Tag Archives: Sea levels

Greenland ice melt feeds glacier instability

In a runaway effect, the Greenland ice melt lets surface water gurgle down to the bedrock – and at unexpected speeds.

LONDON, 6 December, 2019 – British scientists have caught a huge ice sheet in the act of draining away, with significant effects on its surroundings: they have seen what happens to the water created by the Greenland ice melt.

For the first time – and with help from drones – researchers have witnessed water flowing at a million cubic metres an hour from the surface of ice sheets through caverns in the ice and down to the glacial bedrock.

The study does not change the big picture of increasingly rapid melt as greenhouse gases build up in the atmosphere, and ever more of the northern hemisphere’s biggest ice cap flows downhill to raise global sea levels.

But it does throw light on the mechanisms by which glaciers turn to sea water, and it does suggest that many estimates of melt rate so far might prove to be under-estimates.

Greenland is the planet’s second largest ice sheet and the biggest single contributor to global sea level rise. Researchers have been alarmed for years about the increasing rate of summer melt and the accelerating speed of what had once been imperceptible glacial flows.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere, but the overall effect is in fact very significant”

And researchers from the universities of Cambridge, Aberystwyth and Lancaster have now been able to put a measure on water surface loss.

They report in the Proceedings of the National Academy of Sciences that they used custom-built aerial drones and complex computer modelling to work out how fractures form below vast lakes of meltwater that collect on the surface of the Store Glacier on the island’s northwestern sheet.

They watched splits form in the glacial ice, to suddenly open up an escape route for the supraglacial pool. As they watched, such fractures became caverns called moulins, down which in one case five million cubic metres of water – think of 2,000 Olympic swimming pools – flowed in just five hours.

The ice of the glacier is typically a kilometre thick, so the scientists may have observed the planet’s longest waterfall. And as the ice drained away to the bottom of the ice sheet, it may have served as a lubricant to speed up glacier flow over the bedrock.

The ice sheet lifted by half a metre, presumably in response to the sub-surface flood, and four kilometres downstream glacial speed picked up from a speed of two metres to more than five metres a day.

Daily billion-tonne loss

“It’s possible we’ve under-estimated the effects of these glaciers on the overall instability of the Greenland ice sheet. It’s a rare thing to observe these fast-draining lakes – we were lucky to be in the right place at the right time,” said Tom Chudley, of the Scott Polar Research Institute in Cambridge, one of the authors.

Until now, scientists have been able to estimate glacial flow and surface melt only by satellite studies – which reveal little of the detail – or direct on-the-ground measurement under conditions that are difficult even in good weather.

But even with these constraints researchers have been able to calculate the shrinkage of the Greenland ice sheet at the rate of a billion tonnes a day, as temperatures rise in response to ever-increasing use of fossil fuels around the globe.

The next step is to deploy drilling equipment for a closer look at how the water gets below the glacier to reach the bedrock, and calculate how the ice sheet may change not just over hours but over the coming decades as well.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere,” said Poul Christofferson, who led the project, “but the overall effect is in fact very significant.” – Climate News Network

In a runaway effect, the Greenland ice melt lets surface water gurgle down to the bedrock – and at unexpected speeds.

LONDON, 6 December, 2019 – British scientists have caught a huge ice sheet in the act of draining away, with significant effects on its surroundings: they have seen what happens to the water created by the Greenland ice melt.

For the first time – and with help from drones – researchers have witnessed water flowing at a million cubic metres an hour from the surface of ice sheets through caverns in the ice and down to the glacial bedrock.

The study does not change the big picture of increasingly rapid melt as greenhouse gases build up in the atmosphere, and ever more of the northern hemisphere’s biggest ice cap flows downhill to raise global sea levels.

But it does throw light on the mechanisms by which glaciers turn to sea water, and it does suggest that many estimates of melt rate so far might prove to be under-estimates.

Greenland is the planet’s second largest ice sheet and the biggest single contributor to global sea level rise. Researchers have been alarmed for years about the increasing rate of summer melt and the accelerating speed of what had once been imperceptible glacial flows.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere, but the overall effect is in fact very significant”

And researchers from the universities of Cambridge, Aberystwyth and Lancaster have now been able to put a measure on water surface loss.

They report in the Proceedings of the National Academy of Sciences that they used custom-built aerial drones and complex computer modelling to work out how fractures form below vast lakes of meltwater that collect on the surface of the Store Glacier on the island’s northwestern sheet.

They watched splits form in the glacial ice, to suddenly open up an escape route for the supraglacial pool. As they watched, such fractures became caverns called moulins, down which in one case five million cubic metres of water – think of 2,000 Olympic swimming pools – flowed in just five hours.

The ice of the glacier is typically a kilometre thick, so the scientists may have observed the planet’s longest waterfall. And as the ice drained away to the bottom of the ice sheet, it may have served as a lubricant to speed up glacier flow over the bedrock.

The ice sheet lifted by half a metre, presumably in response to the sub-surface flood, and four kilometres downstream glacial speed picked up from a speed of two metres to more than five metres a day.

Daily billion-tonne loss

“It’s possible we’ve under-estimated the effects of these glaciers on the overall instability of the Greenland ice sheet. It’s a rare thing to observe these fast-draining lakes – we were lucky to be in the right place at the right time,” said Tom Chudley, of the Scott Polar Research Institute in Cambridge, one of the authors.

Until now, scientists have been able to estimate glacial flow and surface melt only by satellite studies – which reveal little of the detail – or direct on-the-ground measurement under conditions that are difficult even in good weather.

But even with these constraints researchers have been able to calculate the shrinkage of the Greenland ice sheet at the rate of a billion tonnes a day, as temperatures rise in response to ever-increasing use of fossil fuels around the globe.

The next step is to deploy drilling equipment for a closer look at how the water gets below the glacier to reach the bedrock, and calculate how the ice sheet may change not just over hours but over the coming decades as well.

“These glaciers are already moving quite fast, so the effect of the lakes may not appear as dramatic as on slower-moving glaciers elsewhere,” said Poul Christofferson, who led the project, “but the overall effect is in fact very significant.” – Climate News Network

Earth nears irreversible tipping points

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

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

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

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

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

Happening now

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

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

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

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

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

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

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

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

Inadequate pledges

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

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

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

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

Timescale controlled

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

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

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

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

Risks multiply

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

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

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

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

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

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

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

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

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

Happening now

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

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

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

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

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

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

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

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

Inadequate pledges

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

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

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

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

Timescale controlled

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

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

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

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

Risks multiply

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

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

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

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

Global climate treaty is not working

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

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

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

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

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

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

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

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

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

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

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

Leaking permafrost

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

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

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

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

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

Early warning

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Leaking permafrost

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

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

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

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

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

Early warning

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

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

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

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

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

Climate ‘is the election priority’ for the UK

Britain’s general election campaign is squarely focused on the UK leaving the EU. But persuasive voices say the climate “is the election priority”.

LONDON, 7 November, 2019 − The real issue facing the United Kingdom in next month’s general election is not whether to choose Brexit, to stay in the European Union or leave it, a prominent lawyer says, because the climate “is the election priority” for the UK.

With Britain due to host the November 2020 United Nations climate talks, she told a London conference, it is vital that the new government elected on 12 December takes the lead by enacting policies to tackle the climate emergency.

Farhana Yamin, an international climate change lawyer, said that currently the world was failing to tackle the climate and ecological disaster facing the planet. The UK posed as a climate leader but was “way, way behind” what was needed and did not have the policies in place to reach its own target of net zero emissions by 2050.

“Nothing less than a green industrial revolution is required to turn the situation around. A war-like mobilisation of society to stop nature being destroyed needs to be in place by next year when the climate talks are being held in Glasgow”, she said. British voters had an opportunity to choose a government that could lead the world by example.

“The fact is we already know that normal life is going to be disrupted. Change is coming, whether you like it or not. The electorate has a chance to shape that change.

Inadequate Paris Agreement

“This is going to be a climate and ecological election. The future will be very different depending on the decisions taken in the next five years – and it depends on which direction the new government wants to take,” she said.

This was because it was already clear that the commitments made in Paris in 2015 to cut greenhouse gas emissions were nowhere near enough to hold global temperature rise to safe levels. The whole pack of nations was failing, and needed to make new commitments at the Glasgow talks a year from now.

Yamin, from Pakistan, lives in Britain and is an advocate and adviser to the Marshall Islands. She has represented many members of the Alliance of Small Island States (AOSIS) which are most threatened by climate change, particularly sea level rise.

Talking to an audience of senior business executives and heads of environmental groups at the conference of the Fit for the Future network, she said the horrors of climate change were already apparent.

The 20 million people in Delhi suffering from toxic air pollution, and those in the Marshall Islands which she champions who are facing inundation by the sea, were just two examples of the problem, and 2020 was a crucial year to try to turn the problem round.

“We already know that normal life is going to be disrupted. Change is coming, whether you like it or not. The electorate has a chance to shape that change”

Yamin told the Climate News Network she feared that in the UK election Brexit would crowd out the much more important issue of climate change. This was not to suggest how people should vote, but she asked people to cast aside other considerations and look at the parties’ climate policies.

“Whatever government is elected now will take decisions that will have a fundamental effect on the future of the planet. Take the right decisions in this four-year term of office, and there is still a chance of turning things around,” she said.

The co-leader of the UK Green Party, Sian Berry, said at the launch of the Greens’ campaign yesterday: “Some things are even bigger than Brexit. This must be the climate election.”

Yamin took part in London’s Extinction Rebellion protests and is one of the 1,300 people arrested there: she superglued herself to the entrance of the Shell oil giant’s London HQ. That had been necessary to raise public awareness of the problem, she said.

“For me it is the most historic and meaningful election I can remember. The environmental movement is all about social justice, so people now have the opportunity to vote to live and work in an equal society,” she said. − Climate News Network

Britain’s general election campaign is squarely focused on the UK leaving the EU. But persuasive voices say the climate “is the election priority”.

LONDON, 7 November, 2019 − The real issue facing the United Kingdom in next month’s general election is not whether to choose Brexit, to stay in the European Union or leave it, a prominent lawyer says, because the climate “is the election priority” for the UK.

With Britain due to host the November 2020 United Nations climate talks, she told a London conference, it is vital that the new government elected on 12 December takes the lead by enacting policies to tackle the climate emergency.

Farhana Yamin, an international climate change lawyer, said that currently the world was failing to tackle the climate and ecological disaster facing the planet. The UK posed as a climate leader but was “way, way behind” what was needed and did not have the policies in place to reach its own target of net zero emissions by 2050.

“Nothing less than a green industrial revolution is required to turn the situation around. A war-like mobilisation of society to stop nature being destroyed needs to be in place by next year when the climate talks are being held in Glasgow”, she said. British voters had an opportunity to choose a government that could lead the world by example.

“The fact is we already know that normal life is going to be disrupted. Change is coming, whether you like it or not. The electorate has a chance to shape that change.

Inadequate Paris Agreement

“This is going to be a climate and ecological election. The future will be very different depending on the decisions taken in the next five years – and it depends on which direction the new government wants to take,” she said.

This was because it was already clear that the commitments made in Paris in 2015 to cut greenhouse gas emissions were nowhere near enough to hold global temperature rise to safe levels. The whole pack of nations was failing, and needed to make new commitments at the Glasgow talks a year from now.

Yamin, from Pakistan, lives in Britain and is an advocate and adviser to the Marshall Islands. She has represented many members of the Alliance of Small Island States (AOSIS) which are most threatened by climate change, particularly sea level rise.

Talking to an audience of senior business executives and heads of environmental groups at the conference of the Fit for the Future network, she said the horrors of climate change were already apparent.

The 20 million people in Delhi suffering from toxic air pollution, and those in the Marshall Islands which she champions who are facing inundation by the sea, were just two examples of the problem, and 2020 was a crucial year to try to turn the problem round.

“We already know that normal life is going to be disrupted. Change is coming, whether you like it or not. The electorate has a chance to shape that change”

Yamin told the Climate News Network she feared that in the UK election Brexit would crowd out the much more important issue of climate change. This was not to suggest how people should vote, but she asked people to cast aside other considerations and look at the parties’ climate policies.

“Whatever government is elected now will take decisions that will have a fundamental effect on the future of the planet. Take the right decisions in this four-year term of office, and there is still a chance of turning things around,” she said.

The co-leader of the UK Green Party, Sian Berry, said at the launch of the Greens’ campaign yesterday: “Some things are even bigger than Brexit. This must be the climate election.”

Yamin took part in London’s Extinction Rebellion protests and is one of the 1,300 people arrested there: she superglued herself to the entrance of the Shell oil giant’s London HQ. That had been necessary to raise public awareness of the problem, she said.

“For me it is the most historic and meaningful election I can remember. The environmental movement is all about social justice, so people now have the opportunity to vote to live and work in an equal society,” she said. − Climate News Network

New land height metric raises sea level rise risk

Millions of us now live in danger: we could be at risk from future high tides and winds, says a new approach to measuring land height.

 

LONDON, 4 November, 2019 – Researchers have taken a closer look at estimates of coastal land height – and found that the numbers of people already at risk from sea level rise driven by global heating have multiplied threefold.

More than 100 million people already live below the high tide line, and 250 million live on plains that are lower than the current annual flood heights. Previous estimates have put these numbers at 28 million, and 65 million.

And even if the world takes immediate drastic action and reduces greenhouse gas emissions by the end of the century, at least 190 million people will find themselves below sea level.

If the world’s nations continue on the notorious business-as-usual track and go on burning ever greater volumes of fossil fuels, then around 630 million will, by the year 2100, find themselves on land that will be below the expected annual flood levels.

Protection in question

“These assessments show the potential of climate change to reshape cities, economies, coastlines and entire global regions within our lifetime,” said Scott Kulp of Climate Central, who led a study published in the journal Nature Communications.

“As the tideline rises higher than the ground people call home, nations will increasingly confront questions about whether, how much, and how long coastal defences can protect them.”

At the heart of the new research is a revised estimate of what constitutes sea level, and how it should be measured. Individuals and communities find out the hard way how the highest tides can rise to poison their farmlands with salt and wash away the foundations of their homes.

But the big picture – across nations and regions worldwide – is harder to estimate: for decades researchers have relied on satellite readings, confirmed by flights over limited spaces with radar equipment.

“There is still a great need for . . . more accurate elevation data. Lives and livelihoods depend on it”

But space-based readings by Nasa’s radar topography programme tend to be over-estimates, the researchers argue. That is because the technology measures the height of the first reflecting surface the radar signal touches. In open country, this may not matter. But forests and high buildings in densely-peopled cities distort the picture.

In parts of coastal Australia, and using a new approach, the researchers found that satellite readings delivered over-estimates of 2.5 metres. So global averages in the past have over-estimated, by around 2 metres, the elevation of lands that are home to billions.

Research of this kind helps clarify the challenge that faces governments, civic authorities and private citizens: communities grow up along low-lying coasts and estuaries because these provide good land, reliable water supplies and easy transport. But the catch with flood plains is that, sooner or later, they flood.

The repeated evidence of a decade of climate science is that floods will become more devastating, more frequent and more prolonged for a mix of reasons.

Multiple risks

Soils will subside because of the growing demand for groundwater and for clays and stone for bricks and mortar; because global average temperatures will rise and oceans expand as they warm; glaciers will melt and tip more water into the sea to raise ocean levels; and tropical cyclones will become more intense to drive more destructive storm surges.

Researchers have already warned that sea level rise could be accelerating, to bring more flooding to, for instance, the great cities of the US coasts, while some cities can expect ever more battering from Atlantic storms.

Coastal flooding is likely to create millions of climate refugees even within the US, and the worldwide costs of coastal flooding could reach $1 trillion a year by the end of the century.

The latest study confirms that the hazards are real, and may have so far been under-estimated. The researchers calculated that, in parts of China, Bangladesh, India, Vietnam and Thailand, places now home to 237 million people could face coastal flooding every year by 2050 – a figure 183 million higher than previous estimates.

US coasts threatened

The same study highlights faulty estimates of ground elevation even in the richest and most advanced nations. In some parts of the crowded coastal cities of New York, Boston and Miami, for instance, the researchers believe satellite readings have over-estimated ground height by almost five metres. They say their new approach reduces the margin of error to 2.5 cms.

Right now, around a billion people live on lands less than 10 metres above high tide levels. Around 250 million live within one metre above high tide.

“For all of the critical research that’s been done on climate change and sea level projections, it turns out that for most of the global coast we didn’t know the height of the ground beneath our feet,” said Benjamin Strauss, president and chief scientist of Climate Central, and co-author.

“Our data improves the picture, but there is still a great need for governments and insurance companies to produce and release more accurate elevation data. Lives and livelihoods depend on it.” – Climate News Network

Millions of us now live in danger: we could be at risk from future high tides and winds, says a new approach to measuring land height.

 

LONDON, 4 November, 2019 – Researchers have taken a closer look at estimates of coastal land height – and found that the numbers of people already at risk from sea level rise driven by global heating have multiplied threefold.

More than 100 million people already live below the high tide line, and 250 million live on plains that are lower than the current annual flood heights. Previous estimates have put these numbers at 28 million, and 65 million.

And even if the world takes immediate drastic action and reduces greenhouse gas emissions by the end of the century, at least 190 million people will find themselves below sea level.

If the world’s nations continue on the notorious business-as-usual track and go on burning ever greater volumes of fossil fuels, then around 630 million will, by the year 2100, find themselves on land that will be below the expected annual flood levels.

Protection in question

“These assessments show the potential of climate change to reshape cities, economies, coastlines and entire global regions within our lifetime,” said Scott Kulp of Climate Central, who led a study published in the journal Nature Communications.

“As the tideline rises higher than the ground people call home, nations will increasingly confront questions about whether, how much, and how long coastal defences can protect them.”

At the heart of the new research is a revised estimate of what constitutes sea level, and how it should be measured. Individuals and communities find out the hard way how the highest tides can rise to poison their farmlands with salt and wash away the foundations of their homes.

But the big picture – across nations and regions worldwide – is harder to estimate: for decades researchers have relied on satellite readings, confirmed by flights over limited spaces with radar equipment.

“There is still a great need for . . . more accurate elevation data. Lives and livelihoods depend on it”

But space-based readings by Nasa’s radar topography programme tend to be over-estimates, the researchers argue. That is because the technology measures the height of the first reflecting surface the radar signal touches. In open country, this may not matter. But forests and high buildings in densely-peopled cities distort the picture.

In parts of coastal Australia, and using a new approach, the researchers found that satellite readings delivered over-estimates of 2.5 metres. So global averages in the past have over-estimated, by around 2 metres, the elevation of lands that are home to billions.

Research of this kind helps clarify the challenge that faces governments, civic authorities and private citizens: communities grow up along low-lying coasts and estuaries because these provide good land, reliable water supplies and easy transport. But the catch with flood plains is that, sooner or later, they flood.

The repeated evidence of a decade of climate science is that floods will become more devastating, more frequent and more prolonged for a mix of reasons.

Multiple risks

Soils will subside because of the growing demand for groundwater and for clays and stone for bricks and mortar; because global average temperatures will rise and oceans expand as they warm; glaciers will melt and tip more water into the sea to raise ocean levels; and tropical cyclones will become more intense to drive more destructive storm surges.

Researchers have already warned that sea level rise could be accelerating, to bring more flooding to, for instance, the great cities of the US coasts, while some cities can expect ever more battering from Atlantic storms.

Coastal flooding is likely to create millions of climate refugees even within the US, and the worldwide costs of coastal flooding could reach $1 trillion a year by the end of the century.

The latest study confirms that the hazards are real, and may have so far been under-estimated. The researchers calculated that, in parts of China, Bangladesh, India, Vietnam and Thailand, places now home to 237 million people could face coastal flooding every year by 2050 – a figure 183 million higher than previous estimates.

US coasts threatened

The same study highlights faulty estimates of ground elevation even in the richest and most advanced nations. In some parts of the crowded coastal cities of New York, Boston and Miami, for instance, the researchers believe satellite readings have over-estimated ground height by almost five metres. They say their new approach reduces the margin of error to 2.5 cms.

Right now, around a billion people live on lands less than 10 metres above high tide levels. Around 250 million live within one metre above high tide.

“For all of the critical research that’s been done on climate change and sea level projections, it turns out that for most of the global coast we didn’t know the height of the ground beneath our feet,” said Benjamin Strauss, president and chief scientist of Climate Central, and co-author.

“Our data improves the picture, but there is still a great need for governments and insurance companies to produce and release more accurate elevation data. Lives and livelihoods depend on it.” – Climate News Network

Rugby stars are losing their Pacific islands

Whatever happens on the pitches, rugby stars from the Pacific islands face a battle back home to save their ancestral lands from rising sea levels.

LONDON, 1 October, 2019 – Players from the Pacific islands are performing a prominent role in the intense battles at present going on at the rugby world cup in Japan.

Away from the rough and tumble on the pitch, the players are facing an even bigger challenge back home as their island nations come under increasing threat from climate change, in particular from ever-rising sea levels.

A recent report by the Intergovernmental Panel on Climate Change (IPCC) warns of the catastrophic effect rising sea levels – mainly caused by the melting of ice at the poles – will have on billions of people living in coastal areas and in island states around the world.

In the low-lying island nations of the Pacific, climate change is already having an impact. Coastal communities are frequently inundated by rising seas. Salty seawater poisons precious supplies of fresh water.

Crops are lost and homes damaged. Warming seas are killing off coral reefs, a key source of fish and an industry on which many islanders depend for their living.

Exploited

A report by the charity Christian Aid, focusing on the rugby world cup, says that while Pacific island teams Fiji, Tonga and Samoa are playing a central role in the tournament in Japan, they are, at the same time, being exploited and harmed by the actions of bigger and richer nations involved, including Australia, New Zealand and England.

The report points out that Pacific island states are among the lowest emitters of climate-changing carbon dioxide and other greenhouse gases. Yet they are among those suffering most from a warming world.

Samoa emits 0.7 tonnes of CO2 per capita each year. The equivalent figure for Australia is 16.5 tonnes and for host Japan is 10.4 tonnes.

Jonny Fa’amatuainu is a former Samoan international who has also played for rugby clubs in England, Wales and Japan.

“As a Pacific Island rugby player, tackling the climate crisis is close to my heart. My grandparents and other families who lived in a village on the coast of Samoa moved inland two years ago because of climate change”, he says.

“The island nations in the Pacific are some of the most vulnerable in the world and they have done almost nothing to cause their plight”

“The Pacific Islands are the soul of our sport and we have produced some of the most dynamic and exciting players on the planet … climate change is a crisis these countries did not cause yet it’s a fight they are suffering from the most.

“It’s a fight they need the help of the rugby community to win.”

The Christian Aid report says climate change threatens to undermine the Pacific Islands’ economies. Tourists will stop visiting and young people will be forced to leave, with up to 1.7 million likely to move from their homes in the region over the next 30 years.

Cyclone Gita, which devastated many parts of Tonga last year, was the strongest storm to hit the nation since records began. The report says global warming means such storms will be more frequent across the region in the years ahead.

The study also highlights the way in which many Pacific island rugby players are treated, being paid wages only a fraction of those earned by their counterparts in richer countries. The teams are also often excluded from various international tournaments.

Foot-dragging

“Climate change is the ultimate injustice issue and nowhere is that captured more clearly than among the nations taking part in the rugby world cup”, says Katherine Kramer of Christian Aid, the author of the report.

“The island nations in the Pacific are some of the most vulnerable in the world and they have done almost nothing to cause their plight.

“The main culprits for causing the climate crisis are European nations as well as major coal burners like Australia, the US and Japan.

“Not only have they caused the current dire situation, but they are dragging their feet on making the needed transition to a zero-carbon economy.” – Climate News Network

Whatever happens on the pitches, rugby stars from the Pacific islands face a battle back home to save their ancestral lands from rising sea levels.

LONDON, 1 October, 2019 – Players from the Pacific islands are performing a prominent role in the intense battles at present going on at the rugby world cup in Japan.

Away from the rough and tumble on the pitch, the players are facing an even bigger challenge back home as their island nations come under increasing threat from climate change, in particular from ever-rising sea levels.

A recent report by the Intergovernmental Panel on Climate Change (IPCC) warns of the catastrophic effect rising sea levels – mainly caused by the melting of ice at the poles – will have on billions of people living in coastal areas and in island states around the world.

In the low-lying island nations of the Pacific, climate change is already having an impact. Coastal communities are frequently inundated by rising seas. Salty seawater poisons precious supplies of fresh water.

Crops are lost and homes damaged. Warming seas are killing off coral reefs, a key source of fish and an industry on which many islanders depend for their living.

Exploited

A report by the charity Christian Aid, focusing on the rugby world cup, says that while Pacific island teams Fiji, Tonga and Samoa are playing a central role in the tournament in Japan, they are, at the same time, being exploited and harmed by the actions of bigger and richer nations involved, including Australia, New Zealand and England.

The report points out that Pacific island states are among the lowest emitters of climate-changing carbon dioxide and other greenhouse gases. Yet they are among those suffering most from a warming world.

Samoa emits 0.7 tonnes of CO2 per capita each year. The equivalent figure for Australia is 16.5 tonnes and for host Japan is 10.4 tonnes.

Jonny Fa’amatuainu is a former Samoan international who has also played for rugby clubs in England, Wales and Japan.

“As a Pacific Island rugby player, tackling the climate crisis is close to my heart. My grandparents and other families who lived in a village on the coast of Samoa moved inland two years ago because of climate change”, he says.

“The island nations in the Pacific are some of the most vulnerable in the world and they have done almost nothing to cause their plight”

“The Pacific Islands are the soul of our sport and we have produced some of the most dynamic and exciting players on the planet … climate change is a crisis these countries did not cause yet it’s a fight they are suffering from the most.

“It’s a fight they need the help of the rugby community to win.”

The Christian Aid report says climate change threatens to undermine the Pacific Islands’ economies. Tourists will stop visiting and young people will be forced to leave, with up to 1.7 million likely to move from their homes in the region over the next 30 years.

Cyclone Gita, which devastated many parts of Tonga last year, was the strongest storm to hit the nation since records began. The report says global warming means such storms will be more frequent across the region in the years ahead.

The study also highlights the way in which many Pacific island rugby players are treated, being paid wages only a fraction of those earned by their counterparts in richer countries. The teams are also often excluded from various international tournaments.

Foot-dragging

“Climate change is the ultimate injustice issue and nowhere is that captured more clearly than among the nations taking part in the rugby world cup”, says Katherine Kramer of Christian Aid, the author of the report.

“The island nations in the Pacific are some of the most vulnerable in the world and they have done almost nothing to cause their plight.

“The main culprits for causing the climate crisis are European nations as well as major coal burners like Australia, the US and Japan.

“Not only have they caused the current dire situation, but they are dragging their feet on making the needed transition to a zero-carbon economy.” – Climate News Network

Extreme sea level events ‘will hit once a year by 2050’

This story originally appeared in The Guardian. It is republished here as part of the Climate News Network’s partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Extreme sea level events that used to occur once a century will strike every year on many coasts by 2050, no matter whether climate heating emissions are curbed or not, according to a landmark report by the world’s scientists.

25 September, 2019 − The stark assessment of the climate crisis in the world’s oceans and ice caps concludes that many serious impacts are already inevitable, from more intense storms to melting permafrost and dwindling marine life.

But far worse impacts will hit without urgent action to cut fossil fuel emissions, including eventual sea level rise of more than 4 metres in the worst case, an outcome that would redraw the map of the world and harm billions of people.

The report from the Intergovernmental Panel on Climate Change (IPCC), and approved by its 193 member nations, says that “all people on Earth depend directly or indirectly on the ocean” and ice caps and glaciers to regulate the climate and provide water and oxygen. But it finds unprecedented and dangerous changes being driven by global heating.

Sea level rise is accelerating as losses from Greenland and Antarctica increase, and the ocean is getting hotter, more acidic and less oxygenated. All these trends will continue to the end of the century, the IPCC report said.

Half the world’s megacities, and almost 2 billion people, live on coasts. Even if heating is restricted to just 2C, scientists expect the impact of sea level rise to cause several trillion dollars of damage a year, and result in many millions of migrants.

“The future for low-lying coastal communities looks extremely bleak,” said Prof Jonathan Bamber at Bristol University in the UK, who is not one of the report’s authors. “But the consequences will be felt by all of us. There is plenty to be concerned about for the future of humanity and social order from the headlines in this report.”

The new IPCC projections of likely sea level rise by 2100 are higher than those it made in 2014, due to unexpectedly fast melting in Antarctica. Without cuts in carbon emissions, the ocean is expected to rise between 61cm and 110cm, about 10cm more than the earlier estimate. A 10cm rise means 10 million additional people exposed to flooding, research shows.

The IPCC considers the likely range of sea level rise but not the worst-case scenario. Recent expert analysis led by Bamber concluded that up to 238cm of sea level rise remains possible by 2100, drowning many megacities around the world. “This cannot be ruled out,” said Zita Sebesvari at the United Nations University, a lead author of the IPCC report.

Even if huge cuts in emissions begin immediately, between 29cm and 59cm of sea level rise is already inevitable because the ice caps and glaciers melt slowly. Sea level will rise for centuries without action, Sebesvari warned. “The dramatic thing about sea level rise is if we accept 1 metre happening by 2100, we accept we will get about 4 metres by 2300. That is simply not an option we can risk.”

Extreme sea level impacts will be felt in many places very soon and well before 2050, Sebesvari said. The IPCC report states: “Extreme sea level events that [occur] once per century in the recent past are projected to occur at least once per year at many locations by 2050 in all scenarios.”

The heating oceans are causing more intense tropical storms to batter coasts, the IPCC report found, with stronger winds and greater deluges of rain. For example, Hurricane Harvey’s unprecedented deluge, which caused catastrophic flooding, was made three times more likely by climate change.

Ocean heating also harms kelp forests and other important ecosystems, with the marine heatwaves that sear through them like underwater wildfires having doubled in frequency in the last 40 years. They are projected to increase by at least 20 times by 2100, the IPCC reported.

Extreme El Niño events, which see heatwaves in some regions and floods in others, are projected to occur twice as often this century whether emissions are cut or not, the report said. Coral reefs, vital nurseries for marine life, will suffer major losses and local extinctions. Across the ocean, heat, acidification and lower oxygen is set to cut fisheries by a quarter and all marine life by 15% if emissions are not slashed.

The IPCC report also records the large reduction in Arctic ice. This loss exacerbates global heating, because the exposed darker ocean absorbs more heat from the sun than highly reflective ice. On Monday, scientists announced that the Arctic sea ice in 2019 shrank to its second lowest extent in the 41-year satellite record.

The world’s high mountain glaciers, upon which almost 2 billion people rely for water, are also melting fast, the IPCC found, while landslides are expected to increase. A third of the great Himalayan range is already doomed, with two-thirds projected to vanish if emissions are not cut.

One of the most worrying alarms sounded by the IPCC report is about melting tundra and increasing wildfires in northern latitudes: “Widespread permafrost thaw is projected for this century and beyond.” A quarter is already near certain to melt, it said, and 70% or more would go if emissions are not curbed. In the latter case, hundreds of billions of tonnes of carbon dioxide and methane could be released, supercharging the climate emergency.

“That risks taking us beyond the point where climate change could be easily constrained,” said Richard Black, at the UK’s Energy and Climate Intelligence Unit. “Nevertheless, the IPCC’s 2018 report concluded that governments can shrink emissions quickly enough to keep global warming to 1.5C if they choose. None can claim to be unaware of both the dangers of untrammelled climate change nor the feasibility of preventing it.”

Anne Hidalgo, the mayor of Paris and chair of the C40 Cities climate coalition, said the IPCC report was shocking. “Around 1.9 billion people and over half of the world’s megacities are all in grave danger if we don’t act immediately. Several cities, home to hundreds of thousands of people, are already disappearing underwater. This is what the climate crisis looks like now.”

Taehyun Park, of Greenpeace East Asia, said: “The science is both chilling and compelling. The impacts on our oceans are on a much larger scale and happening way faster than predicted. It will require unprecedented political action to prevent the most severe consequences to our planet.”

As well as cutting fossil fuel emissions, preparing for the inevitable impacts is also vital, said Sebesvari, especially in poorer nations that lack the funds to build sea walls, move settlements or restore protective coastal marshes.

“Action is needed now to secure the coast for our children and coming generations,” she said. The pressure now being exerted by the global school strikes for climate was important, she said. “I have very strong motivation. I have two kids and we are really being tested by our kids on our actions.”

* * * * * * *

Damian Carrington is The Guardian’s environment editor.

This story originally appeared in The Guardian. It is republished here as part of the Climate News Network’s partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Extreme sea level events that used to occur once a century will strike every year on many coasts by 2050, no matter whether climate heating emissions are curbed or not, according to a landmark report by the world’s scientists.

25 September, 2019 − The stark assessment of the climate crisis in the world’s oceans and ice caps concludes that many serious impacts are already inevitable, from more intense storms to melting permafrost and dwindling marine life.

But far worse impacts will hit without urgent action to cut fossil fuel emissions, including eventual sea level rise of more than 4 metres in the worst case, an outcome that would redraw the map of the world and harm billions of people.

The report from the Intergovernmental Panel on Climate Change (IPCC), and approved by its 193 member nations, says that “all people on Earth depend directly or indirectly on the ocean” and ice caps and glaciers to regulate the climate and provide water and oxygen. But it finds unprecedented and dangerous changes being driven by global heating.

Sea level rise is accelerating as losses from Greenland and Antarctica increase, and the ocean is getting hotter, more acidic and less oxygenated. All these trends will continue to the end of the century, the IPCC report said.

Half the world’s megacities, and almost 2 billion people, live on coasts. Even if heating is restricted to just 2C, scientists expect the impact of sea level rise to cause several trillion dollars of damage a year, and result in many millions of migrants.

“The future for low-lying coastal communities looks extremely bleak,” said Prof Jonathan Bamber at Bristol University in the UK, who is not one of the report’s authors. “But the consequences will be felt by all of us. There is plenty to be concerned about for the future of humanity and social order from the headlines in this report.”

The new IPCC projections of likely sea level rise by 2100 are higher than those it made in 2014, due to unexpectedly fast melting in Antarctica. Without cuts in carbon emissions, the ocean is expected to rise between 61cm and 110cm, about 10cm more than the earlier estimate. A 10cm rise means 10 million additional people exposed to flooding, research shows.

The IPCC considers the likely range of sea level rise but not the worst-case scenario. Recent expert analysis led by Bamber concluded that up to 238cm of sea level rise remains possible by 2100, drowning many megacities around the world. “This cannot be ruled out,” said Zita Sebesvari at the United Nations University, a lead author of the IPCC report.

Even if huge cuts in emissions begin immediately, between 29cm and 59cm of sea level rise is already inevitable because the ice caps and glaciers melt slowly. Sea level will rise for centuries without action, Sebesvari warned. “The dramatic thing about sea level rise is if we accept 1 metre happening by 2100, we accept we will get about 4 metres by 2300. That is simply not an option we can risk.”

Extreme sea level impacts will be felt in many places very soon and well before 2050, Sebesvari said. The IPCC report states: “Extreme sea level events that [occur] once per century in the recent past are projected to occur at least once per year at many locations by 2050 in all scenarios.”

The heating oceans are causing more intense tropical storms to batter coasts, the IPCC report found, with stronger winds and greater deluges of rain. For example, Hurricane Harvey’s unprecedented deluge, which caused catastrophic flooding, was made three times more likely by climate change.

Ocean heating also harms kelp forests and other important ecosystems, with the marine heatwaves that sear through them like underwater wildfires having doubled in frequency in the last 40 years. They are projected to increase by at least 20 times by 2100, the IPCC reported.

Extreme El Niño events, which see heatwaves in some regions and floods in others, are projected to occur twice as often this century whether emissions are cut or not, the report said. Coral reefs, vital nurseries for marine life, will suffer major losses and local extinctions. Across the ocean, heat, acidification and lower oxygen is set to cut fisheries by a quarter and all marine life by 15% if emissions are not slashed.

The IPCC report also records the large reduction in Arctic ice. This loss exacerbates global heating, because the exposed darker ocean absorbs more heat from the sun than highly reflective ice. On Monday, scientists announced that the Arctic sea ice in 2019 shrank to its second lowest extent in the 41-year satellite record.

The world’s high mountain glaciers, upon which almost 2 billion people rely for water, are also melting fast, the IPCC found, while landslides are expected to increase. A third of the great Himalayan range is already doomed, with two-thirds projected to vanish if emissions are not cut.

One of the most worrying alarms sounded by the IPCC report is about melting tundra and increasing wildfires in northern latitudes: “Widespread permafrost thaw is projected for this century and beyond.” A quarter is already near certain to melt, it said, and 70% or more would go if emissions are not curbed. In the latter case, hundreds of billions of tonnes of carbon dioxide and methane could be released, supercharging the climate emergency.

“That risks taking us beyond the point where climate change could be easily constrained,” said Richard Black, at the UK’s Energy and Climate Intelligence Unit. “Nevertheless, the IPCC’s 2018 report concluded that governments can shrink emissions quickly enough to keep global warming to 1.5C if they choose. None can claim to be unaware of both the dangers of untrammelled climate change nor the feasibility of preventing it.”

Anne Hidalgo, the mayor of Paris and chair of the C40 Cities climate coalition, said the IPCC report was shocking. “Around 1.9 billion people and over half of the world’s megacities are all in grave danger if we don’t act immediately. Several cities, home to hundreds of thousands of people, are already disappearing underwater. This is what the climate crisis looks like now.”

Taehyun Park, of Greenpeace East Asia, said: “The science is both chilling and compelling. The impacts on our oceans are on a much larger scale and happening way faster than predicted. It will require unprecedented political action to prevent the most severe consequences to our planet.”

As well as cutting fossil fuel emissions, preparing for the inevitable impacts is also vital, said Sebesvari, especially in poorer nations that lack the funds to build sea walls, move settlements or restore protective coastal marshes.

“Action is needed now to secure the coast for our children and coming generations,” she said. The pressure now being exerted by the global school strikes for climate was important, she said. “I have very strong motivation. I have two kids and we are really being tested by our kids on our actions.”

* * * * * * *

Damian Carrington is The Guardian’s environment editor.

Jakarta’s sea level prompts a move – at a price

For its people, Jakarta’s sea level is a nagging anxiety. But moving the Indonesian capital 1,000 kms to safety will be horribly costly.

LONDON, 9 September, 2019 – Spare a thought for the poorer residents of Jakarta, Indonesia’s sprawling capital city.

If your house on the Indonesian coast is threatened by the ocean because of climate change, then maybe – if you’re lucky and wealthy enough – a move to higher ground further inland may be possible.

But what happens when a whole city, with millions of people, is threatened by rising seas?

Jakarta has a population of more than 10 million. Established as the capital of what was the Dutch East Indies in the 17th century, the city is built on swamp land on the north-west coast of the island of Java.

But not only is Jakarta threatened by rising sea levels: rapid, largely unplanned expansion and building work has resulted in the city becoming, according to experts, one of the fastest-sinking urban areas in the world.

It’s estimated that up to 40% of the area of Jakarta is now below sea level. In northern districts of the city bordering the sea, rising sea levels are threatening many neighbourhoods, and flooding is common.

“This huge project will need to be done quickly to prevent Jakarta from sinking into the sea”

Attempts at tackling the issue have so far made little impact. A scheme designed to keep seawater out involving the construction of a 32 kilometre-long outer sea wall called the Great Garuda and 17 artificial islands straddling Jakarta Bay has been subject to long delays and finance problems.

“This huge project will need to be done quickly to prevent Jakarta from sinking into the sea”, says Joko Widodo, Indonesia’s president.

Ongoing extraction of groundwater from beneath the city is another serious problem, leading to frequent land subsidence.

Parts of Jakarta are sinking by as much as 25 cms each year. Experts say that in some areas the land has sunk by 2.5 metres over the last 10 years.

Now the Indonesian government is taking radical action. It’s announced plans to move the country’s capital elsewhere – to more than 1,000 kms away in East Kalimantan, on the Indonesian portion of the island of Borneo.

Five years to completion

Officials talk of creating a “smart and forest” city; the project, which has an initial price tag of US$33 billion (466,650 bn Rupiah), will involve the foundation of a new administrative capital, with up to 1.5 million civil servants being relocated.

Jakarta will retain its role as Indonesia’s commercial and financial hub. The government says work on the new city is due to begin in two years’ time and to be completed by 2024.

The construction of the new capital might go some way to settle one set of problems, but is likely to give birth to others.

The island of Borneo – shared between Indonesia, Malaysia and the small state of Brunei – contains one of the world’s largest remaining rain forests, a carbon sink which soaks up vast amounts of climate-changing greenhouse gases.

In the early 1970s three quarters of Borneo was covered in rainforest. By 2010, the forests had shrunk by more than 30%, with huge areas logged or given over to palm oil plantations.

Orangutans killed

Large areas of peat – another vital repository for hundreds of thousands of tonnes of climate-changing carbon – have also been destroyed. Indonesia has undertaken several coal-mining projects in its part of the island.

As the forests have been chopped down, wildlife has suffered. Numbers of orangutan have dropped by an estimated 100,000 over the past 20 years.

Despite pledges by the Indonesian government to build a sustainable “green” city and carry out various environmental surveys, many are sceptical about the building of the new capital.

Experts point out that many environmentally important areas of Borneo have already been destroyed by haphazard, badly planned development projects. They say the new plans, including the construction of a whole city, are only going to make the situation worse.

The daunting prospect facing Jakarta is likely to confront many other countries within the next few decades. Last month US researchers said the rising threat of flooding caused by climate change meant Americans should prepare for managed retreat from their own coasts. – Climate News Network

For its people, Jakarta’s sea level is a nagging anxiety. But moving the Indonesian capital 1,000 kms to safety will be horribly costly.

LONDON, 9 September, 2019 – Spare a thought for the poorer residents of Jakarta, Indonesia’s sprawling capital city.

If your house on the Indonesian coast is threatened by the ocean because of climate change, then maybe – if you’re lucky and wealthy enough – a move to higher ground further inland may be possible.

But what happens when a whole city, with millions of people, is threatened by rising seas?

Jakarta has a population of more than 10 million. Established as the capital of what was the Dutch East Indies in the 17th century, the city is built on swamp land on the north-west coast of the island of Java.

But not only is Jakarta threatened by rising sea levels: rapid, largely unplanned expansion and building work has resulted in the city becoming, according to experts, one of the fastest-sinking urban areas in the world.

It’s estimated that up to 40% of the area of Jakarta is now below sea level. In northern districts of the city bordering the sea, rising sea levels are threatening many neighbourhoods, and flooding is common.

“This huge project will need to be done quickly to prevent Jakarta from sinking into the sea”

Attempts at tackling the issue have so far made little impact. A scheme designed to keep seawater out involving the construction of a 32 kilometre-long outer sea wall called the Great Garuda and 17 artificial islands straddling Jakarta Bay has been subject to long delays and finance problems.

“This huge project will need to be done quickly to prevent Jakarta from sinking into the sea”, says Joko Widodo, Indonesia’s president.

Ongoing extraction of groundwater from beneath the city is another serious problem, leading to frequent land subsidence.

Parts of Jakarta are sinking by as much as 25 cms each year. Experts say that in some areas the land has sunk by 2.5 metres over the last 10 years.

Now the Indonesian government is taking radical action. It’s announced plans to move the country’s capital elsewhere – to more than 1,000 kms away in East Kalimantan, on the Indonesian portion of the island of Borneo.

Five years to completion

Officials talk of creating a “smart and forest” city; the project, which has an initial price tag of US$33 billion (466,650 bn Rupiah), will involve the foundation of a new administrative capital, with up to 1.5 million civil servants being relocated.

Jakarta will retain its role as Indonesia’s commercial and financial hub. The government says work on the new city is due to begin in two years’ time and to be completed by 2024.

The construction of the new capital might go some way to settle one set of problems, but is likely to give birth to others.

The island of Borneo – shared between Indonesia, Malaysia and the small state of Brunei – contains one of the world’s largest remaining rain forests, a carbon sink which soaks up vast amounts of climate-changing greenhouse gases.

In the early 1970s three quarters of Borneo was covered in rainforest. By 2010, the forests had shrunk by more than 30%, with huge areas logged or given over to palm oil plantations.

Orangutans killed

Large areas of peat – another vital repository for hundreds of thousands of tonnes of climate-changing carbon – have also been destroyed. Indonesia has undertaken several coal-mining projects in its part of the island.

As the forests have been chopped down, wildlife has suffered. Numbers of orangutan have dropped by an estimated 100,000 over the past 20 years.

Despite pledges by the Indonesian government to build a sustainable “green” city and carry out various environmental surveys, many are sceptical about the building of the new capital.

Experts point out that many environmentally important areas of Borneo have already been destroyed by haphazard, badly planned development projects. They say the new plans, including the construction of a whole city, are only going to make the situation worse.

The daunting prospect facing Jakarta is likely to confront many other countries within the next few decades. Last month US researchers said the rising threat of flooding caused by climate change meant Americans should prepare for managed retreat from their own coasts. – Climate News Network

Worse US Atlantic floods need planned retreat

Its coasts are at ever-greater risk from rising seas, and US Atlantic floods will soon force people to move. Why not start planning now?

LONDON, 3 September, 2019 − What are now considered once-in-a-hundred-years floods are on the increase in the US. Later this century, they could happen to northern coastal states every year.

And even in the more fortunate cities along the south-east Atlantic and the Gulf of Mexico coasts, the once-in-a-century floods will happen a lot more often: somewhere between every 30 years and every year.

In a second study, a team of distinguished scientists argues that the US should face the inevitable and begin to plan for a managed, strategic retreat from its own coasts.

At the heart of both studies is a set of new realities imposed by a rapidly-heating ocean and higher air temperatures worldwide. As the icecaps of Greenland and Antarctica melt, and as the glaciers of Canada and Alaska retreat, so sea levels have begun to rise inexorably.

But as the oceans increase in average temperature, thanks to an ever-warmer atmosphere driven by greenhouse gases from profligate combustion of fossil fuels, so the oceans have begun to expand: warmer waters are less dense, and thus higher.

“We need to stop picturing our relationship with nature as a war. We’re not winning or losing, we’re adjusting to changes in nature”

And there is a third factor. With warmer seas there will be more frequent and more violent hurricanes and windstorms, more damaging storm surges and yet more torrential rainfall.

Researchers from Princeton University report in the journal Nature Communications that they considered all three factors to create a flood hazard map of the US. Simply because of rising waters, New England states can expect to see what were once rare events almost every year.

“For the Gulf of Mexico, we found the effect of storm surge is compatible with or more significant than the effect of sea level rise for 40% of counties,” said Ning Lin, a Princeton engineer.

“So if we neglect the effects of storm climatology change, we would significantly underestimate the impact of climate change for these regions.”

Growing Atlantic danger

Exercises of this kind are about planning for the worst: were the Princeton research the only such study, city chiefs could afford to relax. But it is not.

For years climate scientists and oceanographers have been warning of ever-greater hazard to Atlantic America. They have warned of ever more torrential rains and the hazards of ever more damaging floods even in disparate cities such as Charleston and Seattle; they have even warned of high tide floods on a daily basis in some cities, and they have proposed that an estimated 13 million Americans could become climate refugees, driven by the advancing seas from their own homes.

All of which is why a trio of researchers argue for the need to accept the inevitable and step back from the sea, and they say so in the journal Science. They argue that the US should start to prepare for retreat by limiting development in the areas most at risk.

“Fighting the ocean is a losing battle,” said A R Siders of Harvard and the University of Delaware. “The only way to win against water is not to fight. We need to stop picturing our relationship with nature as a war. We’re not winning or losing, we’re adjusting to changes in nature.” − Climate News Network

Its coasts are at ever-greater risk from rising seas, and US Atlantic floods will soon force people to move. Why not start planning now?

LONDON, 3 September, 2019 − What are now considered once-in-a-hundred-years floods are on the increase in the US. Later this century, they could happen to northern coastal states every year.

And even in the more fortunate cities along the south-east Atlantic and the Gulf of Mexico coasts, the once-in-a-century floods will happen a lot more often: somewhere between every 30 years and every year.

In a second study, a team of distinguished scientists argues that the US should face the inevitable and begin to plan for a managed, strategic retreat from its own coasts.

At the heart of both studies is a set of new realities imposed by a rapidly-heating ocean and higher air temperatures worldwide. As the icecaps of Greenland and Antarctica melt, and as the glaciers of Canada and Alaska retreat, so sea levels have begun to rise inexorably.

But as the oceans increase in average temperature, thanks to an ever-warmer atmosphere driven by greenhouse gases from profligate combustion of fossil fuels, so the oceans have begun to expand: warmer waters are less dense, and thus higher.

“We need to stop picturing our relationship with nature as a war. We’re not winning or losing, we’re adjusting to changes in nature”

And there is a third factor. With warmer seas there will be more frequent and more violent hurricanes and windstorms, more damaging storm surges and yet more torrential rainfall.

Researchers from Princeton University report in the journal Nature Communications that they considered all three factors to create a flood hazard map of the US. Simply because of rising waters, New England states can expect to see what were once rare events almost every year.

“For the Gulf of Mexico, we found the effect of storm surge is compatible with or more significant than the effect of sea level rise for 40% of counties,” said Ning Lin, a Princeton engineer.

“So if we neglect the effects of storm climatology change, we would significantly underestimate the impact of climate change for these regions.”

Growing Atlantic danger

Exercises of this kind are about planning for the worst: were the Princeton research the only such study, city chiefs could afford to relax. But it is not.

For years climate scientists and oceanographers have been warning of ever-greater hazard to Atlantic America. They have warned of ever more torrential rains and the hazards of ever more damaging floods even in disparate cities such as Charleston and Seattle; they have even warned of high tide floods on a daily basis in some cities, and they have proposed that an estimated 13 million Americans could become climate refugees, driven by the advancing seas from their own homes.

All of which is why a trio of researchers argue for the need to accept the inevitable and step back from the sea, and they say so in the journal Science. They argue that the US should start to prepare for retreat by limiting development in the areas most at risk.

“Fighting the ocean is a losing battle,” said A R Siders of Harvard and the University of Delaware. “The only way to win against water is not to fight. We need to stop picturing our relationship with nature as a war. We’re not winning or losing, we’re adjusting to changes in nature.” − Climate News Network

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