it could warm enough to hasten the disintegration of the West Antarctic ice sheet, to accelerate the rise of global sea levels and intensify the whole machinery of global heating.

Alarmingly, this process could begin to happen while global temperatures are still not much higher than they are now: 1.5°C has been repeatedly described as the limit beyond which global average temperatures should not rise, but the official global agreed target is a limit of 2°C.

In fact, the chance of a cascade of domino effects − of tipping points that trigger other climate tipping points − could begin somewhere between those two figures, and the probability rises thereafter.

No way back

And, researchers warn, when they say irreversible, they mean it. Once the Greenland ice sheet starts to slide into the sea, there will be no stopping it. The only question is how swiftly all these things could happen.

“Once triggered, the actual tipping process might take several years up to millennia, depending on the respective response times of the system,” the scientists write in the journal Earth System Dynamics.

It’s a scenario, not a prediction. It’s a calculation of possibilities and probabilities inherent in the process of global warming and climate change. It’s an identification of the way atmospheric warming driven by greenhouse gas emissions from human economies can and might change the climate system that drives planetary weather.

“We provide risk analysis, not a prediction, yet our findings still raise concern,” said Ricarda Winkelmann, of the Potsdam Institute for Climate Impact Research, one of the authors.

She and her colleagues base their study on computer simulations of planetary response to temperature rise. And one third of those simulations suggest that if the world reaches 2°C, then one of those elements could begin to tip towards irreversible change, and at the same time trigger other tipping points.

“We’re shifting the odds, and not to our favour − the risk is clearly increasing the more we heat our planet,” said her colleague and co-author Jonathan Donges. “It rises substantially between 1°C and 3°C.

“Rapidly reducing greenhouse gas emissions is indispensable to limit the risks of crossing tipping points in the climate system”

“If greenhouse gas emissions and the resulting climate change cannot be halted, the upper level of this warming range could most likely be crossed by the end of this century. With even higher temperatures, more tipping cascades are to be expected, with long-term devastating effects.”

Climate science has been concerned with the idea of tipping points − temperatures beyond which climate change might be irreversible − for decades. There have been repeated findings that some of these might be nearer than anybody had suspected.

Greenland is in effect the reservoir of most of the Northern hemisphere’s ice − enough to raise sea levels by seven metres − and it is melting at an ever-accelerating rate.

Researchers have again and again identified a possible faltering of the Atlantic current, to warn of a paradoxical consequence: if the Gulf Stream slows, then average temperatures in western Europe could actually fall in a globally-heating world.

The Amazon rainforest − a vital part of the planet’s climate machinery since the end of the last Ice Age − has been hit not just by human degradation but by drought and forest fire, and could be about to slide into permanent savannah.

Overshoot nears

And scientists in Antarctica have been warning for a decade of thinning ice sheets, and accelerating glaciers.

The planet has already warmed by more than a degree Celsius in the last century or so. There is a high chance that some time this decade the annual average planetary temperature could pass the 1.5°C threshold, if only temporarily.

Right now, although 195 nations in Paris in 2015 committed themselves to a target of “well below” 2°C by 2100, the world is heading for a temperature rise by the end of the century of more than 3°C.

The authors concede that their results contain a lot of uncertainties: there is more research to be done. But that doesn’t mean there is no urgency.

“Our analysis is conservative in the sense that several interactions and tipping elements are not yet considered”, said Professor Winkelmann. It would hence be a daring bet to hope that the uncertainties play out in a good way, given what is at stake.

“From a precautionary perspective, rapidly reducing greenhouse gas emissions is indispensable to limit the risks of crossing tipping points in the climate system, and potentially causing domino effects.” − Climate News Network

Global climate catastrophe could be nearer than we think. New research suggests how it could happen.

LONDON, 8 June, 2021 − Here is a set of circumstances that could trigger global climate catastrophe. The Greenland ice sheet could begin a process of irreversible melting.

As it does, greater quantities of fresh water would flood into the Arctic Ocean, to further slow the already slowing Atlantic meridional overturning circulation, that great flow of water sometimes called the Gulf Stream that  distributes warmth from the tropics.

But as the Atlantic flow weakens, so rises the probability of increased and sustained drought and dieback in the Amazon rainforest: the entire region could begin to tip inexorably into savannah.

And the Southern Ocean would begin to warm: it could warm enough to hasten the disintegration of the West Antarctic ice sheet, to accelerate the rise of global sea levels and intensify the whole machinery of global heating.

Alarmingly, this process could begin to happen while global temperatures are still not much higher than they are now: 1.5°C has been repeatedly described as the limit beyond which global average temperatures should not rise, but the official global agreed target is a limit of 2°C.

In fact, the chance of a cascade of domino effects − of tipping points that trigger other climate tipping points − could begin somewhere between those two figures, and the probability rises thereafter.

No way back

And, researchers warn, when they say irreversible, they mean it. Once the Greenland ice sheet starts to slide into the sea, there will be no stopping it. The only question is how swiftly all these things could happen.

“Once triggered, the actual tipping process might take several years up to millennia, depending on the respective response times of the system,” the scientists write in the journal Earth System Dynamics.

It’s a scenario, not a prediction. It’s a calculation of possibilities and probabilities inherent in the process of global warming and climate change. It’s an identification of the way atmospheric warming driven by greenhouse gas emissions from human economies can and might change the climate system that drives planetary weather.

“We provide risk analysis, not a prediction, yet our findings still raise concern,” said Ricarda Winkelmann, of the Potsdam Institute for Climate Impact Research, one of the authors.

She and her colleagues base their study on computer simulations of planetary response to temperature rise. And one third of those simulations suggest that if the world reaches 2°C, then one of those elements could begin to tip towards irreversible change, and at the same time trigger other tipping points.

“We’re shifting the odds, and not to our favour − the risk is clearly increasing the more we heat our planet,” said her colleague and co-author Jonathan Donges. “It rises substantially between 1°C and 3°C.

“Rapidly reducing greenhouse gas emissions is indispensable to limit the risks of crossing tipping points in the climate system”

“If greenhouse gas emissions and the resulting climate change cannot be halted, the upper level of this warming range could most likely be crossed by the end of this century. With even higher temperatures, more tipping cascades are to be expected, with long-term devastating effects.”

Climate science has been concerned with the idea of tipping points − temperatures beyond which climate change might be irreversible − for decades. There have been repeated findings that some of these might be nearer than anybody had suspected.

Greenland is in effect the reservoir of most of the Northern hemisphere’s ice − enough to raise sea levels by seven metres − and it is melting at an ever-accelerating rate.

Researchers have again and again identified a possible faltering of the Atlantic current, to warn of a paradoxical consequence: if the Gulf Stream slows, then average temperatures in western Europe could actually fall in a globally-heating world.

The Amazon rainforest − a vital part of the planet’s climate machinery since the end of the last Ice Age − has been hit not just by human degradation but by drought and forest fire, and could be about to slide into permanent savannah.

Overshoot nears

And scientists in Antarctica have been warning for a decade of thinning ice sheets, and accelerating glaciers.

The planet has already warmed by more than a degree Celsius in the last century or so. There is a high chance that some time this decade the annual average planetary temperature could pass the 1.5°C threshold, if only temporarily.

Right now, although 195 nations in Paris in 2015 committed themselves to a target of “well below” 2°C by 2100, the world is heading for a temperature rise by the end of the century of more than 3°C.

The authors concede that their results contain a lot of uncertainties: there is more research to be done. But that doesn’t mean there is no urgency.

“Our analysis is conservative in the sense that several interactions and tipping elements are not yet considered”, said Professor Winkelmann. It would hence be a daring bet to hope that the uncertainties play out in a good way, given what is at stake.

“From a precautionary perspective, rapidly reducing greenhouse gas emissions is indispensable to limit the risks of crossing tipping points in the climate system, and potentially causing domino effects.” − Climate News Network

Polar cod face new threat from Arctic oil pollution

Already struggling to survive in warming Arctic seas, the polar cod are now at risk from rising oil pollution.

LONDON, 2 June, 2021 – They are small – on average around 25cm long. But polar cod (Boreogadus saida) are a vital part of the Arctic food chain, a major ingredient in the diet of seals, narwhals and a wide variety of seabirds.

The Arctic is warming faster than any other area on the planet, and a study published in 2020 found that declines in winter sea ice cover in the Barents Sea region of the Arctic, plus warmer sea temperatures, were causing declines in polar cod reproduction rates.

The latest research indicates that the polar cod is now under threat not only from warming Arctic seas, but because of oil pollution as well, as the region’s rapidly diminishing ice cover allows more shipping traffic and commercial activity.

Morgan Lizabeth Bender is a researcher in the department of Arctic and Marine Biology at the University of Tromsø (UiT) in northern Norway. Her research has found that when the polar cod is exposed to a combination of warmer waters and only very slight levels of oil pollution, its development is interrupted, with abnormalities common.

“Polar cod is a somewhat difficult species that hasn’t been researched that much,” Dr Bender told the Science Norway website. “The fish are a difficult species to find and to take care of in the lab. However, this species has a very important ecological role.”

“Increased water temperature can increase the harmful effects of oil exposure”

The fish, monitored during the breeding process, were sorted into aquariums – some at a current Arctic water temperature of 0.5°C, others at a warmer 2.8°C to mimic an Arctic affected by climate change.

The aquariums contained either pure water or water contaminated by minuscule amounts of crude oil. “The pollution level would be the equivalent of about five drops of oil in an Olympic-size swimming pool,” says Dr Bender.

Though the study found that polar cod eggs in the warmer water hatched much faster than those in the colder water, at first there was little difference between survival rates in the various aquariums.

But then something strange started happening to the fry – the young fish – that were exposed to oil.

“When they first hatched, there wasn’t much difference,” says Dr Bender. “But as their jaw, face and eyes started to develop, we saw very clearly that they weren’t forming properly.”

Lower survival rates

The research found that the fry were very sensitive to even the slightest amount of oil pollution: death rates were highest among fry exposed to both warmer water and oil.

When the fry became large enough to start feeding, only 8% survived in the contaminated warmer water and 23% in the contaminated cold water.

Marine scientists say that polar cod numbers have shown a downward trend since 2010, despite the fact that they are not a fished species.

Sonnich Meier, of the Norwegian Institute of Marine Research, has been examining the impact of both global warming and oil pollution on Arctic fish species for a number of years.

“Polar cod is one of the fish species that is hardest hit by climate change in the Arctic,” he says. “The study shows that increased water temperature can increase the harmful effects of oil exposure.” – Climate News Network

Already struggling to survive in warming Arctic seas, the polar cod are now at risk from rising oil pollution.

LONDON, 2 June, 2021 – They are small – on average around 25cm long. But polar cod (Boreogadus saida) are a vital part of the Arctic food chain, a major ingredient in the diet of seals, narwhals and a wide variety of seabirds.

The Arctic is warming faster than any other area on the planet, and a study published in 2020 found that declines in winter sea ice cover in the Barents Sea region of the Arctic, plus warmer sea temperatures, were causing declines in polar cod reproduction rates.

The latest research indicates that the polar cod is now under threat not only from warming Arctic seas, but because of oil pollution as well, as the region’s rapidly diminishing ice cover allows more shipping traffic and commercial activity.

Morgan Lizabeth Bender is a researcher in the department of Arctic and Marine Biology at the University of Tromsø (UiT) in northern Norway. Her research has found that when the polar cod is exposed to a combination of warmer waters and only very slight levels of oil pollution, its development is interrupted, with abnormalities common.

“Polar cod is a somewhat difficult species that hasn’t been researched that much,” Dr Bender told the Science Norway website. “The fish are a difficult species to find and to take care of in the lab. However, this species has a very important ecological role.”

“Increased water temperature can increase the harmful effects of oil exposure”

The fish, monitored during the breeding process, were sorted into aquariums – some at a current Arctic water temperature of 0.5°C, others at a warmer 2.8°C to mimic an Arctic affected by climate change.

The aquariums contained either pure water or water contaminated by minuscule amounts of crude oil. “The pollution level would be the equivalent of about five drops of oil in an Olympic-size swimming pool,” says Dr Bender.

Though the study found that polar cod eggs in the warmer water hatched much faster than those in the colder water, at first there was little difference between survival rates in the various aquariums.

But then something strange started happening to the fry – the young fish – that were exposed to oil.

“When they first hatched, there wasn’t much difference,” says Dr Bender. “But as their jaw, face and eyes started to develop, we saw very clearly that they weren’t forming properly.”

Lower survival rates

The research found that the fry were very sensitive to even the slightest amount of oil pollution: death rates were highest among fry exposed to both warmer water and oil.

When the fry became large enough to start feeding, only 8% survived in the contaminated warmer water and 23% in the contaminated cold water.

Marine scientists say that polar cod numbers have shown a downward trend since 2010, despite the fact that they are not a fished species.

Sonnich Meier, of the Norwegian Institute of Marine Research, has been examining the impact of both global warming and oil pollution on Arctic fish species for a number of years.

“Polar cod is one of the fish species that is hardest hit by climate change in the Arctic,” he says. “The study shows that increased water temperature can increase the harmful effects of oil exposure.” – Climate News Network

Faster Greenland ice melt could be unstoppable

A rapid thaw could destroy a whole ice sheet if the faster Greenland ice melt scientists have found spreads across the island.

LONDON, 24 May, 2021 − Researchers say the faster Greenland ice melt affecting part of the island could mean a large area is on the verge of irreversible loss. Their new study shows that the central western region of the ice sheet is near what climate scientists call “a tipping point.”

That is, once the ice starts to slide away, most of it will tip into the sea, to raise global sea levels and potentially to trigger the collapse of the great Atlantic Ocean current that enhances the climate of north-west Europe.

“We have found evidence that the central western part of the Greenland ice sheet has been destabilising and is now close to a critical transition,” said Niklas Boers, of the Potsdam Institute for Climate Impact Research. “Our results suggest there will be substantially enhanced melting in the future − which is quite worrying.”

Dr Boers and his colleague Martin Rypdal of the Arctic University of Norway report in the Proceedings of the National Academy of Sciences that they looked at data since 1880 of melt rates and ice-sheet altitude shifts of a region called the Jakobshavn basin in the central western region of the northern hemisphere’s biggest single block of ice − a block big enough to raise global sea levels by seven metres, were it all to melt.

And what they saw was something alarming: evidence that surface melting is beginning to accelerate. The conclusion, for now, is tentative.

“It’s high time we dramatically and substantially reduce greenhouse gas emissions from burning fossil fuels”

“We might be seeing the beginning of a large scale destabilisation, but at the moment we cannot tell, unfortunately,” Dr Boers said. “So far the signals we see are only regional, but that might simply be due to the scarcity of accurate and long-term data for other parts of the ice sheet.”

The region is home to the Jakobshavn glacier, which began to accelerate its flow to the sea this century, but the alarm is consistent with other studies of the mass of ice piled up on Greenland.

For most of the last 10,000 years or so, the summer loss of ice through melt and glacial flow has been replaced by winter snow. But in recent years, other research teams have warned, repeatedly, that the rate of  melting of Greenland’s surface ice has increased, in ways that really could threaten the stability of the entire sheet. Last year, ice loss reached a new record.

Greenland’s ice sheet is high: colder, therefore, at altitude. As the surface melts, the elevation becomes lower, and therefore increasingly warmer. So once the high ground surface begins to melt away, it could reach a level below which there is no obvious reason why the process should stop.

Climate computer simulations predict a threshold of global average temperature change that could, in effect, start a process in which the loss of the entire ice sheet would become inevitable. The loss would happen over hundreds of years, or perhaps thousands, but once begun it would continue inexorably.

Extreme Arctic warming

Global sea levels would rise at ever faster rates, and the arrival of so much fresh water in the north Atlantic would be enough to interfere with the ocean circulation.

For years oceanographers have been warning that the existing current, which takes warm tropical water as far north as the Arctic, could weaken, or fail, with unpredictable and uncomfortable consequences for north European nations.

The only way to stop Greenland’s accelerated melt, once it reaches a critical point, would be to lower the temperature of the whole planet back to that which was normal more than 200 years ago. That is unlikely to happen. Instead, for the moment, the evidence is that average temperatures worldwide could rise by 3°C or more by 2100. The Arctic, however, is likely to become much, much warmer.

“So practically, the current and near-future mass loss will be irreversible,” said Dr Boers, “That’s why it’s high time we dramatically and substantially reduce greenhouse gas emissions from burning fossil fuels and restabilise the ice sheet and our climate.” − Climate News Network

A rapid thaw could destroy a whole ice sheet if the faster Greenland ice melt scientists have found spreads across the island.

LONDON, 24 May, 2021 − Researchers say the faster Greenland ice melt affecting part of the island could mean a large area is on the verge of irreversible loss. Their new study shows that the central western region of the ice sheet is near what climate scientists call “a tipping point.”

That is, once the ice starts to slide away, most of it will tip into the sea, to raise global sea levels and potentially to trigger the collapse of the great Atlantic Ocean current that enhances the climate of north-west Europe.

“We have found evidence that the central western part of the Greenland ice sheet has been destabilising and is now close to a critical transition,” said Niklas Boers, of the Potsdam Institute for Climate Impact Research. “Our results suggest there will be substantially enhanced melting in the future − which is quite worrying.”

Dr Boers and his colleague Martin Rypdal of the Arctic University of Norway report in the Proceedings of the National Academy of Sciences that they looked at data since 1880 of melt rates and ice-sheet altitude shifts of a region called the Jakobshavn basin in the central western region of the northern hemisphere’s biggest single block of ice − a block big enough to raise global sea levels by seven metres, were it all to melt.

And what they saw was something alarming: evidence that surface melting is beginning to accelerate. The conclusion, for now, is tentative.

“It’s high time we dramatically and substantially reduce greenhouse gas emissions from burning fossil fuels”

“We might be seeing the beginning of a large scale destabilisation, but at the moment we cannot tell, unfortunately,” Dr Boers said. “So far the signals we see are only regional, but that might simply be due to the scarcity of accurate and long-term data for other parts of the ice sheet.”

The region is home to the Jakobshavn glacier, which began to accelerate its flow to the sea this century, but the alarm is consistent with other studies of the mass of ice piled up on Greenland.

For most of the last 10,000 years or so, the summer loss of ice through melt and glacial flow has been replaced by winter snow. But in recent years, other research teams have warned, repeatedly, that the rate of  melting of Greenland’s surface ice has increased, in ways that really could threaten the stability of the entire sheet. Last year, ice loss reached a new record.

Greenland’s ice sheet is high: colder, therefore, at altitude. As the surface melts, the elevation becomes lower, and therefore increasingly warmer. So once the high ground surface begins to melt away, it could reach a level below which there is no obvious reason why the process should stop.

Climate computer simulations predict a threshold of global average temperature change that could, in effect, start a process in which the loss of the entire ice sheet would become inevitable. The loss would happen over hundreds of years, or perhaps thousands, but once begun it would continue inexorably.

Extreme Arctic warming

Global sea levels would rise at ever faster rates, and the arrival of so much fresh water in the north Atlantic would be enough to interfere with the ocean circulation.

For years oceanographers have been warning that the existing current, which takes warm tropical water as far north as the Arctic, could weaken, or fail, with unpredictable and uncomfortable consequences for north European nations.

The only way to stop Greenland’s accelerated melt, once it reaches a critical point, would be to lower the temperature of the whole planet back to that which was normal more than 200 years ago. That is unlikely to happen. Instead, for the moment, the evidence is that average temperatures worldwide could rise by 3°C or more by 2100. The Arctic, however, is likely to become much, much warmer.

“So practically, the current and near-future mass loss will be irreversible,” said Dr Boers, “That’s why it’s high time we dramatically and substantially reduce greenhouse gas emissions from burning fossil fuels and restabilise the ice sheet and our climate.” − Climate News Network

Human activity alters Earth’s spin on its axis

The planet may not catch fire, but climate change really has altered the Earth’s spin on its axis as it rounds the sun.

LONDON, 29 April, 2021 − Human action has altered Earth’s spin on its axis. Climate change since 1990 has altered both the rate and the direction of the drift of the north and south poles.

Chinese researchers report in the journal Geophysical Research Letters that on the basis of their calculations, the dramatic melting of the Antarctic and Greenland ice caps and the Andean glaciers of South America has shifted the weight of the global water storage system and affected the planetary drift of the poles.

This glacial loss has been compounded by massive increases in the use of groundwater − most of the planet’s fresh water is in fact stored in subterranean aquifers − which have helped to accelerate the rate of change.

It sounds like the plot of a science fiction film. It was in fact the plot of a British 1961 science fiction film, The Day the Earth Caught Fire. In that fantasia, Cold War superpower nuclear tests unintentionally alter the planet’s axis of rotation and trigger dramatic changes in climate.

In fact, in the real-life, here-and-now version of planetary rotational shift, climate change driven by economic growth powered by profligate fossil fuel use is the cause. And the superpowers have yet to decide upon a course correction.

Polar speed-up

There is a second difference: the axis of the rotational poles has always shifted, from year to year, in response to the distribution of ice and groundwater, and the oceanic currents; and from aeon to aeon in response to the movements of the continents, and the sloshing of molten iron at the Earth’s core.

What has happened since 1990 is that water loss from both the glaciated land surface and the soil beneath the inhabited surface has been so pronounced that it has tilted the North Pole away from Canada and towards Russia, and accelerated the rate at which this is happening.

Since 1990, geographic North has been tilting, in geodetic language, towards longitude 26°E at the rate of 3.28 milliseconds of arc per year. One millisecond of arc is about 3 cms.

The story has been pieced together by data from a US-German satellite system known as GRACE (short for Gravity Recovery and Climate Experiment), which has been recording ice loss and water storage for most of this century.

“The faster ice-melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s”

The researchers, from the Chinese Academy of Sciences, already had access to 176 years of precision measurement of the polar axial shift. In fact, the loss of ice from both the north and south polar regions has been colossal, and has been happening at speed.

Groundwater, too, has been abstracted at accelerating rates and the study notes that while in 1989 India pumped 194 billion cubic metres from the soil, by 2010 this had reached 351 billion cubic metres. There had, too, been dramatic changes in the water levels of vast inland lakes such as the Aral Sea.

The planet is always in a state of change: the magnetic poles are on the move and scientists have confirmed that climate over very long periods is affected by changes in planetary orbit.

Other teams of researchers had separately confirmed that climate change − and the redistribution of water around the planet − must have altered the length of the day by millionths of a second in the course of a year. But the new research has established something more immediately measurable: the alteration of the pattern of rotational tilt.

“The faster ice-melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s,” the researchers conclude. − Climate News Network

The planet may not catch fire, but climate change really has altered the Earth’s spin on its axis as it rounds the sun.

LONDON, 29 April, 2021 − Human action has altered Earth’s spin on its axis. Climate change since 1990 has altered both the rate and the direction of the drift of the north and south poles.

Chinese researchers report in the journal Geophysical Research Letters that on the basis of their calculations, the dramatic melting of the Antarctic and Greenland ice caps and the Andean glaciers of South America has shifted the weight of the global water storage system and affected the planetary drift of the poles.

This glacial loss has been compounded by massive increases in the use of groundwater − most of the planet’s fresh water is in fact stored in subterranean aquifers − which have helped to accelerate the rate of change.

It sounds like the plot of a science fiction film. It was in fact the plot of a British 1961 science fiction film, The Day the Earth Caught Fire. In that fantasia, Cold War superpower nuclear tests unintentionally alter the planet’s axis of rotation and trigger dramatic changes in climate.

In fact, in the real-life, here-and-now version of planetary rotational shift, climate change driven by economic growth powered by profligate fossil fuel use is the cause. And the superpowers have yet to decide upon a course correction.

Polar speed-up

There is a second difference: the axis of the rotational poles has always shifted, from year to year, in response to the distribution of ice and groundwater, and the oceanic currents; and from aeon to aeon in response to the movements of the continents, and the sloshing of molten iron at the Earth’s core.

What has happened since 1990 is that water loss from both the glaciated land surface and the soil beneath the inhabited surface has been so pronounced that it has tilted the North Pole away from Canada and towards Russia, and accelerated the rate at which this is happening.

Since 1990, geographic North has been tilting, in geodetic language, towards longitude 26°E at the rate of 3.28 milliseconds of arc per year. One millisecond of arc is about 3 cms.

The story has been pieced together by data from a US-German satellite system known as GRACE (short for Gravity Recovery and Climate Experiment), which has been recording ice loss and water storage for most of this century.

“The faster ice-melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s”

The researchers, from the Chinese Academy of Sciences, already had access to 176 years of precision measurement of the polar axial shift. In fact, the loss of ice from both the north and south polar regions has been colossal, and has been happening at speed.

Groundwater, too, has been abstracted at accelerating rates and the study notes that while in 1989 India pumped 194 billion cubic metres from the soil, by 2010 this had reached 351 billion cubic metres. There had, too, been dramatic changes in the water levels of vast inland lakes such as the Aral Sea.

The planet is always in a state of change: the magnetic poles are on the move and scientists have confirmed that climate over very long periods is affected by changes in planetary orbit.

Other teams of researchers had separately confirmed that climate change − and the redistribution of water around the planet − must have altered the length of the day by millionths of a second in the course of a year. But the new research has established something more immediately measurable: the alteration of the pattern of rotational tilt.

“The faster ice-melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s,” the researchers conclude. − Climate News Network

Loss of Arctic sea ice can spoil French wine harvest

What happens in the Arctic may not stay there. Loss of Arctic sea ice can dump the polar blizzards elsewhere.

LONDON, 19 April, 2021 − Once again, scientists have linked a weather-related catastrophe directly to human-induced climate change. Extreme frost and springtime snowfalls in Western Europe can be pinned to the dramatic loss of Arctic sea ice.

So, paradoxically, global heating may have had the unexpected effect of wiping out around one third of the French wine harvest for this coming year, after temperatures so low that growers were forced to light bonfires in their vineyards to save the first buds from the chill.

“Climate change doesn’t always manifest in the most obvious ways,” said Alun Hubbard, of the Arctic University of Norway. “It’s easy to extrapolate models to show that winters are getting warmer and to forecast a virtually snow-free future in Europe, but our most recent study shows that is too simplistic. We should be beware of making broad, sweeping statements about the impacts of climate change.”

Professor Hubbard and colleagues report in the journal Nature Geoscience that they measured telltale isotope signatures in water vapour from Finland in February 2018 during an episode of freezing snow in Europe, in an anticyclone dubbed “the Beast from the East” by meteorologists and the media.

“The abrupt changes being witnessed across the Arctic now really are affecting the entire planet”

They found that the Barents Sea north of Scandinavia was anomalously warm. And 60% of the sea’s surface was free of ice, and the same sea lost 140 billion tonnes of water to evaporation during this too-warm February. This enormous atmospheric burden of water vapour provided, they calculate, 88% of the snow that was to fall over northern Europe that month.

Then they looked at the pattern over the years from 1979 to 2020, to find that, for every square metre of ice that vanished in the month of March − itself part of a pattern of Arctic temperature rise − evaporation across the Barents Sea increased by 70 kg, and this could be matched with increases in Europe’s maximum snowfall.

“Our analysis directly links Arctic sea ice loss with increased evaporation and extreme snow fall,” they write, and warn that by 2080 an ice-free Barents Sea “will be a major source of winter moisture for continental Europe.”

The Beast from the East brought much of Europe to a halt, at an economic cost of an estimated $1bn (£0.72bn) a day. It is still rare for researchers to directly link any particular weather event with climate change driven by profligate use of fossil fuels − that is because climate is what forecasters can reasonably expect, but weather is what actually happens − but some scientists have begun to do so with increasing confidence. And this time, they can explain why.

Natural complexity

The ice cover over the Barents Sea has fallen by 54% since 1979, at the rate of 11,200 sq kms a year, and snow mass across Eurasia has increased. The latest study confirms the link: the isotope signature of Barents water was repeated in the European snows that arrived with the Beast from the East.

“What we’re finding is that sea ice is effectively a lid on the ocean. And with its long term reduction across the Arctic, we’re seeing increasing amounts of moisture enter the atmosphere during winter, which directly impacts our weather further south, causing extremely heavy snowfalls,” said Hannah Bailey of the University of Oulu in Finland, who led the research.

“It might seem counter-intuitive, but nature is complex and what happens in the Arctic doesn’t stay in the Arctic.”

And Professor Hubbard said: “This study illustrates that the abrupt changes being witnessed across the Arctic now really are affecting the entire planet.” − Climate News Network

What happens in the Arctic may not stay there. Loss of Arctic sea ice can dump the polar blizzards elsewhere.

LONDON, 19 April, 2021 − Once again, scientists have linked a weather-related catastrophe directly to human-induced climate change. Extreme frost and springtime snowfalls in Western Europe can be pinned to the dramatic loss of Arctic sea ice.

So, paradoxically, global heating may have had the unexpected effect of wiping out around one third of the French wine harvest for this coming year, after temperatures so low that growers were forced to light bonfires in their vineyards to save the first buds from the chill.

“Climate change doesn’t always manifest in the most obvious ways,” said Alun Hubbard, of the Arctic University of Norway. “It’s easy to extrapolate models to show that winters are getting warmer and to forecast a virtually snow-free future in Europe, but our most recent study shows that is too simplistic. We should be beware of making broad, sweeping statements about the impacts of climate change.”

Professor Hubbard and colleagues report in the journal Nature Geoscience that they measured telltale isotope signatures in water vapour from Finland in February 2018 during an episode of freezing snow in Europe, in an anticyclone dubbed “the Beast from the East” by meteorologists and the media.

“The abrupt changes being witnessed across the Arctic now really are affecting the entire planet”

They found that the Barents Sea north of Scandinavia was anomalously warm. And 60% of the sea’s surface was free of ice, and the same sea lost 140 billion tonnes of water to evaporation during this too-warm February. This enormous atmospheric burden of water vapour provided, they calculate, 88% of the snow that was to fall over northern Europe that month.

Then they looked at the pattern over the years from 1979 to 2020, to find that, for every square metre of ice that vanished in the month of March − itself part of a pattern of Arctic temperature rise − evaporation across the Barents Sea increased by 70 kg, and this could be matched with increases in Europe’s maximum snowfall.

“Our analysis directly links Arctic sea ice loss with increased evaporation and extreme snow fall,” they write, and warn that by 2080 an ice-free Barents Sea “will be a major source of winter moisture for continental Europe.”

The Beast from the East brought much of Europe to a halt, at an economic cost of an estimated $1bn (£0.72bn) a day. It is still rare for researchers to directly link any particular weather event with climate change driven by profligate use of fossil fuels − that is because climate is what forecasters can reasonably expect, but weather is what actually happens − but some scientists have begun to do so with increasing confidence. And this time, they can explain why.

Natural complexity

The ice cover over the Barents Sea has fallen by 54% since 1979, at the rate of 11,200 sq kms a year, and snow mass across Eurasia has increased. The latest study confirms the link: the isotope signature of Barents water was repeated in the European snows that arrived with the Beast from the East.

“What we’re finding is that sea ice is effectively a lid on the ocean. And with its long term reduction across the Arctic, we’re seeing increasing amounts of moisture enter the atmosphere during winter, which directly impacts our weather further south, causing extremely heavy snowfalls,” said Hannah Bailey of the University of Oulu in Finland, who led the research.

“It might seem counter-intuitive, but nature is complex and what happens in the Arctic doesn’t stay in the Arctic.”

And Professor Hubbard said: “This study illustrates that the abrupt changes being witnessed across the Arctic now really are affecting the entire planet.” − Climate News Network

Weakening Gulf Stream may disrupt world weather

The Gulf Stream is growing feebler, the Arctic seas are gaining fresh water. Together they could affect the world’s weather.

LONDON, 2 March, 2021 − The Atlantic Conveyer, otherwise the Gulf Stream − that great flow of surface water pouring northwards that overturns in the Arctic and heads south again at great depth − is now weaker than at any point in the last 1,000 years, European scientists report.

And in a second, separate but related study, researchers have found that the Beaufort Sea, in the Arctic, has gained two-fifths more fresh water in the last 20 years: water that could flow into the Atlantic to affect the Conveyor, and with it, climatic conditions.

Scientists call it the Atlantic Meridional Overturning Circulation or just AMOC. Europeans know it as the Gulf Stream: the current that conveys tropic warmth to their coasts and keeps Britain and Western Europe at a temperature several degrees higher than latitude alone might dictate.

And for years, oceanographers and climate scientists have been observing a slowing of the flow, by as much as 15%. But direct measurement of the great current began only relatively recently in 2004: researchers needed to know whether the slowdown was part of a natural cycle, or a consequence of climate change driven by global heating.

Now they know a little more. European researchers report in Nature Geoscience that they looked for evidence of ocean circulation shifts in what they call “proxy evidence”: the story of climate change told by tree growth rings, ice cores, ocean sediments, corals and historical records, including naval logbooks.

The combined evidence of temperature patterns, the sizes of particles of ocean floor sediment and the salinity and density of sub-surface water helps build up a picture of the Atlantic current for the last 1,600 years.

“The Gulf Stream System moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow”

The verdict? Up to the 19th century, ocean currents were stable. The flow is now more sluggish than at any time in the last millennium.

This is roughly what climate models have predicted: the warm salty water moves north, cools, becomes more dense, sinks to the deep and flows back south. But the Arctic has begun to warm, Greenland to melt, and the flow of fresh water into the northern seas to intensify.

Since the flow is driven by the difference in temperatures, any change in the regional thermometer will play back into the rate of flow. And any extra arrival of fresh water could further slow the overturning circulation.

“The Gulf Stream system works like a giant conveyor belt, carrying warm surface water from the equator up north, and sending cold, low-salinity deep water back down south. It moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow,” said Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research, in Germany, one of the authors.

“For the first time, we have combined a range of previous studies and found they provide a consistent picture of the AMOC evolution over the past 1600 years. The study results suggest that it has been relatively stable until the late 19th century.

“With the end of the Little Ice Age in about 1850, the ocean currents began to decline, with a second, more drastic decline following since the mid-20th century.”

Outcome awaited

The change could have ominous consequences for European weather systems: it could also deliver more intense coastal flooding to the US eastern seaboard. If the current continues to weaken, the consequences could be catastrophic.

Which is why a new study in Nature Communications matters so much. US researchers tracked the flow of fresh water from the Beaufort Sea − melt water from glaciers, rivers and disappearing Arctic sea ice − through the Canadian Archipelago and into the Labrador Sea.

Arctic water is fresher than Atlantic water, and richer in nutrients. But this extra volume, measured at a total of 23,300 cubic kilometres, could also affect the rate of flow of the overturning circulation. That is because relatively fresh water is less dense than saline water, and tends to float on top.

Quite what role it could play is uncertain: the message is that, sooner or later, it will escape into the North Atlantic. Then the world will find out.

“People have already spent a lot of time studying why the Beaufort Sea fresh water has gotten so high in the past few decades,” said Jiaxu Zhang,  of the Los Alamos National Laboratory, first author. “But they rarely care where the freshwater goes, and we think that’s a much more important problem.” − Climate News Network

The Gulf Stream is growing feebler, the Arctic seas are gaining fresh water. Together they could affect the world’s weather.

LONDON, 2 March, 2021 − The Atlantic Conveyer, otherwise the Gulf Stream − that great flow of surface water pouring northwards that overturns in the Arctic and heads south again at great depth − is now weaker than at any point in the last 1,000 years, European scientists report.

And in a second, separate but related study, researchers have found that the Beaufort Sea, in the Arctic, has gained two-fifths more fresh water in the last 20 years: water that could flow into the Atlantic to affect the Conveyor, and with it, climatic conditions.

Scientists call it the Atlantic Meridional Overturning Circulation or just AMOC. Europeans know it as the Gulf Stream: the current that conveys tropic warmth to their coasts and keeps Britain and Western Europe at a temperature several degrees higher than latitude alone might dictate.

And for years, oceanographers and climate scientists have been observing a slowing of the flow, by as much as 15%. But direct measurement of the great current began only relatively recently in 2004: researchers needed to know whether the slowdown was part of a natural cycle, or a consequence of climate change driven by global heating.

Now they know a little more. European researchers report in Nature Geoscience that they looked for evidence of ocean circulation shifts in what they call “proxy evidence”: the story of climate change told by tree growth rings, ice cores, ocean sediments, corals and historical records, including naval logbooks.

The combined evidence of temperature patterns, the sizes of particles of ocean floor sediment and the salinity and density of sub-surface water helps build up a picture of the Atlantic current for the last 1,600 years.

“The Gulf Stream System moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow”

The verdict? Up to the 19th century, ocean currents were stable. The flow is now more sluggish than at any time in the last millennium.

This is roughly what climate models have predicted: the warm salty water moves north, cools, becomes more dense, sinks to the deep and flows back south. But the Arctic has begun to warm, Greenland to melt, and the flow of fresh water into the northern seas to intensify.

Since the flow is driven by the difference in temperatures, any change in the regional thermometer will play back into the rate of flow. And any extra arrival of fresh water could further slow the overturning circulation.

“The Gulf Stream system works like a giant conveyor belt, carrying warm surface water from the equator up north, and sending cold, low-salinity deep water back down south. It moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow,” said Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research, in Germany, one of the authors.

“For the first time, we have combined a range of previous studies and found they provide a consistent picture of the AMOC evolution over the past 1600 years. The study results suggest that it has been relatively stable until the late 19th century.

“With the end of the Little Ice Age in about 1850, the ocean currents began to decline, with a second, more drastic decline following since the mid-20th century.”

Outcome awaited

The change could have ominous consequences for European weather systems: it could also deliver more intense coastal flooding to the US eastern seaboard. If the current continues to weaken, the consequences could be catastrophic.

Which is why a new study in Nature Communications matters so much. US researchers tracked the flow of fresh water from the Beaufort Sea − melt water from glaciers, rivers and disappearing Arctic sea ice − through the Canadian Archipelago and into the Labrador Sea.

Arctic water is fresher than Atlantic water, and richer in nutrients. But this extra volume, measured at a total of 23,300 cubic kilometres, could also affect the rate of flow of the overturning circulation. That is because relatively fresh water is less dense than saline water, and tends to float on top.

Quite what role it could play is uncertain: the message is that, sooner or later, it will escape into the North Atlantic. Then the world will find out.

“People have already spent a lot of time studying why the Beaufort Sea fresh water has gotten so high in the past few decades,” said Jiaxu Zhang,  of the Los Alamos National Laboratory, first author. “But they rarely care where the freshwater goes, and we think that’s a much more important problem.” − Climate News Network

Human rubbish is smothering the planet’s oceans

In a throwaway world garbage may be unseen, but not gone. Human rubbish is everywhere, from ocean abyss to coastal mud.

LONDON, 29 January, 2021 − In the next 30 years, an estimated three billion metric tonnes of human rubbish − everything from abandoned trawl nets to plastic bottles, from broken teacups to tins of toxin − could find its way into the sea, to defile the ocean floor.

One recent survey in the Strait of Messina, the seaway that separates Italy and Sicily, measured this detritus at concentrations of between 121,000 and 1.3 million items per square kilometre trapped in submarine canyons.

In seabed fissures off Portugal, bits of human litter large enough to identify have been counted at rates of 11,000 per sq km. Off the Ryukyu Islands far from mainland Japan, divers and remotely operated vehicles have made estimates of up to 71,000 items per sq km.

There is more and worse lying on other parts of the seabed. An estimated one million tonnes of chemical weaponry could be scattered about the planet’s oceans. The North Sea floor could be host to 1.3 million tonnes of conventional and chemical weapons; the Baltic enfolds and flows over 385,00 tonnes of dropped bombs, grenades, torpedoes, landmines and other weaponry.

“As humans, we have little or no care at all to prevent litter from accumulating everywhere”

And, says a new study in the journal Environmental Research Letters, this conversion of sea floor to careless landfill site creates problems for at least 693 marine species that so far have been observed to “interact” with marine debris: eat it, get caught in it, grow on it. Of these species, around one in six are in some degree endangered.

This list of sea creatures includes 93 kinds of invertebrate, 89 fish, 83 birds, 38 mammals and all species of sea turtle. So many fish now become ensnared in abandoned and derelict fishing gear that they are known as “ghost catches.”

Across the Asia-Pacific region, an estimated 11.1 billion bits of plastic bigger than 25mm could be entangled in the coral reefs. This problem of marine pollution goes far beyond the concern over plastic pollution of the planet’s seas and shores, from pole to pole, and is now found even in marine tissues.

Much of the previous concern has been about the presence of microfibres and small particles of polymer material now found everywhere. But the new study by European scientists tries to address the more obvious problem of these larger items − generally larger than 25mms − of all kinds of detritus, including plastic denser than water and ultimately destined to reach the seabed.

Poor management

The researchers want to try to find standard ways to measure the levels of waste, map its concentrations accurately, identify all the sources of refuse and classify the most problematic kinds: the toxic waste, the heavy metals and radioactive substances, the pharmaceuticals. They also urge international co-operation, and policies designed to discourage marine discharges and to clear up stretches of the sea floor.

“Marine litter has reached the most remote places in the ocean, even the least − or never − frequented by our species and not yet mapped by science,” said Miquel Canals of the University of Barcelona, who led the study.

“In order to correct something bad, we must attack its cause. And the cause of the accumulation of waste on the coasts, seas and oceans , and all over the planet, is the excess waste generation and spillage in the environment, and poor or insufficient management practices.

“As humans, we have little or no care at all to prevent litter from accumulating everywhere.” − Climate News Network

In a throwaway world garbage may be unseen, but not gone. Human rubbish is everywhere, from ocean abyss to coastal mud.

LONDON, 29 January, 2021 − In the next 30 years, an estimated three billion metric tonnes of human rubbish − everything from abandoned trawl nets to plastic bottles, from broken teacups to tins of toxin − could find its way into the sea, to defile the ocean floor.

One recent survey in the Strait of Messina, the seaway that separates Italy and Sicily, measured this detritus at concentrations of between 121,000 and 1.3 million items per square kilometre trapped in submarine canyons.

In seabed fissures off Portugal, bits of human litter large enough to identify have been counted at rates of 11,000 per sq km. Off the Ryukyu Islands far from mainland Japan, divers and remotely operated vehicles have made estimates of up to 71,000 items per sq km.

There is more and worse lying on other parts of the seabed. An estimated one million tonnes of chemical weaponry could be scattered about the planet’s oceans. The North Sea floor could be host to 1.3 million tonnes of conventional and chemical weapons; the Baltic enfolds and flows over 385,00 tonnes of dropped bombs, grenades, torpedoes, landmines and other weaponry.

“As humans, we have little or no care at all to prevent litter from accumulating everywhere”

And, says a new study in the journal Environmental Research Letters, this conversion of sea floor to careless landfill site creates problems for at least 693 marine species that so far have been observed to “interact” with marine debris: eat it, get caught in it, grow on it. Of these species, around one in six are in some degree endangered.

This list of sea creatures includes 93 kinds of invertebrate, 89 fish, 83 birds, 38 mammals and all species of sea turtle. So many fish now become ensnared in abandoned and derelict fishing gear that they are known as “ghost catches.”

Across the Asia-Pacific region, an estimated 11.1 billion bits of plastic bigger than 25mm could be entangled in the coral reefs. This problem of marine pollution goes far beyond the concern over plastic pollution of the planet’s seas and shores, from pole to pole, and is now found even in marine tissues.

Much of the previous concern has been about the presence of microfibres and small particles of polymer material now found everywhere. But the new study by European scientists tries to address the more obvious problem of these larger items − generally larger than 25mms − of all kinds of detritus, including plastic denser than water and ultimately destined to reach the seabed.

Poor management

The researchers want to try to find standard ways to measure the levels of waste, map its concentrations accurately, identify all the sources of refuse and classify the most problematic kinds: the toxic waste, the heavy metals and radioactive substances, the pharmaceuticals. They also urge international co-operation, and policies designed to discourage marine discharges and to clear up stretches of the sea floor.

“Marine litter has reached the most remote places in the ocean, even the least − or never − frequented by our species and not yet mapped by science,” said Miquel Canals of the University of Barcelona, who led the study.

“In order to correct something bad, we must attack its cause. And the cause of the accumulation of waste on the coasts, seas and oceans , and all over the planet, is the excess waste generation and spillage in the environment, and poor or insufficient management practices.

“As humans, we have little or no care at all to prevent litter from accumulating everywhere.” − Climate News Network