Tag Archives: Sea levels

Humans cause Antarctic ice melt, study finds

Yes, it’s us. Human activities are to blame for at least part of what’s melting the West Antarctic Ice Sheet, scientists say.

LONDON, 13 August, 2019 − A team of British and American scientists has found what it says is unequivocal evidence that humans are responsible for significant Antarctic ice melt.

They say their study provides the first evidence of a direct link between global warming from human activities and the melting of the West Antarctic Ice Sheet (WAIS).

The discovery is fundamentally important to international efforts to limit climate change, as a small number of scientists still argue that global warming results from natural rather than human causes. That argument should from now on be harder to sustain.

Ice loss in West Antarctica has increased substantially in the last few decades, and is continuing. Scientists have known for some time that the loss is caused by melting driven from the ocean, and that varying winds in the region cause transitions between relatively warm and cool ocean conditions around key glaciers. But until now it was unclear how these naturally-occurring wind variations could cause the ice loss.

“We knew this region was affected by natural climate cycles. Now we have evidence that a century-long change underlies these cycles, and that it is caused by human activities”

The UK-US team report in the journal Nature Geoscience that, as well as the natural wind variations, which last about a decade, there has been a much longer-term change in the winds that can be linked with human activities.

This result is important for another reason as well: continued ice loss from the WAIS could cause tens of centimetres of sea level rise by the year 2100.

The researchers combined satellite observations and climate model simulations to understand how winds over the ocean near West Antarctica have changed since the 1920s in response to rising greenhouse gas concentrations.

Their investigation shows that human-induced climate change has caused the longer-term change in the winds, and that warm ocean conditions have gradually become more prevalent as a result.

The team’s members are from the British Antarctic Survey (BAS), Columbia University’s Lamont-Doherty Earth Observatory in New York, and the University of Washington.

Galloping speed-up

BAS is one of the organisations researching a huge West Antarctic ice mass in the International Thwaites Glacier Collaboration, aimed at finding out how soon it and its neighbour, the Pine Island glacier, may collapse, with implications for sea levels worldwide.

The fact that melting at both poles has been accelerating fast has been known for some time, though not the reason. Since 1979 Antarctica’s ice loss has grown six times faster, and Greenland’s four times since the turn of the century.

One British scientist, Professor Martin Siegert, has said what is happening in the Antarctic means the world “will be locked into substantial global changes” unless it alters course radically by 2030.

The lead author of the new study, Paul Holland from BAS, said the impact of human-induced climate change on the WAIS was not simple: “Our results imply that a combination of human activity and natural climate variations have caused ice loss in this region, accounting for around 4.5 cm of sea level rise per century.”

Act now

The team also looked at model simulations of future winds. Professor Holland added: “An important finding is that if high greenhouse gas emissions continue in future, the winds keep changing and there could be a further increase in ice melting.

“However, if emissions of greenhouse gases are curtailed, there is little change in the winds from present-day conditions. This shows that curbing greenhouse gas emissions now could reduce the future sea level contribution from this region.”

One co-author, Professor Pierre Dutrieux from Lamont-Doherty Earth Observatory, said: “We knew this region was affected by natural climate cycles lasting about a decade, but these didn’t necessarily explain the ice loss. Now we have evidence that a century-long change underlies these cycles, and that it is caused by human activities.”

Another co-author, Professor Eric Steig from the University of Washington, said: “These results solve a long-standing puzzle.  We have known for some time that varying winds near the West Antarctic Ice Sheet have contributed to the ice loss, but it has not been clear why the ice sheet is changing now.

“Our work with ice cores drilled in the Antarctic Ice Sheet have shown, for example, that wind conditions have been similar in the past. But the ice core data also suggest a subtle long-term trend in the winds. This new work corroborates that evidence and, furthermore, explains why that trend has occurred.” − Climate News Network

Yes, it’s us. Human activities are to blame for at least part of what’s melting the West Antarctic Ice Sheet, scientists say.

LONDON, 13 August, 2019 − A team of British and American scientists has found what it says is unequivocal evidence that humans are responsible for significant Antarctic ice melt.

They say their study provides the first evidence of a direct link between global warming from human activities and the melting of the West Antarctic Ice Sheet (WAIS).

The discovery is fundamentally important to international efforts to limit climate change, as a small number of scientists still argue that global warming results from natural rather than human causes. That argument should from now on be harder to sustain.

Ice loss in West Antarctica has increased substantially in the last few decades, and is continuing. Scientists have known for some time that the loss is caused by melting driven from the ocean, and that varying winds in the region cause transitions between relatively warm and cool ocean conditions around key glaciers. But until now it was unclear how these naturally-occurring wind variations could cause the ice loss.

“We knew this region was affected by natural climate cycles. Now we have evidence that a century-long change underlies these cycles, and that it is caused by human activities”

The UK-US team report in the journal Nature Geoscience that, as well as the natural wind variations, which last about a decade, there has been a much longer-term change in the winds that can be linked with human activities.

This result is important for another reason as well: continued ice loss from the WAIS could cause tens of centimetres of sea level rise by the year 2100.

The researchers combined satellite observations and climate model simulations to understand how winds over the ocean near West Antarctica have changed since the 1920s in response to rising greenhouse gas concentrations.

Their investigation shows that human-induced climate change has caused the longer-term change in the winds, and that warm ocean conditions have gradually become more prevalent as a result.

The team’s members are from the British Antarctic Survey (BAS), Columbia University’s Lamont-Doherty Earth Observatory in New York, and the University of Washington.

Galloping speed-up

BAS is one of the organisations researching a huge West Antarctic ice mass in the International Thwaites Glacier Collaboration, aimed at finding out how soon it and its neighbour, the Pine Island glacier, may collapse, with implications for sea levels worldwide.

The fact that melting at both poles has been accelerating fast has been known for some time, though not the reason. Since 1979 Antarctica’s ice loss has grown six times faster, and Greenland’s four times since the turn of the century.

One British scientist, Professor Martin Siegert, has said what is happening in the Antarctic means the world “will be locked into substantial global changes” unless it alters course radically by 2030.

The lead author of the new study, Paul Holland from BAS, said the impact of human-induced climate change on the WAIS was not simple: “Our results imply that a combination of human activity and natural climate variations have caused ice loss in this region, accounting for around 4.5 cm of sea level rise per century.”

Act now

The team also looked at model simulations of future winds. Professor Holland added: “An important finding is that if high greenhouse gas emissions continue in future, the winds keep changing and there could be a further increase in ice melting.

“However, if emissions of greenhouse gases are curtailed, there is little change in the winds from present-day conditions. This shows that curbing greenhouse gas emissions now could reduce the future sea level contribution from this region.”

One co-author, Professor Pierre Dutrieux from Lamont-Doherty Earth Observatory, said: “We knew this region was affected by natural climate cycles lasting about a decade, but these didn’t necessarily explain the ice loss. Now we have evidence that a century-long change underlies these cycles, and that it is caused by human activities.”

Another co-author, Professor Eric Steig from the University of Washington, said: “These results solve a long-standing puzzle.  We have known for some time that varying winds near the West Antarctic Ice Sheet have contributed to the ice loss, but it has not been clear why the ice sheet is changing now.

“Our work with ice cores drilled in the Antarctic Ice Sheet have shown, for example, that wind conditions have been similar in the past. But the ice core data also suggest a subtle long-term trend in the winds. This new work corroborates that evidence and, furthermore, explains why that trend has occurred.” − Climate News Network

Artificial snow could save world’s coasts

In theory, artificial snow could save the ice caps and limit sea level rise. But rescuing civilisation this way would sacrifice Antarctica.

LONDON, 2 August, 2019 − German scientists have proposed a startling new way of slowing sea level rise and saving New York, Shanghai, Amsterdam and Miami from 3.3 metres of ocean flooding − by using artificial snow.

They suggest the rising seas could be halted by turning West Antarctica, one of the last undisturbed places on Earth, into an industrial snow complex, complete with a sophisticated distribution system.

An estimated 12,000 high-performance wind turbines could be used to generate the 145 Gigawatts of power (one Gigawatt supplies the energy for about 750,000 US homes) needed to lift Antarctic ocean water to heights of, on average, 640 metres, heat it, desalinate it and then spray it over 52,000 square kilometres of the West Antarctic ice sheet in the form of artificial snow, at the rate of several hundred billion tonnes a year, for decades.

Such action could slow or halt the apparently-inevitable collapse of the ice sheet: were this to melt entirely – and right now it is melting at the rate of 361 billion tonnes a year – the world’s oceans would rise by 3.3 metres.

“The fundamental trade-off is whether we as humanity want to sacrifice Antarctica to save the currently inhabited coastal regions and cultural heritage that we have built and are building on our shores,” said Anders Levermann of the Potsdam Institute for Climate Impact Research.

“The apparent absurdity of the endeavour to let it snow in Antarctica to stop an ice instability reflects the breathtaking dimension of the sea level problem”

“It is about global metropolises, from New York to Shanghai, which in the long term will be below sea level if nothing is done. The West Antarctic ice sheet is one of the tipping elements in our climate system. Ice loss is accelerating and might not stop until the West Antarctic ice sheet is practically gone.”

The Potsdam scientists report in the journal Science Advances that their simulations of ice loss from West Antarctica and the measures needed to halt such loss are not an alternative to other steps. Their calculations would be valid “only under a simultaneous drastic reduction” of the global carbon dioxide emissions that drive global heating, and sea level rise, in the first place.

That is, the world would need to abandon fossil fuels, agree to switch to renewable energy, and then use that renewable energy to in effect destroy the Antarctic’s unique ecosystem but save the great cities of the world from the advancing waves later in this millennium.

The researchers acknowledge that the solution is somewhere between impractical and impossible (in their words, it would have to be undertaken “under the difficult circumstances of the Antarctic climate”). But the mere fact that they could write such a proposal is itself an indicator of the accelerating seriousness of the planetary predicament.

In Paris in 2015, 195 nations agreed to take steps to limit global temperature rise to “well below” 2°C above the level that obtained for most of human history. Such steps for the most part have yet to be taken.

3°C rise possible

Carbon dioxide emissions are increasing, the Arctic ice cap is diminishing, the oceans are warming and the loss of ice in Antarctica is increasing.

By 2100, on present trends, the world will be at least 3°C above the historic average.

“The apparent absurdity of the endeavour to let it snow in Antarctica to stop an ice instability reflects the breathtaking dimension of the sea level problem,” Professor Levermann said.

“Yet as scientists we feel it is our duty to inform society about each and every potential option to counter the problems ahead.

“As unbelievable as it might seem, in order to prevent an unprecedented risk, humankind might have to make an unprecedented effort, too.” − Climate News Network

In theory, artificial snow could save the ice caps and limit sea level rise. But rescuing civilisation this way would sacrifice Antarctica.

LONDON, 2 August, 2019 − German scientists have proposed a startling new way of slowing sea level rise and saving New York, Shanghai, Amsterdam and Miami from 3.3 metres of ocean flooding − by using artificial snow.

They suggest the rising seas could be halted by turning West Antarctica, one of the last undisturbed places on Earth, into an industrial snow complex, complete with a sophisticated distribution system.

An estimated 12,000 high-performance wind turbines could be used to generate the 145 Gigawatts of power (one Gigawatt supplies the energy for about 750,000 US homes) needed to lift Antarctic ocean water to heights of, on average, 640 metres, heat it, desalinate it and then spray it over 52,000 square kilometres of the West Antarctic ice sheet in the form of artificial snow, at the rate of several hundred billion tonnes a year, for decades.

Such action could slow or halt the apparently-inevitable collapse of the ice sheet: were this to melt entirely – and right now it is melting at the rate of 361 billion tonnes a year – the world’s oceans would rise by 3.3 metres.

“The fundamental trade-off is whether we as humanity want to sacrifice Antarctica to save the currently inhabited coastal regions and cultural heritage that we have built and are building on our shores,” said Anders Levermann of the Potsdam Institute for Climate Impact Research.

“The apparent absurdity of the endeavour to let it snow in Antarctica to stop an ice instability reflects the breathtaking dimension of the sea level problem”

“It is about global metropolises, from New York to Shanghai, which in the long term will be below sea level if nothing is done. The West Antarctic ice sheet is one of the tipping elements in our climate system. Ice loss is accelerating and might not stop until the West Antarctic ice sheet is practically gone.”

The Potsdam scientists report in the journal Science Advances that their simulations of ice loss from West Antarctica and the measures needed to halt such loss are not an alternative to other steps. Their calculations would be valid “only under a simultaneous drastic reduction” of the global carbon dioxide emissions that drive global heating, and sea level rise, in the first place.

That is, the world would need to abandon fossil fuels, agree to switch to renewable energy, and then use that renewable energy to in effect destroy the Antarctic’s unique ecosystem but save the great cities of the world from the advancing waves later in this millennium.

The researchers acknowledge that the solution is somewhere between impractical and impossible (in their words, it would have to be undertaken “under the difficult circumstances of the Antarctic climate”). But the mere fact that they could write such a proposal is itself an indicator of the accelerating seriousness of the planetary predicament.

In Paris in 2015, 195 nations agreed to take steps to limit global temperature rise to “well below” 2°C above the level that obtained for most of human history. Such steps for the most part have yet to be taken.

3°C rise possible

Carbon dioxide emissions are increasing, the Arctic ice cap is diminishing, the oceans are warming and the loss of ice in Antarctica is increasing.

By 2100, on present trends, the world will be at least 3°C above the historic average.

“The apparent absurdity of the endeavour to let it snow in Antarctica to stop an ice instability reflects the breathtaking dimension of the sea level problem,” Professor Levermann said.

“Yet as scientists we feel it is our duty to inform society about each and every potential option to counter the problems ahead.

“As unbelievable as it might seem, in order to prevent an unprecedented risk, humankind might have to make an unprecedented effort, too.” − Climate News Network

Ice-free Greenland possible in 1,000 years

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

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

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

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

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

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

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

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

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

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

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

Greenhouse gas increase

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Greenhouse gas increase

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

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

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

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

Thirty years to climate meltdown – or not?

For years most of us largely ignored the idea of climate meltdown. Now we’re talking about it. So what should we be doing?

LONDON, 10 June, 2019 − How much of a threat is climate meltdown? Should we treat it as the biggest danger to life in the 21st century, or as one of many problems − serious, but manageable?

A new study says human civilisation itself could pass the point of no return by 2050. The Australian climate think-tank Breakthrough: National Centre for Climate Restoration says that unless humanity takes drastic and immediate action to save the climate, a combination of unstable food production, water shortages and extreme weather could lead to the breakdown of global society.

One renowned US climate scientist, Michael Mann of Pennsylvania State University, says that Breakthrough is exaggerating and its report could be counter-productive.

In the UK, though, Mark Maslin of University College London says the report underlines the deep concerns expressed by some security experts.

Act together

Chris Barrie, a retired Royal Australian Navy admiral and former Chief of the Australian Defence Force, is now an honorary professor at the Australian National University, Canberra.

In a foreword to the Breakthrough study he writes: “We must act collectively. We need strong, determined leadership in government, in business and in our communities to ensure a sustainable future for humankind.”

David Spratt, Breakthrough’s research director and a co-author of the study, says that “much knowledge produced for policymakers is too conservative,” but that the new paper, by showing the extreme end of what could happen in just the next three decades, aims to make the stakes clear. “The report speaks, in our opinion, a harsh but necessary truth,” he says.

“To reduce this risk and protect human civilisation, a massive global mobilisation of resources is needed in the coming decade to build a zero-emissions industrial system and set in train the restoration of a safe climate,” the report reads. “This would be akin in scale to the World War II emergency mobilisation.”

“Maybe, just maybe, it is time for our politicians to be worried and start to act to avoid the scenarios painted so vividly”

Breakthrough acknowledges that the worst possibility it foresees − the total collapse of civilisation by mid-century − is an example of a worst-case scenario, but it insists that “the world is currently completely unprepared to envisage, and even less deal with, the consequences of catastrophic climate change.”

The picture of the possible near future it presents is stark. By 2050, it says, the world could have reached:

  • a 3°C temperature rise, with a further 1°C in store
  • sea levels 0.5 metres above today’s, with a possible eventual rise of 25m
  • 55% of the world’s people subject to more than 20 days a year of heat “beyond the threshold of human survivability”
  • one billion people forced to leave the tropics
  • a 20% decline in crop yields, leaving too little food to feed the world
  • armed conflict likely and nuclear war possible.

The report’s authors conclude: “The scale of destruction is beyond our capacity to model, with a high likelihood of human civilisation coming to an end.”

Warnings examined

Warnings of the possible end of human civilisation are not new. They range from those which offer highly-qualified hope for humanity’s future to others which find very little to celebrate, even tentatively.

The Breakthrough study fits unequivocally into the second group. To weigh the credibility of some of its statements, the journal New Scientist looks at the sources they cite and the wider context of the claims they make.

Its scrutiny ends with the views of two eminent climate scientists. Michael Mann, professor of atmospheric science at Penn State, says: “I respect the authors and appreciate that their intentions are good, but … overblown rhetoric, exaggeration, and unsupportable doomist framing can be counteractive to climate action.”

For his part, Mark Maslin, professor of geography at UCL, tells New Scientist that the Breakthrough report adds to the deep concerns expressed by security experts such as the Pentagon over climate change.

Hope nurtured

“Maybe, just maybe, it is time for our politicians to be worried and start to act to avoid the scenarios painted so vividly,” he says.

The 2020 round of UN climate negotiations is due to take place in November next year, with hopes building that many countries will agree then to make much more radical cuts in greenhouse gas emissions than they have pledged so far.

Altogether 195 countries promised in 2015, in the Paris Agreement, to make the cuts needed to prevent global average temperatures rising more than 2°C, and if possible to stay below a maximum rise of 1.5°C, the levels climate scientists say are the highest that can assure the planet’s safety. But the cuts that many countries have promised so far will not achieve either goal.

Scientists say it is still possible for the world to achieve the 1.5°C limit. But doing so requires immediate emissions cuts, on a scale and at a pace that are not yet in sight − “a very big ‘if’”, as one of them put it. − Climate News Network

For years most of us largely ignored the idea of climate meltdown. Now we’re talking about it. So what should we be doing?

LONDON, 10 June, 2019 − How much of a threat is climate meltdown? Should we treat it as the biggest danger to life in the 21st century, or as one of many problems − serious, but manageable?

A new study says human civilisation itself could pass the point of no return by 2050. The Australian climate think-tank Breakthrough: National Centre for Climate Restoration says that unless humanity takes drastic and immediate action to save the climate, a combination of unstable food production, water shortages and extreme weather could lead to the breakdown of global society.

One renowned US climate scientist, Michael Mann of Pennsylvania State University, says that Breakthrough is exaggerating and its report could be counter-productive.

In the UK, though, Mark Maslin of University College London says the report underlines the deep concerns expressed by some security experts.

Act together

Chris Barrie, a retired Royal Australian Navy admiral and former Chief of the Australian Defence Force, is now an honorary professor at the Australian National University, Canberra.

In a foreword to the Breakthrough study he writes: “We must act collectively. We need strong, determined leadership in government, in business and in our communities to ensure a sustainable future for humankind.”

David Spratt, Breakthrough’s research director and a co-author of the study, says that “much knowledge produced for policymakers is too conservative,” but that the new paper, by showing the extreme end of what could happen in just the next three decades, aims to make the stakes clear. “The report speaks, in our opinion, a harsh but necessary truth,” he says.

“To reduce this risk and protect human civilisation, a massive global mobilisation of resources is needed in the coming decade to build a zero-emissions industrial system and set in train the restoration of a safe climate,” the report reads. “This would be akin in scale to the World War II emergency mobilisation.”

“Maybe, just maybe, it is time for our politicians to be worried and start to act to avoid the scenarios painted so vividly”

Breakthrough acknowledges that the worst possibility it foresees − the total collapse of civilisation by mid-century − is an example of a worst-case scenario, but it insists that “the world is currently completely unprepared to envisage, and even less deal with, the consequences of catastrophic climate change.”

The picture of the possible near future it presents is stark. By 2050, it says, the world could have reached:

  • a 3°C temperature rise, with a further 1°C in store
  • sea levels 0.5 metres above today’s, with a possible eventual rise of 25m
  • 55% of the world’s people subject to more than 20 days a year of heat “beyond the threshold of human survivability”
  • one billion people forced to leave the tropics
  • a 20% decline in crop yields, leaving too little food to feed the world
  • armed conflict likely and nuclear war possible.

The report’s authors conclude: “The scale of destruction is beyond our capacity to model, with a high likelihood of human civilisation coming to an end.”

Warnings examined

Warnings of the possible end of human civilisation are not new. They range from those which offer highly-qualified hope for humanity’s future to others which find very little to celebrate, even tentatively.

The Breakthrough study fits unequivocally into the second group. To weigh the credibility of some of its statements, the journal New Scientist looks at the sources they cite and the wider context of the claims they make.

Its scrutiny ends with the views of two eminent climate scientists. Michael Mann, professor of atmospheric science at Penn State, says: “I respect the authors and appreciate that their intentions are good, but … overblown rhetoric, exaggeration, and unsupportable doomist framing can be counteractive to climate action.”

For his part, Mark Maslin, professor of geography at UCL, tells New Scientist that the Breakthrough report adds to the deep concerns expressed by security experts such as the Pentagon over climate change.

Hope nurtured

“Maybe, just maybe, it is time for our politicians to be worried and start to act to avoid the scenarios painted so vividly,” he says.

The 2020 round of UN climate negotiations is due to take place in November next year, with hopes building that many countries will agree then to make much more radical cuts in greenhouse gas emissions than they have pledged so far.

Altogether 195 countries promised in 2015, in the Paris Agreement, to make the cuts needed to prevent global average temperatures rising more than 2°C, and if possible to stay below a maximum rise of 1.5°C, the levels climate scientists say are the highest that can assure the planet’s safety. But the cuts that many countries have promised so far will not achieve either goal.

Scientists say it is still possible for the world to achieve the 1.5°C limit. But doing so requires immediate emissions cuts, on a scale and at a pace that are not yet in sight − “a very big ‘if’”, as one of them put it. − Climate News Network

Unstable polar glaciers lose ice ever faster

As oceans warm, Antarctica’s ice sheets are at growing risk, with polar glaciers losing ice at rates to match the height of global monuments.

LONDON, 31 May, 2019 – Almost a quarter of all the glaciers in West Antarctica have been pronounced “unstable”. This means, in the simplest terms, that they are losing ice to the ocean faster than they can gain it from falling snow.

In the last 25 years most of the largest flows have accelerated the loss of ice fivefold.

And in places some glaciers, including those known as Pine Island and Thwaites, have “thinned” by 122 metres. That means that the thickness of the ice between the surface and the bedrock over which glaciers flow has fallen by almost the height of the Great Pyramid of Cheops in Egypt, and far more than the Statue of Liberty in New York or the tower of Big Ben in London.

The conclusions are based on climate simulation matched against 800 million measurements of the Antarctic ice sheet recorded by the altimeters aboard four orbiting satellites put up by the European Space Agency between 1992 and 2017. The conclusion is published in the journal Geophysical Research Letters.

“A wave of thinning has spread rapidly across some of Antarctica’s most vulnerable glaciers, and their losses are driving up sea levels around the planet”

Antarctic research is challenging. The continent is enormous – nearly twice the size of Australia – and frozen: 99.4% of it is covered by ice, to huge depths. It is also defined as a desert.

Snowfalls are low, but over millions of years these have built up to a reservoir of about nine-tenths of the planet’s fresh water, in the form of snow and ice.

It is also the coldest place on Earth and – even more of a problem for climate scientists – no observations or measurements of anything in Antarctica date back much further than the beginning of the 19th century. Most of the on-the-ground science is possible only in the Antarctic summer.

The latest study confirms a succession of alarming finds. The West Antarctic ice sheet is not just losing ice, it is doing so at ever-faster speeds. Scientists have already suggested that the rate of loss for the Pine Island and Thwaites glaciers could be irreversible. So much has already been lost that the bedrock, crushed by its burden of ice for aeons, is actually beginning to bounce up in response.

Huge ice losses

“In parts of Antarctica the ice sheet has thinned by extraordinary amounts, and we set out to show how much was due to changes in climate and how much was due to weather,” said Andrew Shepherd of the University of Leeds, UK, who led the research.

Changes in snowfall tended, they found, to be reflected over changes in height over large areas for a few years. But the most pronounced changes have persisted for decades: it’s the climate that is changing things, not the weather.

“Knowing how much snow has fallen has really helped us to detect the underlying change in glacier ice within the satellite record. We can see clearly now that a wave of thinning has spread rapidly across some of Antarctica’s most vulnerable glaciers, and their losses are driving up sea levels around the planet”, Professor Shepherd says.

“Altogether, ice losses from East and West Antarctica have contributed 4.6mm to global sea level rise since 1992.” – Climate News Network

As oceans warm, Antarctica’s ice sheets are at growing risk, with polar glaciers losing ice at rates to match the height of global monuments.

LONDON, 31 May, 2019 – Almost a quarter of all the glaciers in West Antarctica have been pronounced “unstable”. This means, in the simplest terms, that they are losing ice to the ocean faster than they can gain it from falling snow.

In the last 25 years most of the largest flows have accelerated the loss of ice fivefold.

And in places some glaciers, including those known as Pine Island and Thwaites, have “thinned” by 122 metres. That means that the thickness of the ice between the surface and the bedrock over which glaciers flow has fallen by almost the height of the Great Pyramid of Cheops in Egypt, and far more than the Statue of Liberty in New York or the tower of Big Ben in London.

The conclusions are based on climate simulation matched against 800 million measurements of the Antarctic ice sheet recorded by the altimeters aboard four orbiting satellites put up by the European Space Agency between 1992 and 2017. The conclusion is published in the journal Geophysical Research Letters.

“A wave of thinning has spread rapidly across some of Antarctica’s most vulnerable glaciers, and their losses are driving up sea levels around the planet”

Antarctic research is challenging. The continent is enormous – nearly twice the size of Australia – and frozen: 99.4% of it is covered by ice, to huge depths. It is also defined as a desert.

Snowfalls are low, but over millions of years these have built up to a reservoir of about nine-tenths of the planet’s fresh water, in the form of snow and ice.

It is also the coldest place on Earth and – even more of a problem for climate scientists – no observations or measurements of anything in Antarctica date back much further than the beginning of the 19th century. Most of the on-the-ground science is possible only in the Antarctic summer.

The latest study confirms a succession of alarming finds. The West Antarctic ice sheet is not just losing ice, it is doing so at ever-faster speeds. Scientists have already suggested that the rate of loss for the Pine Island and Thwaites glaciers could be irreversible. So much has already been lost that the bedrock, crushed by its burden of ice for aeons, is actually beginning to bounce up in response.

Huge ice losses

“In parts of Antarctica the ice sheet has thinned by extraordinary amounts, and we set out to show how much was due to changes in climate and how much was due to weather,” said Andrew Shepherd of the University of Leeds, UK, who led the research.

Changes in snowfall tended, they found, to be reflected over changes in height over large areas for a few years. But the most pronounced changes have persisted for decades: it’s the climate that is changing things, not the weather.

“Knowing how much snow has fallen has really helped us to detect the underlying change in glacier ice within the satellite record. We can see clearly now that a wave of thinning has spread rapidly across some of Antarctica’s most vulnerable glaciers, and their losses are driving up sea levels around the planet”, Professor Shepherd says.

“Altogether, ice losses from East and West Antarctica have contributed 4.6mm to global sea level rise since 1992.” – Climate News Network

Sea level rise may double forecast for 2100

Scientists say global sea level rise could far exceed predictions because of faster melting in Greenland and Antarctica.

LONDON, 22 May, 2019 − If you are among the many millions of people who live near the world’s coasts, it will probably be worth your while to read this: sea level rise could be much greater than we expect.

A team of international scientists led by the University of Bristol, UK, has looked again at the estimates of how much the world’s oceans are likely to rise during this century. It concludes that the figure could be far higher than previous studies suggested.

In an extreme case, the members say, sea level rise over the next 80 years could mean that by 2100 the oceans will have risen by around six feet (two metres) − roughly twice the level thought likely till now, with “pretty unimaginable” consequences

In its fifth assessment report, published in 2013, the Intergovernmental Panel on Climate Change (IPCC) said the continued warming of the Earth, if there were no major reductions in greenhouse gas emissions, would see the seas rising by between 52cm and 98cm by 2100.

Sombre prospect

Many climate scientists have argued that this was a conservative estimate. The possibility that the eventual figure could be around double the forecast, threatening hundreds of millions of people with having to leave their homes, is sobering. It is published in the Proceedings of the National Academy of Sciences (PNAS).

The Bristol team used a different way of trying to gauge the possible effect of the way the ice is melting in Greenland, West and East Antarctica, not relying simply on projections from numerical models.

Their method used a technique called a structured expert judgement study, which involved 22 ice sheet experts in estimating plausible ranges for future sea level rise caused by the projected melting of the ice sheets in each of the three areas studied, under low and high future global temperature rise scenarios.

If emissions continue on their current path, the business-as-usual scenario, the researchers say, then the world’s seas would be very likely to rise by between 62cm and 238cm by 2100. This would be in a world that had warmed by around 5°C, one of the worst-case scenarios for global warming.

 

“I think that a 5% probability, crikey − I think that’s a serious risk. If we see something like that in the next 80 years we are looking at social breakdown on scales that are pretty unimaginable”

“For 2100, the ice sheet contribution is very likely in the range of 7-178cm but once you add in glaciers and ice caps outside the ice sheets and thermal expansion of the seas, you tip well over two metres,” said the lead author, Jonathan Bamber, of the University of Bristol.

He added: “Such a rise in global sea level could result in land loss of 1.79 million sq km, including critical regions of food production, and potential displacement of up to 187 million people.”

For temperature rises expected up to 2°C Greenland’s ice sheet makes the single biggest contribution to sea level rise. But as temperatures climb further the much larger Antarctic ice sheets become involved.

“When you start to look at these lower-likelihood but still plausible values, then the experts believe that there is a small but statistically significant probability that West Antarctica will transition to a very unstable state, and parts of East Antarctica will start contributing as well,” said Professor Bamber.

“But it’s only at these higher probabilities for 5°C that we see those types of behaviours kicking in.”

Mass exodus

Globally important food-growing areas such as the Nile delta would be liable to vanish beneath the waves, and large parts of Bangladesh. Major global cities including London, New York, Rio de Janeiro and Shanghai would face significant threats.

“To put this into perspective, the Syrian refugee crisis resulted in about a million refugees coming into Europe,” said Professor Bamber.

Polar science is making striking advances in understanding what is happening to the Greenland and Antarctic ice sheets. New satellite measurements are showing ice mass loss happening faster than models expected, and there is also something called the marine ice-cliff instability hypothesis, which assumes that coastal ice cliffs can rapidly collapse after ice shelves disintegrate, as a result of surface and sub-shelf melting caused by global warming.

Serious risk

The chances of sea level rise as devastating as this are small, the Bristol team say − about 5%. But they should be taken seriously.

“If I said to you that there was a one in 20 chance that if you crossed the road you would be squashed you wouldn’t go near it,” Professor Bamber said.

“Even a 1% probability means that a one in a hundred year flood is something that could happen in your lifetime. I think that a 5% probability, crikey − I think that’s a serious risk.

“If we see something like that in the next 80 years we are looking at social breakdown on scales that are pretty unimaginable.” − Climate News Network

Scientists say global sea level rise could far exceed predictions because of faster melting in Greenland and Antarctica.

LONDON, 22 May, 2019 − If you are among the many millions of people who live near the world’s coasts, it will probably be worth your while to read this: sea level rise could be much greater than we expect.

A team of international scientists led by the University of Bristol, UK, has looked again at the estimates of how much the world’s oceans are likely to rise during this century. It concludes that the figure could be far higher than previous studies suggested.

In an extreme case, the members say, sea level rise over the next 80 years could mean that by 2100 the oceans will have risen by around six feet (two metres) − roughly twice the level thought likely till now, with “pretty unimaginable” consequences

In its fifth assessment report, published in 2013, the Intergovernmental Panel on Climate Change (IPCC) said the continued warming of the Earth, if there were no major reductions in greenhouse gas emissions, would see the seas rising by between 52cm and 98cm by 2100.

Sombre prospect

Many climate scientists have argued that this was a conservative estimate. The possibility that the eventual figure could be around double the forecast, threatening hundreds of millions of people with having to leave their homes, is sobering. It is published in the Proceedings of the National Academy of Sciences (PNAS).

The Bristol team used a different way of trying to gauge the possible effect of the way the ice is melting in Greenland, West and East Antarctica, not relying simply on projections from numerical models.

Their method used a technique called a structured expert judgement study, which involved 22 ice sheet experts in estimating plausible ranges for future sea level rise caused by the projected melting of the ice sheets in each of the three areas studied, under low and high future global temperature rise scenarios.

If emissions continue on their current path, the business-as-usual scenario, the researchers say, then the world’s seas would be very likely to rise by between 62cm and 238cm by 2100. This would be in a world that had warmed by around 5°C, one of the worst-case scenarios for global warming.

 

“I think that a 5% probability, crikey − I think that’s a serious risk. If we see something like that in the next 80 years we are looking at social breakdown on scales that are pretty unimaginable”

“For 2100, the ice sheet contribution is very likely in the range of 7-178cm but once you add in glaciers and ice caps outside the ice sheets and thermal expansion of the seas, you tip well over two metres,” said the lead author, Jonathan Bamber, of the University of Bristol.

He added: “Such a rise in global sea level could result in land loss of 1.79 million sq km, including critical regions of food production, and potential displacement of up to 187 million people.”

For temperature rises expected up to 2°C Greenland’s ice sheet makes the single biggest contribution to sea level rise. But as temperatures climb further the much larger Antarctic ice sheets become involved.

“When you start to look at these lower-likelihood but still plausible values, then the experts believe that there is a small but statistically significant probability that West Antarctica will transition to a very unstable state, and parts of East Antarctica will start contributing as well,” said Professor Bamber.

“But it’s only at these higher probabilities for 5°C that we see those types of behaviours kicking in.”

Mass exodus

Globally important food-growing areas such as the Nile delta would be liable to vanish beneath the waves, and large parts of Bangladesh. Major global cities including London, New York, Rio de Janeiro and Shanghai would face significant threats.

“To put this into perspective, the Syrian refugee crisis resulted in about a million refugees coming into Europe,” said Professor Bamber.

Polar science is making striking advances in understanding what is happening to the Greenland and Antarctic ice sheets. New satellite measurements are showing ice mass loss happening faster than models expected, and there is also something called the marine ice-cliff instability hypothesis, which assumes that coastal ice cliffs can rapidly collapse after ice shelves disintegrate, as a result of surface and sub-shelf melting caused by global warming.

Serious risk

The chances of sea level rise as devastating as this are small, the Bristol team say − about 5%. But they should be taken seriously.

“If I said to you that there was a one in 20 chance that if you crossed the road you would be squashed you wouldn’t go near it,” Professor Bamber said.

“Even a 1% probability means that a one in a hundred year flood is something that could happen in your lifetime. I think that a 5% probability, crikey − I think that’s a serious risk.

“If we see something like that in the next 80 years we are looking at social breakdown on scales that are pretty unimaginable.” − Climate News Network

Half of melting glaciers could go by 2100

Melting glaciers worldwide – all treasured for their beauty and as sources of summer water – could be half gone by 2100.

LONDON, 13 May, 2019 – Around half of some of the world’s most beautiful mountain ranges are about to lose their melting glaciers, the force that shapes and highlights their beauty.

Swiss-based scientists investigated 46 world heritage sites nominated by UNESCO, the UN Educational, Scientific and Cultural Organisation, and compiled an inventory of 19,000 glaciers. And then, they report in the journal Earth’s Future, they calculated recent changes and the glaciers’ present condition and projected the rate of mass loss into the future.

They warn that, if the world goes on burning fossil fuels at ever-increasing rates, almost half of all these glaciers will have vanished by 2100.

In somewhere between eight and 21 such world heritage sites – national parks that have a profound role in water management and often a powerful economic role as tourist attractions – there may be no glaciers at all by the century’s end.

Strengthened commitment

“Losing these iconic glaciers would be a tragedy and have major consequences for the availability of water resources, sea level rise and weather patterns,” warned Peter Shadie, who directs the world heritage programme of the International Union for the Conservation of Nature (IUCN).

“This unprecedented decline could also jeopardise the listing of the sites in question on the World Heritage list. States must reinforce their commitments to combat climate change and step up efforts to preserve these glaciers for future generations.”

And Jean-Baptiste Bosson, of the IUCN’s headquarters in Gland, Switzerland, who led the study, said: “We urgently need to see significant cuts in greenhouse gas emissions. This is the only way of avoiding long-lasting and irreversible glacier decline and the major natural, social, economic and migratory cascading consequences.”

Essentially, the study was based on a review of research so far: for more than a decade scientists have been alarmed at the increasing rates of loss in the great frozen rivers at high altitude and on the polar ice caps, in ways that will harm wealthy communities as well as poor farmers in both Asia and South America.

“Losing these iconic glaciers would be a tragedy and have major consequences for the availability of water resources, sea level rise and weather patterns”

But the researchers also looked at North America’s burden of mountain ice to forecast up to 70% of loss by 2100, and in the Pyrenees between France and Spain they warned of losses as early as 2040. Te Wahipounamu in the south-west of New Zealand could say farewell to between 25% and 80% of its ice this century.

The researchers looked at a series of projections for global warming. In some cases, the loss is inexorable. Even if the 195 nations that in Paris in 2015 vowed to keep global average temperatures “well below” a rise of 2°C by the end of the century actually take the drastic steps needed to keep that promise, at least a third of all the ice will disappear, and entirely in eight sites.

If the Paris signatories carry on with business as usual, the rate of loss could reach 60% in the 46 sites, and 21 of those would have lost all traces of ice altogether.

“The study of glacier decline further emphasises the need for individual and collective actions to achieve the mitigation and adaptation aspirations of the Paris Agreement on climate change,” Dr Bosson said. – Climate News Network

Melting glaciers worldwide – all treasured for their beauty and as sources of summer water – could be half gone by 2100.

LONDON, 13 May, 2019 – Around half of some of the world’s most beautiful mountain ranges are about to lose their melting glaciers, the force that shapes and highlights their beauty.

Swiss-based scientists investigated 46 world heritage sites nominated by UNESCO, the UN Educational, Scientific and Cultural Organisation, and compiled an inventory of 19,000 glaciers. And then, they report in the journal Earth’s Future, they calculated recent changes and the glaciers’ present condition and projected the rate of mass loss into the future.

They warn that, if the world goes on burning fossil fuels at ever-increasing rates, almost half of all these glaciers will have vanished by 2100.

In somewhere between eight and 21 such world heritage sites – national parks that have a profound role in water management and often a powerful economic role as tourist attractions – there may be no glaciers at all by the century’s end.

Strengthened commitment

“Losing these iconic glaciers would be a tragedy and have major consequences for the availability of water resources, sea level rise and weather patterns,” warned Peter Shadie, who directs the world heritage programme of the International Union for the Conservation of Nature (IUCN).

“This unprecedented decline could also jeopardise the listing of the sites in question on the World Heritage list. States must reinforce their commitments to combat climate change and step up efforts to preserve these glaciers for future generations.”

And Jean-Baptiste Bosson, of the IUCN’s headquarters in Gland, Switzerland, who led the study, said: “We urgently need to see significant cuts in greenhouse gas emissions. This is the only way of avoiding long-lasting and irreversible glacier decline and the major natural, social, economic and migratory cascading consequences.”

Essentially, the study was based on a review of research so far: for more than a decade scientists have been alarmed at the increasing rates of loss in the great frozen rivers at high altitude and on the polar ice caps, in ways that will harm wealthy communities as well as poor farmers in both Asia and South America.

“Losing these iconic glaciers would be a tragedy and have major consequences for the availability of water resources, sea level rise and weather patterns”

But the researchers also looked at North America’s burden of mountain ice to forecast up to 70% of loss by 2100, and in the Pyrenees between France and Spain they warned of losses as early as 2040. Te Wahipounamu in the south-west of New Zealand could say farewell to between 25% and 80% of its ice this century.

The researchers looked at a series of projections for global warming. In some cases, the loss is inexorable. Even if the 195 nations that in Paris in 2015 vowed to keep global average temperatures “well below” a rise of 2°C by the end of the century actually take the drastic steps needed to keep that promise, at least a third of all the ice will disappear, and entirely in eight sites.

If the Paris signatories carry on with business as usual, the rate of loss could reach 60% in the 46 sites, and 21 of those would have lost all traces of ice altogether.

“The study of glacier decline further emphasises the need for individual and collective actions to achieve the mitigation and adaptation aspirations of the Paris Agreement on climate change,” Dr Bosson said. – Climate News Network

Heat makes ocean winds and waves fiercer

The seas are rising. Ocean winds and waves are growing in speed and force. The oceans could be feeling the heat.

LONDON, 1 May, 2019 − The great swells of the Pacific are beginning to swell even more as fiercer ocean winds and waves leave their mark. The breakers that crash on the storm beaches now do so with greater force. The white horses are gathering pace.

A 33-year-study of data from 31 satellites and 80 ocean buoys has confirmed suspicions. The extreme ocean winds are now fiercer, and the waves are getting measurably higher.

It is a given of global warming that as average planetary temperatures rise, then more energy is available for storm, rainfall and drought.

In the past century, because of ever-increasing combustion of fossil fuels that release growing quantities of greenhouse gases, average global temperatures have crept higher by 1°C and in three decades the speed of extreme winds in the Southern Ocean has increased by 8%, or 1.5 metres per second. Extreme waves have increased by 30cms, or 5%, over the same period.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk”

“Although increases of 5 and 8% might not seem like much, if sustained into the future such changes to our climate will have major impacts,” said Ian Young, an engineer at the University of Melbourne in Australia

He and a colleague report in the journal Science that they reached their conclusion on the basis of 4 billion observations made between 1985 and 2018.

“Flooding events are caused by storm surge and associated breaking waves. The increased sea level makes these events more serious and more frequent,” said Professor Young. “Increases in wave height, and changes in other properties such as wave direction, will further increase the probability of coastal flooding.”

Sea levels have been creeping ever higher, in large part because of the retreat of most of the planet’s great glaciers and the ever-increasing meltwater from Greenland and West Antarctica, and also as a simple matter of physics: as the oceans warm, the waters become less dense and sea levels rise.

Difficult measurements

Surfers and pleasure-seekers began to worry about the impact of global warming and climate change on wave patterns years ago. But seemingly simple phenomena such as the effects wave height and wind speed have in the open oceans on a world-wide basis are harder to measure.

Spanish oceanographers reported earlier this year that they were sure that ocean waves were gathering in force and strength, and European engineers have warned of the impact of more intense storms backed up by rising seas on the Atlantic ports and coastlines of the continent.

But there are problems: precision measurements have been made only recently. Oceanographers cannot be sure that they are not witnessing a natural cycle of ocean change, in which storm intensities slowly vary over a pattern of decades.

Since 1985 earth observation satellites have been equipped with altimeters to measure wave height and wind speed, radiometers to measure wind speed, and scatterometers to record wind speed and direction. The next problem has been calibrating data from a range of different satellites, and indeed the slightly different stories told by instruments on the same satellite.

Worse to come

But the Australian engineers report that they are now 90% confident that they can measure ocean change: violent storms now arrive with higher wave crests and more dangerous winds than they did in 1985, and although this is true worldwide, the effect is most pronounced in the great ocean that swirls around Antarctica.

The next challenge is to make estimates of how much more violent the worst sea storms are likely to become later in the century, as planetary average temperatures – and sea levels – continue to rise.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk,” Professor Young said.

“We need a better understanding of how much this change is due to long-term climate change, and how much is due to multi-decadal fluctuations or cycles.” − Climate News Network

The seas are rising. Ocean winds and waves are growing in speed and force. The oceans could be feeling the heat.

LONDON, 1 May, 2019 − The great swells of the Pacific are beginning to swell even more as fiercer ocean winds and waves leave their mark. The breakers that crash on the storm beaches now do so with greater force. The white horses are gathering pace.

A 33-year-study of data from 31 satellites and 80 ocean buoys has confirmed suspicions. The extreme ocean winds are now fiercer, and the waves are getting measurably higher.

It is a given of global warming that as average planetary temperatures rise, then more energy is available for storm, rainfall and drought.

In the past century, because of ever-increasing combustion of fossil fuels that release growing quantities of greenhouse gases, average global temperatures have crept higher by 1°C and in three decades the speed of extreme winds in the Southern Ocean has increased by 8%, or 1.5 metres per second. Extreme waves have increased by 30cms, or 5%, over the same period.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk”

“Although increases of 5 and 8% might not seem like much, if sustained into the future such changes to our climate will have major impacts,” said Ian Young, an engineer at the University of Melbourne in Australia

He and a colleague report in the journal Science that they reached their conclusion on the basis of 4 billion observations made between 1985 and 2018.

“Flooding events are caused by storm surge and associated breaking waves. The increased sea level makes these events more serious and more frequent,” said Professor Young. “Increases in wave height, and changes in other properties such as wave direction, will further increase the probability of coastal flooding.”

Sea levels have been creeping ever higher, in large part because of the retreat of most of the planet’s great glaciers and the ever-increasing meltwater from Greenland and West Antarctica, and also as a simple matter of physics: as the oceans warm, the waters become less dense and sea levels rise.

Difficult measurements

Surfers and pleasure-seekers began to worry about the impact of global warming and climate change on wave patterns years ago. But seemingly simple phenomena such as the effects wave height and wind speed have in the open oceans on a world-wide basis are harder to measure.

Spanish oceanographers reported earlier this year that they were sure that ocean waves were gathering in force and strength, and European engineers have warned of the impact of more intense storms backed up by rising seas on the Atlantic ports and coastlines of the continent.

But there are problems: precision measurements have been made only recently. Oceanographers cannot be sure that they are not witnessing a natural cycle of ocean change, in which storm intensities slowly vary over a pattern of decades.

Since 1985 earth observation satellites have been equipped with altimeters to measure wave height and wind speed, radiometers to measure wind speed, and scatterometers to record wind speed and direction. The next problem has been calibrating data from a range of different satellites, and indeed the slightly different stories told by instruments on the same satellite.

Worse to come

But the Australian engineers report that they are now 90% confident that they can measure ocean change: violent storms now arrive with higher wave crests and more dangerous winds than they did in 1985, and although this is true worldwide, the effect is most pronounced in the great ocean that swirls around Antarctica.

The next challenge is to make estimates of how much more violent the worst sea storms are likely to become later in the century, as planetary average temperatures – and sea levels – continue to rise.

“These changes have impacts that are felt all over the world. Storm waves can increase coastal erosion, putting coastal settlements and infrastructures at risk,” Professor Young said.

“We need a better understanding of how much this change is due to long-term climate change, and how much is due to multi-decadal fluctuations or cycles.” − Climate News Network

Fast Arctic melt could cost $70 trillion

Polar change, notably the fast Arctic melt, could impose huge costs on world economies. New evidence shows how rapidly the frozen north is changing.

LONDON, 26 April, 2019 – The northern reaches of the planet are undergoing very rapid change: the fast Arctic melt means the region is warming at twice the speed of the planetary average.

The loss of sea ice and land snow could tip the planet into a new and unprecedented cycle of climatic change and add yet another $70 trillion (£54 tn) to the estimated economic cost of global warming.

In yet another sombre statement of the challenge presented by climate change, driven by ever-increasing emissions of greenhouse gases from the fossil fuels that power the global economy, British, European and US researchers took a look at two manifestations of warming.

One is the growing levels of ancient carbon now being released into the atmosphere as the Arctic permafrost begins to melt. The other is the reduced reflection of solar radiation back into space as what had once been an expanse of snow and ice melts, to expose ever greater areas of light-absorbing blue sea, dark rock and scrubby tundra.

Abrupt surprises

The concern is with what the scientists like to call “non-linear transitions”. The fear is not that global warming will simply get more pronounced as more snow and ice disappears. The fear is that at some point the melting will reach a threshold that could tip the planet into a new climate regime that would be irreversible, and for which there has been no parallel in human history.

And if so, the costs in terms of climate disruption, heat waves, rising sea levels, harvest failures, more violent storms and more devastating floods and so on could start to soar.

The scientists report in the journal Nature Communications that if the nations of the world were to keep a promise made in Paris in 2015 to contain planetary warming to “well below” 2°C above the average for most of human history by the year 2100, the extra cost of Arctic ice loss would still tip $24 tn.

But on the evidence of national plans tabled so far, the world seems on course to hit 3°C by the century’s end, and the extra cost to the global economies is estimated at almost $70 tn.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic”

If the world goes on burning more and more fossil fuels – this is called the business-as-usual scenario – then global temperatures could rise to 4°C above the historic average by 2100. The bill for what the scientists call “the most expensive and least desirable scenario” is set at $2197 tn. And, they stress, their forecast $70 tn is just the extra cost of the melting Arctic.

They have not factored in all the other much-feared potential “tipping points” such as the loss of the tropical rainforests that absorb so much of the atmospheric carbon, the collapse of the great Atlantic current that distributes equatorial heat to temperate climates, the loss of the West Antarctic ice sheet, and other irreversible changes.

As they see it, even to contain global warming to 1.5°C by 2100 could cost a global $600 trillion.

And although the thawing of the permafrost and the opening of the Arctic Ocean would deliver mining and shipping opportunities, any such rewards would be dwarfed by the cost of the emissions from the thawing permafrost, and the reduction of what scientists call albedo: the reflectivity of pristine ice and snow that helps keep the Arctic frozen.

Model-based estimates

Research of this kind is based on vast numbers of simulations of the global economies under a range of scenarios, and the calculations of cost remain just that, estimates based on models of what nations might or might not do. The price economies must pay will be real enough, but the advanced accounting of what has yet to happen remains academic.

But the changes in the Arctic are far from academic, according to a series of new studies of what has been happening, and is happening right now.

●Researchers in California report in the Proceedings of the National Academy of Sciences that they have now reconstructed change in the Greenland ice sheet between 1972 and 2018, to estimate the loss of ice.

Fifty years ago, the northern hemisphere’s greatest sheet of ice was losing 47 billion tonnes of ice every year, and by the next decade 50 bn tonnes annually.

Sea levels raised

Since then the losses have risen almost six-fold, and since 2010 the island has been losing ice at the rate of 290 billion tonnes a year. So far, ice from Greenland alone has raised sea levels by almost 14 mm.

●German scientists have looked at the results of 15 years of observations by the Grace satellite system – the acronym stands for Gravity Recovery and Climate Experiment – which ended in 2018. They calculate that between April 2002 and June 2017, Greenland lost about 260 bn tonnes of ice each year, and Antarctica 140 bn tonnes.

They warn in the journal Nature Climate Change that melting at this rate could accelerate sea level rise to 10 mm a year – faster than at any time in the last 5,000 years – as a direct consequence of a warming climate.

●And the traffic of sea ice across the Arctic ocean has begun to falter, according to German oceanographers. The Transpolar Drift is a slow flow of new sea ice from the Siberian Arctic across the pole to the Fram Strait east of Greenland.

Melting too early

It has its place in the history of polar exploration: in 1893 the Norwegian explorer Fridtjof Nansen deliberately sailed his ship the Fram into the ice pack off Siberia and went with the floes across the Arctic.

The Drift is a kind of frozen ocean conveyor that carries nutrients, algae and sediments across the pole. But, researchers say in the journal Scientific Reports, this flow has started to vary. Most of the young ice off the Siberian coast now melts before it can leave its “nursery”. Once, half the ice from the Russian shelf completed the journey. Now, only one-fifth does.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic,” said Thomas Krumpen of the Alfred Wegener Institute, who led the study.

“The ice now leaving the Arctic through the Fram Strait is, on average, 30% thinner than it was 15 years ago.” – Climate News Network

Polar change, notably the fast Arctic melt, could impose huge costs on world economies. New evidence shows how rapidly the frozen north is changing.

LONDON, 26 April, 2019 – The northern reaches of the planet are undergoing very rapid change: the fast Arctic melt means the region is warming at twice the speed of the planetary average.

The loss of sea ice and land snow could tip the planet into a new and unprecedented cycle of climatic change and add yet another $70 trillion (£54 tn) to the estimated economic cost of global warming.

In yet another sombre statement of the challenge presented by climate change, driven by ever-increasing emissions of greenhouse gases from the fossil fuels that power the global economy, British, European and US researchers took a look at two manifestations of warming.

One is the growing levels of ancient carbon now being released into the atmosphere as the Arctic permafrost begins to melt. The other is the reduced reflection of solar radiation back into space as what had once been an expanse of snow and ice melts, to expose ever greater areas of light-absorbing blue sea, dark rock and scrubby tundra.

Abrupt surprises

The concern is with what the scientists like to call “non-linear transitions”. The fear is not that global warming will simply get more pronounced as more snow and ice disappears. The fear is that at some point the melting will reach a threshold that could tip the planet into a new climate regime that would be irreversible, and for which there has been no parallel in human history.

And if so, the costs in terms of climate disruption, heat waves, rising sea levels, harvest failures, more violent storms and more devastating floods and so on could start to soar.

The scientists report in the journal Nature Communications that if the nations of the world were to keep a promise made in Paris in 2015 to contain planetary warming to “well below” 2°C above the average for most of human history by the year 2100, the extra cost of Arctic ice loss would still tip $24 tn.

But on the evidence of national plans tabled so far, the world seems on course to hit 3°C by the century’s end, and the extra cost to the global economies is estimated at almost $70 tn.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic”

If the world goes on burning more and more fossil fuels – this is called the business-as-usual scenario – then global temperatures could rise to 4°C above the historic average by 2100. The bill for what the scientists call “the most expensive and least desirable scenario” is set at $2197 tn. And, they stress, their forecast $70 tn is just the extra cost of the melting Arctic.

They have not factored in all the other much-feared potential “tipping points” such as the loss of the tropical rainforests that absorb so much of the atmospheric carbon, the collapse of the great Atlantic current that distributes equatorial heat to temperate climates, the loss of the West Antarctic ice sheet, and other irreversible changes.

As they see it, even to contain global warming to 1.5°C by 2100 could cost a global $600 trillion.

And although the thawing of the permafrost and the opening of the Arctic Ocean would deliver mining and shipping opportunities, any such rewards would be dwarfed by the cost of the emissions from the thawing permafrost, and the reduction of what scientists call albedo: the reflectivity of pristine ice and snow that helps keep the Arctic frozen.

Model-based estimates

Research of this kind is based on vast numbers of simulations of the global economies under a range of scenarios, and the calculations of cost remain just that, estimates based on models of what nations might or might not do. The price economies must pay will be real enough, but the advanced accounting of what has yet to happen remains academic.

But the changes in the Arctic are far from academic, according to a series of new studies of what has been happening, and is happening right now.

●Researchers in California report in the Proceedings of the National Academy of Sciences that they have now reconstructed change in the Greenland ice sheet between 1972 and 2018, to estimate the loss of ice.

Fifty years ago, the northern hemisphere’s greatest sheet of ice was losing 47 billion tonnes of ice every year, and by the next decade 50 bn tonnes annually.

Sea levels raised

Since then the losses have risen almost six-fold, and since 2010 the island has been losing ice at the rate of 290 billion tonnes a year. So far, ice from Greenland alone has raised sea levels by almost 14 mm.

●German scientists have looked at the results of 15 years of observations by the Grace satellite system – the acronym stands for Gravity Recovery and Climate Experiment – which ended in 2018. They calculate that between April 2002 and June 2017, Greenland lost about 260 bn tonnes of ice each year, and Antarctica 140 bn tonnes.

They warn in the journal Nature Climate Change that melting at this rate could accelerate sea level rise to 10 mm a year – faster than at any time in the last 5,000 years – as a direct consequence of a warming climate.

●And the traffic of sea ice across the Arctic ocean has begun to falter, according to German oceanographers. The Transpolar Drift is a slow flow of new sea ice from the Siberian Arctic across the pole to the Fram Strait east of Greenland.

Melting too early

It has its place in the history of polar exploration: in 1893 the Norwegian explorer Fridtjof Nansen deliberately sailed his ship the Fram into the ice pack off Siberia and went with the floes across the Arctic.

The Drift is a kind of frozen ocean conveyor that carries nutrients, algae and sediments across the pole. But, researchers say in the journal Scientific Reports, this flow has started to vary. Most of the young ice off the Siberian coast now melts before it can leave its “nursery”. Once, half the ice from the Russian shelf completed the journey. Now, only one-fifth does.

“What we are witnessing is a major transport current faltering, which is bringing the world one step closer to a sea ice-free summer in the Arctic,” said Thomas Krumpen of the Alfred Wegener Institute, who led the study.

“The ice now leaving the Arctic through the Fram Strait is, on average, 30% thinner than it was 15 years ago.” – Climate News Network

Life within The Wall keeps The Others at bay

What would it be like to live behind a barrier built to keep the world out? The Wall explores a post-climate change world.

LONDON, 25 April, 2019 − John Lanchester’s latest novel, The Wall, is pure fiction. Isn’t it?

It has haves and have-nots battling each other in the aftermath of dramatic alterations in climate. Right now, ignored for the most part by the outside world, thousands of people are being held in appalling conditions in camps in Libya.

Libya is a key setting-off point for migrants, mostly from countries in Africa, seeking a better life across the Mediterranean in Europe. Often they are fleeing from violence and persecution in their home countries. Many are escaping from hunger and the impact climate change is having on agricultural communities.

The European Union, anxious to secure its borders, has been sending millions of euros to military forces in Libya to control the migrant flow.

Now there is a growing threat of full-scale civil war in Libya, and the migrants are trapped – often going for days without provisions – as fighting goes on around them. It is a humanitarian disaster – and a terrible indictment of EU migration policy.

Frantic search

In Lanchester’s futuristic novel The Wall, people are roaming the world in ever greater numbers. We are not told when the book is set but, as with those migrants captive in Libya today, they are desperately searching for some sort of safe haven.

To prevent incursions, a massive concrete wall has been built around the entire coast of Britain.

Kavanagh, the book’s main character, is what’s called a Defender, part of an army of guards which patrols the wall to prevent it being breached by the seaborne forces of those known as the Others − in today’s parlance, migrants or refugees.

Slowly, as in the best kind of mystery writing, we accumulate some background. There has been a momentous event which, in Defender terminology, is referred to as the Change but in the language of one of the Others is called kuishia, a Swahili word that means “the ending”.

“In living memory the sea floor below us was dry land. All drowned now. Part of the old drowned world”

We are not told directly about the Change but can surmise it refers to a profound shift in the global climate leading to, among other things, a sudden rise in sea levels.

It is a harsh, amoral, world. For Kavanagh and his fellow Defenders, all Others are the enemy and have to be killed. The only Others allowed to exist within the wall are what are called Help – virtual slaves who assist in doing menial jobs or who can be called upon to act as carers.

Lanchester might be writing of an imagined future, but there are striking parallels with today’s labour market in the UK and elsewhere. And of course the book appears at a time when countries seem to be increasingly turning in on themselves: walls and other barriers are not going up just in the US.

In the book the Change is described as happening over a relatively short time span, in the space of a single generation.

Kavanagh goes home on leave. He doesn’t like his parents and they feel uncomfortable round their son.

Culpable generation

“It’s guilt: mass guilt, generational guilt”, Kavanagh tells us. “The olds feel they irretrievably fucked up the world, then allowed us to be born into it. You know what? It’s true. That’s exactly what they did. They know it, we know it. Everybody knows it.”

The world’s beaches have disappeared, along with the old riverscapes. Kavanagh leaves his parents as they watch images of the past on TV – an old documentary showing golden beaches and surfers cavorting in the waves.

An elite constantly warns that as the Change continues and intensifies, the numbers of Others attempting to scale the wall will grow. There are traitors within who might even try to assist these invaders.

We are drawn into Kavanagh’s world. He is bored, he yearns to be away from the wall, yet it becomes a part of him.

Kavanagh falls in love. He gets drunk. He is hungry. (Britain has became self-sufficient in food, though this seems limited to berries and root crops, with turnips a staple).

Fierce fighters

There are dramatic, deadly, fights. Lanchester is a master at letting the reader’s imagination fill in the blanks. Only once are we given some hint of the Others’ identities.

“They were trained and competent. They were from sub-Saharan Africa. It was quite likely that they had been professional soldiers in their previous lives.”

For failing to stop a group of Others from vaulting the wall, Kavanagh and his fellow guards have their all-important identity microchips removed from their bodies and are left to fend for themselves on a boat at sea. They come across an outcrop.

“We stood for a moment and looked at the island and I imagined what it had once been like – beaches, gentle slopes, maybe a few houses down near the water.

“In living memory the sea floor below us was dry land. All drowned now. Part of the old drowned world.”

Some might view Lanchester’s book as pure fiction, a rattling good yarn set in a future that will never come about. Let’s hope, for all our sakes and for the sake of future generations, they are right. − Climate News Network

* * * * *

The Wall, Faber & Faber, £14.99 in the UK.

What would it be like to live behind a barrier built to keep the world out? The Wall explores a post-climate change world.

LONDON, 25 April, 2019 − John Lanchester’s latest novel, The Wall, is pure fiction. Isn’t it?

It has haves and have-nots battling each other in the aftermath of dramatic alterations in climate. Right now, ignored for the most part by the outside world, thousands of people are being held in appalling conditions in camps in Libya.

Libya is a key setting-off point for migrants, mostly from countries in Africa, seeking a better life across the Mediterranean in Europe. Often they are fleeing from violence and persecution in their home countries. Many are escaping from hunger and the impact climate change is having on agricultural communities.

The European Union, anxious to secure its borders, has been sending millions of euros to military forces in Libya to control the migrant flow.

Now there is a growing threat of full-scale civil war in Libya, and the migrants are trapped – often going for days without provisions – as fighting goes on around them. It is a humanitarian disaster – and a terrible indictment of EU migration policy.

Frantic search

In Lanchester’s futuristic novel The Wall, people are roaming the world in ever greater numbers. We are not told when the book is set but, as with those migrants captive in Libya today, they are desperately searching for some sort of safe haven.

To prevent incursions, a massive concrete wall has been built around the entire coast of Britain.

Kavanagh, the book’s main character, is what’s called a Defender, part of an army of guards which patrols the wall to prevent it being breached by the seaborne forces of those known as the Others − in today’s parlance, migrants or refugees.

Slowly, as in the best kind of mystery writing, we accumulate some background. There has been a momentous event which, in Defender terminology, is referred to as the Change but in the language of one of the Others is called kuishia, a Swahili word that means “the ending”.

“In living memory the sea floor below us was dry land. All drowned now. Part of the old drowned world”

We are not told directly about the Change but can surmise it refers to a profound shift in the global climate leading to, among other things, a sudden rise in sea levels.

It is a harsh, amoral, world. For Kavanagh and his fellow Defenders, all Others are the enemy and have to be killed. The only Others allowed to exist within the wall are what are called Help – virtual slaves who assist in doing menial jobs or who can be called upon to act as carers.

Lanchester might be writing of an imagined future, but there are striking parallels with today’s labour market in the UK and elsewhere. And of course the book appears at a time when countries seem to be increasingly turning in on themselves: walls and other barriers are not going up just in the US.

In the book the Change is described as happening over a relatively short time span, in the space of a single generation.

Kavanagh goes home on leave. He doesn’t like his parents and they feel uncomfortable round their son.

Culpable generation

“It’s guilt: mass guilt, generational guilt”, Kavanagh tells us. “The olds feel they irretrievably fucked up the world, then allowed us to be born into it. You know what? It’s true. That’s exactly what they did. They know it, we know it. Everybody knows it.”

The world’s beaches have disappeared, along with the old riverscapes. Kavanagh leaves his parents as they watch images of the past on TV – an old documentary showing golden beaches and surfers cavorting in the waves.

An elite constantly warns that as the Change continues and intensifies, the numbers of Others attempting to scale the wall will grow. There are traitors within who might even try to assist these invaders.

We are drawn into Kavanagh’s world. He is bored, he yearns to be away from the wall, yet it becomes a part of him.

Kavanagh falls in love. He gets drunk. He is hungry. (Britain has became self-sufficient in food, though this seems limited to berries and root crops, with turnips a staple).

Fierce fighters

There are dramatic, deadly, fights. Lanchester is a master at letting the reader’s imagination fill in the blanks. Only once are we given some hint of the Others’ identities.

“They were trained and competent. They were from sub-Saharan Africa. It was quite likely that they had been professional soldiers in their previous lives.”

For failing to stop a group of Others from vaulting the wall, Kavanagh and his fellow guards have their all-important identity microchips removed from their bodies and are left to fend for themselves on a boat at sea. They come across an outcrop.

“We stood for a moment and looked at the island and I imagined what it had once been like – beaches, gentle slopes, maybe a few houses down near the water.

“In living memory the sea floor below us was dry land. All drowned now. Part of the old drowned world.”

Some might view Lanchester’s book as pure fiction, a rattling good yarn set in a future that will never come about. Let’s hope, for all our sakes and for the sake of future generations, they are right. − Climate News Network

* * * * *

The Wall, Faber & Faber, £14.99 in the UK.