Tag Archives: Sea levels

Antarctic melting could bring a much hotter future

Antarctic melting can force sea ice retreat of 50 metres daily. CO2 levels are at their highest for 23 million years. Learn from the past.

LONDON, 23 June, 2020 – Antarctic melting starts with dramatic speed. Ice shelves during the sudden warm spell at the close of the last Ice Age retreated at up to 50 metres a day.

This finding is not based on climate simulations generated by computer algorithms. It is based on direct evidence left 12,000 years ago on the Antarctic sea floor by retreating ice.

The finding is an indirect indicator of how warm things could get – and how high sea levels could rise – as humans burn ever more fossil fuels and raise atmospheric greenhouse gas levels to ever higher ratios.

And as if to highlight the approaching climate catastrophe, a second and separate study finds that the measure of carbon dioxide in the atmosphere now is not just higher than at any time in human history or at any interval in the Ice Ages. It is the highest for at least 23 million years.

“Should climate change continue to weaken the ice shelves in the coming decades, we could see similar rates of retreat, with profound implications for global sea level rise”

British scientists report in the journal Science that they used an autonomous underwater vehicle (AUV), cruising at depth in the Weddell Sea, to read the pattern of the past preserved in ridges of the Antarctic seabed.

The original push for the expedition had been to search for the ship Endurance, commanded by the polar explorer Ernest Shackleton on his doomed voyage in 1914. The loss of the ship, crushed in the polar ice, and the rescue of his crew became one of the epic stories of maritime history.

The researchers did not find Endurance. But they did find an enduring record of past ice retreat.

Sea ice skirts about 75% of the continent’s coastline: when it melts it makes no difference to sea levels, but while it remains frozen it does serve the purpose of buttressing glacial flow from the high Antarctic interior. Brushed by increasingly warm air each summer, and swept by slowly warming ocean currents all year round, the ice shelves are thinning and retreating.

Tell-tale line

Underneath the ice, the research team’s robot submarine spotted wave-like ridges, each about a metre high and 20 to 25 metres apart: ridges formed at what had once been the grounding line – the point at which a grounded ice sheet starts to float, and evidence of ice rising and falling with the tides.

There are twelve hours between high tide and low, so by measuring the distance between the ridges, scientists could measure the pace of retreat at the end of the last Ice Age. It is estimated at 40 to 50 metres a day.

Right now, the fastest retreat measured from grounding lines in Antarctica is only about 1.6 kms a year. The implication is that it could get a lot faster.

“Should climate change continue to weaken the ice shelves in the coming decades, we could see similar rates of retreat, with profound implications for global sea level rise,” said Julian Dowdeswell, director of the Scott Polar Research Institute in Cambridge, who led the research.

Faster change ahead

Past warm periods are associated only with relatively modest rises in atmospheric carbon dioxide. Right now, researchers have repeatedly confirmed that the present increasingly rapid rise is the highest in the last 800,000 years.

Now a team from the US and Norway report in the journal Geology that they have measured past atmospheric carbon levels in fossil plants to establish that present day carbon levels are higher currently than at any time in the last 23 million years.

This means that – unless there are drastic steps to contain global warming – the retreat will become increasingly more rapid, and the rate of glacial flow towards the sea ever faster.

Were all the ice in Antarctica to melt, sea levels would rise by about 60 metres, completely submerging many of the world’s great cities. – Climate News Network

Antarctic melting can force sea ice retreat of 50 metres daily. CO2 levels are at their highest for 23 million years. Learn from the past.

LONDON, 23 June, 2020 – Antarctic melting starts with dramatic speed. Ice shelves during the sudden warm spell at the close of the last Ice Age retreated at up to 50 metres a day.

This finding is not based on climate simulations generated by computer algorithms. It is based on direct evidence left 12,000 years ago on the Antarctic sea floor by retreating ice.

The finding is an indirect indicator of how warm things could get – and how high sea levels could rise – as humans burn ever more fossil fuels and raise atmospheric greenhouse gas levels to ever higher ratios.

And as if to highlight the approaching climate catastrophe, a second and separate study finds that the measure of carbon dioxide in the atmosphere now is not just higher than at any time in human history or at any interval in the Ice Ages. It is the highest for at least 23 million years.

“Should climate change continue to weaken the ice shelves in the coming decades, we could see similar rates of retreat, with profound implications for global sea level rise”

British scientists report in the journal Science that they used an autonomous underwater vehicle (AUV), cruising at depth in the Weddell Sea, to read the pattern of the past preserved in ridges of the Antarctic seabed.

The original push for the expedition had been to search for the ship Endurance, commanded by the polar explorer Ernest Shackleton on his doomed voyage in 1914. The loss of the ship, crushed in the polar ice, and the rescue of his crew became one of the epic stories of maritime history.

The researchers did not find Endurance. But they did find an enduring record of past ice retreat.

Sea ice skirts about 75% of the continent’s coastline: when it melts it makes no difference to sea levels, but while it remains frozen it does serve the purpose of buttressing glacial flow from the high Antarctic interior. Brushed by increasingly warm air each summer, and swept by slowly warming ocean currents all year round, the ice shelves are thinning and retreating.

Tell-tale line

Underneath the ice, the research team’s robot submarine spotted wave-like ridges, each about a metre high and 20 to 25 metres apart: ridges formed at what had once been the grounding line – the point at which a grounded ice sheet starts to float, and evidence of ice rising and falling with the tides.

There are twelve hours between high tide and low, so by measuring the distance between the ridges, scientists could measure the pace of retreat at the end of the last Ice Age. It is estimated at 40 to 50 metres a day.

Right now, the fastest retreat measured from grounding lines in Antarctica is only about 1.6 kms a year. The implication is that it could get a lot faster.

“Should climate change continue to weaken the ice shelves in the coming decades, we could see similar rates of retreat, with profound implications for global sea level rise,” said Julian Dowdeswell, director of the Scott Polar Research Institute in Cambridge, who led the research.

Faster change ahead

Past warm periods are associated only with relatively modest rises in atmospheric carbon dioxide. Right now, researchers have repeatedly confirmed that the present increasingly rapid rise is the highest in the last 800,000 years.

Now a team from the US and Norway report in the journal Geology that they have measured past atmospheric carbon levels in fossil plants to establish that present day carbon levels are higher currently than at any time in the last 23 million years.

This means that – unless there are drastic steps to contain global warming – the retreat will become increasingly more rapid, and the rate of glacial flow towards the sea ever faster.

Were all the ice in Antarctica to melt, sea levels would rise by about 60 metres, completely submerging many of the world’s great cities. – Climate News Network

Threatened mangrove forests won’t protect coasts

Rising tides driven by global heating could swamp the mangrove forests – bad news for the natural world, and for humans.

LONDON, 17 June, 2020 – If sea levels go on rising at ever higher rates, then by 2050 the world’s mangrove forests could be obliterated, drowned by rising tides.

Mangrove forests cover between 140,000 and 200,000 square kilometres of the intertidal zones that fringe more than 100 tropical and subtropical countries, and have become among the richest ecosystems of the planet.

They are estimated to store at least 30 million tonnes of atmospheric carbon each year, and a couple of sq kms of this saltwater forest can harbour nursery space for what could become 100 tonnes of commercial fish catch every year.

They also provide shelter for a huge range of creatures, including an estimated 500 Bengal tigers in the vast Sundarbans mangrove forests along the Ganges-Brahmaputra delta.

And while most of the 80 or so species of mangrove tree can keep up with an annual sea level rise of around 5mm a year, they seem unlikely, on evidence from the past, to be able to survive a 10mm rise. Right now, the world is heading for the higher end of the scale.

Sheltering people

A second and separate study finds that, importantly for humans, along with coral reefs, the mangrove forests provide vital natural protection from tropical storms for 31 million very vulnerable people in North and Central America and the crowded archipelagos of Indonesia and the Philippines.

Researchers from Australia, China, Singapore and the US report in the journal Science that they looked at the evidence locked in the sediments in 78 locations from the last 10,000 years, to work out how mangrove forests have – through the millennia – responded to changes in sea level.

At the close of the last ice age, sea levels rose at 10mm a year and slowed to nearly stable conditions 4000 years ago.

In a high emissions scenario, by 2050 sea level rise would exceed 6mm: the scientists found a 90% probability that mangroves would not be able to grow fast enough to keep up. Nor – because of the development of coastal settlements worldwide – would the forests be able to shift inland.

“Simply put, it’s much cheaper to conserve a mangrove than build a sea wall”

“This research therefore highlights yet another compelling reason why countries must take urgent action to reduce carbon emissions,” said Benjamin Horton of Nanyang Technical University in Singapore., one of the researchers.

“Mangroves are among the most valuable of natural ecosystems, supporting coastal fisheries and biodiversity, while protecting shorelines from wave and storm attack across the tropics.”

As so often happens in research, confirmatory evidence of the importance of mangroves had been published only days earlier, in the Public Library of Science journal PLOS One.

US researchers found that – in the Gulf of Mexico and the Caribbean, off the coasts of east Africa and in the Indo-Pacific – a total of 30.9 million people lived in regions vulnerable to powerful tropical storms such as Typhoon Haiyan and Hurricane Harvey.

Of these, more than 8 million people were offered severe weather protection by shoreline mangrove forests and coral reefs, both of which absorb wave energy, reduce wave heights and keep coastal settlements safer.

Not enough protection

But only 38% of mangroves and 11% of coral reefs along the vulnerable coastlines are protected, they found.

A 100-metre screen of shoreline mangrove forest can reduce wave heights by as much as two-thirds. By 2100, coastal floods could be costing the world’s nations US$1 trillion a year in economic damage.

Geographers have argued for decades that natural protection is the most efficient way of saving lives and settlements from the storm surges and flooding associated with tropical cyclone extremes.

“Simply put”, said Holly Jones of Northern Illinois University, who led the research, “it’s much cheaper to conserve a mangrove than build a sea wall.” – Climate News Network

Rising tides driven by global heating could swamp the mangrove forests – bad news for the natural world, and for humans.

LONDON, 17 June, 2020 – If sea levels go on rising at ever higher rates, then by 2050 the world’s mangrove forests could be obliterated, drowned by rising tides.

Mangrove forests cover between 140,000 and 200,000 square kilometres of the intertidal zones that fringe more than 100 tropical and subtropical countries, and have become among the richest ecosystems of the planet.

They are estimated to store at least 30 million tonnes of atmospheric carbon each year, and a couple of sq kms of this saltwater forest can harbour nursery space for what could become 100 tonnes of commercial fish catch every year.

They also provide shelter for a huge range of creatures, including an estimated 500 Bengal tigers in the vast Sundarbans mangrove forests along the Ganges-Brahmaputra delta.

And while most of the 80 or so species of mangrove tree can keep up with an annual sea level rise of around 5mm a year, they seem unlikely, on evidence from the past, to be able to survive a 10mm rise. Right now, the world is heading for the higher end of the scale.

Sheltering people

A second and separate study finds that, importantly for humans, along with coral reefs, the mangrove forests provide vital natural protection from tropical storms for 31 million very vulnerable people in North and Central America and the crowded archipelagos of Indonesia and the Philippines.

Researchers from Australia, China, Singapore and the US report in the journal Science that they looked at the evidence locked in the sediments in 78 locations from the last 10,000 years, to work out how mangrove forests have – through the millennia – responded to changes in sea level.

At the close of the last ice age, sea levels rose at 10mm a year and slowed to nearly stable conditions 4000 years ago.

In a high emissions scenario, by 2050 sea level rise would exceed 6mm: the scientists found a 90% probability that mangroves would not be able to grow fast enough to keep up. Nor – because of the development of coastal settlements worldwide – would the forests be able to shift inland.

“Simply put, it’s much cheaper to conserve a mangrove than build a sea wall”

“This research therefore highlights yet another compelling reason why countries must take urgent action to reduce carbon emissions,” said Benjamin Horton of Nanyang Technical University in Singapore., one of the researchers.

“Mangroves are among the most valuable of natural ecosystems, supporting coastal fisheries and biodiversity, while protecting shorelines from wave and storm attack across the tropics.”

As so often happens in research, confirmatory evidence of the importance of mangroves had been published only days earlier, in the Public Library of Science journal PLOS One.

US researchers found that – in the Gulf of Mexico and the Caribbean, off the coasts of east Africa and in the Indo-Pacific – a total of 30.9 million people lived in regions vulnerable to powerful tropical storms such as Typhoon Haiyan and Hurricane Harvey.

Of these, more than 8 million people were offered severe weather protection by shoreline mangrove forests and coral reefs, both of which absorb wave energy, reduce wave heights and keep coastal settlements safer.

Not enough protection

But only 38% of mangroves and 11% of coral reefs along the vulnerable coastlines are protected, they found.

A 100-metre screen of shoreline mangrove forest can reduce wave heights by as much as two-thirds. By 2100, coastal floods could be costing the world’s nations US$1 trillion a year in economic damage.

Geographers have argued for decades that natural protection is the most efficient way of saving lives and settlements from the storm surges and flooding associated with tropical cyclone extremes.

“Simply put”, said Holly Jones of Northern Illinois University, who led the research, “it’s much cheaper to conserve a mangrove than build a sea wall.” – Climate News Network

Unanswered questions dog UK’s new nuclear plans

A French company has designs on the United Kingdom: new nuclear plans for more reactors, with British consumers footing the bill.

LONDON, 11 June, 2020 – The French company EDF, a company in a hurry, wants permission to start building two more reactors in the United Kingdom, and it hopes to save money – by arranging for British taxpayers to pay the capital costs of its new nuclear plans.

EDF is already building two reactors at Hinkley Point in the West of England, and it is hoping to transfer workers from that site to Suffolk, on the east coast, believing that will help it to save up to 20% of the construction cost of the two planned reactors, because everyone employed there will know already what to do.

The catch is that EDF has no money itself to finance the construction and wants the UK government to impose a new tax on British electricity consumers so that they will pay the cost through their electricity bills.

The UK has yet to decide whether to go ahead with this tax, euphemistically called a Regulated Asset Base. If adopted, what the scheme means is that the UK consumer will pay EDF’s bills rather than the company having to borrow the money from banks, which are increasingly unlikely to lend money to such expensive schemes because they take so long to build and promise little return.

Anxieties abound

Meanwhile EDF, which has a Chinese nuclear company as its junior partner, promises to create 25,000 jobs, including 1,000 apprenticeships during construction, and says 900 full-time jobs will be available when Sizewell C, as the station will be called, is complete.

If all goes to plan the company hopes to start work in 18 months and says the two reactors will take 10 years to build. It expects them to provide 7% of the UK’s electricity, enough for six million homes.

There are many objectors. Some say much of the coastline will be badly affected, including internationally important nature reserves. Others fear the site is highly vulnerable to sea level rise and therefore a danger to the public.

Local people also fear that the construction site, with its attendant lorry and commuter traffic, will disrupt their lives for a decade, destroying the important tourist trade.

Cheaper options

Other more strategic objections, which might weigh heavier with the government, are that nuclear power is very expensive and much cheaper and less controversial alternatives exist, particularly on-shore and off-shore wind and solar power, and biogas.

More importantly, a drive for energy efficiency, badly neglected in the UK at present, would render the whole project unnecessary.

The problem EDF has is its track record on construction and repairs. The type of reactor it plans to build, the European Pressurised Water Reactor, said by the company to be the most powerful in the world, is proving extremely difficult to build, and till now none has yet been completed outside China.

Construction is running more than 10 years late in both Finland and France, and costs continue to escalate.

“It is hard to understand why, when the scale of the problems became clear, EDF did not cut its losses and close the reactors”

EDF’s debts are now huge, so big that the French state is working out how to restructure the company by splitting it into a renewables arm (which is profitable) and a nuclear branch.

There are serious doubts about the reliability of EDF’s claims and timetables for fixing existing power stations and opening new ones. The company currently owns all of the UK’s operating nuclear reactors, most of which are near the end of their lives, and there are serious doubts about whether they are economic and in some cases even safe.

Two reactors at Hunterston in Scotland have serious cracking in the graphite blocks that are part of the control mechanism. The company has spent two years trying to justify continuing to operate the reactors to the Office for Nuclear Regulation (ONR).

Similarly, at the other end of the UK, at Dungeness in south-east England, the station is also closed for extensive repairs, an outage that was going to take weeks has now stretched to two years – and the start-up date has just been put back again.

Looking on the bright side

One of the features of all of EDF’s activities is the extraordinary optimism the company seems to have, particularly about when reactors will be finished or ready to restart after repairs. With the Hunterston reactors restart dates have been announced nine times, only to be postponed each time.

This track record led the Climate News Network to ask EDF some searching questions, including why they continued to offer optimistic start-up dates that were repeatedly postponed. We also asked why the company kept the Hunterston and Dungeness stations open at all, since repairing them was costly and they were already near the end of their operating lives.

We asked EDF: “At what point do you cut your losses and close the stations permanently?” After five days of pleading for more time to answer, it sent us already published press releases extolling the virtues of the plan to build Sizewell, and several comments.

On Dungeness B it said: “For the past two years we have undertaken a major investment programme at Dungeness to secure the station’s longer-term future. Since the start of the year we have made great progress in  tackling some of the complex problems our works identified.

Extensive repairs

“However we still have further engineering works to complete, and a detailed safety case to finalise, before we ask for restart approval from our regulator. Our present position for estimated return to service is 11 September for Reactor 22 and 21 September for Reactor 21.”

On Hunterston B, EDF said: “We are continuing to work constructively with the regulator to ensure the work at Hunterston B is done thoroughly and helps inform future decisions. The safety case for Hunterston B, Reactor 3, has been submitted to the ONR for its independent assessment.

“Since the first reactor was taken offline we have carried out the most extensive graphite inspection programme ever undertaken, the results of which have been fed into this case”, referring us to the information the company provides on graphite blocks.

The ONR could not answer for EDF on its estimated reactor re-opening dates, but on Hunterston it said it was looking at the safety case, would not be hurried and would not give permission to restart until it was satisfied it was safe to do so.

Unexpected snags

Stephen Thomas, professor of energy policy at the University of Greenwich, commented on the constantly postponed start-up dates for the ageing reactors:

“It is clear, given that shutdowns expected to take two months are now expected to take two years or more, that EDF has found huge unanticipated problems”, he said.

“It is hard to understand why, when the scale of the problems became clear, EDF did not cut its losses and close the reactors, but continues to pour money into plants to get a couple more years of operation out of plants highly likely to be loss-makers.

“It is depressing that ONR, which has a duty to keep the public informed on such important issues, chooses to hide behind bland statements such as that it will take as long as it takes, and that it will not comment on EDF’s decisions.” – Climate News Network

A French company has designs on the United Kingdom: new nuclear plans for more reactors, with British consumers footing the bill.

LONDON, 11 June, 2020 – The French company EDF, a company in a hurry, wants permission to start building two more reactors in the United Kingdom, and it hopes to save money – by arranging for British taxpayers to pay the capital costs of its new nuclear plans.

EDF is already building two reactors at Hinkley Point in the West of England, and it is hoping to transfer workers from that site to Suffolk, on the east coast, believing that will help it to save up to 20% of the construction cost of the two planned reactors, because everyone employed there will know already what to do.

The catch is that EDF has no money itself to finance the construction and wants the UK government to impose a new tax on British electricity consumers so that they will pay the cost through their electricity bills.

The UK has yet to decide whether to go ahead with this tax, euphemistically called a Regulated Asset Base. If adopted, what the scheme means is that the UK consumer will pay EDF’s bills rather than the company having to borrow the money from banks, which are increasingly unlikely to lend money to such expensive schemes because they take so long to build and promise little return.

Anxieties abound

Meanwhile EDF, which has a Chinese nuclear company as its junior partner, promises to create 25,000 jobs, including 1,000 apprenticeships during construction, and says 900 full-time jobs will be available when Sizewell C, as the station will be called, is complete.

If all goes to plan the company hopes to start work in 18 months and says the two reactors will take 10 years to build. It expects them to provide 7% of the UK’s electricity, enough for six million homes.

There are many objectors. Some say much of the coastline will be badly affected, including internationally important nature reserves. Others fear the site is highly vulnerable to sea level rise and therefore a danger to the public.

Local people also fear that the construction site, with its attendant lorry and commuter traffic, will disrupt their lives for a decade, destroying the important tourist trade.

Cheaper options

Other more strategic objections, which might weigh heavier with the government, are that nuclear power is very expensive and much cheaper and less controversial alternatives exist, particularly on-shore and off-shore wind and solar power, and biogas.

More importantly, a drive for energy efficiency, badly neglected in the UK at present, would render the whole project unnecessary.

The problem EDF has is its track record on construction and repairs. The type of reactor it plans to build, the European Pressurised Water Reactor, said by the company to be the most powerful in the world, is proving extremely difficult to build, and till now none has yet been completed outside China.

Construction is running more than 10 years late in both Finland and France, and costs continue to escalate.

“It is hard to understand why, when the scale of the problems became clear, EDF did not cut its losses and close the reactors”

EDF’s debts are now huge, so big that the French state is working out how to restructure the company by splitting it into a renewables arm (which is profitable) and a nuclear branch.

There are serious doubts about the reliability of EDF’s claims and timetables for fixing existing power stations and opening new ones. The company currently owns all of the UK’s operating nuclear reactors, most of which are near the end of their lives, and there are serious doubts about whether they are economic and in some cases even safe.

Two reactors at Hunterston in Scotland have serious cracking in the graphite blocks that are part of the control mechanism. The company has spent two years trying to justify continuing to operate the reactors to the Office for Nuclear Regulation (ONR).

Similarly, at the other end of the UK, at Dungeness in south-east England, the station is also closed for extensive repairs, an outage that was going to take weeks has now stretched to two years – and the start-up date has just been put back again.

Looking on the bright side

One of the features of all of EDF’s activities is the extraordinary optimism the company seems to have, particularly about when reactors will be finished or ready to restart after repairs. With the Hunterston reactors restart dates have been announced nine times, only to be postponed each time.

This track record led the Climate News Network to ask EDF some searching questions, including why they continued to offer optimistic start-up dates that were repeatedly postponed. We also asked why the company kept the Hunterston and Dungeness stations open at all, since repairing them was costly and they were already near the end of their operating lives.

We asked EDF: “At what point do you cut your losses and close the stations permanently?” After five days of pleading for more time to answer, it sent us already published press releases extolling the virtues of the plan to build Sizewell, and several comments.

On Dungeness B it said: “For the past two years we have undertaken a major investment programme at Dungeness to secure the station’s longer-term future. Since the start of the year we have made great progress in  tackling some of the complex problems our works identified.

Extensive repairs

“However we still have further engineering works to complete, and a detailed safety case to finalise, before we ask for restart approval from our regulator. Our present position for estimated return to service is 11 September for Reactor 22 and 21 September for Reactor 21.”

On Hunterston B, EDF said: “We are continuing to work constructively with the regulator to ensure the work at Hunterston B is done thoroughly and helps inform future decisions. The safety case for Hunterston B, Reactor 3, has been submitted to the ONR for its independent assessment.

“Since the first reactor was taken offline we have carried out the most extensive graphite inspection programme ever undertaken, the results of which have been fed into this case”, referring us to the information the company provides on graphite blocks.

The ONR could not answer for EDF on its estimated reactor re-opening dates, but on Hunterston it said it was looking at the safety case, would not be hurried and would not give permission to restart until it was satisfied it was safe to do so.

Unexpected snags

Stephen Thomas, professor of energy policy at the University of Greenwich, commented on the constantly postponed start-up dates for the ageing reactors:

“It is clear, given that shutdowns expected to take two months are now expected to take two years or more, that EDF has found huge unanticipated problems”, he said.

“It is hard to understand why, when the scale of the problems became clear, EDF did not cut its losses and close the reactors, but continues to pour money into plants to get a couple more years of operation out of plants highly likely to be loss-makers.

“It is depressing that ONR, which has a duty to keep the public informed on such important issues, chooses to hide behind bland statements such as that it will take as long as it takes, and that it will not comment on EDF’s decisions.” – Climate News Network

Human action will decide how much sea levels rise

Sea levels will go on rising, because of human action. By how much, though, depends on what humans do next.

LONDON, 21 May 2020 – It’s a racing certainty that sea levels everywhere will go on climbing. Unless the world’s nations act to contain global warming, by 2100 the tides around the world will be one metre higher. And by 2300, they could be five metres higher.

Humans will not be able to blame natural causes: if beaches wash away and coastal towns flood, it will be because of deliberate human inaction.

And even if the 195 nations that met in Paris in 2015 and vowed to limit global warming to “well below” a maximum of 2°C by 2100 actually keep their promise, sea levels around the world will almost certainly rise by at least half a metre, as ever warmer oceans expand, and mountain glaciers and polar icecaps continue to melt.

The predicted levels are not new – individual research teams and the Intergovernmental Panel on Climate Change have said as much many times – but they represent a second and closer look, by 106 experts, at the forecasts for the future.

The charge of human complicity in sea level rise, too, is not new, but science has a way of continuously re-examining its own conclusions to see if they could be wrong. And the message is: they are not wrong.

“This provides a great deal of hope for the future, as well as strong motivation to act now”

Researchers from Hong Kong, Ireland, the UK, the US and Germany joined scientists from Singapore to consider, once again, what could happen to the world’s oceans under two scenarios: one in which global warming – already at least 1°C higher now than for most of human history – rose by no more than 2°C altogether, and one in which humankind went on burning fossil fuels and destroying tropical rainforests at ever greater rates.

The conclusion? They report in the journal Climate and Atmospheric Science that at the 2°C limit, seas will rise by 0.5 metres by 2100 and two metres by 2300.

If temperatures by 2100 reach 4.5°C, then by the century’s end the tides could reach anywhere between 0.6 and 1.3 metres above present levels. Two centuries on, the high tide mark could be anywhere between 1.7 and 5.6 metres above the present.

And these are the judgments of 106 scientists, each of whom has published at least six peer-reviewed scientific studies of future sea level rise in the last six years.

“We know that the planet will see additional sea level rise in the future. But there are stark differences in the amount of sea level rise experts project for low emissions compared to high emissions,” said one of the scientists, Andra Garner of Rowan University in the US.

Lessons from prehistory

“This provides a great deal of hope for the future, as well as strong motivation to act now to avoid the more severe impacts of rising sea levels.”

Quite separately, researchers in the US report in the journal Science Advances that they too, took a closer look at puzzles posed by past sea level change. Long before humans ever started burning coal, oil and natural gas, the ice caps retreated, and the seas rose.

The scientists reconstructed the history of sea levels and glaciation since the end of the Cretaceous era 60 million or so years ago, and matched them to estimated carbon dioxide levels long before the emergence of any human ancestry.

They concluded that all the changes in the past had natural explanations, but not the changes happening now.

Kenneth Miller of Rutgers University who led the study said: “Although carbon dioxide levels had an important influence on ice-free periods, minor variations in the Earth’s orbit were the dominant factor in terms of ice volume and sea level changes – until modern times.” – Climate News Network

Sea levels will go on rising, because of human action. By how much, though, depends on what humans do next.

LONDON, 21 May 2020 – It’s a racing certainty that sea levels everywhere will go on climbing. Unless the world’s nations act to contain global warming, by 2100 the tides around the world will be one metre higher. And by 2300, they could be five metres higher.

Humans will not be able to blame natural causes: if beaches wash away and coastal towns flood, it will be because of deliberate human inaction.

And even if the 195 nations that met in Paris in 2015 and vowed to limit global warming to “well below” a maximum of 2°C by 2100 actually keep their promise, sea levels around the world will almost certainly rise by at least half a metre, as ever warmer oceans expand, and mountain glaciers and polar icecaps continue to melt.

The predicted levels are not new – individual research teams and the Intergovernmental Panel on Climate Change have said as much many times – but they represent a second and closer look, by 106 experts, at the forecasts for the future.

The charge of human complicity in sea level rise, too, is not new, but science has a way of continuously re-examining its own conclusions to see if they could be wrong. And the message is: they are not wrong.

“This provides a great deal of hope for the future, as well as strong motivation to act now”

Researchers from Hong Kong, Ireland, the UK, the US and Germany joined scientists from Singapore to consider, once again, what could happen to the world’s oceans under two scenarios: one in which global warming – already at least 1°C higher now than for most of human history – rose by no more than 2°C altogether, and one in which humankind went on burning fossil fuels and destroying tropical rainforests at ever greater rates.

The conclusion? They report in the journal Climate and Atmospheric Science that at the 2°C limit, seas will rise by 0.5 metres by 2100 and two metres by 2300.

If temperatures by 2100 reach 4.5°C, then by the century’s end the tides could reach anywhere between 0.6 and 1.3 metres above present levels. Two centuries on, the high tide mark could be anywhere between 1.7 and 5.6 metres above the present.

And these are the judgments of 106 scientists, each of whom has published at least six peer-reviewed scientific studies of future sea level rise in the last six years.

“We know that the planet will see additional sea level rise in the future. But there are stark differences in the amount of sea level rise experts project for low emissions compared to high emissions,” said one of the scientists, Andra Garner of Rowan University in the US.

Lessons from prehistory

“This provides a great deal of hope for the future, as well as strong motivation to act now to avoid the more severe impacts of rising sea levels.”

Quite separately, researchers in the US report in the journal Science Advances that they too, took a closer look at puzzles posed by past sea level change. Long before humans ever started burning coal, oil and natural gas, the ice caps retreated, and the seas rose.

The scientists reconstructed the history of sea levels and glaciation since the end of the Cretaceous era 60 million or so years ago, and matched them to estimated carbon dioxide levels long before the emergence of any human ancestry.

They concluded that all the changes in the past had natural explanations, but not the changes happening now.

Kenneth Miller of Rutgers University who led the study said: “Although carbon dioxide levels had an important influence on ice-free periods, minor variations in the Earth’s orbit were the dominant factor in terms of ice volume and sea level changes – until modern times.” – Climate News Network

Sea level rise threatens UK nuclear reactor plans

Sea level rise may consign the planned UK site for two large nuclear reactors to vanish beneath the waves.

LONDON, 28 April, 2020 – Controversial plans by the French nuclear giant EDF to build two of its massive new reactors on the low-lying east coast of England are causing alarm: the shore is eroding and local people fear sea level rise could maroon the station on an island.

A newly published paper adds weight to the objections of two local government bodies, East Suffolk Council and Suffolk County Council, which have already lodged objections to EDF’s plans because they fear the proposed sea defences for the new station, Sizewell C, will be inadequate.

EDF, which is currently expecting the go-ahead to start building the station from the British government, says it has done its own expert assessment, had its calculations independently checked, and is satisfied that the coast is stable and the planned concrete sea defences will be adequate.

The argument is whether the coastal banks which prevent storm waves hitting this part of the coast will remain intact for the next 150 years – roughly the life of the station, taking into account 20 years of construction, 60 years of operation and then the time needed to decommission it.

The paper is the work of a structural engineer, Nick Scarr, a member of the Nuclear Consulting Group, which is an independent, non-profit virtual institute that provides expert research and analysis of nuclear issues.

As relevant, though, is his knowledge of the coastal waters of Suffolk, where he spends time sailing. He believes the coast is inherently unstable.

Catastrophic accident risk

With sea level rise and storm surges, he says, the site will become an island with its defences eroded by the sea well before the station reaches the end of its active life, risking a catastrophic accident, which is why he wrote his report.

He told the Climate News Network: “Any sailor, or lifeboat crew, knows that East Coast banks need respect – they have dynamic patterns, and even the latest charts cannot be accurate for long.

“I was deeply concerned by EDF’s premise that there is micro-stability at the Sizewell site, which makes it suitable for new-build nuclear. It is true if you restrict analysis to recent historical data, but it is false if you look at longer-term data and evidence-based climate science predictions.

“Climate science not only tells us that storm surges have a higher median level to work from, but that they will also render the banks ineffective for mitigating wave power on the Sizewell foreshore (because of reduced friction, as the water depth is greater).”

The longer-term data Scarr mentions are not altogether reassuring. Less than 10 miles from the site are the remains of Dunwich, once a thriving medieval port that disappeared in 1338 because of coastal erosion and a huge storm.

Nick Scarr added: “Note that Sizewell security needs to last at least from now to the year 2150. A shorter period than this, 1868-1992, shown in hydrographic charting, tells us clearly how unstable the offshore banks are over a longer time frame, and that is without sea level rise.”

“Any sailor, or lifeboat crew, knows that East Coast banks need respect – they have dynamic patterns, and even the latest charts cannot be accurate for long”

Sea level rise is expected to be up to a metre on this coast by the end of the century, but that is only part of the problem – the “once in a century” storm surges are expected to occur as often as once a year by 2050.

This is not the first time that ambitious plans by the government to build nuclear power stations on the British coast have been questioned. A proposed station at Dungeness in Kent, on England’s south-east coast,  has already been shelved because the existing station there is in danger from the sea.

The Suffolk site already has two stations. Sizewell A has been closed and is being decommissioned. The second, Sizewell B,  owned by EDF, has been operating since the early 1990s and is due to close some time in the 2030s.

The new reactors, together called Sizewell C, will be built further out to sea than A and B and will rely on an undersea ridge, a coralline crag, as a bastion against storm waves crashing into the station.

EDF’s contention that the site is safe is partly based on a report by engineers Mott Macdonald, compiled in 2014 and based on historical data, which says that this undersea ridge is stable and will continue to be a form of natural coastal defence.

However, East Suffolk and Suffolk County Councils, in their joint response to EDF’s consultation, make it clear that Sizewell C’s development has not in their view been shown to be able to be  protected from erosion or flood risk over the site’s life.

Fuel storage problem

Scarr’s report goes further, concluding: “This threat to the Sizewell foreshore is clearly an untenable risk.”

One contentious issue on nuclear sites, including those at Sizewell, is the need for decades-long storage of large quantities of highly dangerous spent nuclear fuel in cooling ponds once it is removed from the reactors. Currently the UK has no such disposal route.

Asked about Starr’s report and the councils’ objections, EDF told the Network: “The design of the power station, including its sea defence and the raised platform it will be built on, will protect Sizewell C from flooding.”

It added: “Sizewell C will safely manage the spent fuel from the station on the site for its lifetime, or until a deep geological repository becomes available.

“Sizewell is located within a stable part of the Suffolk coastline between two hard points and the offshore bank of sediment, the Dunwich-Sizewell bank.  We have undertaken extensive studies of the coastline in developing our plans.

“We have performed a great deal of modelling to forecast potential future scenarios along the Sizewell coast, with and without Sizewell C, to fully assess the effect of the station on coastal processes. We then asked independent experts to critique the forecasts to provide the very best assessment of long-term coastal change.

Dungeness jeopardy

“When built, the permanent sea defences would protect the power station from a 1 in 10,000-year storm event, including climate change and sea level rise. We’ve designed flexibility into our permanent coastal sea defence, meaning it could be raised during the lifetime of Sizewell C if needed.”

Another of EDF’s existing reactors, at Dungeness, which is built on a vast shingle bank, was taken offline seven years ago for five months while an emergency sea wall was built to prevent it being flooded.

For decades the defences of the twin reactors have had constantly to be reinforced because the shingle banks on which they stand are being eroded by the sea.

That station was designed more than 30 years ago, before scientists realised the dangers that sea level rise posed, and apparently without understanding how the shingle constantly moves.

Although it is due to shut later this decade it will still represent a serious danger to the public for another century until it can be safely decommissioned and demolished.

During that time millions of pounds will have to be spent making sure it is not overwhelmed by storms and sea level rise. – Climate News Network

Sea level rise may consign the planned UK site for two large nuclear reactors to vanish beneath the waves.

LONDON, 28 April, 2020 – Controversial plans by the French nuclear giant EDF to build two of its massive new reactors on the low-lying east coast of England are causing alarm: the shore is eroding and local people fear sea level rise could maroon the station on an island.

A newly published paper adds weight to the objections of two local government bodies, East Suffolk Council and Suffolk County Council, which have already lodged objections to EDF’s plans because they fear the proposed sea defences for the new station, Sizewell C, will be inadequate.

EDF, which is currently expecting the go-ahead to start building the station from the British government, says it has done its own expert assessment, had its calculations independently checked, and is satisfied that the coast is stable and the planned concrete sea defences will be adequate.

The argument is whether the coastal banks which prevent storm waves hitting this part of the coast will remain intact for the next 150 years – roughly the life of the station, taking into account 20 years of construction, 60 years of operation and then the time needed to decommission it.

The paper is the work of a structural engineer, Nick Scarr, a member of the Nuclear Consulting Group, which is an independent, non-profit virtual institute that provides expert research and analysis of nuclear issues.

As relevant, though, is his knowledge of the coastal waters of Suffolk, where he spends time sailing. He believes the coast is inherently unstable.

Catastrophic accident risk

With sea level rise and storm surges, he says, the site will become an island with its defences eroded by the sea well before the station reaches the end of its active life, risking a catastrophic accident, which is why he wrote his report.

He told the Climate News Network: “Any sailor, or lifeboat crew, knows that East Coast banks need respect – they have dynamic patterns, and even the latest charts cannot be accurate for long.

“I was deeply concerned by EDF’s premise that there is micro-stability at the Sizewell site, which makes it suitable for new-build nuclear. It is true if you restrict analysis to recent historical data, but it is false if you look at longer-term data and evidence-based climate science predictions.

“Climate science not only tells us that storm surges have a higher median level to work from, but that they will also render the banks ineffective for mitigating wave power on the Sizewell foreshore (because of reduced friction, as the water depth is greater).”

The longer-term data Scarr mentions are not altogether reassuring. Less than 10 miles from the site are the remains of Dunwich, once a thriving medieval port that disappeared in 1338 because of coastal erosion and a huge storm.

Nick Scarr added: “Note that Sizewell security needs to last at least from now to the year 2150. A shorter period than this, 1868-1992, shown in hydrographic charting, tells us clearly how unstable the offshore banks are over a longer time frame, and that is without sea level rise.”

“Any sailor, or lifeboat crew, knows that East Coast banks need respect – they have dynamic patterns, and even the latest charts cannot be accurate for long”

Sea level rise is expected to be up to a metre on this coast by the end of the century, but that is only part of the problem – the “once in a century” storm surges are expected to occur as often as once a year by 2050.

This is not the first time that ambitious plans by the government to build nuclear power stations on the British coast have been questioned. A proposed station at Dungeness in Kent, on England’s south-east coast,  has already been shelved because the existing station there is in danger from the sea.

The Suffolk site already has two stations. Sizewell A has been closed and is being decommissioned. The second, Sizewell B,  owned by EDF, has been operating since the early 1990s and is due to close some time in the 2030s.

The new reactors, together called Sizewell C, will be built further out to sea than A and B and will rely on an undersea ridge, a coralline crag, as a bastion against storm waves crashing into the station.

EDF’s contention that the site is safe is partly based on a report by engineers Mott Macdonald, compiled in 2014 and based on historical data, which says that this undersea ridge is stable and will continue to be a form of natural coastal defence.

However, East Suffolk and Suffolk County Councils, in their joint response to EDF’s consultation, make it clear that Sizewell C’s development has not in their view been shown to be able to be  protected from erosion or flood risk over the site’s life.

Fuel storage problem

Scarr’s report goes further, concluding: “This threat to the Sizewell foreshore is clearly an untenable risk.”

One contentious issue on nuclear sites, including those at Sizewell, is the need for decades-long storage of large quantities of highly dangerous spent nuclear fuel in cooling ponds once it is removed from the reactors. Currently the UK has no such disposal route.

Asked about Starr’s report and the councils’ objections, EDF told the Network: “The design of the power station, including its sea defence and the raised platform it will be built on, will protect Sizewell C from flooding.”

It added: “Sizewell C will safely manage the spent fuel from the station on the site for its lifetime, or until a deep geological repository becomes available.

“Sizewell is located within a stable part of the Suffolk coastline between two hard points and the offshore bank of sediment, the Dunwich-Sizewell bank.  We have undertaken extensive studies of the coastline in developing our plans.

“We have performed a great deal of modelling to forecast potential future scenarios along the Sizewell coast, with and without Sizewell C, to fully assess the effect of the station on coastal processes. We then asked independent experts to critique the forecasts to provide the very best assessment of long-term coastal change.

Dungeness jeopardy

“When built, the permanent sea defences would protect the power station from a 1 in 10,000-year storm event, including climate change and sea level rise. We’ve designed flexibility into our permanent coastal sea defence, meaning it could be raised during the lifetime of Sizewell C if needed.”

Another of EDF’s existing reactors, at Dungeness, which is built on a vast shingle bank, was taken offline seven years ago for five months while an emergency sea wall was built to prevent it being flooded.

For decades the defences of the twin reactors have had constantly to be reinforced because the shingle banks on which they stand are being eroded by the sea.

That station was designed more than 30 years ago, before scientists realised the dangers that sea level rise posed, and apparently without understanding how the shingle constantly moves.

Although it is due to shut later this decade it will still represent a serious danger to the public for another century until it can be safely decommissioned and demolished.

During that time millions of pounds will have to be spent making sure it is not overwhelmed by storms and sea level rise. – Climate News Network

US coasts face far more frequent severe floods

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

For US coasts, high-water hazards have just become more hazardous: a lot more hazardous, say scientists.

LONDON, 24 April, 2020 − A new study of high-water levels on US coasts in 200 regions brings ominous news for those who live in vulnerable towns and cities.

By 2050, floods expected perhaps once every 50 years will happen almost every year in nearly three fourths of all the coasts under study.

And by 2100, the kind of extreme high tides that now happen once in a lifetime could wash over the streets and gardens of 93% of these communities, almost every day.

The message, from researchers led by the US Geological Survey, is that sea levels will go on rising steadily by millimetres every year, but the number of extreme flooding events could double every five years.

Researchers outline their argument in the journal Scientific Reports. They looked at the data routinely collected from 202 tide gauges distributed around the US coasts and then extended the tidal levels forward in time in line with predictions based on global sea level rise that will inevitably accompany ever-increasing global average temperatures, driven by greenhouse gas emissions from fossil fuel use.

“The impact of this finding bears repeating: sea level rise will likely cause ‘once-in-a-lifetime’ coastal flooding events to occur nearly every day before 2100”

Other scientists have warned that the damage from coastal flooding, storm surges and marine invasion will rise to colossal levels by the century’s end, that routine high-tide floods will become increasingly common, and that up to 13 million US citizens now in coastal settlements could become climate refugees.

But researchers based in Chicago, Santa Cruz and Hawaii wanted more than that: they wanted to know what sea level rise will do, as the waters lap ever higher, from year to year.

“Sea level rise is slow, yet consequential and accelerating,” they point out. “Upper end sea level rise scenarios could displace hundreds of millions of people by the end of the 21st century. However, even small amounts of sea level rise can disproportionately increase coastal flood frequency.”

The researchers selected 202 sites, most of them in sheltered harbours or bays, for their tide data: that way their record reflected the highest tides and storm surges, but not the haphazard readings of waves.

They concentrated on what they called “extreme water-level events” of the kind that happened once every 50 years, because most US coastal engineering work is based on that kind of hazard frequency. And then they started doing the calculations.

Exponential hazard growth

For nine out of 10 locations, the difference between the kind of flood that happened every 50 years and the sort that occurred maybe once a year was about half a metre. For 73% of their chosen tide gauges, the difference between the daily highest tide and the once-every-50-years event was less than a metre. Most projections for sea level rise worldwide by the end of the century are higher than a metre.

Once the researchers had set their algorithms to work, they found that even in median sea-level rise scenarios, the hazards grew exponentially. They found that all tidal stations would by 2050 be recording what remain for the moment 50-year events, every year. When they set the timetable to 2100, 93% of their locations would be recording a once-in-50-years flood every day.

“The impact of this finding bears repeating: sea level rise will likely cause ‘once-in-a-lifetime’ coastal flooding events to occur nearly every day before 2100,” they warn.

This would have profound consequences for what they call extreme events. And even in ordinary circumstances, beaches are increasingly likely to be washed away, and cliffs eroded.

The researchers conclude: “Our society has yet to fully comprehend the imminence of the projected regime shifts in coastal hazards and the consequences thereof.” − Climate News Network

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

For US coasts, high-water hazards have just become more hazardous: a lot more hazardous, say scientists.

LONDON, 24 April, 2020 − A new study of high-water levels on US coasts in 200 regions brings ominous news for those who live in vulnerable towns and cities.

By 2050, floods expected perhaps once every 50 years will happen almost every year in nearly three fourths of all the coasts under study.

And by 2100, the kind of extreme high tides that now happen once in a lifetime could wash over the streets and gardens of 93% of these communities, almost every day.

The message, from researchers led by the US Geological Survey, is that sea levels will go on rising steadily by millimetres every year, but the number of extreme flooding events could double every five years.

Researchers outline their argument in the journal Scientific Reports. They looked at the data routinely collected from 202 tide gauges distributed around the US coasts and then extended the tidal levels forward in time in line with predictions based on global sea level rise that will inevitably accompany ever-increasing global average temperatures, driven by greenhouse gas emissions from fossil fuel use.

“The impact of this finding bears repeating: sea level rise will likely cause ‘once-in-a-lifetime’ coastal flooding events to occur nearly every day before 2100”

Other scientists have warned that the damage from coastal flooding, storm surges and marine invasion will rise to colossal levels by the century’s end, that routine high-tide floods will become increasingly common, and that up to 13 million US citizens now in coastal settlements could become climate refugees.

But researchers based in Chicago, Santa Cruz and Hawaii wanted more than that: they wanted to know what sea level rise will do, as the waters lap ever higher, from year to year.

“Sea level rise is slow, yet consequential and accelerating,” they point out. “Upper end sea level rise scenarios could displace hundreds of millions of people by the end of the 21st century. However, even small amounts of sea level rise can disproportionately increase coastal flood frequency.”

The researchers selected 202 sites, most of them in sheltered harbours or bays, for their tide data: that way their record reflected the highest tides and storm surges, but not the haphazard readings of waves.

They concentrated on what they called “extreme water-level events” of the kind that happened once every 50 years, because most US coastal engineering work is based on that kind of hazard frequency. And then they started doing the calculations.

Exponential hazard growth

For nine out of 10 locations, the difference between the kind of flood that happened every 50 years and the sort that occurred maybe once a year was about half a metre. For 73% of their chosen tide gauges, the difference between the daily highest tide and the once-every-50-years event was less than a metre. Most projections for sea level rise worldwide by the end of the century are higher than a metre.

Once the researchers had set their algorithms to work, they found that even in median sea-level rise scenarios, the hazards grew exponentially. They found that all tidal stations would by 2050 be recording what remain for the moment 50-year events, every year. When they set the timetable to 2100, 93% of their locations would be recording a once-in-50-years flood every day.

“The impact of this finding bears repeating: sea level rise will likely cause ‘once-in-a-lifetime’ coastal flooding events to occur nearly every day before 2100,” they warn.

This would have profound consequences for what they call extreme events. And even in ordinary circumstances, beaches are increasingly likely to be washed away, and cliffs eroded.

The researchers conclude: “Our society has yet to fully comprehend the imminence of the projected regime shifts in coastal hazards and the consequences thereof.” − Climate News Network

Cloudless skies hasten Greenland’s ice loss

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

The bad news about Greenland’s ice loss has just got even worse. Blame it on mischief by blue skies all day long.

LONDON, 22 April, 2020 – Greenland’s ice loss reached record levels in 2019, and scientists think they’ve identified the culprit: the good weather which normally brings the snow-bearing clouds to the High Arctic.

The huge island, the biggest bank of ice in the northern hemisphere, has been losing ice at an ever-increasing rate in a rapidly warming world. Last year it shed more ice than ever, and this time because the skies were unusually clear.

There is enough ice on Greenland to raise global sea levels by more than seven metres. A recent study established that in the years between 1992 and 2018, rates of polar ice loss have risen six-fold, and so much water has flowed off the Greenland ice surface that sea levels have risen by more than 10mm everywhere.

Now a new study by US and Belgian scientists in the journal The Cryosphere confirms that 2019 was even worse. Because of good weather and cloudless skies, only enough snow fell to deposit 50 billion tonnes of ice into the island’s profit-and-loss ice account. The average annual deposit between 1981 and 2010 was about 375bn tonnes.

But glaciers still flowed towards the sea at an ever-increasing rate, summer snow melt continued to flow off the ice sheet, and icebergs continued to calve, so on balance the island lost 600 billion tonnes of ice: enough to raise global sea levels by 1.5mm. This is the biggest overall loss of ice since records in Greenland began in 1948.

“These atmospheric conditions are becoming more and more frequent over the past few decades. It is very likely that this is due to the waviness of the jet stream”

The cause: unusual spells of high atmospheric pressure over the island for unusually long periods of time. That stopped the formation of clouds, and that meant less precipitation, in the form of snow. Snow reflects solar radiation more effectively than ice, so the surface absorbed more heat and melting also accelerated.

The pattern of warm moist clouds trapped over northern Greenland by the heat that would normally radiate off the ice, instead of releasing snow, also emitted their own heat, to make things worse. The worst year for surface melting remains 2012, but the summer of 2019 was a good second.

The implication is that things could get worse, and losses of Greenland ice could accelerate.

“These atmospheric conditions are becoming more and more frequent over the past few decades,” said Marco Tedesco, of the Lamont-Doherty Earth Observatory at the University of Columbia in the US, the lead author.

“It is very likely that this is due to the waviness of the jet stream, which we think is related to, among other things, the disappearance of snow cover in Siberia, the disappearance of sea ice, and the difference in the rate at which temperature is increasing in the Arctic versus the mid-latitudes.” – Climate News Network

This story is a part of Covering Climate Now’s week of coverage focused on Climate Solutions, to mark the 50th anniversary of Earth Day. Covering Climate Now is a global journalism collaboration committed to strengthening coverage of the climate story.

 

The bad news about Greenland’s ice loss has just got even worse. Blame it on mischief by blue skies all day long.

LONDON, 22 April, 2020 – Greenland’s ice loss reached record levels in 2019, and scientists think they’ve identified the culprit: the good weather which normally brings the snow-bearing clouds to the High Arctic.

The huge island, the biggest bank of ice in the northern hemisphere, has been losing ice at an ever-increasing rate in a rapidly warming world. Last year it shed more ice than ever, and this time because the skies were unusually clear.

There is enough ice on Greenland to raise global sea levels by more than seven metres. A recent study established that in the years between 1992 and 2018, rates of polar ice loss have risen six-fold, and so much water has flowed off the Greenland ice surface that sea levels have risen by more than 10mm everywhere.

Now a new study by US and Belgian scientists in the journal The Cryosphere confirms that 2019 was even worse. Because of good weather and cloudless skies, only enough snow fell to deposit 50 billion tonnes of ice into the island’s profit-and-loss ice account. The average annual deposit between 1981 and 2010 was about 375bn tonnes.

But glaciers still flowed towards the sea at an ever-increasing rate, summer snow melt continued to flow off the ice sheet, and icebergs continued to calve, so on balance the island lost 600 billion tonnes of ice: enough to raise global sea levels by 1.5mm. This is the biggest overall loss of ice since records in Greenland began in 1948.

“These atmospheric conditions are becoming more and more frequent over the past few decades. It is very likely that this is due to the waviness of the jet stream”

The cause: unusual spells of high atmospheric pressure over the island for unusually long periods of time. That stopped the formation of clouds, and that meant less precipitation, in the form of snow. Snow reflects solar radiation more effectively than ice, so the surface absorbed more heat and melting also accelerated.

The pattern of warm moist clouds trapped over northern Greenland by the heat that would normally radiate off the ice, instead of releasing snow, also emitted their own heat, to make things worse. The worst year for surface melting remains 2012, but the summer of 2019 was a good second.

The implication is that things could get worse, and losses of Greenland ice could accelerate.

“These atmospheric conditions are becoming more and more frequent over the past few decades,” said Marco Tedesco, of the Lamont-Doherty Earth Observatory at the University of Columbia in the US, the lead author.

“It is very likely that this is due to the waviness of the jet stream, which we think is related to, among other things, the disappearance of snow cover in Siberia, the disappearance of sea ice, and the difference in the rate at which temperature is increasing in the Arctic versus the mid-latitudes.” – Climate News Network

Polar ice melt raises sea level dangers

polar ice

Greenland’s polar ice is now melting far faster than 30 years ago, Antarctic ice is retreating at an accelerating rate, and sea levels are creeping up.

LONDON, 19 March, 2020 – Greenland and Antarctica, the two greatest stores of frozen water on the planet, are now losing polar ice at a rate at least six times faster than they were at the close of the last century.

The fact that polar ice is melting ever faster has been clear for a decade, but the latest research is authoritative.

To establish the rate of loss, 89 polar scientists from 50 of the world’s great research institutions looked at data from 26 separate surveys between 1992 and 2018, along with information from 11 different satellite missions.

Gloomiest forecasts

And the finding is in line with the worst-case scenarios considered by the Intergovernmental Panel on Climate Change (IPCC). If this rate of increase continues, sea levels at the close of this century will be at least 17 centimetres higher than the gloomiest official forecasts so far.

Between 1992 and 2017, the global sea level rose by 17.8 millimetres, as 6.4 trillion tonnes of polar ice turned to water and trickled into the oceans – 10.6 mm from Greenland and 7.2 mm from Antarctica.

In the last decade of the last century, the northern and southern icecaps dwindled at the rate of 81 billion tonnes a year. In the last decade, this had risen to 475 billion tonnes a year. This means that a third of all sea level rise is now caused by the loss of polar ice.

The most recent assessment by the IPCC is that, by 2100, sea levels will have risen by 53 cms, putting 360 million people who live at sea level at some risk.

“This would mean 400 million people at risk of annual coastal flooding by 2100”

But the latest finding from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) scientists is that seas will rise even higher, and even more people will have to move.

“Every centimetre of sea level rise leads to coastal flooding and coastal erosion, disrupting people’s lives around the planet,” said Andrew Shepherd, professor of Earth observation at the University of Leeds, UK, as he and colleagues published their findings of Greenland losses in Nature journal.

“If Antarctica and Greenland continue to track the worst-case climate warning scenario, they will cause an extra 17 cms of sea level rise by the end of the century.

“This would mean 400 million people at risk of annual coastal flooding by 2100. These are not unlikely events with small impacts; they are already under way and will be devastating for coastal communities.”

Global picture

Professor Shepherd and his IMBIE colleagues established almost two years ago that Antarctica was losing ice at an ever-accelerating rate, but the Greenland survey completes the global picture.

And it remains a picture in which the Arctic seems to be warming at an accelerating rate and sea levels seem to be rising ever faster.

This is not just because the polar ice caps are melting, but also because, almost everywhere, mountain glaciers are in retreat, and the oceans are expanding as sea temperatures rise in response to the steady warming of the planetary atmosphere. – Climate News Network

Greenland’s polar ice is now melting far faster than 30 years ago, Antarctic ice is retreating at an accelerating rate, and sea levels are creeping up.

LONDON, 19 March, 2020 – Greenland and Antarctica, the two greatest stores of frozen water on the planet, are now losing polar ice at a rate at least six times faster than they were at the close of the last century.

The fact that polar ice is melting ever faster has been clear for a decade, but the latest research is authoritative.

To establish the rate of loss, 89 polar scientists from 50 of the world’s great research institutions looked at data from 26 separate surveys between 1992 and 2018, along with information from 11 different satellite missions.

Gloomiest forecasts

And the finding is in line with the worst-case scenarios considered by the Intergovernmental Panel on Climate Change (IPCC). If this rate of increase continues, sea levels at the close of this century will be at least 17 centimetres higher than the gloomiest official forecasts so far.

Between 1992 and 2017, the global sea level rose by 17.8 millimetres, as 6.4 trillion tonnes of polar ice turned to water and trickled into the oceans – 10.6 mm from Greenland and 7.2 mm from Antarctica.

In the last decade of the last century, the northern and southern icecaps dwindled at the rate of 81 billion tonnes a year. In the last decade, this had risen to 475 billion tonnes a year. This means that a third of all sea level rise is now caused by the loss of polar ice.

The most recent assessment by the IPCC is that, by 2100, sea levels will have risen by 53 cms, putting 360 million people who live at sea level at some risk.

“This would mean 400 million people at risk of annual coastal flooding by 2100”

But the latest finding from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) scientists is that seas will rise even higher, and even more people will have to move.

“Every centimetre of sea level rise leads to coastal flooding and coastal erosion, disrupting people’s lives around the planet,” said Andrew Shepherd, professor of Earth observation at the University of Leeds, UK, as he and colleagues published their findings of Greenland losses in Nature journal.

“If Antarctica and Greenland continue to track the worst-case climate warning scenario, they will cause an extra 17 cms of sea level rise by the end of the century.

“This would mean 400 million people at risk of annual coastal flooding by 2100. These are not unlikely events with small impacts; they are already under way and will be devastating for coastal communities.”

Global picture

Professor Shepherd and his IMBIE colleagues established almost two years ago that Antarctica was losing ice at an ever-accelerating rate, but the Greenland survey completes the global picture.

And it remains a picture in which the Arctic seems to be warming at an accelerating rate and sea levels seem to be rising ever faster.

This is not just because the polar ice caps are melting, but also because, almost everywhere, mountain glaciers are in retreat, and the oceans are expanding as sea temperatures rise in response to the steady warming of the planetary atmosphere. – Climate News Network

Sandy beaches may succumb to rising seas

Ever higher seas are already eroding shorelines and flooding coasts. Soon the waves could wash away half the world’s sandy beaches.

LONDON, 5 March, 2020 – Right now, around a third of the world’s coastline is made up of sandy beaches and dunes which slope gently and softly to the sea. By the end of the century, these could make up only one-sixth of the frontier between land and ocean. Sea level rise driven by global heating could sweep half of them away.

Beaches are nature’s buffers between eroding land and tempestuous sea: they protect the coast, they provide a unique habitat for wildlife, and they have become powerful socio-economic resources.

But the paradise for surfers around sunlit Australia is almost certain to be diminished in the coming climate crisis as the waves lap ever higher, storm surges sweep away vast volumes of sand, and seas flood low-lying coasts. And – according to new European research in the journal Nature Climate Change – what is true for Australia is true for much of the rest of the world.

How much beach is lost will depend on how nations respond to the challenge of climate change. But in the worst-case scenario, Australia and Canada could each say goodbye to nearly 15,000 kilometres of sandy shore by 2100. Chile could lose more than 6,000 km, Mexico, China and the US more than 5,000 km, Russia more than 4,000 km and Argentina more than 3,000 km.

“Much of the world’s coast is already eroding, which could get worse with sea level rise”

And that’s the outlook for countries with vast coastlines. Some could fare even worse. Guinea-Bissau and The Gambia in West Africa, for instance, could lose 60% of their beaches.

The European scientists looked at more than 30 years of satellite data on coastal change – from 1984 to 2015 – and 82 years of climate and sea level predictions from a range of climate models. They also simulated 100 million storm events.

There is plenty of evidence that the world’s seas are responding to climate change; that sea levels are rising in response to warmer atmospheric temperatures driven by profligate combustion of fossil fuels; and that coastal flooding is likely to become more extreme.

But the detailed questions remain: how exactly will ever-higher tides exact their toll of the wetlands, mangrove forests, estuaries, cliff faces, rocky coasts, storm beaches and dunes that serve as a barrier between the maritime cities and towns of the world, and the saltwater? The researchers found that even in the more hopeful scenarios, there would be considerable losses.

UK backs study

But if nations delivered on the promise made in Paris in 2015 – a promise that still has to be backed up by urgent action on a global scale – to contain global heating to “well below” a maximum of 2°C by 2100, then perhaps 40% of the projected erosion of beaches could be halted.

Beaches are natural features of tidal landscapes: sand swept away by violent storms is eventually replaced by silt carried down the rivers to the coasts. The shoreline has always changed. But change is accelerating. Scientists in the UK have endorsed the European study.

“Much of the world’s coast is already eroding, which could get worse with sea level rise,” said Sally Brown, of Bournemouth University. Bournemouth is a famous British seaside resort.

“Building defences helps maintain coastline position, but defences are known to reduce beach width or depth over multiple decades. Responding to sea level rise means looking strategically at how and where we defend coasts today, which may mean protecting only limited parts of the coast.” – Climate News Network

Ever higher seas are already eroding shorelines and flooding coasts. Soon the waves could wash away half the world’s sandy beaches.

LONDON, 5 March, 2020 – Right now, around a third of the world’s coastline is made up of sandy beaches and dunes which slope gently and softly to the sea. By the end of the century, these could make up only one-sixth of the frontier between land and ocean. Sea level rise driven by global heating could sweep half of them away.

Beaches are nature’s buffers between eroding land and tempestuous sea: they protect the coast, they provide a unique habitat for wildlife, and they have become powerful socio-economic resources.

But the paradise for surfers around sunlit Australia is almost certain to be diminished in the coming climate crisis as the waves lap ever higher, storm surges sweep away vast volumes of sand, and seas flood low-lying coasts. And – according to new European research in the journal Nature Climate Change – what is true for Australia is true for much of the rest of the world.

How much beach is lost will depend on how nations respond to the challenge of climate change. But in the worst-case scenario, Australia and Canada could each say goodbye to nearly 15,000 kilometres of sandy shore by 2100. Chile could lose more than 6,000 km, Mexico, China and the US more than 5,000 km, Russia more than 4,000 km and Argentina more than 3,000 km.

“Much of the world’s coast is already eroding, which could get worse with sea level rise”

And that’s the outlook for countries with vast coastlines. Some could fare even worse. Guinea-Bissau and The Gambia in West Africa, for instance, could lose 60% of their beaches.

The European scientists looked at more than 30 years of satellite data on coastal change – from 1984 to 2015 – and 82 years of climate and sea level predictions from a range of climate models. They also simulated 100 million storm events.

There is plenty of evidence that the world’s seas are responding to climate change; that sea levels are rising in response to warmer atmospheric temperatures driven by profligate combustion of fossil fuels; and that coastal flooding is likely to become more extreme.

But the detailed questions remain: how exactly will ever-higher tides exact their toll of the wetlands, mangrove forests, estuaries, cliff faces, rocky coasts, storm beaches and dunes that serve as a barrier between the maritime cities and towns of the world, and the saltwater? The researchers found that even in the more hopeful scenarios, there would be considerable losses.

UK backs study

But if nations delivered on the promise made in Paris in 2015 – a promise that still has to be backed up by urgent action on a global scale – to contain global heating to “well below” a maximum of 2°C by 2100, then perhaps 40% of the projected erosion of beaches could be halted.

Beaches are natural features of tidal landscapes: sand swept away by violent storms is eventually replaced by silt carried down the rivers to the coasts. The shoreline has always changed. But change is accelerating. Scientists in the UK have endorsed the European study.

“Much of the world’s coast is already eroding, which could get worse with sea level rise,” said Sally Brown, of Bournemouth University. Bournemouth is a famous British seaside resort.

“Building defences helps maintain coastline position, but defences are known to reduce beach width or depth over multiple decades. Responding to sea level rise means looking strategically at how and where we defend coasts today, which may mean protecting only limited parts of the coast.” – Climate News Network

North Sea dams could save Europe’s coasts

There is a way to stop Europe’s coastal cities from vanishing below the waves – enclose the North Sea. But there’s a simpler solution.

LONDON, 4 March, 2020 − Two European scientists have proposed the ultimate flood barrier: they want to dam the North Sea and the English Channel with more than 600 kilometres (373 miles) of sea wall.

This would protect 15 nations in western Europe against the ravages of what could one day be 10 metres (33 feet) of sea level rise. It would ultimately turn the North Sea into a freshwater lake and, at up to €500 billion (£435 bn) or more, represent the single most costly piece of engineering ever.

But, the pair reason, to do nothing could cost the people of Europe perhaps 10 times as much as coasts eroded, the sea overwhelmed the Low Countries, reshaped the contours of a continent and forced 25 million people to move inland.

In their paper in the Bulletin of the American Meteorological SocietySjoerd Groeskamp of the Royal Netherlands Institute for Sea Research and Joakim Kjellsson of Geomar, the Helmholtz oceanographic research centre in Kiel, Germany, concede that what they propose “may seem an overwhelming and unrealistic solution at first.”

But compared with the cost of inaction, or the cost of managed retreat from the coastline that would displace millions, it could be the cheapest option. “It might be impossible to truly fathom the magnitude of the threat that global-mean sea level rise poses,” they warn.

Least bad option

Global average temperatures have risen by 1°C and sea levels by 21 cms (8 inches) since 1880. Sea level rise lags behind atmospheric warming, but the guess is that every degree Celsius in the air will be followed eventually by 2.3 metres (7.5 feet) of higher seas.

By 2100, temperatures could have risen more than 3°C and sea levels by up to 1.5 metres (5 feet). If nations carry on burning fossil fuels the icecaps will melt inexorably, and by 2500 seas could have risen by 10 metres.

“The best solution will always be the treatment of the cause: human-caused climate change,” they write. However, if nations do not act to control the greenhouse gas emissions and forest destruction that cause global heating, and ever higher tides, then solutions such as the North European Enclosure Dam, known for short as NEED, are the only option.

The two researchers propose a barrier, a dike of sloping sides 50 metres wide across the North Sea from Bergen in Norway to the north-east tip of Scotland, via the Shetland and Orkney Islands.

This would be 475 kms (295 miles) long, with an average depth of 127 metres (417 feet), but would have to cross a trench more than 300 metres (985 feet) deep. To withstand continued sea level rise beyond 2500, it would need to be 20 metres or more above the Atlantic waves.

“This dam is mainly a call to do something about climate change now. If we do nothing, then this extreme dam might just be the only solution”

The 160 kms (100 miles) of sea defence from south-west England to the westernmost point of France would be a little less problematic: sea depths are hardly more than 100 metres (330 feet).

But the engineers would also have to factor in the 40,000 cubic metres of river water that would discharge into this enclosed basin every second. This would mean the same volume would need pumping continuously into the Atlantic on the far side of the dikes.

Since the barrier would enclose a number of the world’s great shipping ports, there would have to be sluice gates to let the big ships through, or alternatively new ports on the ocean side of the barriers.

The very nature of the enclosed North Sea would begin to change. Within a decade or two, it would start to turn into a freshwater lake: it would be the end of centuries of a fishing industry.

It could – the scientists admit their calculations are of the “back of an envelope” variety – be done. They scaled up the costs of the world’s largest dikes so far in the Netherlands and South Korea, to calculate the 51 billion tonnes of sand needed for the project. This is about what the world uses every year in construction.

Technology tested

They note that fixed seabed oil platforms have been constructed to a depth of 500 metres (1,640 feet), so engineers already know how to do such things. Pumps of the scale required to handle the incoming river discharges are already in use, but they would be needed in their hundreds.

And although the cost would reach somewhere between €250-550 bn (£220-480 bn), this − spread over the 20 years the project would take − would represent only at most 0.32% of the gross domestic product of the UK, Netherlands, Germany, Belgium and Denmark combined: the five nations with most to lose from the rising tides.

It would, the authors argue, cost just the Netherlands – which already has 3,600 km (2,240 miles) of flood protection − a third of that sum to defend against sea level rises of only 1.5 metres. The good news is that, if such a project worked for western Europe, then the same techniques could enclose the Irish Sea, the Mediterranean, the Red Sea and the Persian Gulf.

“This dam makes it almost tangible what the consequences of continued sea level rise will be; a rise of 10 metres by the year 2500 according to the bleakest scenarios,” said Dr Groeskamp.

“This dam is therefore mainly a call to do something about climate change now. If we do nothing, then this extreme dam might just be the only solution.” − Climate News Network

There is a way to stop Europe’s coastal cities from vanishing below the waves – enclose the North Sea. But there’s a simpler solution.

LONDON, 4 March, 2020 − Two European scientists have proposed the ultimate flood barrier: they want to dam the North Sea and the English Channel with more than 600 kilometres (373 miles) of sea wall.

This would protect 15 nations in western Europe against the ravages of what could one day be 10 metres (33 feet) of sea level rise. It would ultimately turn the North Sea into a freshwater lake and, at up to €500 billion (£435 bn) or more, represent the single most costly piece of engineering ever.

But, the pair reason, to do nothing could cost the people of Europe perhaps 10 times as much as coasts eroded, the sea overwhelmed the Low Countries, reshaped the contours of a continent and forced 25 million people to move inland.

In their paper in the Bulletin of the American Meteorological SocietySjoerd Groeskamp of the Royal Netherlands Institute for Sea Research and Joakim Kjellsson of Geomar, the Helmholtz oceanographic research centre in Kiel, Germany, concede that what they propose “may seem an overwhelming and unrealistic solution at first.”

But compared with the cost of inaction, or the cost of managed retreat from the coastline that would displace millions, it could be the cheapest option. “It might be impossible to truly fathom the magnitude of the threat that global-mean sea level rise poses,” they warn.

Least bad option

Global average temperatures have risen by 1°C and sea levels by 21 cms (8 inches) since 1880. Sea level rise lags behind atmospheric warming, but the guess is that every degree Celsius in the air will be followed eventually by 2.3 metres (7.5 feet) of higher seas.

By 2100, temperatures could have risen more than 3°C and sea levels by up to 1.5 metres (5 feet). If nations carry on burning fossil fuels the icecaps will melt inexorably, and by 2500 seas could have risen by 10 metres.

“The best solution will always be the treatment of the cause: human-caused climate change,” they write. However, if nations do not act to control the greenhouse gas emissions and forest destruction that cause global heating, and ever higher tides, then solutions such as the North European Enclosure Dam, known for short as NEED, are the only option.

The two researchers propose a barrier, a dike of sloping sides 50 metres wide across the North Sea from Bergen in Norway to the north-east tip of Scotland, via the Shetland and Orkney Islands.

This would be 475 kms (295 miles) long, with an average depth of 127 metres (417 feet), but would have to cross a trench more than 300 metres (985 feet) deep. To withstand continued sea level rise beyond 2500, it would need to be 20 metres or more above the Atlantic waves.

“This dam is mainly a call to do something about climate change now. If we do nothing, then this extreme dam might just be the only solution”

The 160 kms (100 miles) of sea defence from south-west England to the westernmost point of France would be a little less problematic: sea depths are hardly more than 100 metres (330 feet).

But the engineers would also have to factor in the 40,000 cubic metres of river water that would discharge into this enclosed basin every second. This would mean the same volume would need pumping continuously into the Atlantic on the far side of the dikes.

Since the barrier would enclose a number of the world’s great shipping ports, there would have to be sluice gates to let the big ships through, or alternatively new ports on the ocean side of the barriers.

The very nature of the enclosed North Sea would begin to change. Within a decade or two, it would start to turn into a freshwater lake: it would be the end of centuries of a fishing industry.

It could – the scientists admit their calculations are of the “back of an envelope” variety – be done. They scaled up the costs of the world’s largest dikes so far in the Netherlands and South Korea, to calculate the 51 billion tonnes of sand needed for the project. This is about what the world uses every year in construction.

Technology tested

They note that fixed seabed oil platforms have been constructed to a depth of 500 metres (1,640 feet), so engineers already know how to do such things. Pumps of the scale required to handle the incoming river discharges are already in use, but they would be needed in their hundreds.

And although the cost would reach somewhere between €250-550 bn (£220-480 bn), this − spread over the 20 years the project would take − would represent only at most 0.32% of the gross domestic product of the UK, Netherlands, Germany, Belgium and Denmark combined: the five nations with most to lose from the rising tides.

It would, the authors argue, cost just the Netherlands – which already has 3,600 km (2,240 miles) of flood protection − a third of that sum to defend against sea level rises of only 1.5 metres. The good news is that, if such a project worked for western Europe, then the same techniques could enclose the Irish Sea, the Mediterranean, the Red Sea and the Persian Gulf.

“This dam makes it almost tangible what the consequences of continued sea level rise will be; a rise of 10 metres by the year 2500 according to the bleakest scenarios,” said Dr Groeskamp.

“This dam is therefore mainly a call to do something about climate change now. If we do nothing, then this extreme dam might just be the only solution.” − Climate News Network