Tag Archives: Warming

Cloud forests risk drying out by 2060

For the world’s cloud forests, the future is overcast. Some face fiercer storm and flood: they could even lose their unique clouds.

LONDON, 23 April, 2019 – Planet Earth may be about to lose a whole ecosystem: the cloud forests – those species-rich, high altitude rainforests found mostly in Central and South America – could be all but gone in 40 years.

Researchers warn that within 25 years, global warming driven by ever increasing use of fossil fuels could dry up 60-80% of the misty mountain forests of Mexico, Puerto Rico, Costa Rica, Ecuador and Peru, simply by dispersing the clouds that keep them ever moist, and rich with plant, insect and bird life.

And as the habitat alters, that could be it for the Monarch butterflies that migrate in their millions to the mountains of Mexico, the elfin woods warbler found only in Puerto Rico, and the other creatures that make their homes in forests so rich and wet that even the trees are home to yet more green habitat: ferns, lichens, mosses and other epiphytes nourished by year-round water and water vapour.

And the reason? The clouds will have dispersed, or moved uphill, or simply been blown away as greenhouse gas ratios in the atmosphere continue to grow and temperatures creep ever higher, according to new research in the Public Library of Science journal PLOS One.

“Maria is more extreme in its precipitation than anything else the island has ever seen. I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years”

And if nations go on burning ever greater quantities of coal, oil and natural gas to power economic growth, then the cloud and frost that keep the equatorial cloud forests unique homes to living things will have gone.

Nine-tenths of the cloud forests in the Western Hemisphere will have been lost by 2060, if the calculations funded by the US Department of Agriculture’s Forest Service are correct.

Researchers mapped cloud forest across the Western Hemisphere with data collected over the last 60 years and then used climate simulations to see how the habitat would change with time.

They found that indeed some regions would become even more immersed in cloud: this however would only add up to perhaps 1%. For the most part the clouds would thin, the steady supply of moisture would thin, and the forests would begin to change inexorably.

Trees head uphill

This is not the first research to suggest that ever higher temperatures would affect cloud patterns. Scientists using a different approach reported earlier this year that tropical cloud formation of the kind that damps down equatorial temperatures could be at risk.

Other researchers have used historic data to record the steady uphill march of characteristic trees in the Andean forests in response to average global temperature increases of 1°C in the past century.

And yet another team has warned that the increasingly violent winds that arrived in Puerto Rico with Hurricane Maria in 2017 would in any case change the make-up of forest species.

Devastating winds that uproot forest giants at all altitudes won’t be the only problem for the climate-hit forests and the region. Hurricane Maria dumped an unprecedented 1.029 mm of rain in a day on Puerto Rico.

Recurrence likely

A second study from the American Geophysical Union has confirmed that the extreme rainfall that accompanied Maria was not only the worst in the last 60 years, but has become much more likely to happen again.

Thanks to global warming, which increased the capacity of the atmosphere to absorb moisture, such floods are now five times more likely, they write in the journal Geophysical Research Letters.

“Maria is more extreme in its precipitation than anything else the island has ever seen,” said David Keellings of the University of Alabama, one of the authors.

“I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years.” – Climate News Network

For the world’s cloud forests, the future is overcast. Some face fiercer storm and flood: they could even lose their unique clouds.

LONDON, 23 April, 2019 – Planet Earth may be about to lose a whole ecosystem: the cloud forests – those species-rich, high altitude rainforests found mostly in Central and South America – could be all but gone in 40 years.

Researchers warn that within 25 years, global warming driven by ever increasing use of fossil fuels could dry up 60-80% of the misty mountain forests of Mexico, Puerto Rico, Costa Rica, Ecuador and Peru, simply by dispersing the clouds that keep them ever moist, and rich with plant, insect and bird life.

And as the habitat alters, that could be it for the Monarch butterflies that migrate in their millions to the mountains of Mexico, the elfin woods warbler found only in Puerto Rico, and the other creatures that make their homes in forests so rich and wet that even the trees are home to yet more green habitat: ferns, lichens, mosses and other epiphytes nourished by year-round water and water vapour.

And the reason? The clouds will have dispersed, or moved uphill, or simply been blown away as greenhouse gas ratios in the atmosphere continue to grow and temperatures creep ever higher, according to new research in the Public Library of Science journal PLOS One.

“Maria is more extreme in its precipitation than anything else the island has ever seen. I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years”

And if nations go on burning ever greater quantities of coal, oil and natural gas to power economic growth, then the cloud and frost that keep the equatorial cloud forests unique homes to living things will have gone.

Nine-tenths of the cloud forests in the Western Hemisphere will have been lost by 2060, if the calculations funded by the US Department of Agriculture’s Forest Service are correct.

Researchers mapped cloud forest across the Western Hemisphere with data collected over the last 60 years and then used climate simulations to see how the habitat would change with time.

They found that indeed some regions would become even more immersed in cloud: this however would only add up to perhaps 1%. For the most part the clouds would thin, the steady supply of moisture would thin, and the forests would begin to change inexorably.

Trees head uphill

This is not the first research to suggest that ever higher temperatures would affect cloud patterns. Scientists using a different approach reported earlier this year that tropical cloud formation of the kind that damps down equatorial temperatures could be at risk.

Other researchers have used historic data to record the steady uphill march of characteristic trees in the Andean forests in response to average global temperature increases of 1°C in the past century.

And yet another team has warned that the increasingly violent winds that arrived in Puerto Rico with Hurricane Maria in 2017 would in any case change the make-up of forest species.

Devastating winds that uproot forest giants at all altitudes won’t be the only problem for the climate-hit forests and the region. Hurricane Maria dumped an unprecedented 1.029 mm of rain in a day on Puerto Rico.

Recurrence likely

A second study from the American Geophysical Union has confirmed that the extreme rainfall that accompanied Maria was not only the worst in the last 60 years, but has become much more likely to happen again.

Thanks to global warming, which increased the capacity of the atmosphere to absorb moisture, such floods are now five times more likely, they write in the journal Geophysical Research Letters.

“Maria is more extreme in its precipitation than anything else the island has ever seen,” said David Keellings of the University of Alabama, one of the authors.

“I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years.” – Climate News Network

Glaciers’ global melt may leave Alps bare

High mountain ice is vital to millions. As the world warms, the glaciers’ global melt could see the frozen peaks vanish.

LONDON, 12 April, 2019 – Many of the planet’s most scenic – and most valued – high-altitude landscapes are likely to look quite different within the next 80 years: the glaciers’ global melt will have left just bare rock.

By the century’s end, Europe’s famous Alps – the chain of snow- and ice-covered peaks that have become a playground of the wealthy and a source of income and pleasure for generations – will have lost more than nine-tenths of all its glacier ice.

And in the last 50 years, the world’s glaciers – in Asia, the Americas, Europe, Africa and the sub-Arctic mountains – have lost more than nine trillion tonnes of ice as global temperatures creep ever upwards in response to profligate combustion of fossil fuels.

And as meltwater has trickled down the mountains, the seas have risen by 27mm, thanks entirely to glacial retreat.

“Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century”

In two separate studies, Swiss scientists have tried to audit a profit and loss account for the world’s frozen high-altitude rivers, and found a steady downhill trend.

Glacial ice is a source of security and even wealth: in the poorest regions the annual summer melt of winter snow and ice banked at altitude can guarantee both energy as hydropower and water for crops in the valleys and floodplains.

In wealthy regions, the white peaks and slopes become sources of income as tourist attractions and centres for winter sport – as well as reliable sources of power and water.

Swiss focus

In the journal The Cryosphere, a team from the Swiss Federal Institute of Technology, almost always known simply as ETH Zurich, looked into the future of the nation’s own landscape, and beyond.

They made computer models of the annual flow of ice and its melting patterns and took 2017 as the reference year: a year when the Alpine glaciers bore 100 cubic kilometres of ice. And then they started simulating the future.

If humankind kept the promise made by 195 nations in Paris in 2015, to drastically reduce fossil fuel use, lower emissions of carbon dioxide, restore the forests and keep global warming to no more than 2°C above historic levels, then the stores of high ice would be reduced by more than a third over the next eight decades. If humankind went on expanding its use of fossil fuels at the present rates, then half of all the ice would be lost by 2050 and 95% by 2100.

Time lag

But there will be losses in all scenarios: warming so far has seen to that. Ice reflects radiation and keeps itself cold, so change lags behind atmospheric temperature.

“The future evolution of glaciers will strongly depend on how the climate will evolve,” said Harry Zekollari, once of ETH and now at Delft University of Technology in the Netherlands, who led the research. “In the case of a more limited warming, a far more substantial part of the glaciers could be saved.”

The Alpine glaciers were made world-famous first by Romantic painters and poets of the 19th century, among them JMW Turner and Lord Byron. But their contribution to rising sea levels is, in a global context, negligible.

When Swiss researchers and their Russian, Canadian and European partners looked at the big picture, they found that the mass loss of ice from the mountains of AlaskaCanada, parts of Asia and the Andes matched the increasing flow of water from the melting Greenland ice cap, and exceeded the flow of melting water from the Antarctic continent.

Europe’s modest melt

They report in Nature that glaciers separate from the Greenland and Antarctic sheets covered 706,000 square kilometres of the planet, with a total volume of 170,000 cubic kilometres, or 40 centimetres of potential sea level rise.

And in the five decades from 1961 to 2016, according to careful study of satellite imagery and historic observations, the seas have already risen by 27mm as a consequence of increasing rates of glacial retreat. This is already between 25% and 30% of observed sea level rise so far.

Europe did not figure much in the reckoning. “Globally, we lose three times the ice volume stored in the entirety of the European Alps – every single year,” said Michael Zemp, a glaciologist at the University of Zurich.

He and his colleagues warn: “Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century, while heavily glacierised regions will continue to contribute to sea level rise beyond 2100.” – Climate News Network

High mountain ice is vital to millions. As the world warms, the glaciers’ global melt could see the frozen peaks vanish.

LONDON, 12 April, 2019 – Many of the planet’s most scenic – and most valued – high-altitude landscapes are likely to look quite different within the next 80 years: the glaciers’ global melt will have left just bare rock.

By the century’s end, Europe’s famous Alps – the chain of snow- and ice-covered peaks that have become a playground of the wealthy and a source of income and pleasure for generations – will have lost more than nine-tenths of all its glacier ice.

And in the last 50 years, the world’s glaciers – in Asia, the Americas, Europe, Africa and the sub-Arctic mountains – have lost more than nine trillion tonnes of ice as global temperatures creep ever upwards in response to profligate combustion of fossil fuels.

And as meltwater has trickled down the mountains, the seas have risen by 27mm, thanks entirely to glacial retreat.

“Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century”

In two separate studies, Swiss scientists have tried to audit a profit and loss account for the world’s frozen high-altitude rivers, and found a steady downhill trend.

Glacial ice is a source of security and even wealth: in the poorest regions the annual summer melt of winter snow and ice banked at altitude can guarantee both energy as hydropower and water for crops in the valleys and floodplains.

In wealthy regions, the white peaks and slopes become sources of income as tourist attractions and centres for winter sport – as well as reliable sources of power and water.

Swiss focus

In the journal The Cryosphere, a team from the Swiss Federal Institute of Technology, almost always known simply as ETH Zurich, looked into the future of the nation’s own landscape, and beyond.

They made computer models of the annual flow of ice and its melting patterns and took 2017 as the reference year: a year when the Alpine glaciers bore 100 cubic kilometres of ice. And then they started simulating the future.

If humankind kept the promise made by 195 nations in Paris in 2015, to drastically reduce fossil fuel use, lower emissions of carbon dioxide, restore the forests and keep global warming to no more than 2°C above historic levels, then the stores of high ice would be reduced by more than a third over the next eight decades. If humankind went on expanding its use of fossil fuels at the present rates, then half of all the ice would be lost by 2050 and 95% by 2100.

Time lag

But there will be losses in all scenarios: warming so far has seen to that. Ice reflects radiation and keeps itself cold, so change lags behind atmospheric temperature.

“The future evolution of glaciers will strongly depend on how the climate will evolve,” said Harry Zekollari, once of ETH and now at Delft University of Technology in the Netherlands, who led the research. “In the case of a more limited warming, a far more substantial part of the glaciers could be saved.”

The Alpine glaciers were made world-famous first by Romantic painters and poets of the 19th century, among them JMW Turner and Lord Byron. But their contribution to rising sea levels is, in a global context, negligible.

When Swiss researchers and their Russian, Canadian and European partners looked at the big picture, they found that the mass loss of ice from the mountains of AlaskaCanada, parts of Asia and the Andes matched the increasing flow of water from the melting Greenland ice cap, and exceeded the flow of melting water from the Antarctic continent.

Europe’s modest melt

They report in Nature that glaciers separate from the Greenland and Antarctic sheets covered 706,000 square kilometres of the planet, with a total volume of 170,000 cubic kilometres, or 40 centimetres of potential sea level rise.

And in the five decades from 1961 to 2016, according to careful study of satellite imagery and historic observations, the seas have already risen by 27mm as a consequence of increasing rates of glacial retreat. This is already between 25% and 30% of observed sea level rise so far.

Europe did not figure much in the reckoning. “Globally, we lose three times the ice volume stored in the entirety of the European Alps – every single year,” said Michael Zemp, a glaciologist at the University of Zurich.

He and his colleagues warn: “Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century, while heavily glacierised regions will continue to contribute to sea level rise beyond 2100.” – Climate News Network

Ice melt makes Arctic soils slip more often

As warm summers loosen the grip of the polar ice, the Arctic soils begin to shift. And they are now shifting faster than ever before.

LONDON, 9 April, 2019 − Global warming is about to change the face of the frozen polar landmass, where the Arctic soils are slipping and sliding at record speed. Once-firm ground has begun to shift.

Researchers who closely examined landslips and slumps on Banks Island in the Canadian Arctic Archipelago have found a sixty-fold increase in ground movement in the last 30 years.

In 1984, summer temperatures accounted for just 60 events of the kind glaciologists know as retrogressive thaw slumps or collapses of surface soil as the permafrost ice begins to melt. In 2014, there were more than 4,000 such slumps, including about 300 in an area protected as a natural park.

And on Banks Island alone, even under a relatively conservative scenario, this number could grow to 10,000 a decade by 2075, to precipitate as many as 30,000 active landslides in any future year.

“We can encourage our politicians to take the necessary measures to help reduce our greenhouse emissions, so that future warming is as limited as possible”

Researchers report in the journal Nature Communications that massive amounts of sediment released by the slumps have choked river valleys and changed the colour of 288 lakes. Once a thaw slump begins, soils once held stable by the frost can go on sliding or slipping.

Nobody can be sure of the impact on the natural ecosystems, but the island is home to arctic foxes, caribou, polar bears, wolves, musk oxen, arctic hare, lemmings, ermine, seal and even grizzly bears.

It also provides feeding grounds for lesser snow geese, black brants, eiders, peregrine falcons, snowy owls, rough-legged hawks and ravens.

And, the scientists say, a small local Inuit population based on the island can confirm the ground truth of satellite records: ground slumps increasingly make it difficult to go hunting or fishing.

Methane risk

The study is hardly the first to suggest that global warming will change the high Arctic, but it may be the first to put firm estimates to the increasing scale of damage through time. The implication is that what happens on Banks Island could also happen at the same latitudes anywhere.

Climate scientists have been increasingly alarmed at the hazards of permafrost thaw, if only because locked in the frozen soils are millennia of plant remains, all of which could decay into methane and accelerate global warming to melt yet more permafrost and drive global average temperatures ever higher.

Geographers have already warned that what had once been hard ground beneath roads, buildings, factories, airfields and housing has already begun to slump, to devastate infrastructure and even threaten oil and gas piping.

“We cannot stop thousands of thaw slumps once they start,” said Antoni Lewkowicz of the University of Ottawa, who led the research. “We can only make changes in our own lives to reduce our carbon footprint and we can encourage our politicians to take the necessary measures to help reduce our greenhouse emissions, so that future warming is as limited as possible.” − Climate News Network

As warm summers loosen the grip of the polar ice, the Arctic soils begin to shift. And they are now shifting faster than ever before.

LONDON, 9 April, 2019 − Global warming is about to change the face of the frozen polar landmass, where the Arctic soils are slipping and sliding at record speed. Once-firm ground has begun to shift.

Researchers who closely examined landslips and slumps on Banks Island in the Canadian Arctic Archipelago have found a sixty-fold increase in ground movement in the last 30 years.

In 1984, summer temperatures accounted for just 60 events of the kind glaciologists know as retrogressive thaw slumps or collapses of surface soil as the permafrost ice begins to melt. In 2014, there were more than 4,000 such slumps, including about 300 in an area protected as a natural park.

And on Banks Island alone, even under a relatively conservative scenario, this number could grow to 10,000 a decade by 2075, to precipitate as many as 30,000 active landslides in any future year.

“We can encourage our politicians to take the necessary measures to help reduce our greenhouse emissions, so that future warming is as limited as possible”

Researchers report in the journal Nature Communications that massive amounts of sediment released by the slumps have choked river valleys and changed the colour of 288 lakes. Once a thaw slump begins, soils once held stable by the frost can go on sliding or slipping.

Nobody can be sure of the impact on the natural ecosystems, but the island is home to arctic foxes, caribou, polar bears, wolves, musk oxen, arctic hare, lemmings, ermine, seal and even grizzly bears.

It also provides feeding grounds for lesser snow geese, black brants, eiders, peregrine falcons, snowy owls, rough-legged hawks and ravens.

And, the scientists say, a small local Inuit population based on the island can confirm the ground truth of satellite records: ground slumps increasingly make it difficult to go hunting or fishing.

Methane risk

The study is hardly the first to suggest that global warming will change the high Arctic, but it may be the first to put firm estimates to the increasing scale of damage through time. The implication is that what happens on Banks Island could also happen at the same latitudes anywhere.

Climate scientists have been increasingly alarmed at the hazards of permafrost thaw, if only because locked in the frozen soils are millennia of plant remains, all of which could decay into methane and accelerate global warming to melt yet more permafrost and drive global average temperatures ever higher.

Geographers have already warned that what had once been hard ground beneath roads, buildings, factories, airfields and housing has already begun to slump, to devastate infrastructure and even threaten oil and gas piping.

“We cannot stop thousands of thaw slumps once they start,” said Antoni Lewkowicz of the University of Ottawa, who led the research. “We can only make changes in our own lives to reduce our carbon footprint and we can encourage our politicians to take the necessary measures to help reduce our greenhouse emissions, so that future warming is as limited as possible.” − Climate News Network

CO2 levels pass 3-million-year record

The modern world is about to pass a temperature peak dating back for millions of years – because CO2 levels have already passed an ancient record..

LONDON, 8 April, 2019 – German scientists have confirmed, once again, that carbon dioxide is reaching concentrations unprecedented on any human time scale, with CO2 levels in the atmosphere already higher than they have been for at least three million years.

And their computer simulations – backed up by analysis of ocean sediments that tell a tale of changing temperatures and greenhouse gas levels – show that before the century’s close the world will become warmer than at any time in the last three million years.

The last time planetary temperatures reached a level higher than the target set by 195 nations in Paris in 2015 was during a bygone geological period, the Pliocene.

“It seems we are now pushing our home planet beyond any climatic conditions experienced during the entire current geological period, the Quaternary,” said Matteo Willeit of the Potsdam Institute for Climate Impact Research.

“Our results imply a strong sensitivity of the Earth system to relatively small changes in atmospheric CO2. As fascinating as this is, it is also worrying”

“A period that started almost three million years ago and saw human civilisation beginning only 11,000 years ago. So the modern change we see is big, really big, even by the standards of Earth history.”

He and colleagues report in the journal Science Advances  that they made a numerical model of all the astronomical and geological data available for the last few million years and fed in algorithms to represent the physics and chemistry of planet Earth.

So they had a simulation of a rocky planet complete with active volcanoes that emit carbon dioxide with their magma, on a journey many times around a slowly-changing elliptical orbit that subtly changed the levels of sunshine that slammed into the rocks, oceans and forests – patterns of change called the Milankovitch cycles, long implicated in periodic shifts in planetary climate.

They also fed in data about sediments in the high latitudes: important because ice sheets advance more easily over gravel than bedrock, and atmospheric dust from such attrition makes ice surfaces darker and more vulnerable to melting. The result: confirmation of one thing already observed and another much feared.

Carbon ratio leaps

At a time in the astronomical cycle when Earthlings might expect a slow return of the Ice Ages, human action over the last two centuries – the profligate combustion of fossil fuels that emit greenhouse gases, the wholesale clearance of the great forests that absorb atmospheric carbon – has already lifted carbon dioxide ratios from a long-term average of around 280 parts per million to more than 400 ppm.

Human action has also raised long-term average planetary temperatures by a whole degree Celsius, with more warming on the way.

A new Ice Age seems increasingly unlikely, and other researchers have already pointed to the Pliocene data as a soon-to-be-exceeded record.

Entirely different studies have shown the world to be on course to exceed the 2°C limit, so the research confirms other findings and delivers a test of the reliability of evidence from the past. It also backs up the value of simulation as an increasingly reliable form of climate forecasting.

CO2’s key role

“We know from the analysis of sediments on the bottom of our seas about past ocean temperatures and ice volumes, but so far the role of CO2 in shaping the glacial cycles has not been fully understood,” said Dr Willeit.

“It is a breakthrough that we can now show in computer simulations that changes in CO2 levels were a main driver of the Ice Ages, together with variations of how the Earth orbits around the sun, the so-called Milankovitch cycles. These are actually not just simulations: we compared our results with hard data from the deep sea, and they prove to be in good agreement,” he said.

“Our results imply a strong sensitivity of the Earth system to relatively small changes in atmospheric CO2. As fascinating as this is, it is also worrying.” – Climate News Network

The modern world is about to pass a temperature peak dating back for millions of years – because CO2 levels have already passed an ancient record..

LONDON, 8 April, 2019 – German scientists have confirmed, once again, that carbon dioxide is reaching concentrations unprecedented on any human time scale, with CO2 levels in the atmosphere already higher than they have been for at least three million years.

And their computer simulations – backed up by analysis of ocean sediments that tell a tale of changing temperatures and greenhouse gas levels – show that before the century’s close the world will become warmer than at any time in the last three million years.

The last time planetary temperatures reached a level higher than the target set by 195 nations in Paris in 2015 was during a bygone geological period, the Pliocene.

“It seems we are now pushing our home planet beyond any climatic conditions experienced during the entire current geological period, the Quaternary,” said Matteo Willeit of the Potsdam Institute for Climate Impact Research.

“Our results imply a strong sensitivity of the Earth system to relatively small changes in atmospheric CO2. As fascinating as this is, it is also worrying”

“A period that started almost three million years ago and saw human civilisation beginning only 11,000 years ago. So the modern change we see is big, really big, even by the standards of Earth history.”

He and colleagues report in the journal Science Advances  that they made a numerical model of all the astronomical and geological data available for the last few million years and fed in algorithms to represent the physics and chemistry of planet Earth.

So they had a simulation of a rocky planet complete with active volcanoes that emit carbon dioxide with their magma, on a journey many times around a slowly-changing elliptical orbit that subtly changed the levels of sunshine that slammed into the rocks, oceans and forests – patterns of change called the Milankovitch cycles, long implicated in periodic shifts in planetary climate.

They also fed in data about sediments in the high latitudes: important because ice sheets advance more easily over gravel than bedrock, and atmospheric dust from such attrition makes ice surfaces darker and more vulnerable to melting. The result: confirmation of one thing already observed and another much feared.

Carbon ratio leaps

At a time in the astronomical cycle when Earthlings might expect a slow return of the Ice Ages, human action over the last two centuries – the profligate combustion of fossil fuels that emit greenhouse gases, the wholesale clearance of the great forests that absorb atmospheric carbon – has already lifted carbon dioxide ratios from a long-term average of around 280 parts per million to more than 400 ppm.

Human action has also raised long-term average planetary temperatures by a whole degree Celsius, with more warming on the way.

A new Ice Age seems increasingly unlikely, and other researchers have already pointed to the Pliocene data as a soon-to-be-exceeded record.

Entirely different studies have shown the world to be on course to exceed the 2°C limit, so the research confirms other findings and delivers a test of the reliability of evidence from the past. It also backs up the value of simulation as an increasingly reliable form of climate forecasting.

CO2’s key role

“We know from the analysis of sediments on the bottom of our seas about past ocean temperatures and ice volumes, but so far the role of CO2 in shaping the glacial cycles has not been fully understood,” said Dr Willeit.

“It is a breakthrough that we can now show in computer simulations that changes in CO2 levels were a main driver of the Ice Ages, together with variations of how the Earth orbits around the sun, the so-called Milankovitch cycles. These are actually not just simulations: we compared our results with hard data from the deep sea, and they prove to be in good agreement,” he said.

“Our results imply a strong sensitivity of the Earth system to relatively small changes in atmospheric CO2. As fascinating as this is, it is also worrying.” – Climate News Network

Half a degree may make heat impact far worse

Half a degree of warming doesn’t sound like much. But there is fresh evidence that it could make a huge difference to rainfall and drought.

LONDON, 4 April, 2019 − Japanese scientists have found new evidence that a global average temperature rise as small as half a degree could have a drastic effect.

They conclude that the world cannot afford to delay action to reduce greenhouse gas emissions and slow global warming to 1.5°C by 2100 – the “ideal target” enshrined in the promise by 195 nations to limit warming to well below 2°C above the long-term average for most of human history.

The evidence is this: a shift of even 0.5°C could make a dramatic difference to the risks of devastating droughts and calamitous floods.

If governments keep to the letter of the Paris Agreement of 2015 but not the spirit, and let warming rise to the maximum of 2°, then there will be more intense rainfall across North America, Europe and Asia, and more intense droughts around the Mediterranean.

And although the average intensity of each flood or drought would increase measurably, the intensity of the most extreme event could be even more intense: 10 times greater. That is: the worst imaginable floods 80 years from now would be ten times worse than the worst today.

“Such drastic changes between flood and drought conditions pose a major challenge . . . risks could be substantially reduced by achieving a 1.5°C target”

At the heart of research like this is a new way of looking at future climate projections devised – by researchers all over the world – on a range of possible outcomes for a planet that has recognised climate change, vowed to respond, but failed to take sufficiently energetic steps.

The planet is already warmer by 1°C on average than it was a century ago. Since the Paris Agreement researchers have warned that on present form, and with the present state of commitment nationally and internationally, global average temperatures will top an increase of at least 3°C by the century’s close.

This would be catastrophic. But since then, a slew of fresh studies has defined fresh shades of potential catastrophe even at 2°C maximum, and delivered evidence that a limit of overall warming to the target of 1.5°C would save not just economic damage but even lost lands.

They have demonstrated that just half a degree more would see sea levels rise by 10cms, to threaten the existence of already vulnerable small island states and low-lying coastal floodplains, to put at risk the survival of the coral reefs, and the Arctic ice.

The latest study simply addressed a phenomenon known in the scientific language as the event-to-event hydrological intensification index. This awkward mouthful of syllables masks the crude consequence of average warming: if the overall temperature rises, then so do the extremes of temperature. That is what is meant by average: the mean of all the extremes.

Harder rain

But if average temperatures rise, so does the capacity of the air to hold moisture, which means that when it does rain, then it will rain harder. And when it doesn’t, the groundwater will evaporate more easily.

So landscapes such as the US south-west, already prone to heat and drought, can expect more heat waves, more forest fires and more intense and prolonged drought, while the northeast could see more flooding.

And the latest study in the journal Scientific Reports, by researchers at the University of Tokyo, looked at the difference of outcomes between 1.5°C and 2°C in an already rapidly-warming world, to find that when it came to rainfall – and the attendant floods, droughts, mudslides, harvest failures and water shortages – even half a degree beyond the ideal could make the very bad 10 times worse.

“The high damage potential of such drastic changes between flood and drought conditions poses a major challenge to adaptation,” the researchers conclude, “and the findings suggest that risks could be substantially reduced by achieving a 1.5°C target.” − Climate News Network

Half a degree of warming doesn’t sound like much. But there is fresh evidence that it could make a huge difference to rainfall and drought.

LONDON, 4 April, 2019 − Japanese scientists have found new evidence that a global average temperature rise as small as half a degree could have a drastic effect.

They conclude that the world cannot afford to delay action to reduce greenhouse gas emissions and slow global warming to 1.5°C by 2100 – the “ideal target” enshrined in the promise by 195 nations to limit warming to well below 2°C above the long-term average for most of human history.

The evidence is this: a shift of even 0.5°C could make a dramatic difference to the risks of devastating droughts and calamitous floods.

If governments keep to the letter of the Paris Agreement of 2015 but not the spirit, and let warming rise to the maximum of 2°, then there will be more intense rainfall across North America, Europe and Asia, and more intense droughts around the Mediterranean.

And although the average intensity of each flood or drought would increase measurably, the intensity of the most extreme event could be even more intense: 10 times greater. That is: the worst imaginable floods 80 years from now would be ten times worse than the worst today.

“Such drastic changes between flood and drought conditions pose a major challenge . . . risks could be substantially reduced by achieving a 1.5°C target”

At the heart of research like this is a new way of looking at future climate projections devised – by researchers all over the world – on a range of possible outcomes for a planet that has recognised climate change, vowed to respond, but failed to take sufficiently energetic steps.

The planet is already warmer by 1°C on average than it was a century ago. Since the Paris Agreement researchers have warned that on present form, and with the present state of commitment nationally and internationally, global average temperatures will top an increase of at least 3°C by the century’s close.

This would be catastrophic. But since then, a slew of fresh studies has defined fresh shades of potential catastrophe even at 2°C maximum, and delivered evidence that a limit of overall warming to the target of 1.5°C would save not just economic damage but even lost lands.

They have demonstrated that just half a degree more would see sea levels rise by 10cms, to threaten the existence of already vulnerable small island states and low-lying coastal floodplains, to put at risk the survival of the coral reefs, and the Arctic ice.

The latest study simply addressed a phenomenon known in the scientific language as the event-to-event hydrological intensification index. This awkward mouthful of syllables masks the crude consequence of average warming: if the overall temperature rises, then so do the extremes of temperature. That is what is meant by average: the mean of all the extremes.

Harder rain

But if average temperatures rise, so does the capacity of the air to hold moisture, which means that when it does rain, then it will rain harder. And when it doesn’t, the groundwater will evaporate more easily.

So landscapes such as the US south-west, already prone to heat and drought, can expect more heat waves, more forest fires and more intense and prolonged drought, while the northeast could see more flooding.

And the latest study in the journal Scientific Reports, by researchers at the University of Tokyo, looked at the difference of outcomes between 1.5°C and 2°C in an already rapidly-warming world, to find that when it came to rainfall – and the attendant floods, droughts, mudslides, harvest failures and water shortages – even half a degree beyond the ideal could make the very bad 10 times worse.

“The high damage potential of such drastic changes between flood and drought conditions poses a major challenge to adaptation,” the researchers conclude, “and the findings suggest that risks could be substantially reduced by achieving a 1.5°C target.” − Climate News Network

Gulf Stream slowdown may bring later cold

The Gulf Stream is weakening, and Europe could expect a prolonged cold spell as the world warms – but not the day after tomorrow.

LONDON, 25 March, 2019 – As the Gulf Stream weakens in a rapidly warming world, north-western Europe could paradoxically become cooler. There is, however, a time lag between those two climate change-related events, and US scientists now think they know how long that could be.
It could be as much as 400 years.

They know this because the world has warmed and cooled before, and as the difference between tropics and Arctic narrows, there is a change in the so-called Atlantic conveyor, an important part of the climate machine.

This vast Atlantic current carries a steady flow of warm water to the far north, making north-western Europe up to 5°C warmer than its latitude would otherwise dictate. Then, as it meets colder, denser Arctic waters, it dives, to carry its burden of surface carbon to the depths, and then flows southwards again.

This phenomenon, known as the Atlantic Meridional Overturning Circulation, or AMOC, is in effect Europe’s bespoke heating system: Britain’s chief scientific adviser once calculated that it delivers to the UK alone the warmth of 27,000 power stations.

“There are some precursors in the ocean, so we should be watching the ocean”

But evidence from climate history shows that this heating has been turned off a number of times. Europe was plunged into a cold snap 13,000 years ago during a period known as the Younger Dryas and then warmed up about 11,000 years ago.

New and sophisticated studies of fossil carbon show that anybody taking notes at the time might have observed the warning signs. About 400 years before the abrupt shift to a frosty spell, the Atlantic current weakened. And it started to strengthen again about four centuries before the world warmed.

The study, published in the journal Nature Communications, confirms what climate scientists have always known: any sudden catastrophic return of the Ice Ages – dramatised in Hollywood’s notorious 2004 climate change movie The Day After Tomorrow – won’t happen at action movie pace. But it will happen over decades, and now seemingly with several centuries of advance notice.

“Our reconstructions indicate that there are clear climate precursors provided by the ocean state – like warning signs, so to speak,” said Francesco Muschitiello, then of the Lamont-Doherty Earth Observatory at Columbia University, US, and now at the University of Cambridge in the UK, who led the research.

Timing established

Climate scientists have clear dates for the timing of the Younger Dryas event: ice cores from the Arctic show both that Greenland’s temperature fell by 6°C or more at the beginning of the cycle, and that it rose by at least 8°C at its end.

To time the changes in the ocean current, they used carbon-dating techniques to identify a pattern of change in the marine sediments in the Norwegian Sea.

Since marine sediments settle very slowly, over very long periods of time, they needed a more precise “clock” to help calibrate their calculations: they found this in the fossilised ancient plants in a Scandinavian lake.

The isotope carbon-14 is pulled directly from the atmosphere each season by growing foliage. It decays at a predictable rate, and the amount of surviving C14 delivered a reliable clock. The identification of two volcanic ash layers from eruptions in Iceland, in both lake and seabed, provided yet more confidence in the timings. From these factors, the researchers were able to identify a slowdown in the transport of carbon from surface to the deep – and thus a slowdown in the current.

Long wait

The research confirms a link between ocean circulation patterns and northern hemisphere climate shifts: it provides evidence of what could be a considerable interval between the two.

Researchers have repeatedly warned that the Atlantic current seemed to be slowing, in response to global warming driven by profligate fossil fuel use by humankind, and that the consequences of continued slowdown could be very uncomfortable for hundreds of millions.

If the evidence from the Younger Dryas provides a sure parallel to today’s conditions, then Europeans might have time to prepare.

“It is clear that there are some precursors in the ocean, so we should be watching the ocean,” said Dr Muschitiello. “The mere fact that AMOC has been slowing down, that should be a concern based on what we have found.” – Climate News Network

The Gulf Stream is weakening, and Europe could expect a prolonged cold spell as the world warms – but not the day after tomorrow.

LONDON, 25 March, 2019 – As the Gulf Stream weakens in a rapidly warming world, north-western Europe could paradoxically become cooler. There is, however, a time lag between those two climate change-related events, and US scientists now think they know how long that could be.
It could be as much as 400 years.

They know this because the world has warmed and cooled before, and as the difference between tropics and Arctic narrows, there is a change in the so-called Atlantic conveyor, an important part of the climate machine.

This vast Atlantic current carries a steady flow of warm water to the far north, making north-western Europe up to 5°C warmer than its latitude would otherwise dictate. Then, as it meets colder, denser Arctic waters, it dives, to carry its burden of surface carbon to the depths, and then flows southwards again.

This phenomenon, known as the Atlantic Meridional Overturning Circulation, or AMOC, is in effect Europe’s bespoke heating system: Britain’s chief scientific adviser once calculated that it delivers to the UK alone the warmth of 27,000 power stations.

“There are some precursors in the ocean, so we should be watching the ocean”

But evidence from climate history shows that this heating has been turned off a number of times. Europe was plunged into a cold snap 13,000 years ago during a period known as the Younger Dryas and then warmed up about 11,000 years ago.

New and sophisticated studies of fossil carbon show that anybody taking notes at the time might have observed the warning signs. About 400 years before the abrupt shift to a frosty spell, the Atlantic current weakened. And it started to strengthen again about four centuries before the world warmed.

The study, published in the journal Nature Communications, confirms what climate scientists have always known: any sudden catastrophic return of the Ice Ages – dramatised in Hollywood’s notorious 2004 climate change movie The Day After Tomorrow – won’t happen at action movie pace. But it will happen over decades, and now seemingly with several centuries of advance notice.

“Our reconstructions indicate that there are clear climate precursors provided by the ocean state – like warning signs, so to speak,” said Francesco Muschitiello, then of the Lamont-Doherty Earth Observatory at Columbia University, US, and now at the University of Cambridge in the UK, who led the research.

Timing established

Climate scientists have clear dates for the timing of the Younger Dryas event: ice cores from the Arctic show both that Greenland’s temperature fell by 6°C or more at the beginning of the cycle, and that it rose by at least 8°C at its end.

To time the changes in the ocean current, they used carbon-dating techniques to identify a pattern of change in the marine sediments in the Norwegian Sea.

Since marine sediments settle very slowly, over very long periods of time, they needed a more precise “clock” to help calibrate their calculations: they found this in the fossilised ancient plants in a Scandinavian lake.

The isotope carbon-14 is pulled directly from the atmosphere each season by growing foliage. It decays at a predictable rate, and the amount of surviving C14 delivered a reliable clock. The identification of two volcanic ash layers from eruptions in Iceland, in both lake and seabed, provided yet more confidence in the timings. From these factors, the researchers were able to identify a slowdown in the transport of carbon from surface to the deep – and thus a slowdown in the current.

Long wait

The research confirms a link between ocean circulation patterns and northern hemisphere climate shifts: it provides evidence of what could be a considerable interval between the two.

Researchers have repeatedly warned that the Atlantic current seemed to be slowing, in response to global warming driven by profligate fossil fuel use by humankind, and that the consequences of continued slowdown could be very uncomfortable for hundreds of millions.

If the evidence from the Younger Dryas provides a sure parallel to today’s conditions, then Europeans might have time to prepare.

“It is clear that there are some precursors in the ocean, so we should be watching the ocean,” said Dr Muschitiello. “The mere fact that AMOC has been slowing down, that should be a concern based on what we have found.” – Climate News Network

Ocean heatwaves drive more fish north

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

Pacific climate wobble speeds Arctic ice melt

Thanks to a natural sea temperature cycle, a Pacific climate wobble, the Arctic Ocean could be ice-free in the summer in a decade or two.

LONDON, 6 March, 2019 – Sunlit skies and bright blue water could come earlier to the Arctic – much earlier, thanks to a distant Pacific climate wobble.

Scientists now think that the Arctic Ocean could be effectively ice-free within the next 20 years, opening it to sea lanes across the polar waters between Europe, the US and east Asia.

Climate researchers have repeatedly warned, in the last two decades, that because of global warming the ice sheet that masks the Arctic Ocean has been thinning and could in effect vanish altogether in summertime by 2050.

New research has brought forward the prediction date. And this time the effective agency is not just global warming driven by profligate combustion of fossil fuels worldwide, but a natural cyclic phenomenon known to oceanographers as the interdecadal Pacific oscillation, or IPO.

“The trajectory is towards becoming ice-free in the summer …  there’s more chance of it being on the earlier end of that window than the later end”

Over a cycle of between one to three decades, the average ocean temperatures of the north Pacific shift up or down by about 0.5°C.

And a new study in the journal Geophysical Research Letters pinpoints the state of the present cycle: the Pacific ended its cold phase and started to warm up about five years ago.

James Screen of the University of Exeter, UK, and a colleague used computer modelling to merge the continuous upward rise in global average temperatures as a consequence of the build-up of greenhouse gases in the atmosphere with the pattern of predicted natural change in ocean surface temperatures to identify the moment when the summer ice will have melted.

The phrase “ice-free” is not a simple one, because some sea ice always remains, but oceanographers and glaciologists have their own definition: it happens when the area of summer sea ice falls below a million square kilometres.

Dramatic change likely

And this is now likely to happen some time between 2030 and 2050. Any argument is not about if, but when. The Arctic is just about the fastest-warming region of the planet, and in 2016 polar sea ice in both hemispheres  reached a record low: an area of ice the size of Mexico was lost.

Temperatures in the Arctic were recorded as up to 20°C above the average for some of the winter months. The long-term consequences are unpredictable, but since both ocean current and air movement are driven by the difference between equatorial and polar temperatures, dramatic climate change is likely to follow.

“The trajectory is towards becoming ice-free in the summer, but there is uncertainty as to when that is going to occur,” Dr Screen said.

“You can hedge your bets. The shift in the IPO means there’s more chance of it being on the earlier end of that window than the later end.” – Climate News Network

Thanks to a natural sea temperature cycle, a Pacific climate wobble, the Arctic Ocean could be ice-free in the summer in a decade or two.

LONDON, 6 March, 2019 – Sunlit skies and bright blue water could come earlier to the Arctic – much earlier, thanks to a distant Pacific climate wobble.

Scientists now think that the Arctic Ocean could be effectively ice-free within the next 20 years, opening it to sea lanes across the polar waters between Europe, the US and east Asia.

Climate researchers have repeatedly warned, in the last two decades, that because of global warming the ice sheet that masks the Arctic Ocean has been thinning and could in effect vanish altogether in summertime by 2050.

New research has brought forward the prediction date. And this time the effective agency is not just global warming driven by profligate combustion of fossil fuels worldwide, but a natural cyclic phenomenon known to oceanographers as the interdecadal Pacific oscillation, or IPO.

“The trajectory is towards becoming ice-free in the summer …  there’s more chance of it being on the earlier end of that window than the later end”

Over a cycle of between one to three decades, the average ocean temperatures of the north Pacific shift up or down by about 0.5°C.

And a new study in the journal Geophysical Research Letters pinpoints the state of the present cycle: the Pacific ended its cold phase and started to warm up about five years ago.

James Screen of the University of Exeter, UK, and a colleague used computer modelling to merge the continuous upward rise in global average temperatures as a consequence of the build-up of greenhouse gases in the atmosphere with the pattern of predicted natural change in ocean surface temperatures to identify the moment when the summer ice will have melted.

The phrase “ice-free” is not a simple one, because some sea ice always remains, but oceanographers and glaciologists have their own definition: it happens when the area of summer sea ice falls below a million square kilometres.

Dramatic change likely

And this is now likely to happen some time between 2030 and 2050. Any argument is not about if, but when. The Arctic is just about the fastest-warming region of the planet, and in 2016 polar sea ice in both hemispheres  reached a record low: an area of ice the size of Mexico was lost.

Temperatures in the Arctic were recorded as up to 20°C above the average for some of the winter months. The long-term consequences are unpredictable, but since both ocean current and air movement are driven by the difference between equatorial and polar temperatures, dramatic climate change is likely to follow.

“The trajectory is towards becoming ice-free in the summer, but there is uncertainty as to when that is going to occur,” Dr Screen said.

“You can hedge your bets. The shift in the IPO means there’s more chance of it being on the earlier end of that window than the later end.” – Climate News Network

Food supply falls as fish flee warmer seas

On the fishing grounds, they already know about global warming. As fish flee warmer seas there are winners – but many more losers.

LONDON, 4 March 2019 – Global warming has already begun to affect fishing worldwide as fish flee warmer seas, a new study says.

In the last 80 years, there has been an estimated drop of more than 4% in sustainable catches for many kinds of fish and shellfish. That is the average. In some regions – the East China Sea, for instance, and Europe’s North Sea –  the estimated decline was between 15% and 35%.

In the course of the last century, global average temperatures have crept up by about 1°C above the average for most of human history, as a reaction to the unconstrained burning of fossil fuels. If the world continues to burn ever-greater volumes of coal, oil and natural gas, it could be 3°C warmer or more by the end of the century.

Last year was only the fourth warmest for air surface temperatures, but the warmest since records began for the world’s oceans.

“Fisheries around the world have already responded to global warming. These aren’t hypothetical changes some time in the future”

US researchers report in the journal Science that they looked at the impact of ocean warming in 235 populations of 124 species of fish, crustaceans and molluscs in 38 ecological regions between the years 1930 and 2010.

They then matched the world data on fish catches with ocean temperature maps to estimate what warming has done to the sustainable catch – that is, the biggest haul fishing crews can make without reducing breeding stocks for the seasons to follow.

“We were stunned to find that fisheries around the world have already responded to global warming,” said Malin Pinsky of Rutgers University, and one of the authors. “These aren’t hypothetical changes some time in the future.”

The researchers found that some species in some climate zones actually benefited from warming, and fish with faster life cycles sometimes responded well, sometimes badly to the temperature changes. Some responded by shifting their geographical range.

More climate losers

But overall, said Christopher Free, once of Rutgers and now at the University of California, Santa Barbara, “among the populations we studied, the climate losers outweigh the climate winners.”

And his colleague Olaf Jensen, also from Rutgers, said: “Fish populations can only tolerate so much warning, though. Many of the species that have benefited from warming so far are likely to start declining as temperatures continue to rise.”

Fishermen off the coasts of Labrador and Newfoundland, in the Baltic, the Indian Ocean and the northeast US shelf may have seen more productive hauls of fish. But the biggest losses were in the Sea of Japan, the North Sea, off the Iberian coast and the Celtic-Biscay shelf.

Many fish species are adapted to a precise range of temperatures: they flourish not just in specific marine ecosystems but in thermal niches as well. Once things begin to change, they swim away or perish.

Marauding invaders

Fishermen in the North Atlantic have repeatedly observed changes in the available catch, as the cod shift north and the sardines migrate from increasingly uncomfortable warm waters. Warming in Mediterranean waters creates enticing conditions for invaders from the Red Sea and further south, at huge cost to the resident species.

The lesson is that fish stocks must be carefully conserved, and ocean reserves protected. Researchers have consistently warned that global warming and climate change – especially when combined with changes in ocean water chemistry as a consequence of carbon dioxide build-up in the atmosphere – could soon start to constrain an important source of nutrition: an estimated 3.2 billion people rely on the sea for an estimated 20% of their animal protein, especially in East Asia.

“This means 15% to 35% less fish available for food and employment in a region with some of the fastest-growing human populations in the world,” said Dr Free.

“Knowing exactly how fisheries will change under future warming is challenging, but we do know that failing to adapt to changing fisheries productivity will result in less food and fewer profits relative to today.” – Climate News Network

On the fishing grounds, they already know about global warming. As fish flee warmer seas there are winners – but many more losers.

LONDON, 4 March 2019 – Global warming has already begun to affect fishing worldwide as fish flee warmer seas, a new study says.

In the last 80 years, there has been an estimated drop of more than 4% in sustainable catches for many kinds of fish and shellfish. That is the average. In some regions – the East China Sea, for instance, and Europe’s North Sea –  the estimated decline was between 15% and 35%.

In the course of the last century, global average temperatures have crept up by about 1°C above the average for most of human history, as a reaction to the unconstrained burning of fossil fuels. If the world continues to burn ever-greater volumes of coal, oil and natural gas, it could be 3°C warmer or more by the end of the century.

Last year was only the fourth warmest for air surface temperatures, but the warmest since records began for the world’s oceans.

“Fisheries around the world have already responded to global warming. These aren’t hypothetical changes some time in the future”

US researchers report in the journal Science that they looked at the impact of ocean warming in 235 populations of 124 species of fish, crustaceans and molluscs in 38 ecological regions between the years 1930 and 2010.

They then matched the world data on fish catches with ocean temperature maps to estimate what warming has done to the sustainable catch – that is, the biggest haul fishing crews can make without reducing breeding stocks for the seasons to follow.

“We were stunned to find that fisheries around the world have already responded to global warming,” said Malin Pinsky of Rutgers University, and one of the authors. “These aren’t hypothetical changes some time in the future.”

The researchers found that some species in some climate zones actually benefited from warming, and fish with faster life cycles sometimes responded well, sometimes badly to the temperature changes. Some responded by shifting their geographical range.

More climate losers

But overall, said Christopher Free, once of Rutgers and now at the University of California, Santa Barbara, “among the populations we studied, the climate losers outweigh the climate winners.”

And his colleague Olaf Jensen, also from Rutgers, said: “Fish populations can only tolerate so much warning, though. Many of the species that have benefited from warming so far are likely to start declining as temperatures continue to rise.”

Fishermen off the coasts of Labrador and Newfoundland, in the Baltic, the Indian Ocean and the northeast US shelf may have seen more productive hauls of fish. But the biggest losses were in the Sea of Japan, the North Sea, off the Iberian coast and the Celtic-Biscay shelf.

Many fish species are adapted to a precise range of temperatures: they flourish not just in specific marine ecosystems but in thermal niches as well. Once things begin to change, they swim away or perish.

Marauding invaders

Fishermen in the North Atlantic have repeatedly observed changes in the available catch, as the cod shift north and the sardines migrate from increasingly uncomfortable warm waters. Warming in Mediterranean waters creates enticing conditions for invaders from the Red Sea and further south, at huge cost to the resident species.

The lesson is that fish stocks must be carefully conserved, and ocean reserves protected. Researchers have consistently warned that global warming and climate change – especially when combined with changes in ocean water chemistry as a consequence of carbon dioxide build-up in the atmosphere – could soon start to constrain an important source of nutrition: an estimated 3.2 billion people rely on the sea for an estimated 20% of their animal protein, especially in East Asia.

“This means 15% to 35% less fish available for food and employment in a region with some of the fastest-growing human populations in the world,” said Dr Free.

“Knowing exactly how fisheries will change under future warming is challenging, but we do know that failing to adapt to changing fisheries productivity will result in less food and fewer profits relative to today.” – Climate News Network

World may hit 56m year carbon level by 2159

Long ago the polar ice vanished and tropical animals swam the Arctic. Greenhouse gases could reach that 56m year carbon level again in 140 years.

LONDON, 26 February, 2019 – Humankind could be about to open the throttle on greenhouse gas emissions and revert to a 56m year carbon level – to a world with a global temperature marked by ice-free poles and crocodiles in the waters of the Arctic.

And it could happen by the year 2159 – just five human generations or 140 years from now.

By then, if humans go on burning ever-greater quantities of fossil fuels to underwrite ever-accelerating destruction of forests, wetlands and savannahs, they will have pumped into the atmosphere about as much carbon as accumulated during a geological period called the Palaeocene-Eocene Thermal Maximum (PETM), a dramatic global warming event that reached its peak 56 million years ago.

The long-ago warming event occurred naturally, and the build-up of carbon dioxide in the atmosphere happened over a timespan of between 3,000 and 20,000 years.

The present sprint from a cool to an uncomfortably warm state will have happened in fewer than 300 years, because greenhouse gases from coal, oil and natural gas fumes are building up in the atmosphere nine or 10 times faster than in the PETM, according to a new study in the American Geophysical Union journal Paleoceanography and Paleoclimatology.

“You and I won’t be here in 2159, but that’s only about four generations away,” said Philip Gingerich, of the University of Michigan and author of the new study. “When you start to think about your children and your grandchildren, and your great-grandchildren, you’re about there.”

“To me, it really brought home how rapidly and how great the consequences are of the carbon we’re producing”

About 10 million years after the extinction of the dinosaurs, some natural event began to release ever-greater ratios of greenhouse gases into the atmosphere. The sediments and fossilised fragments of the Palaeocene-Eocene period tell the story.

Temperatures rose and settled at a global average of up to 7°C higher than today. Deep in the polar permafrost right now are fragments of tropical trees that flourished in the once-balmy polar regions: the event was accompanied by the most dramatic extinction of marine life for more than 90 million years, the tropic seas reached almost to human body temperature and land animals dwindled in size and migrated towards the poles as they evolved in response to the air temperatures.

Climate scientists now know, with a great deal of precision, how much carbon has been released into the atmosphere since 1959.

“One way to appreciate the rates and risks of present-day carbon release to the earth’s atmosphere and oceans is to compare current emissions to those in earth history,” writes Professor Gingerich.

“The PETM raised global temperatures by 5-8°C, to the warmest temperatures since the extinction of the dinosaurs 66 million years ago. The PETM altered the earth’s carbon cycle, climate, ocean chemistry and marine and continental ecosystems.”

Half-way there

In the 3,000-year run-up to this maximum, carbon concentrations in the atmosphere built up to at the very lowest estimate 3,000 billion metric tons. As of 2016, humans have emitted around 1,500 billion tons since the start of the Industrial Revolution early in the 19th century.

Under the business-as-usual scenario in which humans go on and on burning fossil fuels, humans could hit the 3,000 billion ton mark by 2159, Professor Gingerich calculates.

His warning is dramatic, but not new. Other researchers have prefigured his conclusions. At intervals over the last six years, researchers have unearthed evidence in the Eocene period of rapid climate change. They have identified it as an era of massive extinction of many species and dwarfism among the survivors.

In hotter conditions smaller creatures have an advantage because they shed heat more quickly: this could, researchers warned in 2013, happen again.

Since then, other teams have warned of marine devastation as well as confirming the evidence of mammalian dwarfism. They have repeatedly presented this long-ago event as an indicator of things to come and confirmed that the long, slow cooling of the globe since the maximum has now been reversed.

So the latest study is yet another reminder that conditions that have no precedent in human history are in train. “To me, it really brought home how rapidly and how great the consequences are of the carbon we’re producing as people,” Professor Gingerich said. – Climate News Network

Long ago the polar ice vanished and tropical animals swam the Arctic. Greenhouse gases could reach that 56m year carbon level again in 140 years.

LONDON, 26 February, 2019 – Humankind could be about to open the throttle on greenhouse gas emissions and revert to a 56m year carbon level – to a world with a global temperature marked by ice-free poles and crocodiles in the waters of the Arctic.

And it could happen by the year 2159 – just five human generations or 140 years from now.

By then, if humans go on burning ever-greater quantities of fossil fuels to underwrite ever-accelerating destruction of forests, wetlands and savannahs, they will have pumped into the atmosphere about as much carbon as accumulated during a geological period called the Palaeocene-Eocene Thermal Maximum (PETM), a dramatic global warming event that reached its peak 56 million years ago.

The long-ago warming event occurred naturally, and the build-up of carbon dioxide in the atmosphere happened over a timespan of between 3,000 and 20,000 years.

The present sprint from a cool to an uncomfortably warm state will have happened in fewer than 300 years, because greenhouse gases from coal, oil and natural gas fumes are building up in the atmosphere nine or 10 times faster than in the PETM, according to a new study in the American Geophysical Union journal Paleoceanography and Paleoclimatology.

“You and I won’t be here in 2159, but that’s only about four generations away,” said Philip Gingerich, of the University of Michigan and author of the new study. “When you start to think about your children and your grandchildren, and your great-grandchildren, you’re about there.”

“To me, it really brought home how rapidly and how great the consequences are of the carbon we’re producing”

About 10 million years after the extinction of the dinosaurs, some natural event began to release ever-greater ratios of greenhouse gases into the atmosphere. The sediments and fossilised fragments of the Palaeocene-Eocene period tell the story.

Temperatures rose and settled at a global average of up to 7°C higher than today. Deep in the polar permafrost right now are fragments of tropical trees that flourished in the once-balmy polar regions: the event was accompanied by the most dramatic extinction of marine life for more than 90 million years, the tropic seas reached almost to human body temperature and land animals dwindled in size and migrated towards the poles as they evolved in response to the air temperatures.

Climate scientists now know, with a great deal of precision, how much carbon has been released into the atmosphere since 1959.

“One way to appreciate the rates and risks of present-day carbon release to the earth’s atmosphere and oceans is to compare current emissions to those in earth history,” writes Professor Gingerich.

“The PETM raised global temperatures by 5-8°C, to the warmest temperatures since the extinction of the dinosaurs 66 million years ago. The PETM altered the earth’s carbon cycle, climate, ocean chemistry and marine and continental ecosystems.”

Half-way there

In the 3,000-year run-up to this maximum, carbon concentrations in the atmosphere built up to at the very lowest estimate 3,000 billion metric tons. As of 2016, humans have emitted around 1,500 billion tons since the start of the Industrial Revolution early in the 19th century.

Under the business-as-usual scenario in which humans go on and on burning fossil fuels, humans could hit the 3,000 billion ton mark by 2159, Professor Gingerich calculates.

His warning is dramatic, but not new. Other researchers have prefigured his conclusions. At intervals over the last six years, researchers have unearthed evidence in the Eocene period of rapid climate change. They have identified it as an era of massive extinction of many species and dwarfism among the survivors.

In hotter conditions smaller creatures have an advantage because they shed heat more quickly: this could, researchers warned in 2013, happen again.

Since then, other teams have warned of marine devastation as well as confirming the evidence of mammalian dwarfism. They have repeatedly presented this long-ago event as an indicator of things to come and confirmed that the long, slow cooling of the globe since the maximum has now been reversed.

So the latest study is yet another reminder that conditions that have no precedent in human history are in train. “To me, it really brought home how rapidly and how great the consequences are of the carbon we’re producing as people,” Professor Gingerich said. – Climate News Network