Category Archives: Oceans

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

Global warming hot spots pass safe limit

A study says Earth’s hot spots have already warmed by more than the safe limit for avoiding dangerous climate change.

LONDON, 15 September, 2019 − By land and sea, some of the planet’s hot spots are already above the temperature agreed by scientists and politicians as the maximum allowable to prevent a disastrous climate crisis.

The limit was accepted by 195 governments in the Paris Agreement, reached in 2015: it committed them to preventing the global average temperature rising by more than 2°C (3.6°F) above its pre-industrial level, and doing all they could to keep it below 1.5°C. It is making slow progress.

But a novel study, an analysis of scientific data by a leading US newspaper, says that about 10% of the Earth has already passed the 2°C level, with roughly twice as many hot spots above the 1.5°C mark.

The analysis, by journalists on the Washington Post, examined four global temperature data sets, from the 1800s to the present. It found that dangerous hot spots are spreading, both on land and in the seas.

Using data from US federal scientists as well as several academic groups, the journalists find that over the past five years − the hottest on record − about 10% of the planet has exceeded warming of over 2°C, or 3.6°F. Areas that have warmed by 1.5°C are about twice as common, already beyond 20% of the Earth’s area over the last five years.

“Much more than just the Arctic has crossed this threshold. Depending on the analysis used, we see 2°C of warming in much of Europe, northern Asia, the Middle East, and in key ocean hot zones”

The writers say defining how much heating has occurred requires choosing two separate time periods to compare. They considered two pre-industrial periods − from 1850 to 1899, and from 1880 to 1899 − and what they call two “end periods”, 2014 to 2018 and 2009 to 2018.

They acknowledge that some choices clearly push more of the globe beyond 2°C, especially choosing the very warm years between 2014 and 2018. They comment: “But the lowest total we got for how much of the globe is above 2°C was about 5%. That’s still an enormous area.”

The fastest-warming part of the world is the Arctic, but they say what they found applies far more widely than the far north: “Our analysis … shows that huge swaths of the region are above 2°C − if not 3°C”, they write.

“But we also find that much more than just the Arctic has crossed this threshold. Depending on the analysis used, we see 2°C of warming in much of Europe, northern Asia, the Middle East, and in key ocean hot zones.”

The analysis shows, they say, that changes in ocean currents are creating “dramatic” hot zones. Huge ocean currents, which transport heat, salt, and nutrients around the globe, are on the move, driven by changes in winds and atmospheric circulation.

Rapid heating

And because these ocean currents are warm, when they reach new areas those areas heat up fast. This is a particular problem in the southern hemisphere, where changes have occurred in every major ocean basin, leaving distinct hotspots in the regions of the Brazil Current in the South Atlantic, the Agulhas Current in the southern Indian Ocean, and the South Pacific’s East Australian Current.

The newspaper’s analysis focuses on the Brazil Current, which shows a particularly rapid warming. But the writers say it’s not alone.

The Agulhas Current, which travels southward along the coast of south-east Africa before swinging east towards Australia, shows a warming of well above 1.5°C in many regions — and occasionally even above 2°C in some datasets and scenarios.

Scientists have been studying this change for nearly four decades, and the newspaper says it is significant. The Agulhas is now spinning off more rings of warm water that swirl into the South Atlantic, transporting heat and salt from the Indian Ocean and potentially affecting a global circulation of currents.

The analysis reports on the plight of Uruguay, where a fast-warming ocean hot spot, linked with the Brazil Current, has been associated with major disruption of marine ecosystems.

Changing catches

Clams are dying on beaches, ocean heat waves are killing fish, and algal blooms are worsening. Uruguay’s fishing fleet is now bringing up up more tropical, warm-water-loving species in its nets.

The journalists point out that while fish can swim elsewhere, that’s not always an option for other species, including humans. Some species may adjust easily − for instance, many fish swim towards cooler waters nearer the poles. But shellfish and corals have to stay put. Fishing communities depend on specific fisheries, and may not be able to move or adjust.

The Paris Agreement deals in global averages, and by definition there are exceptions to averages, in both directions. So this analysis can expect to be received with some scepticism.

But the writers are convinced that the climate crisis is happening too fast for safety, and that more of the globe will be at 2°C very soon. The Post’s method considers five- and 10-year averages to identify which regions have already eclipsed 2°C. The past five years have been especially hot so, naturally, they show more of these hot spots.

But over the long term, they say, both averages are marching steadily upward. It just takes a little while for the 10-year average to catch up. − Climate News Network

A study says Earth’s hot spots have already warmed by more than the safe limit for avoiding dangerous climate change.

LONDON, 15 September, 2019 − By land and sea, some of the planet’s hot spots are already above the temperature agreed by scientists and politicians as the maximum allowable to prevent a disastrous climate crisis.

The limit was accepted by 195 governments in the Paris Agreement, reached in 2015: it committed them to preventing the global average temperature rising by more than 2°C (3.6°F) above its pre-industrial level, and doing all they could to keep it below 1.5°C. It is making slow progress.

But a novel study, an analysis of scientific data by a leading US newspaper, says that about 10% of the Earth has already passed the 2°C level, with roughly twice as many hot spots above the 1.5°C mark.

The analysis, by journalists on the Washington Post, examined four global temperature data sets, from the 1800s to the present. It found that dangerous hot spots are spreading, both on land and in the seas.

Using data from US federal scientists as well as several academic groups, the journalists find that over the past five years − the hottest on record − about 10% of the planet has exceeded warming of over 2°C, or 3.6°F. Areas that have warmed by 1.5°C are about twice as common, already beyond 20% of the Earth’s area over the last five years.

“Much more than just the Arctic has crossed this threshold. Depending on the analysis used, we see 2°C of warming in much of Europe, northern Asia, the Middle East, and in key ocean hot zones”

The writers say defining how much heating has occurred requires choosing two separate time periods to compare. They considered two pre-industrial periods − from 1850 to 1899, and from 1880 to 1899 − and what they call two “end periods”, 2014 to 2018 and 2009 to 2018.

They acknowledge that some choices clearly push more of the globe beyond 2°C, especially choosing the very warm years between 2014 and 2018. They comment: “But the lowest total we got for how much of the globe is above 2°C was about 5%. That’s still an enormous area.”

The fastest-warming part of the world is the Arctic, but they say what they found applies far more widely than the far north: “Our analysis … shows that huge swaths of the region are above 2°C − if not 3°C”, they write.

“But we also find that much more than just the Arctic has crossed this threshold. Depending on the analysis used, we see 2°C of warming in much of Europe, northern Asia, the Middle East, and in key ocean hot zones.”

The analysis shows, they say, that changes in ocean currents are creating “dramatic” hot zones. Huge ocean currents, which transport heat, salt, and nutrients around the globe, are on the move, driven by changes in winds and atmospheric circulation.

Rapid heating

And because these ocean currents are warm, when they reach new areas those areas heat up fast. This is a particular problem in the southern hemisphere, where changes have occurred in every major ocean basin, leaving distinct hotspots in the regions of the Brazil Current in the South Atlantic, the Agulhas Current in the southern Indian Ocean, and the South Pacific’s East Australian Current.

The newspaper’s analysis focuses on the Brazil Current, which shows a particularly rapid warming. But the writers say it’s not alone.

The Agulhas Current, which travels southward along the coast of south-east Africa before swinging east towards Australia, shows a warming of well above 1.5°C in many regions — and occasionally even above 2°C in some datasets and scenarios.

Scientists have been studying this change for nearly four decades, and the newspaper says it is significant. The Agulhas is now spinning off more rings of warm water that swirl into the South Atlantic, transporting heat and salt from the Indian Ocean and potentially affecting a global circulation of currents.

The analysis reports on the plight of Uruguay, where a fast-warming ocean hot spot, linked with the Brazil Current, has been associated with major disruption of marine ecosystems.

Changing catches

Clams are dying on beaches, ocean heat waves are killing fish, and algal blooms are worsening. Uruguay’s fishing fleet is now bringing up up more tropical, warm-water-loving species in its nets.

The journalists point out that while fish can swim elsewhere, that’s not always an option for other species, including humans. Some species may adjust easily − for instance, many fish swim towards cooler waters nearer the poles. But shellfish and corals have to stay put. Fishing communities depend on specific fisheries, and may not be able to move or adjust.

The Paris Agreement deals in global averages, and by definition there are exceptions to averages, in both directions. So this analysis can expect to be received with some scepticism.

But the writers are convinced that the climate crisis is happening too fast for safety, and that more of the globe will be at 2°C very soon. The Post’s method considers five- and 10-year averages to identify which regions have already eclipsed 2°C. The past five years have been especially hot so, naturally, they show more of these hot spots.

But over the long term, they say, both averages are marching steadily upward. It just takes a little while for the 10-year average to catch up. − Climate News Network

Worse US Atlantic floods need planned retreat

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

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

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

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

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

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

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

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

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

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

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

Growing Atlantic danger

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Growing Atlantic danger

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

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

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

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

Ocean heat waves damage reefs and kill coral

Heat extremes on land can kill. Ocean heat waves can devastate coral reefs and other ecosystems – and these too are on the increase.

LONDON, 12 August, 2019 − Heat extremes on the high seas are on the increase, with ocean heat waves disturbing ecosystems in two hemispheres and two great oceans, US scientists report.

And these same sudden rises in sea temperatures don’t just damage coral reefs, they kill the corals and start the process of reef decay, according to a separate study by Australian researchers.

Andrew Pershing of the Gulf of Maine Research Institute and colleagues report in the Proceedings of the National Academy of Sciences that they examined data from 65 marine ecosystems over the years 1854 to 2018 to work out how frequently ocean temperatures suddenly rose to unexpected levels.

They found such deviations from the average in the Arctic, North Atlantic, eastern Pacific and off the Australian coasts. They expected to find evidence of occasional hot flushes. But they did not expect to find quite so many.

“Severe marine heatwave events can have a far more severe impact than coral bleaching – the animal dies and its underlying skeleton is all that remains”

“Across the 65 ecosystems we examined, we expected about six or seven of them would experience these ‘surprises’ each year,” Dr Pershing said. “Instead, we’ve seen an average of 12 ecosystems experiencing these warming events each year over the past seven years, including a high of 23 ‘surprises’ in 2016.”

Intense and sudden changes in sea temperatures affect crustaceans, algae, corals, molluscs and many millions of humans who depend on the oceans for income. And a new study by researchers from Australian universities reports that even a rise of 0.5°C is reflected in deaths during an outbreak of coral bleaching.

Corals live in symbiosis with algae: ocean warming periodically disturbs this normally beneficial relationship. The coral animals evert (turn out) the algae and once-lurid reefs will bleach, and become more vulnerable to disease.

Corals support the world’s richest ocean ecosystems so such changes are a challenge, both to the survival of biodiversity and to local incomes from the tourism linked to the beauty of the reefs.

Very warm water

“What we are seeing is that severe marine heatwave events can have a far more severe impact than coral bleaching: the water temperatures are so warm that that the coral animal doesn’t bleach – in terms of a loss of its symbiosis – the animal dies and its underlying skeleton is all that remains,” said Tracy Ainsworth of the University of New South Wales.

The researchers report in the journal Current Biology that they used computer tomography scanning techniques to explore the marine destruction. In 2016, more than 30% of the northern part of Australia’s Great Barrier Reef experienced temperatures higher than those in which corals can survive.

“We find that the skeleton is immediately overgrown by rapid growth of algae and bacteria,” said Bill Leggat of the University of Newcastle, a co-author.

“We show that this process is devastating not just for the animal tissue but also for the skeleton that is left behind, which is rapidly eroded and weakened.” − Climate News Network

Heat extremes on land can kill. Ocean heat waves can devastate coral reefs and other ecosystems – and these too are on the increase.

LONDON, 12 August, 2019 − Heat extremes on the high seas are on the increase, with ocean heat waves disturbing ecosystems in two hemispheres and two great oceans, US scientists report.

And these same sudden rises in sea temperatures don’t just damage coral reefs, they kill the corals and start the process of reef decay, according to a separate study by Australian researchers.

Andrew Pershing of the Gulf of Maine Research Institute and colleagues report in the Proceedings of the National Academy of Sciences that they examined data from 65 marine ecosystems over the years 1854 to 2018 to work out how frequently ocean temperatures suddenly rose to unexpected levels.

They found such deviations from the average in the Arctic, North Atlantic, eastern Pacific and off the Australian coasts. They expected to find evidence of occasional hot flushes. But they did not expect to find quite so many.

“Severe marine heatwave events can have a far more severe impact than coral bleaching – the animal dies and its underlying skeleton is all that remains”

“Across the 65 ecosystems we examined, we expected about six or seven of them would experience these ‘surprises’ each year,” Dr Pershing said. “Instead, we’ve seen an average of 12 ecosystems experiencing these warming events each year over the past seven years, including a high of 23 ‘surprises’ in 2016.”

Intense and sudden changes in sea temperatures affect crustaceans, algae, corals, molluscs and many millions of humans who depend on the oceans for income. And a new study by researchers from Australian universities reports that even a rise of 0.5°C is reflected in deaths during an outbreak of coral bleaching.

Corals live in symbiosis with algae: ocean warming periodically disturbs this normally beneficial relationship. The coral animals evert (turn out) the algae and once-lurid reefs will bleach, and become more vulnerable to disease.

Corals support the world’s richest ocean ecosystems so such changes are a challenge, both to the survival of biodiversity and to local incomes from the tourism linked to the beauty of the reefs.

Very warm water

“What we are seeing is that severe marine heatwave events can have a far more severe impact than coral bleaching: the water temperatures are so warm that that the coral animal doesn’t bleach – in terms of a loss of its symbiosis – the animal dies and its underlying skeleton is all that remains,” said Tracy Ainsworth of the University of New South Wales.

The researchers report in the journal Current Biology that they used computer tomography scanning techniques to explore the marine destruction. In 2016, more than 30% of the northern part of Australia’s Great Barrier Reef experienced temperatures higher than those in which corals can survive.

“We find that the skeleton is immediately overgrown by rapid growth of algae and bacteria,” said Bill Leggat of the University of Newcastle, a co-author.

“We show that this process is devastating not just for the animal tissue but also for the skeleton that is left behind, which is rapidly eroded and weakened.” − Climate News Network