Category Archives: Oceans

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

Acid oceans may trigger mass extinction

A stable carbon cycle means life goes on. Too much carbon could wipe out many species. And acid oceans could hold the key.

LONDON, 23 July, 2019 − Catastrophically widespread die-offs of many creatures could be inevitable if human activities continue to lead to more acid oceans, a new study suggests.

Mass extinction may not be an enduring mystery. Instead, it may be an intrinsic property of the carbon cycle. Once levels of dissolved carbon dioxide in the oceans reach a certain threshold, life undergoes dramatic and catastrophic change.

If a US mathematician is right – and his argument is based on statistical reasoning and the evidence in the marine sediments – then once the seas become too acidic for marine organisms to form carbonate shells, a cascade of extinction begins.

And, he warns, the “unusually strong but geologically brief duration” of manmade carbon dioxide increase in the oceans can be matched with slow but devastating extinctions in the past.

In short, human combustion of fossil fuels, combined with the destruction of the forests, could be building up to extinctions on a scale so colossal that they will be visible in the fossil record hundreds of millions of years from now.

After a certain point, the carbon cycle will take over and decide life’s direction. It happened many times long before the emergence of the human species, and it could happen again, according to a new study in the  Proceedings of the National Academy of Sciences.

“It’s a positive feedback. More carbon dioxide leads to more carbon dioxide. Is such a feedback enough to render the system unstable?”

“Once we are over the threshold, how we got there may not matter,” said Daniel Rothman of the Massachusetts Institute of Technology. “Once you get over it, you’re dealing with how the Earth works, and it goes on its own ride.”

Professor Rothman developed his hypothesis in 2017, in the journal Science Advances, after he analysed 31 changes in the makeup of carbonate sediments laid down over the last 542 million years, and connected five great extinctions not just with carbon dioxide levels but with the rate at which these increased.

He may be for the moment a lone voice in linking four of the five major extinctions with critical levels of oceanic acidification as a consequence of a carbon dioxide threshold. But climate scientists and palaeontologists have been looking at possible links between carbon and extinction for decades.

They have also repeatedly warned that humans are about to precipitate a sixth mass extinction, chiefly on the basis that we are destroying natural habitat and erasing the conditions in which millions of species – many of them still not identified – were once able to flourish.

The carbon factor

But climate change driven by ever-increasing atmospheric carbon dioxide levels – powered in turn by ever-increasing combustion of fossil fuels – has also been a factor.

Whatever the risk to species or ecosystems, biologists and conservationists have warned that climate change driven by global heating can only make things worse.

And the more carefully researchers have looked at evidence of earlier catastrophic extinctions, the more bygone climate change has revealed itself. What caused the most dramatic and unequivocal of these – the “great dying” at the close of the Permian – is still hotly debated, but atmospheric conditions in one form or another have been repeatedly invoked and researchers have repeatedly drawn lessons for today.

But arguments so far have settled on whether such extinctions are a consequence of slow but inexorable episodes of volcanic discharge or some other geological shift.

Forget the trigger

Professor Rothman’s point is that the trigger itself may not be the important thing: what decides the fate of life on Earth is the level of carbon in the oceans and the rate at which it increases.

Once levels of acidification in the upper ocean reach a certain critical threshold, life is in for major disruption. If marine creatures cannot form shells, they are at risk. But even more dangerously, shells sink to the ocean floor, effectively removing carbon from circulation.

If there are fewer calcifying organisms, then less carbon dioxide is removed from the atmosphere and oceans become even more acidic. A vicious cycle has begun.

“It’s a positive feedback,” Professor Rothman said. “More carbon dioxide leads to more carbon dioxide. The question, from a mathematical point of view is, is such a feedback enough to render the system unstable?”

Balance restored

In his mathematical model, once carbon levels reached a critical threshold, a cascade of positive feedbacks amplified the effect. Severe ocean acidification set in.

The effect was not permanent. After tens of thousands of years, the carbon cycle did slip back to equilibrium and life could evolve and adapt again.

Carbon is now entering the oceans at an unprecedented rate, over what – in geological terms – is a very brief timespan. If human-triggered greenhouse gas emissions cross a critical threshold, the consequences could be as severe as any of the previous mass extinctions.

“It’s difficult to know how things will end up, given what is happening today,” he said. “But we are probably close to a critical threshold. Any spike would reach its maximum after about 10,000 years. Hopefully, that would give us time to find a solution.” − Climate News Network

A stable carbon cycle means life goes on. Too much carbon could wipe out many species. And acid oceans could hold the key.

LONDON, 23 July, 2019 − Catastrophically widespread die-offs of many creatures could be inevitable if human activities continue to lead to more acid oceans, a new study suggests.

Mass extinction may not be an enduring mystery. Instead, it may be an intrinsic property of the carbon cycle. Once levels of dissolved carbon dioxide in the oceans reach a certain threshold, life undergoes dramatic and catastrophic change.

If a US mathematician is right – and his argument is based on statistical reasoning and the evidence in the marine sediments – then once the seas become too acidic for marine organisms to form carbonate shells, a cascade of extinction begins.

And, he warns, the “unusually strong but geologically brief duration” of manmade carbon dioxide increase in the oceans can be matched with slow but devastating extinctions in the past.

In short, human combustion of fossil fuels, combined with the destruction of the forests, could be building up to extinctions on a scale so colossal that they will be visible in the fossil record hundreds of millions of years from now.

After a certain point, the carbon cycle will take over and decide life’s direction. It happened many times long before the emergence of the human species, and it could happen again, according to a new study in the  Proceedings of the National Academy of Sciences.

“It’s a positive feedback. More carbon dioxide leads to more carbon dioxide. Is such a feedback enough to render the system unstable?”

“Once we are over the threshold, how we got there may not matter,” said Daniel Rothman of the Massachusetts Institute of Technology. “Once you get over it, you’re dealing with how the Earth works, and it goes on its own ride.”

Professor Rothman developed his hypothesis in 2017, in the journal Science Advances, after he analysed 31 changes in the makeup of carbonate sediments laid down over the last 542 million years, and connected five great extinctions not just with carbon dioxide levels but with the rate at which these increased.

He may be for the moment a lone voice in linking four of the five major extinctions with critical levels of oceanic acidification as a consequence of a carbon dioxide threshold. But climate scientists and palaeontologists have been looking at possible links between carbon and extinction for decades.

They have also repeatedly warned that humans are about to precipitate a sixth mass extinction, chiefly on the basis that we are destroying natural habitat and erasing the conditions in which millions of species – many of them still not identified – were once able to flourish.

The carbon factor

But climate change driven by ever-increasing atmospheric carbon dioxide levels – powered in turn by ever-increasing combustion of fossil fuels – has also been a factor.

Whatever the risk to species or ecosystems, biologists and conservationists have warned that climate change driven by global heating can only make things worse.

And the more carefully researchers have looked at evidence of earlier catastrophic extinctions, the more bygone climate change has revealed itself. What caused the most dramatic and unequivocal of these – the “great dying” at the close of the Permian – is still hotly debated, but atmospheric conditions in one form or another have been repeatedly invoked and researchers have repeatedly drawn lessons for today.

But arguments so far have settled on whether such extinctions are a consequence of slow but inexorable episodes of volcanic discharge or some other geological shift.

Forget the trigger

Professor Rothman’s point is that the trigger itself may not be the important thing: what decides the fate of life on Earth is the level of carbon in the oceans and the rate at which it increases.

Once levels of acidification in the upper ocean reach a certain critical threshold, life is in for major disruption. If marine creatures cannot form shells, they are at risk. But even more dangerously, shells sink to the ocean floor, effectively removing carbon from circulation.

If there are fewer calcifying organisms, then less carbon dioxide is removed from the atmosphere and oceans become even more acidic. A vicious cycle has begun.

“It’s a positive feedback,” Professor Rothman said. “More carbon dioxide leads to more carbon dioxide. The question, from a mathematical point of view is, is such a feedback enough to render the system unstable?”

Balance restored

In his mathematical model, once carbon levels reached a critical threshold, a cascade of positive feedbacks amplified the effect. Severe ocean acidification set in.

The effect was not permanent. After tens of thousands of years, the carbon cycle did slip back to equilibrium and life could evolve and adapt again.

Carbon is now entering the oceans at an unprecedented rate, over what – in geological terms – is a very brief timespan. If human-triggered greenhouse gas emissions cross a critical threshold, the consequences could be as severe as any of the previous mass extinctions.

“It’s difficult to know how things will end up, given what is happening today,” he said. “But we are probably close to a critical threshold. Any spike would reach its maximum after about 10,000 years. Hopefully, that would give us time to find a solution.” − Climate News Network

Arctic sea ice loss affects the jet stream

The jet stream affects northern hemisphere climates. And global warming affects the behaviour of the jet stream. Prepare for yet more extremes of seasonal weather.

LONDON, 6 June, 2019 − Did you shiver in a winter ice storm? Could you wilt in a protracted heatwave this summer? German scientists have just identified the guilty agency and delivered the evidence implicating the jet stream.

Blame it on Arctic warming, they conclude: the retreat of the sea ice over the polar ocean has distorted the pattern of flow of the stratospheric winds usually known as the jet stream.

It is not a new idea. But this time, scientists have employed artificial intelligence and a machine-learning programme to accurately model the changes in the jet stream and then link these to changes in the chemistry of the upper atmosphere, and increasing patterns of twisting waves in the high altitude winds which then distort seasonal weather in the northern hemisphere mid-latitudes. They describe their research in the journal Scientific Reports.

“Our study shows that the changes in the jet stream are at least partly due to the loss of Arctic sea ice. If the ice cover continues to dwindle, we believe that both the frequency and intensity of the extreme weather events previously observed in the middle latitudes will increase,” said Markus Rex, who heads atmospheric research at the Alfred Wegener Institute in Potsdam, Germany.

Cold bouts explained

“In addition, our findings confirm that the more frequently occurring cold phases in winter in the USA, Europe and Asia are by no means a contradiction to global warming; rather they are part of anthropogenic climate change.”

The jet stream – exploited by jet aircraft on the trans-Atlantic routes – is made up of westerly winds that, at an altitude of 10 kilometres, stream around the planet in the mid-latitudes, at speeds of up to 500 km an hour, and push weather systems from west to east.

But researchers have already observed this: they have been changing, in response to global warming and in particular to the rapid warming of the Arctic, as greenhouse gas ratios in the atmosphere rise, and go on rising, in response to profligate human combustion of fossil fuels.

Rather than stick to a course more or less parallel to the Equator, these winds have been observed describing dramatic waves.

“If the ice cover continues to dwindle, we believe that both the frequency and intensity of the extreme weather events previously observed in the middle latitudes will increase”

These twists of direction have been linked to blasts of Arctic air into regions that could normally expect relatively mild winters: in particular to the ferocious cold that hit the US Midwest in January 2019.

These winds have also weakened and been linked to prolonged drought and extremes of heat that hit Europe in 2003, 2006, 2015 and 2018.

But association is not the same as demonstration of cause-and-effect. The Potsdam scientists wanted surer evidence. And their new climate simulations now include a machine-learning component that accounts for ozone chemistry at high altitudes.

And what their new model found was that as the Arctic sea ice retreats, the atmospheric waves have warmed the polar stratosphere in ways that have been amplified by the behaviour of the ozone layer.

Ozone response

Since what powers the jet stream is the difference between the cold Arctic and the warm tropics, the jet stream has weakened, and begun to meander, like a river flowing across a flood plain towards the sea.

In effect, the new study introduces a new piece to the climate puzzle: the response of the ozone layer and its role in the play of winds around the planet. The pay-off could be a clearer picture of things to come.

“We are now for the first time employing artificial intelligence in climate modelling, helping us arrive at more realistic model systems,” said Professor Rex.

“This holds tremendous potential for future climate models, which we believe will deliver more reliable climate projections and therefore a more robust basis for political decision-making.” − Climate News Network

The jet stream affects northern hemisphere climates. And global warming affects the behaviour of the jet stream. Prepare for yet more extremes of seasonal weather.

LONDON, 6 June, 2019 − Did you shiver in a winter ice storm? Could you wilt in a protracted heatwave this summer? German scientists have just identified the guilty agency and delivered the evidence implicating the jet stream.

Blame it on Arctic warming, they conclude: the retreat of the sea ice over the polar ocean has distorted the pattern of flow of the stratospheric winds usually known as the jet stream.

It is not a new idea. But this time, scientists have employed artificial intelligence and a machine-learning programme to accurately model the changes in the jet stream and then link these to changes in the chemistry of the upper atmosphere, and increasing patterns of twisting waves in the high altitude winds which then distort seasonal weather in the northern hemisphere mid-latitudes. They describe their research in the journal Scientific Reports.

“Our study shows that the changes in the jet stream are at least partly due to the loss of Arctic sea ice. If the ice cover continues to dwindle, we believe that both the frequency and intensity of the extreme weather events previously observed in the middle latitudes will increase,” said Markus Rex, who heads atmospheric research at the Alfred Wegener Institute in Potsdam, Germany.

Cold bouts explained

“In addition, our findings confirm that the more frequently occurring cold phases in winter in the USA, Europe and Asia are by no means a contradiction to global warming; rather they are part of anthropogenic climate change.”

The jet stream – exploited by jet aircraft on the trans-Atlantic routes – is made up of westerly winds that, at an altitude of 10 kilometres, stream around the planet in the mid-latitudes, at speeds of up to 500 km an hour, and push weather systems from west to east.

But researchers have already observed this: they have been changing, in response to global warming and in particular to the rapid warming of the Arctic, as greenhouse gas ratios in the atmosphere rise, and go on rising, in response to profligate human combustion of fossil fuels.

Rather than stick to a course more or less parallel to the Equator, these winds have been observed describing dramatic waves.

“If the ice cover continues to dwindle, we believe that both the frequency and intensity of the extreme weather events previously observed in the middle latitudes will increase”

These twists of direction have been linked to blasts of Arctic air into regions that could normally expect relatively mild winters: in particular to the ferocious cold that hit the US Midwest in January 2019.

These winds have also weakened and been linked to prolonged drought and extremes of heat that hit Europe in 2003, 2006, 2015 and 2018.

But association is not the same as demonstration of cause-and-effect. The Potsdam scientists wanted surer evidence. And their new climate simulations now include a machine-learning component that accounts for ozone chemistry at high altitudes.

And what their new model found was that as the Arctic sea ice retreats, the atmospheric waves have warmed the polar stratosphere in ways that have been amplified by the behaviour of the ozone layer.

Ozone response

Since what powers the jet stream is the difference between the cold Arctic and the warm tropics, the jet stream has weakened, and begun to meander, like a river flowing across a flood plain towards the sea.

In effect, the new study introduces a new piece to the climate puzzle: the response of the ozone layer and its role in the play of winds around the planet. The pay-off could be a clearer picture of things to come.

“We are now for the first time employing artificial intelligence in climate modelling, helping us arrive at more realistic model systems,” said Professor Rex.

“This holds tremendous potential for future climate models, which we believe will deliver more reliable climate projections and therefore a more robust basis for political decision-making.” − Climate News Network

Unstable polar glaciers lose ice ever faster

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

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

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

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

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

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

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

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

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

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

Huge ice losses

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Huge ice losses

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

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

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

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

Sea level rise may double forecast for 2100

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

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

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

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

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

Sombre prospect

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

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

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

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

 

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

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

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

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

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

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

Mass exodus

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

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

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

Serious risk

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

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

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

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

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

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

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

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

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

Sombre prospect

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

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

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

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

 

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

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

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

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

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

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

Mass exodus

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

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

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

Serious risk

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

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

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

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

Marine microbes may fuel ocean warming

Warmer air means warmer seas, and marine microbes in warmer seas could mean yet warmer air. The climate cycle could get increasingly vicious.

LONDON, 6 May, 2019 − US scientists say marine microbes are the cause of yet another potentially positive feedback that could accelerate global warming.

As the oceans warm, marine microbial life might start to pump yet more carbon dioxide into the air. This process would of course increase the greenhouse gas levels still further and warm the oceans to increasing temperatures.

The finding is a reminder that the atmosphere, oceans, ice caps, rocks, algae, bacteria and forests are all intricate parts of the planetary climate machinery, and researchers still have a long way to go before they understand all the working parts in detail. But it is also a reminder that every small rise in planetary average temperatures in some way feeds back into this complex system.

The new study, based on analysis of data gathered during a research cruise in 2013 from Peru to Tahiti, is published in the Proceedings of the National Academy of Sciences.

“Warming will cause faster recycling of carbon in many areas, and that means less carbon will reach the deep ocean and get stored”

The shipboard scientists looked in depth at processes in highly productive waters off the South American coasts, and at the more or less barren waters south of the equator that cycle in a set of currents known as the South Pacific Gyre.

They did so to estimate the fate of tiny green plants – plankton – as they flourished in the ocean surface, and then perished and sank to the depths.

In the great and far-from-complete reckoning of the planet’s carbon budget – from atmosphere to plants to animals and back to the air, or to the rocks – climate scientists think that the oceans absorb around one fourth of all the extra carbon dioxide that humans burn as fossil fuels to power economic growth.

Plankton produce about 40 to 50 billion tonnes of organic carbon as they flourish, and then perish. Microbes set to work and begin the process of decay, recycling the carbon into the atmosphere. But somewhere between 8bn and 10bn tonnes of green tissue sink below 100 metres, into waters increasingly starved of oxygen, and decay stops.

Long sojourn

Once the dead plankton reach the ocean bottom, they could be there for centuries. More heat, however, could alter the balance of recycling and long-term storage.

“The results are telling us that warming will cause faster recycling of carbon in many areas, and that means less carbon will reach the deep ocean and get stored,” said Robert Anderson, of Columbia University’s Lamont-Doherty Earth Observatory, and one of the authors.

The fear is that as the oceans warm, the oxygen-low zones will increase and expand. That could suggest more long-term carbon burial. But as the surface waters warm, the microbial activity could accelerate, and release even more carbon into the atmosphere. In which case, the world would warm more swiftly.

Research like this is necessarily inconclusive: marine biologists have a lot more to do before they get a convincing answer to a global puzzle. Climate scientists started worrying about oxygen depletion in the oceans years ago, but they have been more bothered by evidence that in a warmer world microbial scavengers and recyclers work ever harder, and not just on land.

Positive feedbacks

As the polar ice retreats, there are more emissions of potent greenhouse gases from the tundra. And as high latitude ice and snow retreats, the levels of radiation back into space are reduced, while deep blue sea and brown rock absorb ever higher doses of sunlight.

All these are instances of positive feedback: planetary responses that seem overall to make climate change more likely, and climate extremes more hazardous. And the increasing evidence of oxygen depletion in the oceans provides no comfort: as the seas warm, less oxygen is available for the ocean’s animals: including of course the huge hauls of fish on which millions depend for income and nourishment.

As the scientists say, in the opaque language of a research journal: “Our findings imply that climate warming will result in reduced ocean carbon storage due to expanding oligotrophic gyres, but opposing effects on ocean carbon storage from expanding suboxic waters will require modelling and future work to disentangle.”

In other words, there is more research to be done. − Climate News Network

Warmer air means warmer seas, and marine microbes in warmer seas could mean yet warmer air. The climate cycle could get increasingly vicious.

LONDON, 6 May, 2019 − US scientists say marine microbes are the cause of yet another potentially positive feedback that could accelerate global warming.

As the oceans warm, marine microbial life might start to pump yet more carbon dioxide into the air. This process would of course increase the greenhouse gas levels still further and warm the oceans to increasing temperatures.

The finding is a reminder that the atmosphere, oceans, ice caps, rocks, algae, bacteria and forests are all intricate parts of the planetary climate machinery, and researchers still have a long way to go before they understand all the working parts in detail. But it is also a reminder that every small rise in planetary average temperatures in some way feeds back into this complex system.

The new study, based on analysis of data gathered during a research cruise in 2013 from Peru to Tahiti, is published in the Proceedings of the National Academy of Sciences.

“Warming will cause faster recycling of carbon in many areas, and that means less carbon will reach the deep ocean and get stored”

The shipboard scientists looked in depth at processes in highly productive waters off the South American coasts, and at the more or less barren waters south of the equator that cycle in a set of currents known as the South Pacific Gyre.

They did so to estimate the fate of tiny green plants – plankton – as they flourished in the ocean surface, and then perished and sank to the depths.

In the great and far-from-complete reckoning of the planet’s carbon budget – from atmosphere to plants to animals and back to the air, or to the rocks – climate scientists think that the oceans absorb around one fourth of all the extra carbon dioxide that humans burn as fossil fuels to power economic growth.

Plankton produce about 40 to 50 billion tonnes of organic carbon as they flourish, and then perish. Microbes set to work and begin the process of decay, recycling the carbon into the atmosphere. But somewhere between 8bn and 10bn tonnes of green tissue sink below 100 metres, into waters increasingly starved of oxygen, and decay stops.

Long sojourn

Once the dead plankton reach the ocean bottom, they could be there for centuries. More heat, however, could alter the balance of recycling and long-term storage.

“The results are telling us that warming will cause faster recycling of carbon in many areas, and that means less carbon will reach the deep ocean and get stored,” said Robert Anderson, of Columbia University’s Lamont-Doherty Earth Observatory, and one of the authors.

The fear is that as the oceans warm, the oxygen-low zones will increase and expand. That could suggest more long-term carbon burial. But as the surface waters warm, the microbial activity could accelerate, and release even more carbon into the atmosphere. In which case, the world would warm more swiftly.

Research like this is necessarily inconclusive: marine biologists have a lot more to do before they get a convincing answer to a global puzzle. Climate scientists started worrying about oxygen depletion in the oceans years ago, but they have been more bothered by evidence that in a warmer world microbial scavengers and recyclers work ever harder, and not just on land.

Positive feedbacks

As the polar ice retreats, there are more emissions of potent greenhouse gases from the tundra. And as high latitude ice and snow retreats, the levels of radiation back into space are reduced, while deep blue sea and brown rock absorb ever higher doses of sunlight.

All these are instances of positive feedback: planetary responses that seem overall to make climate change more likely, and climate extremes more hazardous. And the increasing evidence of oxygen depletion in the oceans provides no comfort: as the seas warm, less oxygen is available for the ocean’s animals: including of course the huge hauls of fish on which millions depend for income and nourishment.

As the scientists say, in the opaque language of a research journal: “Our findings imply that climate warming will result in reduced ocean carbon storage due to expanding oligotrophic gyres, but opposing effects on ocean carbon storage from expanding suboxic waters will require modelling and future work to disentangle.”

In other words, there is more research to be done. − Climate News Network