Category Archives: Oceans

Rising tides will leave no choice for US millions

Time and tide wait for no-one. As sea levels rise, the rising tides will become more impatient. Millions of Americans will have to migrate.

LONDON, 26 February, 2020 – The Texan city of Houston is about to grow in unexpected ways, thanks to the rising tides. So will Dallas. Real estate agents in Atlanta, Georgia; Denver, Colorado; and Las Vegas, Nevada could expect to do roaring business.

The inland counties around Los Angeles, and close to New Orleans in Louisiana, will suddenly get a little more crowded. And from Boston in the north-east to the tip of Florida, Americans will be on the move.

That is because an estimated 13 million US citizens could some time in this century become climate refugees, driven from their seaside homes by sea level rise of possibly 1.8 metres, according to new research.

And they will have to move home in a poorer economic climate: worldwide. If governments and city authorities do not take the right steps, sea level rise could erode 4% of the global annual economy, says a separate study. That is, coast-dwellers could witness not just their towns and even cities washed away: they could see their prosperity go under as well.

Californian scientists report in the Public Library of Science journal PLOS One that they used machine learning techniques – in effect, artificial intelligence systems – to calculate what is most likely to happen as US citizens desert Delaware Bay, slip away from the cities of North and South Carolina, and flee Florida in the face of rising sea levels, coastal flooding and increasingly catastrophic windstorms.

“Sea level rise will affect every county in the United States … everybody should care about sea level rise, whether they live on the coast or not”

In the year 2000, a third of all the planet’s urban land was in a zone vulnerable to flood. By 2040, this could rise to 40%. In 2010, in the US, more than 120m citizens – that is nearly 40% of the entire population – lived in coastal counties. By 2020, this proportion could already be higher.

And by 2100, at least 13.1m people could be living on land likely to be inundated if sea levels rise by 1.8 metres. Except that they won’t: they will have already seen the future and moved away from it, to some settlement well away from the rising tides.

Those who might otherwise have purchased their abandoned seaside houses will be looking for somewhere safer and adding to the pressure on the housing market.

“Sea level rise will affect every county in the United States,” said Bistra Dilkina of the University of Southern California at Irvine, a computer scientist who worked with engineers to model the human response to the future.

She and her colleagues started from patterns of movement that began with Hurricane Katrina, in 2004, and Hurricane Rita a year later, both in Louisiana. They then let the algorithms take over the challenge of guessing what American families and businesses are most likely to do as the tides begin to flood the high streets.

Action promised

“We hope this research will empower urban planners and local decision-makers to prepare to accept populations displaced by sea level rise. Our findings indicate that everybody should care about sea level rise, whether they live on the coast or not,” she said.

The California team’s worst-case forecasts are based on a premise that the world takes no real action to combat sea level rise, which is driven by global warming powered in turn by fossil fuel emissions into the atmosphere on an ever-increasing scale.

But in Paris in 2015, more than 190 nations did agree to act: to contain global warming to “well below” 2°C by the century’s end. So far, very few have committed to sufficient action, and the President of the US has pronounced climate change a “hoax” and announced a withdrawal from the Paris Agreement.

Researchers in Austria report in the journal Environmental Research Communications that they decided to consider the potential economic cost worldwide of sea level rise alone. Scientists have been trying for years to guess the cost of flood damage to come: the latest study is of the impact of sea level rise and coastal flooding upon national economies worldwide.

The scientists considered two scenarios, including one in which the world kept the promises made in Paris, and one in which it did not, and made no attempt to adapt to or mitigate climate change.

Significant impact

By 2050 losses in each scenario would be significant and much the same. But by 2100, the do-nothing option promised to hit the gross domestic product – an economist’s favourite measure of economic well-being – by 4%.

Europe and Japan would be significantly hit; China , India and Canada hardest of all. If the world’s richest nations actually worked to limit climate change and adapt to the challenges ahead, the impact on the economy could be limited to 1%.

“The findings of this paper demonstrate that we need to think long term while acting swiftly,” said Thomas Schinko of the International Institute for Applied Systems Analysis in Austria, who led the study.

“Macroeconomic impacts up to and beyond 2050 as a result of coastal flooding due to sea level rise – not taking into account any other climate-related impacts such as drought – are severe and increasing.

“We, as a global society, need to further co-ordinate mitigation, adaptation and climate-resilient development and consider where we build cities and situate important infrastructure.” – Climate News Network

Time and tide wait for no-one. As sea levels rise, the rising tides will become more impatient. Millions of Americans will have to migrate.

LONDON, 26 February, 2020 – The Texan city of Houston is about to grow in unexpected ways, thanks to the rising tides. So will Dallas. Real estate agents in Atlanta, Georgia; Denver, Colorado; and Las Vegas, Nevada could expect to do roaring business.

The inland counties around Los Angeles, and close to New Orleans in Louisiana, will suddenly get a little more crowded. And from Boston in the north-east to the tip of Florida, Americans will be on the move.

That is because an estimated 13 million US citizens could some time in this century become climate refugees, driven from their seaside homes by sea level rise of possibly 1.8 metres, according to new research.

And they will have to move home in a poorer economic climate: worldwide. If governments and city authorities do not take the right steps, sea level rise could erode 4% of the global annual economy, says a separate study. That is, coast-dwellers could witness not just their towns and even cities washed away: they could see their prosperity go under as well.

Californian scientists report in the Public Library of Science journal PLOS One that they used machine learning techniques – in effect, artificial intelligence systems – to calculate what is most likely to happen as US citizens desert Delaware Bay, slip away from the cities of North and South Carolina, and flee Florida in the face of rising sea levels, coastal flooding and increasingly catastrophic windstorms.

“Sea level rise will affect every county in the United States … everybody should care about sea level rise, whether they live on the coast or not”

In the year 2000, a third of all the planet’s urban land was in a zone vulnerable to flood. By 2040, this could rise to 40%. In 2010, in the US, more than 120m citizens – that is nearly 40% of the entire population – lived in coastal counties. By 2020, this proportion could already be higher.

And by 2100, at least 13.1m people could be living on land likely to be inundated if sea levels rise by 1.8 metres. Except that they won’t: they will have already seen the future and moved away from it, to some settlement well away from the rising tides.

Those who might otherwise have purchased their abandoned seaside houses will be looking for somewhere safer and adding to the pressure on the housing market.

“Sea level rise will affect every county in the United States,” said Bistra Dilkina of the University of Southern California at Irvine, a computer scientist who worked with engineers to model the human response to the future.

She and her colleagues started from patterns of movement that began with Hurricane Katrina, in 2004, and Hurricane Rita a year later, both in Louisiana. They then let the algorithms take over the challenge of guessing what American families and businesses are most likely to do as the tides begin to flood the high streets.

Action promised

“We hope this research will empower urban planners and local decision-makers to prepare to accept populations displaced by sea level rise. Our findings indicate that everybody should care about sea level rise, whether they live on the coast or not,” she said.

The California team’s worst-case forecasts are based on a premise that the world takes no real action to combat sea level rise, which is driven by global warming powered in turn by fossil fuel emissions into the atmosphere on an ever-increasing scale.

But in Paris in 2015, more than 190 nations did agree to act: to contain global warming to “well below” 2°C by the century’s end. So far, very few have committed to sufficient action, and the President of the US has pronounced climate change a “hoax” and announced a withdrawal from the Paris Agreement.

Researchers in Austria report in the journal Environmental Research Communications that they decided to consider the potential economic cost worldwide of sea level rise alone. Scientists have been trying for years to guess the cost of flood damage to come: the latest study is of the impact of sea level rise and coastal flooding upon national economies worldwide.

The scientists considered two scenarios, including one in which the world kept the promises made in Paris, and one in which it did not, and made no attempt to adapt to or mitigate climate change.

Significant impact

By 2050 losses in each scenario would be significant and much the same. But by 2100, the do-nothing option promised to hit the gross domestic product – an economist’s favourite measure of economic well-being – by 4%.

Europe and Japan would be significantly hit; China , India and Canada hardest of all. If the world’s richest nations actually worked to limit climate change and adapt to the challenges ahead, the impact on the economy could be limited to 1%.

“The findings of this paper demonstrate that we need to think long term while acting swiftly,” said Thomas Schinko of the International Institute for Applied Systems Analysis in Austria, who led the study.

“Macroeconomic impacts up to and beyond 2050 as a result of coastal flooding due to sea level rise – not taking into account any other climate-related impacts such as drought – are severe and increasing.

“We, as a global society, need to further co-ordinate mitigation, adaptation and climate-resilient development and consider where we build cities and situate important infrastructure.” – Climate News Network

Record Antarctic temperatures fuel sea level worry


Sea levels may threaten coastal cities sooner than expected, scientists say, as ice loss speeds up and Antarctic temperatures rise.

LONDON, 20 February, 2020 − Across the world, people now alive in coastal areas may face dangerously rising seas within their lifetimes, as record Antarctic temperatures and rapid melting of the continent’s ice drive global sea levels upwards.

Temperatures on the Antarctic Peninsula reached more than 20°C for the first time in history earlier this month, the Guardian reported: “The 20.75C logged by Brazilian scientists at Seymour Island on 9 February was almost a full degree higher than the previous record of 19.8C, taken on Signy Island in January 1982.”

The Antarctic Peninsula has warmed by almost 3°C since the start of the Industrial Revolution around 200 years ago − faster than almost anywhere else on Earth. But scientists are increasingly concerned not only about the Peninsula, but with the possibility that the entire southern continent may be heating up much faster than current estimates suggest.

Among evidence of increasing scientific effort to determine what is happening is a joint UK-US collaboration, due to report in 2023 on the chances of the collapse of the huge Thwaites glacier in West Antarctica, where from 1992 to 2017 the annual rate of ice loss rose threefold.

Big speed-up

Now a study by scientists co-ordinated by Germany’s Potsdam Institute for Climate Impact Research (PIK) says sea level rise caused by Antarctica’s ice loss could become a major risk for coastal protection in the near future.

After what they call “an exceptionally comprehensive comparison of state-of-the-art computer models from around the world”, they conclude that Antarctica alone could cause global sea level to rise by 2100 by up to three times more than it did in the last century.

“The ‘Antarctica Factor’ turns out to be the greatest risk, and also the greatest uncertainty, for sea levels around the globe,” says the lead author, Anders Levermann of PIK and Columbia University’s Lamont-Doherty Earth Observatory (LDEO) in New York.

“While we saw about 19 centimetres of sea level rise in the past 100 years, Antarctic ice loss could lead to up to 58 centimetres within this century”, he said.

“We know for certain that not stopping the burning of coal, oil and gas will drive up the risks for coastal metropolises from New York to Mumbai, Hamburg and Shanghai”

“Coastal planning cannot merely rely on the best guess. It requires a risk analysis. Our study provides exactly that. The sea level contribution of Antarctica is very likely not going to be more than 58 centimetres.”

Thermal expansion of the oceans by global warming and the melting of glaciers, which so far have been the most important factors in sea level rise, will add to the contribution from Antarctic ice loss, making the overall sea level rise risk even bigger. But the ‘Antarctica Factor’ is about to become the most important element, according to the study, published in the journal Earth System Dynamics.

The range of sea-level rise estimates the scientists have come up with is fairly large. Assuming that humanity keeps on emitting greenhouse gases as before, they say, the range they call “very likely” to describe the future is between 6 and 58 cms for this century.

If greenhouse gas emissions were reduced rapidly, it would be between 4 and 37 cms. Importantly, the difference between a business-as-usual scenario and one of emissions reductions becomes substantially greater as time passes.

More robust insights

Sixteen ice sheet modelling groups consisting of 36 researchers from 27 institutes contributed to the new study. A similar study six years ago had to rely on the output of only five ice sheet models.

“The more computer simulation models we use, all of them with slightly different dynamic representations of the Antarctic ice sheet, the wider the range of results that we yield − but also the more robust the insights that we gain”, said co-author Sophie Nowicki of the NASA Goddard Space Flight Center.

“There are still large uncertainties, but we are constantly improving our understanding of the largest ice sheet on Earth. Comparing model outputs is a forceful tool to provide society with the necessary information for rational decisions.”

Over the long term, the Antarctic ice sheet has the potential ultimately to raise sea levels by many tens of metres. “What we know for certain”, said Professor Levermann, “is that not stopping the burning of coal, oil and gas will drive up the risks for coastal metropolises from New York to Mumbai, Hamburg and Shanghai.” − Climate News Network


Sea levels may threaten coastal cities sooner than expected, scientists say, as ice loss speeds up and Antarctic temperatures rise.

LONDON, 20 February, 2020 − Across the world, people now alive in coastal areas may face dangerously rising seas within their lifetimes, as record Antarctic temperatures and rapid melting of the continent’s ice drive global sea levels upwards.

Temperatures on the Antarctic Peninsula reached more than 20°C for the first time in history earlier this month, the Guardian reported: “The 20.75C logged by Brazilian scientists at Seymour Island on 9 February was almost a full degree higher than the previous record of 19.8C, taken on Signy Island in January 1982.”

The Antarctic Peninsula has warmed by almost 3°C since the start of the Industrial Revolution around 200 years ago − faster than almost anywhere else on Earth. But scientists are increasingly concerned not only about the Peninsula, but with the possibility that the entire southern continent may be heating up much faster than current estimates suggest.

Among evidence of increasing scientific effort to determine what is happening is a joint UK-US collaboration, due to report in 2023 on the chances of the collapse of the huge Thwaites glacier in West Antarctica, where from 1992 to 2017 the annual rate of ice loss rose threefold.

Big speed-up

Now a study by scientists co-ordinated by Germany’s Potsdam Institute for Climate Impact Research (PIK) says sea level rise caused by Antarctica’s ice loss could become a major risk for coastal protection in the near future.

After what they call “an exceptionally comprehensive comparison of state-of-the-art computer models from around the world”, they conclude that Antarctica alone could cause global sea level to rise by 2100 by up to three times more than it did in the last century.

“The ‘Antarctica Factor’ turns out to be the greatest risk, and also the greatest uncertainty, for sea levels around the globe,” says the lead author, Anders Levermann of PIK and Columbia University’s Lamont-Doherty Earth Observatory (LDEO) in New York.

“While we saw about 19 centimetres of sea level rise in the past 100 years, Antarctic ice loss could lead to up to 58 centimetres within this century”, he said.

“We know for certain that not stopping the burning of coal, oil and gas will drive up the risks for coastal metropolises from New York to Mumbai, Hamburg and Shanghai”

“Coastal planning cannot merely rely on the best guess. It requires a risk analysis. Our study provides exactly that. The sea level contribution of Antarctica is very likely not going to be more than 58 centimetres.”

Thermal expansion of the oceans by global warming and the melting of glaciers, which so far have been the most important factors in sea level rise, will add to the contribution from Antarctic ice loss, making the overall sea level rise risk even bigger. But the ‘Antarctica Factor’ is about to become the most important element, according to the study, published in the journal Earth System Dynamics.

The range of sea-level rise estimates the scientists have come up with is fairly large. Assuming that humanity keeps on emitting greenhouse gases as before, they say, the range they call “very likely” to describe the future is between 6 and 58 cms for this century.

If greenhouse gas emissions were reduced rapidly, it would be between 4 and 37 cms. Importantly, the difference between a business-as-usual scenario and one of emissions reductions becomes substantially greater as time passes.

More robust insights

Sixteen ice sheet modelling groups consisting of 36 researchers from 27 institutes contributed to the new study. A similar study six years ago had to rely on the output of only five ice sheet models.

“The more computer simulation models we use, all of them with slightly different dynamic representations of the Antarctic ice sheet, the wider the range of results that we yield − but also the more robust the insights that we gain”, said co-author Sophie Nowicki of the NASA Goddard Space Flight Center.

“There are still large uncertainties, but we are constantly improving our understanding of the largest ice sheet on Earth. Comparing model outputs is a forceful tool to provide society with the necessary information for rational decisions.”

Over the long term, the Antarctic ice sheet has the potential ultimately to raise sea levels by many tens of metres. “What we know for certain”, said Professor Levermann, “is that not stopping the burning of coal, oil and gas will drive up the risks for coastal metropolises from New York to Mumbai, Hamburg and Shanghai.” − Climate News Network

Speeding sea level rise threatens nuclear plants

With sea level rise accelerating faster than thought, the risk is growing for coastal cities − and for nuclear power stations.

LONDON, 14 February, 2020 − The latest science shows how the pace of sea level rise is speeding up, fuelling fears that not only millions of homes will be under threat, but that vulnerable installations like docks and power plants will be overwhelmed by the waves.

New research using satellite data over a 30-year period shows that around the year 2000 sea level rise was 2mm a year, by 2010 it was 3mm and now it is at 4mm, with the pace of change still increasing.

The calculations were made by a research student, Tadea Veng, at the Technical University of Denmark, which has a special interest in Greenland, where the icecap is melting fast. That, combined with accelerating melting in Antarctica and further warming of the oceans, is raising sea levels across the globe.

The report coincides with a European Environment Agency (EEA) study whose maps show large areas of the shorelines of countries with coastlines on the North Sea will go under water unless heavily defended against sea level rise.

Based on the maps, newspapers like The Guardian in London have predicted that more than half of one key UK east coast provincial port − Hull − will be swamped. Ironically, Hull is the base for making giant wind turbine blades for use in the North Sea.

“It’s not just the height of the rise in sea level that is important for the protection of nuclear facilities, it’s also the likely increase in storm surges”

The argument about how much the sea level will rise this century has been raging in scientific circles since the 1990s. At the start, predictions of sea level rise took into account only two possible causes: the expansion of seawater as it warmed, and the melting of mountain glaciers away from the poles.

In the early Intergovernmental Panel on Climate Change reports back then, the melting of the polar ice caps was not included, because scientists could not agree whether greater snowfall on the top of the ice caps in winter might balance out summer melting. Many of them also thought Antarctica would not melt at all, or not for centuries, because it was too cold.

Both the extra snow theory and the “too cold to melt” idea have now been discounted. In Antarctica this is partly because the sea has warmed up so much that it is melting the glaciers’ ice from beneath – something the scientists had not foreseen.

Alarm about sea level rise elsewhere has been increasing outside the scientific community, partly because many nuclear power plants are on coasts. Even those that are nearing the end of their working lives will be radio-active for another century, and many have highly dangerous spent fuel on site in storage ponds with no disposal route organised.

Perhaps most alarmed are British residents, whose government is currently planning a number of new seaside nuclear stations in low-lying coastal areas. Some will be under water this century according to the EEA, particularly one planned for Sizewell in eastern England.

Hard to tell

The Agency’s report says estimates of sea level rise by 2100 vary, with an upper limit of one metre generally accepted, but up to 2.5 metres predicted by some scientists. The latest research by Danish scientists suggests judiciously that with the speed of sea level rise continuing to accelerate, it is impossible to be sure.

A report by campaigners who oppose building nuclear power stations on Britain’s vulnerable coast expresses extreme alarm, saying both nuclear regulators and the giant French energy company EDF are too complacent about the problem.

The report says: “Polar ice caps appear to be melting faster than expected, and what is particularly worrying is that the rate of melting seems to be increasing. Some researchers say sea levels could rise by as much as six metres or more by 2100, even if the 2°C Paris targethttps://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement is met.

“But it’s not just the height of the rise in sea level that is important for the protection of nuclear facilities, it’s also the likely increase in storm surges. An increase in sea level of 50cm would mean the storm that used to come every thousand years will now come every 100 years. If you increase that to a metre, then that millennial storm is likely to come once a decade.

“Bearing in mind that there will probably be nuclear waste on the Hinkley Point C site [home to the new twin reactors being built by EDF in the West of England] until at least 2150, the question neither the Office of Nuclear Regulation nor EDF seem to be asking is whether further flood protection measures can be put in place fast enough to deal with unexpected and unpredicted storm surges.” − Climate News Network

With sea level rise accelerating faster than thought, the risk is growing for coastal cities − and for nuclear power stations.

LONDON, 14 February, 2020 − The latest science shows how the pace of sea level rise is speeding up, fuelling fears that not only millions of homes will be under threat, but that vulnerable installations like docks and power plants will be overwhelmed by the waves.

New research using satellite data over a 30-year period shows that around the year 2000 sea level rise was 2mm a year, by 2010 it was 3mm and now it is at 4mm, with the pace of change still increasing.

The calculations were made by a research student, Tadea Veng, at the Technical University of Denmark, which has a special interest in Greenland, where the icecap is melting fast. That, combined with accelerating melting in Antarctica and further warming of the oceans, is raising sea levels across the globe.

The report coincides with a European Environment Agency (EEA) study whose maps show large areas of the shorelines of countries with coastlines on the North Sea will go under water unless heavily defended against sea level rise.

Based on the maps, newspapers like The Guardian in London have predicted that more than half of one key UK east coast provincial port − Hull − will be swamped. Ironically, Hull is the base for making giant wind turbine blades for use in the North Sea.

“It’s not just the height of the rise in sea level that is important for the protection of nuclear facilities, it’s also the likely increase in storm surges”

The argument about how much the sea level will rise this century has been raging in scientific circles since the 1990s. At the start, predictions of sea level rise took into account only two possible causes: the expansion of seawater as it warmed, and the melting of mountain glaciers away from the poles.

In the early Intergovernmental Panel on Climate Change reports back then, the melting of the polar ice caps was not included, because scientists could not agree whether greater snowfall on the top of the ice caps in winter might balance out summer melting. Many of them also thought Antarctica would not melt at all, or not for centuries, because it was too cold.

Both the extra snow theory and the “too cold to melt” idea have now been discounted. In Antarctica this is partly because the sea has warmed up so much that it is melting the glaciers’ ice from beneath – something the scientists had not foreseen.

Alarm about sea level rise elsewhere has been increasing outside the scientific community, partly because many nuclear power plants are on coasts. Even those that are nearing the end of their working lives will be radio-active for another century, and many have highly dangerous spent fuel on site in storage ponds with no disposal route organised.

Perhaps most alarmed are British residents, whose government is currently planning a number of new seaside nuclear stations in low-lying coastal areas. Some will be under water this century according to the EEA, particularly one planned for Sizewell in eastern England.

Hard to tell

The Agency’s report says estimates of sea level rise by 2100 vary, with an upper limit of one metre generally accepted, but up to 2.5 metres predicted by some scientists. The latest research by Danish scientists suggests judiciously that with the speed of sea level rise continuing to accelerate, it is impossible to be sure.

A report by campaigners who oppose building nuclear power stations on Britain’s vulnerable coast expresses extreme alarm, saying both nuclear regulators and the giant French energy company EDF are too complacent about the problem.

The report says: “Polar ice caps appear to be melting faster than expected, and what is particularly worrying is that the rate of melting seems to be increasing. Some researchers say sea levels could rise by as much as six metres or more by 2100, even if the 2°C Paris targethttps://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement is met.

“But it’s not just the height of the rise in sea level that is important for the protection of nuclear facilities, it’s also the likely increase in storm surges. An increase in sea level of 50cm would mean the storm that used to come every thousand years will now come every 100 years. If you increase that to a metre, then that millennial storm is likely to come once a decade.

“Bearing in mind that there will probably be nuclear waste on the Hinkley Point C site [home to the new twin reactors being built by EDF in the West of England] until at least 2150, the question neither the Office of Nuclear Regulation nor EDF seem to be asking is whether further flood protection measures can be put in place fast enough to deal with unexpected and unpredicted storm surges.” − Climate News Network

Ice-free Arctic Ocean allowed ancient carbon leaks

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

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

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

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

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

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

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

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

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

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

Permafrost in jeopardy

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Permafrost in jeopardy

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

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

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

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

Atlantic current could falter before 2100

The Atlantic current won’t come to a full stop the day after tomorrow. But it could face a temporary halt later this century.

LONDON, 3 January, 2020 − European scientists think they have settled one of the more alarming questions of the climate crisis: the potential collapse of the Atlantic current, the Gulf Stream that delivers heat from the tropics to the Arctic.

The answer is clear. Total collapse is not likely for another 1000 years. But there is roughly a one in six chance in the next century that the flow of the north Atlantic current may temporarily halt or falter because of climate change.

That is because faster melting of the Greenland ice cap, and more freshwater in the Arctic Ocean, could trigger a slowdown in what scientists like to call the Atlantic meridional overturning circulation.

And a team of US researchers has separately highlighted one of the potential mechanisms of ocean change: for every 1°C rise in average global temperature, there will be roughly six days fewer on which many of the world’s rivers are frozen, which will mean more freshwater in the northern seas.

The findings are based in the first case on sophisticated use of computer simulations, and in the second on the careful study of 400,000 satellite images collected over more than 30 years.

“The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette”

Researchers from the universities of Groningen and Utrecht say, in the journal Scientific Reports, that they modelled the likelihood and impact of small changes in the flow of freshwater into the ocean at high latitudes.

The Atlantic current – sometimes called the Gulf Stream – is a massive flow of warm, salty water from the tropics to the Arctic that keeps  northwestern Europe much warmer than, for example, the same latitudes of North America.

As the water flows north, it cools and becomes more dense, and begins to sink below the fresh meltwater of the summer Arctic: the cold, dense, salty water then flows along the sea bed southwards, and this one dramatic global oceanic conveyor belt ultimately delivers nutrients and dissolved oxygen to the Southern Ocean. It also stores dissolved carbon dioxide, distributes heat and moderates high latitude weather.

But in the past 150 years the flow has been weakening, and there have been fears that the circulation could halt entirely, with unforeseeable consequences. This notional failure became the trigger for a 2004 disaster movie called The Day After Tomorrow. Something so sudden and catastrophic as the Hollywood version was never going to happen – but there have been repeated fears that the weakening could continue, and tip the planet’s climate into a new and potentially dangerous state.

The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette, in which a player spins a six-chambered revolver with one bullet in it, and points it at his or her head.

River ice lost

Their model simulated small changes in the delivery of freshwater. This is likely to accelerate however, according to research in the journal Nature. Researchers combed through 407,880 satellite pictures taken between 1984 and 2018, to find that 56% of rivers were affected by winter freezing, which masked altogether 87,000 square kilometres of water surface.

Freezing is important to both humans and wild things: frozen rivers traditionally have provided good surfaces for ground transport in the high latitudes. The act of freezing also regulates greenhouse gas emissions that would otherwise escape from the rivers. Ice-jams during the spring melt can trigger flooding, which – though damaging to human settlements – spreads fresh water, nutrients and sediments around the flood plains.

But these benefits are at risk. The researchers found that river and lake surfaces were freezing ever later, as global temperatures crept up, and that the world had lost 2.5% of its river ice in the last 30 years.

If the world’s nations stick to the agreement reached in Paris in 2015 and contain global heating to just 2°C above the average for most of human history, then by the end of the century the world could see a reduction of another 16 days in the length of ice cover, compared with the present, they calculate.

If they achieve the Paris ideal of no more than 1.5°C, this extra ice-free period could be reduced to just over seven days. Right now, global average temperatures are already 1°C above the historic average, and the planet is on course for a warming by the end of the century of more than 3°C. − Climate News Network

The Atlantic current won’t come to a full stop the day after tomorrow. But it could face a temporary halt later this century.

LONDON, 3 January, 2020 − European scientists think they have settled one of the more alarming questions of the climate crisis: the potential collapse of the Atlantic current, the Gulf Stream that delivers heat from the tropics to the Arctic.

The answer is clear. Total collapse is not likely for another 1000 years. But there is roughly a one in six chance in the next century that the flow of the north Atlantic current may temporarily halt or falter because of climate change.

That is because faster melting of the Greenland ice cap, and more freshwater in the Arctic Ocean, could trigger a slowdown in what scientists like to call the Atlantic meridional overturning circulation.

And a team of US researchers has separately highlighted one of the potential mechanisms of ocean change: for every 1°C rise in average global temperature, there will be roughly six days fewer on which many of the world’s rivers are frozen, which will mean more freshwater in the northern seas.

The findings are based in the first case on sophisticated use of computer simulations, and in the second on the careful study of 400,000 satellite images collected over more than 30 years.

“The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette”

Researchers from the universities of Groningen and Utrecht say, in the journal Scientific Reports, that they modelled the likelihood and impact of small changes in the flow of freshwater into the ocean at high latitudes.

The Atlantic current – sometimes called the Gulf Stream – is a massive flow of warm, salty water from the tropics to the Arctic that keeps  northwestern Europe much warmer than, for example, the same latitudes of North America.

As the water flows north, it cools and becomes more dense, and begins to sink below the fresh meltwater of the summer Arctic: the cold, dense, salty water then flows along the sea bed southwards, and this one dramatic global oceanic conveyor belt ultimately delivers nutrients and dissolved oxygen to the Southern Ocean. It also stores dissolved carbon dioxide, distributes heat and moderates high latitude weather.

But in the past 150 years the flow has been weakening, and there have been fears that the circulation could halt entirely, with unforeseeable consequences. This notional failure became the trigger for a 2004 disaster movie called The Day After Tomorrow. Something so sudden and catastrophic as the Hollywood version was never going to happen – but there have been repeated fears that the weakening could continue, and tip the planet’s climate into a new and potentially dangerous state.

The Dutch scientists now think that the likelihood of even a temporary halt is only 15%. This is more or less the chance offered in the grim game of Russian roulette, in which a player spins a six-chambered revolver with one bullet in it, and points it at his or her head.

River ice lost

Their model simulated small changes in the delivery of freshwater. This is likely to accelerate however, according to research in the journal Nature. Researchers combed through 407,880 satellite pictures taken between 1984 and 2018, to find that 56% of rivers were affected by winter freezing, which masked altogether 87,000 square kilometres of water surface.

Freezing is important to both humans and wild things: frozen rivers traditionally have provided good surfaces for ground transport in the high latitudes. The act of freezing also regulates greenhouse gas emissions that would otherwise escape from the rivers. Ice-jams during the spring melt can trigger flooding, which – though damaging to human settlements – spreads fresh water, nutrients and sediments around the flood plains.

But these benefits are at risk. The researchers found that river and lake surfaces were freezing ever later, as global temperatures crept up, and that the world had lost 2.5% of its river ice in the last 30 years.

If the world’s nations stick to the agreement reached in Paris in 2015 and contain global heating to just 2°C above the average for most of human history, then by the end of the century the world could see a reduction of another 16 days in the length of ice cover, compared with the present, they calculate.

If they achieve the Paris ideal of no more than 1.5°C, this extra ice-free period could be reduced to just over seven days. Right now, global average temperatures are already 1°C above the historic average, and the planet is on course for a warming by the end of the century of more than 3°C. − Climate News Network

Marine climate impacts are intensifying

Fish catches are falling in the Gulf of Maine, Baltic cod are getting smaller. Sharks suffer acid waters’ effects as marine climate impacts grow.

LONDON, 20 December, 2019 – Marine climate impacts are starting to make their mark on marine life at almost every level, according to a range of entirely unrelated scientific studies published in the last month.

Baltic codfish – a valuable commercial catch – have steadily become smaller, scrawnier and less valuable because of the loss of oxygen in ocean waters as a consequence of an increasingly warmer world.

Changes in climate over the last two decades have cost the fishermen of New England their jobs: their numbers have fallen by 16% since 1996 as the total catch has fallen, along with fishermen’s incomes.

The change may be linked to a natural ocean climate cycle, but nobody can be sure the decline will not continue as waters warm in response to ever higher atmospheric levels of carbon dioxide, driven by ever greater use of fossil fuels to power modern economic growth.

That steady rise in carbon dioxide means that marine waters are also becoming steadily more acidic, and this could be bad news for the sharks. Laboratory experiments suggest they can respond to short-term changes in water chemistry, but in the long term increasingly acidic waters can begin to dissolve not just the characteristic skin scales of the shark family, but the teeth as well.

And if environmental change goes on hitting tropical corals and the anemones that co-exist with them, then one of the world’s most iconic and culturally popular species could also disappear: the clownfish sub-family Amphiprioninae may not survive the continued bleaching of the coral reefs. Amphiprion ocellaris swam into the world’s hearts as the much sought-after cartoon character in the 2003 film Finding Nemo.

“We find that Nemo is at the mercy of a habitat that is degrading more and more every year”

Scientists based in the US and Sweden report in the journal Biology Letters that the average weight of specimens of Gadus morhua or the cod fish 40 cms long had dropped from 900 to 600 grams in the last 30 years.

They examined the otoliths or ear stones of 134 individuals trawled in the last months of the Baltic winter to read the evidence from trace elements such as magnesium and manganese and identify the cause: the continued fall in sea water oxygen levels as a consequence of global warming and pollution.

“The cod themselves are telling us through their internal logbooks that they’re affected by hypoxia [reduced oxygen availability], which we know is driven by climate change and nutrient loading,” said Karin Limburg, an ecologist at the State University of New York, who led the study. “Our findings suggest fish are in a worse condition because of hypoxia.”

In the Gulf of Maine, off the US Atlantic coast, catches of fish and shellfish have been falling, and with them the number of people employed in the fishery. Kimberly Oremus of the University of Delaware reports in the Proceedings of the National Academy of Sciences that successive warm winters have hit the catch, and incomes.

Pattern found

She matched decades of climate data, landing figures and sales data to identify a pattern of decline linked principally to a hot-and-cold pattern of change known as the North Atlantic Oscillation.

“New England waters are among the fastest-warming in the world,” she said. “Warmer than average sea surface temperatures have been shown to impact the productivity of lobsters, sea scallops, groundfish and other fisheries important to the region, especially when they are most vulnerable, from spawning through their first year of life.”

The region has 34,000 commercial fishermen, a significant proportion of the 166,000 or so throughout the whole of the US. The oscillation is a shift in ocean temperatures over decades, and catches could improve in decades to come – but marine waters worldwide are warming.

“This is an important signal to incorporate into the fisheries management process,” she said. “We need to figure out what climate is doing to fisheries in order to cope with it.”

Acid hazard

One important part of the marine ecosystem might not in the long run be able to cope: short episodes of hypercapnia, or a dramatic rise in dissolved carbon dioxide, are a feature linked to seasonal oceanic upwellings, and can last for days in some waters before normal ocean chemistry is restored.

In the journal Scientific Reports, European and South Africa researchers offer evidence that though cartilaginous fishes – the huge and varied family to which sharks belong – have evolved to cope with such spells, ever more acidic oceans offer a new hazard.

They caught a number of puffadder shysharks, known to scientists as Haploblepharus edwardsii and a species small enough for laboratory tanks, from shallow waters off South Africa and exposed them to acidic conditions predicted by the year 2300.

The increasingly acid environment was, literally, corrosive. Their specimens lost a quarter of their skin denticles – the shark equivalent of scales. Sharks’ teeth are made of the same biological fabric as the skin, and the implication is that such losses could, in their words “compromise hydrodynamics and skin protection.” In other words, some of the ocean’s most feared predators might have trouble both swimming and feeding.

Poor adapters

Australian and US scientists have more bad news for Nemo, the film star from the clownfish family. Rather than experiment in a laboratory tank, they monitored the numbers and the DNA of real life specimens for decades in Kimbe Bay off Papua-New Guinea. As waters warmed and began to bleach the coral reefs, the anemones that live in the reefs were put at risk.

They report in Ecology Letters that the tiny clownfish that live in the anemone tentacles proved bad at adapting to environmental change. The implication is that, as the coral reefs are lost, many species could be homeless and helpless.

“We find that Nemo is at the mercy of a habitat that is degrading more and more every year,” said Serge Planes of the French National Centre of Scientific Research, and one of the authors.

“To expect a clownfish to genetically adapt at a pace that would allow it to persist is unreasonable.” And Simon Thorrold of the Woods Hole Oceanographic Institution in the US added: “It seems Nemo won’t be able to save himself.” – Climate News Network

Fish catches are falling in the Gulf of Maine, Baltic cod are getting smaller. Sharks suffer acid waters’ effects as marine climate impacts grow.

LONDON, 20 December, 2019 – Marine climate impacts are starting to make their mark on marine life at almost every level, according to a range of entirely unrelated scientific studies published in the last month.

Baltic codfish – a valuable commercial catch – have steadily become smaller, scrawnier and less valuable because of the loss of oxygen in ocean waters as a consequence of an increasingly warmer world.

Changes in climate over the last two decades have cost the fishermen of New England their jobs: their numbers have fallen by 16% since 1996 as the total catch has fallen, along with fishermen’s incomes.

The change may be linked to a natural ocean climate cycle, but nobody can be sure the decline will not continue as waters warm in response to ever higher atmospheric levels of carbon dioxide, driven by ever greater use of fossil fuels to power modern economic growth.

That steady rise in carbon dioxide means that marine waters are also becoming steadily more acidic, and this could be bad news for the sharks. Laboratory experiments suggest they can respond to short-term changes in water chemistry, but in the long term increasingly acidic waters can begin to dissolve not just the characteristic skin scales of the shark family, but the teeth as well.

And if environmental change goes on hitting tropical corals and the anemones that co-exist with them, then one of the world’s most iconic and culturally popular species could also disappear: the clownfish sub-family Amphiprioninae may not survive the continued bleaching of the coral reefs. Amphiprion ocellaris swam into the world’s hearts as the much sought-after cartoon character in the 2003 film Finding Nemo.

“We find that Nemo is at the mercy of a habitat that is degrading more and more every year”

Scientists based in the US and Sweden report in the journal Biology Letters that the average weight of specimens of Gadus morhua or the cod fish 40 cms long had dropped from 900 to 600 grams in the last 30 years.

They examined the otoliths or ear stones of 134 individuals trawled in the last months of the Baltic winter to read the evidence from trace elements such as magnesium and manganese and identify the cause: the continued fall in sea water oxygen levels as a consequence of global warming and pollution.

“The cod themselves are telling us through their internal logbooks that they’re affected by hypoxia [reduced oxygen availability], which we know is driven by climate change and nutrient loading,” said Karin Limburg, an ecologist at the State University of New York, who led the study. “Our findings suggest fish are in a worse condition because of hypoxia.”

In the Gulf of Maine, off the US Atlantic coast, catches of fish and shellfish have been falling, and with them the number of people employed in the fishery. Kimberly Oremus of the University of Delaware reports in the Proceedings of the National Academy of Sciences that successive warm winters have hit the catch, and incomes.

Pattern found

She matched decades of climate data, landing figures and sales data to identify a pattern of decline linked principally to a hot-and-cold pattern of change known as the North Atlantic Oscillation.

“New England waters are among the fastest-warming in the world,” she said. “Warmer than average sea surface temperatures have been shown to impact the productivity of lobsters, sea scallops, groundfish and other fisheries important to the region, especially when they are most vulnerable, from spawning through their first year of life.”

The region has 34,000 commercial fishermen, a significant proportion of the 166,000 or so throughout the whole of the US. The oscillation is a shift in ocean temperatures over decades, and catches could improve in decades to come – but marine waters worldwide are warming.

“This is an important signal to incorporate into the fisheries management process,” she said. “We need to figure out what climate is doing to fisheries in order to cope with it.”

Acid hazard

One important part of the marine ecosystem might not in the long run be able to cope: short episodes of hypercapnia, or a dramatic rise in dissolved carbon dioxide, are a feature linked to seasonal oceanic upwellings, and can last for days in some waters before normal ocean chemistry is restored.

In the journal Scientific Reports, European and South Africa researchers offer evidence that though cartilaginous fishes – the huge and varied family to which sharks belong – have evolved to cope with such spells, ever more acidic oceans offer a new hazard.

They caught a number of puffadder shysharks, known to scientists as Haploblepharus edwardsii and a species small enough for laboratory tanks, from shallow waters off South Africa and exposed them to acidic conditions predicted by the year 2300.

The increasingly acid environment was, literally, corrosive. Their specimens lost a quarter of their skin denticles – the shark equivalent of scales. Sharks’ teeth are made of the same biological fabric as the skin, and the implication is that such losses could, in their words “compromise hydrodynamics and skin protection.” In other words, some of the ocean’s most feared predators might have trouble both swimming and feeding.

Poor adapters

Australian and US scientists have more bad news for Nemo, the film star from the clownfish family. Rather than experiment in a laboratory tank, they monitored the numbers and the DNA of real life specimens for decades in Kimbe Bay off Papua-New Guinea. As waters warmed and began to bleach the coral reefs, the anemones that live in the reefs were put at risk.

They report in Ecology Letters that the tiny clownfish that live in the anemone tentacles proved bad at adapting to environmental change. The implication is that, as the coral reefs are lost, many species could be homeless and helpless.

“We find that Nemo is at the mercy of a habitat that is degrading more and more every year,” said Serge Planes of the French National Centre of Scientific Research, and one of the authors.

“To expect a clownfish to genetically adapt at a pace that would allow it to persist is unreasonable.” And Simon Thorrold of the Woods Hole Oceanographic Institution in the US added: “It seems Nemo won’t be able to save himself.” – 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

Waste plastic can find a useful new life

Here’s what to do with all that waste plastic, the scrap, waste and flotsam: turn it back into brand-new plastic and use it again, and again.

LONDON, 1 November, 2019 – Swedish scientists say they have found a way to recycle plastic perfectly: their new process can turn any waste plastic back into new plastic of identical quality – and recover all of it.

The process can convert thrown-away plastic bottles, cups, bags, buckets and other detritus into a gas and, from that, fashion new materials. That is, complete recycling would be possible from existing, no-longer-wanted materials rather than petrochemical feedstock.

In 2015, the world generated more than 320 million tonnes of polystyrene, polyvinyl chloride, polyethylene and other polymers. Perhaps 200 million tonnes was neither incinerated nor recycled. As much as 12 million tonnes may have escaped into the oceans. No more than 14% was collected for recovery. Only 2% could be converted to a high-quality product, and 8% became plastic of lower quality. Around 4% was lost altogether.

“We should not forget that plastic is a fantastic material – it gives us products that we could otherwise only dream of. The problem is that it is manufactured at such low cost that it has been cheaper to produce new plastics from oil and fossil gas than reusing plastic waste,” said Henrik Thunman of Chalmers University of Technology in Gothenburg, who with colleagues developed a way of “cracking” plastic with steam.

“Through finding the right temperature – which is around 850°C – and the right heating rate and residence time, we have been able to demonstrate the proposed method at a scale where we can turn 200kg of plastic waste an hour into a useful gas mixture. This can then be recycled at the molecular level to become new plastic materials of virgin quality.”

“Circular use would help give used plastics a true value, and thus an economic impetus for collecting it anywhere on Earth”

Professor Thunman and his fellow researchers report in the journal Sustainable Materials and Technologies that their process could be designed and integrated into existing petrochemical plants, and scaled up a hundredfold or more, ultimately to transform them into tomorrow’s recycling refineries.

It would work for all plastic waste, including detritus swept up by the tide, or unearthed from landfill.

Plastic is likely to be the enduring legacy of human occupation of the planet. Long after the species is extinguished, seemingly indestructible polymer evidence will endure in the rock strata to mark the Anthropocene, the human epoch.

Plastic waste pollution has been identified as a growing international  challenge and the polymers, sometimes in microparticle form, are finding their way to every part of the planet, and into the tissues of the great marine animals.

Creating a market

About 40% of global plastic waste in 2015 was collected in some form for incineration; about 60% was “disposed of”. Around 1% leaked into the natural world, to add to the threat to living things.

The latest demonstration of laboratory ingenuity from researchers determined to confront the Anthropocene challenge promises the possibility of a circular economy for the plastic that exists already.

“Circular use would help give used plastics a true value, and thus an economic impetus for collecting it anywhere on Earth,” said Professor Thunman.

“In turn, this would help minimise the release of plastic into nature, and create a market for collection of plastic that has already polluted the natural environment.” – Climate News Network

Here’s what to do with all that waste plastic, the scrap, waste and flotsam: turn it back into brand-new plastic and use it again, and again.

LONDON, 1 November, 2019 – Swedish scientists say they have found a way to recycle plastic perfectly: their new process can turn any waste plastic back into new plastic of identical quality – and recover all of it.

The process can convert thrown-away plastic bottles, cups, bags, buckets and other detritus into a gas and, from that, fashion new materials. That is, complete recycling would be possible from existing, no-longer-wanted materials rather than petrochemical feedstock.

In 2015, the world generated more than 320 million tonnes of polystyrene, polyvinyl chloride, polyethylene and other polymers. Perhaps 200 million tonnes was neither incinerated nor recycled. As much as 12 million tonnes may have escaped into the oceans. No more than 14% was collected for recovery. Only 2% could be converted to a high-quality product, and 8% became plastic of lower quality. Around 4% was lost altogether.

“We should not forget that plastic is a fantastic material – it gives us products that we could otherwise only dream of. The problem is that it is manufactured at such low cost that it has been cheaper to produce new plastics from oil and fossil gas than reusing plastic waste,” said Henrik Thunman of Chalmers University of Technology in Gothenburg, who with colleagues developed a way of “cracking” plastic with steam.

“Through finding the right temperature – which is around 850°C – and the right heating rate and residence time, we have been able to demonstrate the proposed method at a scale where we can turn 200kg of plastic waste an hour into a useful gas mixture. This can then be recycled at the molecular level to become new plastic materials of virgin quality.”

“Circular use would help give used plastics a true value, and thus an economic impetus for collecting it anywhere on Earth”

Professor Thunman and his fellow researchers report in the journal Sustainable Materials and Technologies that their process could be designed and integrated into existing petrochemical plants, and scaled up a hundredfold or more, ultimately to transform them into tomorrow’s recycling refineries.

It would work for all plastic waste, including detritus swept up by the tide, or unearthed from landfill.

Plastic is likely to be the enduring legacy of human occupation of the planet. Long after the species is extinguished, seemingly indestructible polymer evidence will endure in the rock strata to mark the Anthropocene, the human epoch.

Plastic waste pollution has been identified as a growing international  challenge and the polymers, sometimes in microparticle form, are finding their way to every part of the planet, and into the tissues of the great marine animals.

Creating a market

About 40% of global plastic waste in 2015 was collected in some form for incineration; about 60% was “disposed of”. Around 1% leaked into the natural world, to add to the threat to living things.

The latest demonstration of laboratory ingenuity from researchers determined to confront the Anthropocene challenge promises the possibility of a circular economy for the plastic that exists already.

“Circular use would help give used plastics a true value, and thus an economic impetus for collecting it anywhere on Earth,” said Professor Thunman.

“In turn, this would help minimise the release of plastic into nature, and create a market for collection of plastic that has already polluted the natural environment.” – 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

Seabed carbon storage may help in climate crisis

The Blue Planet hasn’t been considered as a solution to the climate crisis. Three scientists advocate a sea change in global thinking: seabed carbon storage.

LONDON, 27 September, 2019 – Climate scientists say seabed carbon storage could be a new ally to help reduce greenhouse gas emissions by a volume greater than all the carbon dioxide pumped into the atmosphere from the planet’s coal-burning power stations.

It is the biggest ally possible: the 70% of the globe covered by ocean.

In a detailed argument in the journal Science, Ove Hoegh-Guldberg of the University of Queensland, Eliza Northrop of the World Resources Institute in Washington DC and Jane Lubchenco of Oregon State University outline five areas of action that could mitigate potentially calamitous climate change driven by profligate use of fossil fuels.

These include renewable energy, shipping and transport, protection of marine and coastal ecosystems, fisheries and aquaculture and – perhaps in future – carbon storage on the sea bed.

“Make no mistake: these actions are ambitious, but we argue they are necessary, could pay major dividends towards closing the emissions gap in coming decades, and achieve other co-benefits along the way”, they write.

“For far too long, the ocean has been mostly absent from policy discussions about reducing carbon emissions and meeting the challenges of climate change”

The argument was deliberately timed to coincide with a major new report by the Intergovernmental Panel on Climate Change on the oceans and the cryosphere.

If the world’s nations pursue ocean policy ambitions in the right way, they could reduce global greenhouse gas emissions by up to 4 billion tonnes of CO2 equivalent by 2030 and up to 11 billion by 2050.

And this could tot up to 21% of the reductions required in 2050 to limit warming to the declared 1.5°C target favoured at the Paris climate summit in 2015, and up to a fourth of all emissions for the formal 2°C target identified in the agreement.

“Reductions of this magnitude are larger than the annual emissions from all current coal-fired power plants worldwide,” they argue.

The first step is to set clear national targets for getting renewable energy from the restless seas, in terms of offshore wind, tidal and wave energy,  by 2030 and then by 2050.

Other benefits

Then the trio want nations to think about ways to reduce or eliminate carbon from the world’s shipping fleets. That means alternative fuels and a revolution in shore-based supply chains. Fuel efficiency in existing technologies could be improved, and hybrid power systems – including fuel cells and battery technologies – should be explored.

And, they point out, the sea itself is a carbon consumer. Mangrove swamps, seagrass meadows and salt marshes could be considered as “blue carbon ecosystems” in the way that terrestrial forests are considered “sinks” for atmospheric carbon.

These coastal and submarine “forests” make up only1.5% of the area of the land-based forests and woodlands, but their loss and degradation are equivalent to 8.4% of carbon emissions from terrestrial forests now being destroyed by human intrusion. So it would pay to restore and protect such marine habitats.

There would be other benefits: harvested seaweed could be turned into food, cattle feed, fertiliser, biofuels and bioplastics. Some seaweeds could help in even more dramatic ways.

Experiments with a red alga called Asparagopsis taxiformis, they say, “can reduce methane emissions from ruminants by up to 99% when constituting only 2% of the feed, and several other common species show potential methane reductions of 33 to 50%.”

‘Daunting’ change needed

The scientists urge a diet shift towards fish and seafood in pursuit of sustainable low-carbon protein; they also want to see the fishing industry worldwide pursue lower emissions while optimising the sustainable global catch.

“Such large-scale shifts in food policy and behaviour are daunting,” they concede. But there would be considerable climate benefits.

And, they admit, there are “considerable challenges” to the idea that carbon dioxide captured at source could be safely and cheaply stored on the seabed for many thousands of years. But they say “the theoretical potential” is very high.

“For far too long, the ocean has been mostly absent from policy discussions about reducing carbon emissions and meeting the challenges of climate change,” they conclude.

“Ocean-based actions provide increased hope that reaching the 1.5°C target might be possible, along with addressing other societal challenges, including economic development, food security and coastal community resilience.” – Climate News Network

The Blue Planet hasn’t been considered as a solution to the climate crisis. Three scientists advocate a sea change in global thinking: seabed carbon storage.

LONDON, 27 September, 2019 – Climate scientists say seabed carbon storage could be a new ally to help reduce greenhouse gas emissions by a volume greater than all the carbon dioxide pumped into the atmosphere from the planet’s coal-burning power stations.

It is the biggest ally possible: the 70% of the globe covered by ocean.

In a detailed argument in the journal Science, Ove Hoegh-Guldberg of the University of Queensland, Eliza Northrop of the World Resources Institute in Washington DC and Jane Lubchenco of Oregon State University outline five areas of action that could mitigate potentially calamitous climate change driven by profligate use of fossil fuels.

These include renewable energy, shipping and transport, protection of marine and coastal ecosystems, fisheries and aquaculture and – perhaps in future – carbon storage on the sea bed.

“Make no mistake: these actions are ambitious, but we argue they are necessary, could pay major dividends towards closing the emissions gap in coming decades, and achieve other co-benefits along the way”, they write.

“For far too long, the ocean has been mostly absent from policy discussions about reducing carbon emissions and meeting the challenges of climate change”

The argument was deliberately timed to coincide with a major new report by the Intergovernmental Panel on Climate Change on the oceans and the cryosphere.

If the world’s nations pursue ocean policy ambitions in the right way, they could reduce global greenhouse gas emissions by up to 4 billion tonnes of CO2 equivalent by 2030 and up to 11 billion by 2050.

And this could tot up to 21% of the reductions required in 2050 to limit warming to the declared 1.5°C target favoured at the Paris climate summit in 2015, and up to a fourth of all emissions for the formal 2°C target identified in the agreement.

“Reductions of this magnitude are larger than the annual emissions from all current coal-fired power plants worldwide,” they argue.

The first step is to set clear national targets for getting renewable energy from the restless seas, in terms of offshore wind, tidal and wave energy,  by 2030 and then by 2050.

Other benefits

Then the trio want nations to think about ways to reduce or eliminate carbon from the world’s shipping fleets. That means alternative fuels and a revolution in shore-based supply chains. Fuel efficiency in existing technologies could be improved, and hybrid power systems – including fuel cells and battery technologies – should be explored.

And, they point out, the sea itself is a carbon consumer. Mangrove swamps, seagrass meadows and salt marshes could be considered as “blue carbon ecosystems” in the way that terrestrial forests are considered “sinks” for atmospheric carbon.

These coastal and submarine “forests” make up only1.5% of the area of the land-based forests and woodlands, but their loss and degradation are equivalent to 8.4% of carbon emissions from terrestrial forests now being destroyed by human intrusion. So it would pay to restore and protect such marine habitats.

There would be other benefits: harvested seaweed could be turned into food, cattle feed, fertiliser, biofuels and bioplastics. Some seaweeds could help in even more dramatic ways.

Experiments with a red alga called Asparagopsis taxiformis, they say, “can reduce methane emissions from ruminants by up to 99% when constituting only 2% of the feed, and several other common species show potential methane reductions of 33 to 50%.”

‘Daunting’ change needed

The scientists urge a diet shift towards fish and seafood in pursuit of sustainable low-carbon protein; they also want to see the fishing industry worldwide pursue lower emissions while optimising the sustainable global catch.

“Such large-scale shifts in food policy and behaviour are daunting,” they concede. But there would be considerable climate benefits.

And, they admit, there are “considerable challenges” to the idea that carbon dioxide captured at source could be safely and cheaply stored on the seabed for many thousands of years. But they say “the theoretical potential” is very high.

“For far too long, the ocean has been mostly absent from policy discussions about reducing carbon emissions and meeting the challenges of climate change,” they conclude.

“Ocean-based actions provide increased hope that reaching the 1.5°C target might be possible, along with addressing other societal challenges, including economic development, food security and coastal community resilience.” – Climate News Network