Author: Tim Radford

About Tim Radford

Tim Radford, a founding editor of Climate News Network, worked for The Guardian for 32 years, for most of that time as science editor. He has been covering climate change since 1988.

Poles attract marine life avoiding rising heat

In a warming ocean, some species will swim, others sink. But all agree: the poles attract marine life without exception.

LONDON, 3 April, 2020 − It’s the same the whole world over: everywhere in the oceans of this warming planet, the poles attract marine life.

Molluscs are on the move, haddock are feeling the heat, and penguins are shifting further south. Nautilus are heading north, and plankton are edging towards both poles.

New analysis of marine species has confirmed what commercial fishermen already know to their cost: that as the oceans warm, the sea’s citizens shift their grounds.

Researchers report in the journal Current Biology that they surveyed the evidence assembled in 540 records of 304 widely distributed marine animals over the last century, to find that all of them are shifting their range: away from the equatorial waters, and in both hemispheres nearer to the poles.

In the past century, overall, the world’s oceans have warmed by around 1°C. By 2050, the rise may reach 1.5°C, and all the evidence so far suggests fish and shellfish, along with the microbial creatures at the bottom of the food chain and the marine mammals and seabirds that prey on them all, will have shifted their latitudinal range.

“Both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem”

The greatest abundance of any species, the researchers found, was likely to be at the poleward edge of the preferred range, and the sparsest nearest to the tropical waters.

“The main surprise is how pervasive the effects were. We found the same trend across all groups of marine life we looked at, from plankton to marine invertebrates, and from fish to seabirds,” said Martin Genner, an evolutionary ecologist at the University of Bristol in the UK.

“This matters because it means that climate change is not only leading abundance changes, but intrinsically affecting the performance of species locally. We see species such as the Emperor penguin becoming less abundant as the water becomes too warm at their equatorward edge, and we see some fish such as the European sea bass thriving at their poleward edge, where historically they were uncommon.”

Fish and many marine animals have a preferred range of temperatures, and even seemingly imperceptible shifts can have unpredictable effects. Both individual research and commercial catch data have confirmed a series of shifts in response to global heating.

Winners and losers

Tropical fish are shifting away from the hottest waters, North Sea catches are more likely to be found in north Atlantic waters, and some Mediterranean species have now shifted to the waters of Western Europe.

The latest research suggests that whole ecosystems may be on the move, and with them Atlantic herring and Adelie penguins, loggerhead turtles and phytoplankton.

“Some marine species appear to benefit from climate change, particularly some populations at the poleward limits that are now able to thrive,” said Louise Rutterford, another of the research team at Bristol.

“Meanwhile, some marine life suffers as it is not able to adapt fast enough to survive warming, and this is most noticeable in populations nearer the equator.

“This is concerning, as both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem.” − Climate News Network

In a warming ocean, some species will swim, others sink. But all agree: the poles attract marine life without exception.

LONDON, 3 April, 2020 − It’s the same the whole world over: everywhere in the oceans of this warming planet, the poles attract marine life.

Molluscs are on the move, haddock are feeling the heat, and penguins are shifting further south. Nautilus are heading north, and plankton are edging towards both poles.

New analysis of marine species has confirmed what commercial fishermen already know to their cost: that as the oceans warm, the sea’s citizens shift their grounds.

Researchers report in the journal Current Biology that they surveyed the evidence assembled in 540 records of 304 widely distributed marine animals over the last century, to find that all of them are shifting their range: away from the equatorial waters, and in both hemispheres nearer to the poles.

In the past century, overall, the world’s oceans have warmed by around 1°C. By 2050, the rise may reach 1.5°C, and all the evidence so far suggests fish and shellfish, along with the microbial creatures at the bottom of the food chain and the marine mammals and seabirds that prey on them all, will have shifted their latitudinal range.

“Both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem”

The greatest abundance of any species, the researchers found, was likely to be at the poleward edge of the preferred range, and the sparsest nearest to the tropical waters.

“The main surprise is how pervasive the effects were. We found the same trend across all groups of marine life we looked at, from plankton to marine invertebrates, and from fish to seabirds,” said Martin Genner, an evolutionary ecologist at the University of Bristol in the UK.

“This matters because it means that climate change is not only leading abundance changes, but intrinsically affecting the performance of species locally. We see species such as the Emperor penguin becoming less abundant as the water becomes too warm at their equatorward edge, and we see some fish such as the European sea bass thriving at their poleward edge, where historically they were uncommon.”

Fish and many marine animals have a preferred range of temperatures, and even seemingly imperceptible shifts can have unpredictable effects. Both individual research and commercial catch data have confirmed a series of shifts in response to global heating.

Winners and losers

Tropical fish are shifting away from the hottest waters, North Sea catches are more likely to be found in north Atlantic waters, and some Mediterranean species have now shifted to the waters of Western Europe.

The latest research suggests that whole ecosystems may be on the move, and with them Atlantic herring and Adelie penguins, loggerhead turtles and phytoplankton.

“Some marine species appear to benefit from climate change, particularly some populations at the poleward limits that are now able to thrive,” said Louise Rutterford, another of the research team at Bristol.

“Meanwhile, some marine life suffers as it is not able to adapt fast enough to survive warming, and this is most noticeable in populations nearer the equator.

“This is concerning, as both increasing and decreasing abundances may have harmful knock-on effects for the wider ecosystem.” − Climate News Network

Northern Europe’s warm water flow may falter

Global heating can stop the flow of Europe’s warm water from the tropics. Happening often during the Ice Ages, it could soon recur.

LONDON, 1 April, 2020 – Oceanographers have confirmed once again that global heating could slow or shut down the flow of currents such as the Gulf Stream, ending northern Europe’s warm water supply with an unexpected and prolonged cold snap.

This time the confidence is based neither on ocean measurements made now, nor complex computer simulations of the future. There is fresh evidence from the sea floor that such an ocean shutdown happened many times in the last half a million years of Ice Ages.

The Gulf Stream is part of a much larger flow of water called the Atlantic Meridional Overturning Circulation, an ocean recycling system that both nourishes marine life and moderates the climate in two hemispheres.

For the last 10,000 years of human history, tropical water has flowed north from the Caribbean and equatorial regions and washed the shores of Europe as far north as Norway, bringing equatorial heat to soften the impact of European winters.

A former UK chief scientist once calculated that the Gulf Stream delivered the warmth of 27,000 power stations and kept Britain about 5°C warmer than its citizens had any right to expect, given the latitude at which they lived.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions”

But as that stretch of the Gulf Stream known to oceanographers as the North Atlantic drift current reaches the Greenland Sea it becomes increasingly colder and saltier and thus more dense, and sinks to the ocean floor, loaded with dissolved atmospheric carbon dioxide and oxygen, to become a southward flow called the North Atlantic Deepwater formation.

And it also mingles with fresh water melting each summer from the Greenland ice sheet. But as the rate of Arctic melting accelerates, more fresh water will plunge into the same sea, with an increasing probability that it will disrupt the ocean cycle, turn off the flow of warm tropical water, and plunge Europe into a prolonged cold spell.

In its most dramatic form, this hypothesis was the basis for a 2004 Hollywood disaster movie called The Day After Tomorrow. Climate scientists are fairly sure that such an event would not mean the sudden advance of glacial ice over much of Europe and North America. But they have repeatedly identified evidence that the flow of the northward current is beginning to weaken.

And the journal Science now carries additional evidence that the ocean circulation was repeatedly interrupted for periods of a century or more during the warm spells or interglacials that have happened during the last 450,000 years.

Shells’ signatures

The signature of ocean change is there in the tiny sea shells from marine creatures called foraminifera that rain down onto the ocean floor to form annual layers of silent testimony to past climates.

When the mix of carbon isotope ratios preserved in them is high, that is a sign that the Atlantic circulation was once vigorous. When it is low, then this overturning circulation is feeble, or has stopped altogether.

The signal from the deep ocean is that when they happen, these disruptions seem to happen very swiftly, and to linger for 100 years or more. And, the scientists say, these interruptions in the flow of the ocean – and with it, the transport of heat from the tropics – happen more easily than previously appreciated, and they occurred in past climate conditions similar to those the world may soon face.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions,” said Yair Rosenthal of Rutgers University in the US, one of the authors.

“Although the disruptions in circulation and possible coolings may be relatively short-lived – lasting maybe a century or more – the consequences might be large.” – Climate News Network

Global heating can stop the flow of Europe’s warm water from the tropics. Happening often during the Ice Ages, it could soon recur.

LONDON, 1 April, 2020 – Oceanographers have confirmed once again that global heating could slow or shut down the flow of currents such as the Gulf Stream, ending northern Europe’s warm water supply with an unexpected and prolonged cold snap.

This time the confidence is based neither on ocean measurements made now, nor complex computer simulations of the future. There is fresh evidence from the sea floor that such an ocean shutdown happened many times in the last half a million years of Ice Ages.

The Gulf Stream is part of a much larger flow of water called the Atlantic Meridional Overturning Circulation, an ocean recycling system that both nourishes marine life and moderates the climate in two hemispheres.

For the last 10,000 years of human history, tropical water has flowed north from the Caribbean and equatorial regions and washed the shores of Europe as far north as Norway, bringing equatorial heat to soften the impact of European winters.

A former UK chief scientist once calculated that the Gulf Stream delivered the warmth of 27,000 power stations and kept Britain about 5°C warmer than its citizens had any right to expect, given the latitude at which they lived.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions”

But as that stretch of the Gulf Stream known to oceanographers as the North Atlantic drift current reaches the Greenland Sea it becomes increasingly colder and saltier and thus more dense, and sinks to the ocean floor, loaded with dissolved atmospheric carbon dioxide and oxygen, to become a southward flow called the North Atlantic Deepwater formation.

And it also mingles with fresh water melting each summer from the Greenland ice sheet. But as the rate of Arctic melting accelerates, more fresh water will plunge into the same sea, with an increasing probability that it will disrupt the ocean cycle, turn off the flow of warm tropical water, and plunge Europe into a prolonged cold spell.

In its most dramatic form, this hypothesis was the basis for a 2004 Hollywood disaster movie called The Day After Tomorrow. Climate scientists are fairly sure that such an event would not mean the sudden advance of glacial ice over much of Europe and North America. But they have repeatedly identified evidence that the flow of the northward current is beginning to weaken.

And the journal Science now carries additional evidence that the ocean circulation was repeatedly interrupted for periods of a century or more during the warm spells or interglacials that have happened during the last 450,000 years.

Shells’ signatures

The signature of ocean change is there in the tiny sea shells from marine creatures called foraminifera that rain down onto the ocean floor to form annual layers of silent testimony to past climates.

When the mix of carbon isotope ratios preserved in them is high, that is a sign that the Atlantic circulation was once vigorous. When it is low, then this overturning circulation is feeble, or has stopped altogether.

The signal from the deep ocean is that when they happen, these disruptions seem to happen very swiftly, and to linger for 100 years or more. And, the scientists say, these interruptions in the flow of the ocean – and with it, the transport of heat from the tropics – happen more easily than previously appreciated, and they occurred in past climate conditions similar to those the world may soon face.

“These findings suggest that our climate system, which depends greatly on deep ocean circulation, is critically poised near a tipping point for abrupt disruptions,” said Yair Rosenthal of Rutgers University in the US, one of the authors.

“Although the disruptions in circulation and possible coolings may be relatively short-lived – lasting maybe a century or more – the consequences might be large.” – Climate News Network

Coal exit will benefit health, wealth and nature

Human economies still depend on hydrocarbon fuels. But there are ways to achieve a coal exit, cut emissions and protect health.

LONDON, 30 March, 2020 − A fast coal exit and a switch away from all fossil fuels will offer multiple global benefits. In almost all circumstances, electric cars will be more climate-friendly than petrol-driven machines, even when that electricity is generated by coal combustion.

And nations that so far rely on coal will save substantially on health costs and environmental damage if they close the pits and convert to renewable energy.

The making and use of concrete – a big source of greenhouse gas emissions into the atmosphere – remains an obdurate source of global warming. But even so there are ways to cut the climate and health damage costs of cement and mortar by more than 40%.

Each of these three studies is a reminder that there is for the moment no way to stop all carbon emissions in human economies. But each also confirms that a switch away from fossil fuels continues to make economic sense.

Clear reduction

Almost one fourth of all the fossil fuel combustion emissions that threaten a climate crisis come from passenger road transport and household heating. It takes energy to manufacture an electric car, or a heat pump, and it takes energy to generate the electricity to make them function.

Dutch and British researchers report in the journal Nature Sustainability that they considered the challenge in 59 regions of the globe and found that in 53 of their studies the switch to electric meant a clear reduction in climate-damaging emissions.

By 2050, half of all cars on the road could be electric. This would cut global emissions by up to 1.5 billion tonnes of carbon dioxide a year. This is about what Russia puts into the atmosphere now.

The switch from homes heated by gas, coal or oil to electric pumps could save 800 million tonnes. This is about the same as Germany’s current greenhouse gas emissions.

Mythical increase

Lifetime emissions from electric cars in Sweden and France − which already get most of their electricity from renewables or nuclear power − would be up to 70% lower than from petrol-driven cars, and 30% lower in the UK.

“The answer is clear: to reduce carbon emissions, we should choose electric cars and household heat pumps over fossil-fuel alternatives,” said Florian Knobloch, of Radboud University in the Netherlands and Cambridge in the UK.

“In other words, the idea that electric vehicles or electric heat pumps could increase emissions is a myth. We’ve seen a lot of discussion of this recently, with lots of disinformation going around. Here is a definitive study that can dispel those myths.”

The 53 regions in the study represent 95% of world transport and heating demand. The scientists took into account energy use from the production chain at the beginning of a car’s or a heating system’s life, and the waste processing at the end, to find that the only exceptions were in places like Poland, which is still heavily dependent on coal.

“We decided to comprehensively test the case for a global coal exit: does it add up, economically speaking? The short answer is: yes, by far”

In 2015, the world’s nations agreed at an historic Paris meeting to attempt to limit average planetary warming to “well below” 2°C by the century’s end. Right now, by 2100 global temperatures could rise by a catastrophic 3°C.

A new study in Nature Climate Change confirms that to get to the 2°C target it doesn’t just make climate sense to shut the mines and close down the coal-burning power stations: it would save money as well, just in terms of reducing the health hazards associated with pollution and the damage to ecosystems and the loss of wildlife.

“We’re well into the 21st century now and still rely heavily on burning coal, making it one of the biggest threats to our climate, our health and our environment.

“That’s why we decided to comprehensively test the case for a global coal exit: does it add up, economically speaking? The short answer is: yes, by far,” said Sebastian Rauner of the Potsdam Institute for Climate Impact Research, who led the study.

Concrete burden

And his colleague Gunnar Luderer added: “Benefits from reduced health and ecosystem impacts clearly overcompensate the direct economic costs of a coal exit – they amount to a net saving of about 1.5% of global economic output by 2050. That is, $370 (£300) for every human on Earth in 2050.”

Around 8% of all greenhouse gases come from the concrete industry: it too is a source of air pollution and environmental destruction. Cement has to be baked from stone, and aggregate has to be gathered, hauled and brought to building sites, and the two have to be mixed.

US researchers report in Nature Climate Change that they quantified the costs in terms of climate, death and illness from the industry and arrived at damages of about $335bn a year.

They looked at ways of cleaner combustion in kiln fuel, the more efficient use of mineral additions that might replace cement, and the applications of clean energy: all of them available now.

Neglect of health

Methods to capture and store carbon emissions from the process are not yet ready: these could reduce climate damage costs by 50% to 65%.

If manufacturers used a fuel that burned more efficiently, they could reduce health damages by 14%. A mix of already available methods could, together, reduce climate and health damage by 44%.

“There is a high emissions burden associated with the production of concrete because there is so much demand for it,” said Sabbie Miller of the University of California Davis, who led the study.

“We clearly care a great deal about greenhouse gas emissions. But we haven’t paid as much attention to health burdens, which are also driven in large part by this demand.” − Climate News Network

Human economies still depend on hydrocarbon fuels. But there are ways to achieve a coal exit, cut emissions and protect health.

LONDON, 30 March, 2020 − A fast coal exit and a switch away from all fossil fuels will offer multiple global benefits. In almost all circumstances, electric cars will be more climate-friendly than petrol-driven machines, even when that electricity is generated by coal combustion.

And nations that so far rely on coal will save substantially on health costs and environmental damage if they close the pits and convert to renewable energy.

The making and use of concrete – a big source of greenhouse gas emissions into the atmosphere – remains an obdurate source of global warming. But even so there are ways to cut the climate and health damage costs of cement and mortar by more than 40%.

Each of these three studies is a reminder that there is for the moment no way to stop all carbon emissions in human economies. But each also confirms that a switch away from fossil fuels continues to make economic sense.

Clear reduction

Almost one fourth of all the fossil fuel combustion emissions that threaten a climate crisis come from passenger road transport and household heating. It takes energy to manufacture an electric car, or a heat pump, and it takes energy to generate the electricity to make them function.

Dutch and British researchers report in the journal Nature Sustainability that they considered the challenge in 59 regions of the globe and found that in 53 of their studies the switch to electric meant a clear reduction in climate-damaging emissions.

By 2050, half of all cars on the road could be electric. This would cut global emissions by up to 1.5 billion tonnes of carbon dioxide a year. This is about what Russia puts into the atmosphere now.

The switch from homes heated by gas, coal or oil to electric pumps could save 800 million tonnes. This is about the same as Germany’s current greenhouse gas emissions.

Mythical increase

Lifetime emissions from electric cars in Sweden and France − which already get most of their electricity from renewables or nuclear power − would be up to 70% lower than from petrol-driven cars, and 30% lower in the UK.

“The answer is clear: to reduce carbon emissions, we should choose electric cars and household heat pumps over fossil-fuel alternatives,” said Florian Knobloch, of Radboud University in the Netherlands and Cambridge in the UK.

“In other words, the idea that electric vehicles or electric heat pumps could increase emissions is a myth. We’ve seen a lot of discussion of this recently, with lots of disinformation going around. Here is a definitive study that can dispel those myths.”

The 53 regions in the study represent 95% of world transport and heating demand. The scientists took into account energy use from the production chain at the beginning of a car’s or a heating system’s life, and the waste processing at the end, to find that the only exceptions were in places like Poland, which is still heavily dependent on coal.

“We decided to comprehensively test the case for a global coal exit: does it add up, economically speaking? The short answer is: yes, by far”

In 2015, the world’s nations agreed at an historic Paris meeting to attempt to limit average planetary warming to “well below” 2°C by the century’s end. Right now, by 2100 global temperatures could rise by a catastrophic 3°C.

A new study in Nature Climate Change confirms that to get to the 2°C target it doesn’t just make climate sense to shut the mines and close down the coal-burning power stations: it would save money as well, just in terms of reducing the health hazards associated with pollution and the damage to ecosystems and the loss of wildlife.

“We’re well into the 21st century now and still rely heavily on burning coal, making it one of the biggest threats to our climate, our health and our environment.

“That’s why we decided to comprehensively test the case for a global coal exit: does it add up, economically speaking? The short answer is: yes, by far,” said Sebastian Rauner of the Potsdam Institute for Climate Impact Research, who led the study.

Concrete burden

And his colleague Gunnar Luderer added: “Benefits from reduced health and ecosystem impacts clearly overcompensate the direct economic costs of a coal exit – they amount to a net saving of about 1.5% of global economic output by 2050. That is, $370 (£300) for every human on Earth in 2050.”

Around 8% of all greenhouse gases come from the concrete industry: it too is a source of air pollution and environmental destruction. Cement has to be baked from stone, and aggregate has to be gathered, hauled and brought to building sites, and the two have to be mixed.

US researchers report in Nature Climate Change that they quantified the costs in terms of climate, death and illness from the industry and arrived at damages of about $335bn a year.

They looked at ways of cleaner combustion in kiln fuel, the more efficient use of mineral additions that might replace cement, and the applications of clean energy: all of them available now.

Neglect of health

Methods to capture and store carbon emissions from the process are not yet ready: these could reduce climate damage costs by 50% to 65%.

If manufacturers used a fuel that burned more efficiently, they could reduce health damages by 14%. A mix of already available methods could, together, reduce climate and health damage by 44%.

“There is a high emissions burden associated with the production of concrete because there is so much demand for it,” said Sabbie Miller of the University of California Davis, who led the study.

“We clearly care a great deal about greenhouse gas emissions. But we haven’t paid as much attention to health burdens, which are also driven in large part by this demand.” − Climate News Network

A second US Dust Bowl would hit world food stocks

When the US Great Plains are hit again by sustained drought, the world’s food stocks will feel the heat.

LONDON, 27 March, 2020 – The next time the fertile soils of North America turn to dust, the consequences will hit food stocks worldwide.

Within four years of a climate crisis of the kind that fired John Steinbeck’s 1939 masterpiece The Grapes of Wrath, the US would have consumed almost all its grain reserves.

And the ripple effects would be felt in all those countries to which America normally exports grain. That is because America feeds much of the world: in a good year, the US exports wheat with an energy value of more than 90 trillion kilocalories. The collapse of farmland into wasteland on the scale that inspired John Steinbeck could reduce this over a four-year period to around 50 trillion kcal.

Worldwide, global wheat reserves would fall by 31% in the first year, and four years on somewhere between 36 and 52 countries would have consumed three-fourths of their own reserves. Food prices would rise around the planet.

“In today’s system of global food trade, disruptions are not bound by borders. Shocks to production are expected to affect trade partners who depend on imports for their domestic food supply,” said Alison Heslin, a climate scientist at Columbia University in the US.

“Accessing food reserves can, for a time, buffer populations from trade-induced supply shortages, but as reserves deplete, people are at risk of food shortages”

“Our results remind us that mitigating climate risks requires accounting not only for the direct effects of climate change, like local extreme weather events, but also the climate impacts which travel through our interconnected system of global trade.”

By some time in the mid-century, most of the US will be between 1.5°C to 2°C warmer. Researchers have already warned that the border between the arid western states and the more fertile mid-western plains has shifted to the east.

There have been repeated warnings that as global average temperatures rise, in response to ever greater use of fossil fuels, the US will become increasingly vulnerable to climate extremes, including megadroughts. Drought is already becoming the “new normal” for Californians, and the fertility of the Great Plains is in any case vulnerable to human changes to a natural landscape.

A succession of droughts of the kind that turned the farmland of Kansas and Oklahoma into a devastated landscape, and turned thousands of Americans into climate refugees, would not necessarily now mean the onset of regional famine.

Dr Heslin and her colleagues report in the journal Frontiers in Sustainable Food Systems that they contemplated the likelihood of a four-year drought of the kind that created the notorious 1930s Dust Bowl, and then examined the possible impact on world trade systems.

Yields and nutrition affected

Just one such climate event could hit hard those nations that rely on food imports, but even the other great grain-producing countries – among them China, India, Iran, Canada, Russia, Morocco, Australia and Egypt – would see their reserves fall.

The climate crisis is in any case a threat to the world’s supper tables. There has been repeated evidence that food output will inevitably be at risk in a warming world. With higher temperatures, yields will be reduced and with higher atmospheric levels of carbon dioxide that warm the planet, nutrition levels of many staples are expected to fall.

The researchers factored in none of these things. They supposed that a climate catastrophe that paralleled the Dust Bowl era would occur only in the US, and found that, despite strain, the world’s markets could probably cope.

But other studies have repeatedly found that the potential for climate catastrophe and massive crop failure to strike in more than one region at any one time are increasing, with ominous consequences for world food security.

“In the context of food security, we show that accessing food reserves can, for a time, buffer populations from trade-induced supply shortages,” said Dr Heslin, “but as reserves deplete, people are at risk of food shortages.” – Climate News Network

When the US Great Plains are hit again by sustained drought, the world’s food stocks will feel the heat.

LONDON, 27 March, 2020 – The next time the fertile soils of North America turn to dust, the consequences will hit food stocks worldwide.

Within four years of a climate crisis of the kind that fired John Steinbeck’s 1939 masterpiece The Grapes of Wrath, the US would have consumed almost all its grain reserves.

And the ripple effects would be felt in all those countries to which America normally exports grain. That is because America feeds much of the world: in a good year, the US exports wheat with an energy value of more than 90 trillion kilocalories. The collapse of farmland into wasteland on the scale that inspired John Steinbeck could reduce this over a four-year period to around 50 trillion kcal.

Worldwide, global wheat reserves would fall by 31% in the first year, and four years on somewhere between 36 and 52 countries would have consumed three-fourths of their own reserves. Food prices would rise around the planet.

“In today’s system of global food trade, disruptions are not bound by borders. Shocks to production are expected to affect trade partners who depend on imports for their domestic food supply,” said Alison Heslin, a climate scientist at Columbia University in the US.

“Accessing food reserves can, for a time, buffer populations from trade-induced supply shortages, but as reserves deplete, people are at risk of food shortages”

“Our results remind us that mitigating climate risks requires accounting not only for the direct effects of climate change, like local extreme weather events, but also the climate impacts which travel through our interconnected system of global trade.”

By some time in the mid-century, most of the US will be between 1.5°C to 2°C warmer. Researchers have already warned that the border between the arid western states and the more fertile mid-western plains has shifted to the east.

There have been repeated warnings that as global average temperatures rise, in response to ever greater use of fossil fuels, the US will become increasingly vulnerable to climate extremes, including megadroughts. Drought is already becoming the “new normal” for Californians, and the fertility of the Great Plains is in any case vulnerable to human changes to a natural landscape.

A succession of droughts of the kind that turned the farmland of Kansas and Oklahoma into a devastated landscape, and turned thousands of Americans into climate refugees, would not necessarily now mean the onset of regional famine.

Dr Heslin and her colleagues report in the journal Frontiers in Sustainable Food Systems that they contemplated the likelihood of a four-year drought of the kind that created the notorious 1930s Dust Bowl, and then examined the possible impact on world trade systems.

Yields and nutrition affected

Just one such climate event could hit hard those nations that rely on food imports, but even the other great grain-producing countries – among them China, India, Iran, Canada, Russia, Morocco, Australia and Egypt – would see their reserves fall.

The climate crisis is in any case a threat to the world’s supper tables. There has been repeated evidence that food output will inevitably be at risk in a warming world. With higher temperatures, yields will be reduced and with higher atmospheric levels of carbon dioxide that warm the planet, nutrition levels of many staples are expected to fall.

The researchers factored in none of these things. They supposed that a climate catastrophe that paralleled the Dust Bowl era would occur only in the US, and found that, despite strain, the world’s markets could probably cope.

But other studies have repeatedly found that the potential for climate catastrophe and massive crop failure to strike in more than one region at any one time are increasing, with ominous consequences for world food security.

“In the context of food security, we show that accessing food reserves can, for a time, buffer populations from trade-induced supply shortages,” said Dr Heslin, “but as reserves deplete, people are at risk of food shortages.” – Climate News Network

Regional nuclear war could bring global hunger

Limited nuclear war could certainly slow planetary heating. But it could also cast a lethal wider chill, unleashing global hunger.

LONDON, 25 March, 2020 – If a limited nuclear war is not already a contradiction in terms, it could still prove far wider in scope, inflicting global hunger without limit.

US and European scientists have worked out how to dramatically lower planetary temperatures and reduce rainfall. They do not recommend their latest study of explosive geo-engineering as a way of addressing the climate crisis, warning instead that even a very limited nuclear war between two nations could devastate global harvests.

Just possibly, they say, it could claim more lives in the non-combatant nations than in the incinerated cities of the warring states.

“Our results add to the reasons that nuclear weapons must be eliminated because, if they exist, they can be used with tragic consequences for the world,” said Alan Robock of Rutgers University in the US.

“As horrible as the direct effects of nuclear weapons would be, more people could die outside the target areas due to famine.”

Hypothetical studies like this can help illustrate the vulnerability of world food stocks to climate change, the scale on which climate change can and may yet happen, and the difficulties inherent in any attempts at global technofix.

No winners

They also demonstrate that – for everybody on the planet – nuclear war of any kind could be a confrontation with no winners.

It is a given among climate scientists that violent volcanic eruptions which hurl sulphate aerosols and soot particles into the stratosphere can suppress global average temperatures over a period of years.

That is why, as greenhouse gas emissions from fossil fuel use build up in the atmosphere, and annual average global temperatures continue to climb, researchers repeatedly revisit the argument for deliberately and systematically darkening the skies to blot out some of the incoming sunlight and reduce global heating.

But again and again, scientists have used their war game models of potential nuclear battle to highlight the hazards of darkening the skies precipitately in a nuclear exchange.

The latest is published in the Proceedings of the National Academy of Sciences and calculates that any encounter that uses less than even 1% of the world’s nuclear arsenal could trigger the worst global food losses in modern history, and disrupt harvests and food trade worldwide for about a decade.

“Major breadbasket regions would cut exports, leaving countries worldwide short of supplies. A regional crisis would become global”

The impact of this would turn out to be even worse than the impact of human-made climate change by the end of the century.

“We now know that nuclear conflict would not be just a terrible tragedy in the region where it happens – it is also an underestimated risk for food security,” said Jonas Jägermeyr of Germany’s Potsdam Institute for Climate Impact Research.

“We find severe losses in agricultural production, but more importantly we evaluate trade repercussions affecting local food availability. It turns out that major breadbasket regions would cut exports, leaving countries worldwide short of supplies. A regional crisis would become global, because we all depend on the same climate system.”

The regional crisis, in this case, would be a nuclear exchange involving perhaps 100 Hiroshima-scale warheads over the most densely populated cities of India and Pakistan, neighbouring states with both nuclear weapons and a history of hostility.

The exchange could put five million tonnes of smoke and soot into the upper atmosphere, where the jet stream winds would start to sweep it around the hemisphere. Global average temperatures would drop by 1.8°C, and rainfall would be reduced by 8% for at least five years.

Fossil fuel combustion over the last two centuries has already warmed the planet by around 1°C, to threaten world harvests. But until now, nobody has calculated the cost of a sudden plunge in temperatures.

Four years to zero

The researchers did not factor in the losses in the combatant countries, nor the worldwide damage from radioactive fallout. They just considered the impact on all the other nations that stayed neutral.

In the first year, stocks of maize, wheat, rice and soy in the world’s granaries would buffer the immediate losses. But within four years, global grain stocks would be at almost zero and international trade systems would come to a stop.

Maize and wheat supplies would shrink by at least 20% in more than 70 countries, with about 1.3bn people. By the fourth year, 132 out of 153 countries, home to 5bn people, would experience shortages higher than 10%. Corn production in the US and Canada – source of 40% of all maize – would drop by 17.5% by the fifth year of darkened skies.

The scientists based their calculations on only 5 million tonnes of soot and ash in the stratosphere. In fact, a war between the two nations could yield 16 million tonnes of soot, and be three times as devastating.

And anyone who thinks that at least global warming would have been brought to a halt can think again. After about a decade, the researchers say, global temperatures would again start to surge. – Climate News Network

Limited nuclear war could certainly slow planetary heating. But it could also cast a lethal wider chill, unleashing global hunger.

LONDON, 25 March, 2020 – If a limited nuclear war is not already a contradiction in terms, it could still prove far wider in scope, inflicting global hunger without limit.

US and European scientists have worked out how to dramatically lower planetary temperatures and reduce rainfall. They do not recommend their latest study of explosive geo-engineering as a way of addressing the climate crisis, warning instead that even a very limited nuclear war between two nations could devastate global harvests.

Just possibly, they say, it could claim more lives in the non-combatant nations than in the incinerated cities of the warring states.

“Our results add to the reasons that nuclear weapons must be eliminated because, if they exist, they can be used with tragic consequences for the world,” said Alan Robock of Rutgers University in the US.

“As horrible as the direct effects of nuclear weapons would be, more people could die outside the target areas due to famine.”

Hypothetical studies like this can help illustrate the vulnerability of world food stocks to climate change, the scale on which climate change can and may yet happen, and the difficulties inherent in any attempts at global technofix.

No winners

They also demonstrate that – for everybody on the planet – nuclear war of any kind could be a confrontation with no winners.

It is a given among climate scientists that violent volcanic eruptions which hurl sulphate aerosols and soot particles into the stratosphere can suppress global average temperatures over a period of years.

That is why, as greenhouse gas emissions from fossil fuel use build up in the atmosphere, and annual average global temperatures continue to climb, researchers repeatedly revisit the argument for deliberately and systematically darkening the skies to blot out some of the incoming sunlight and reduce global heating.

But again and again, scientists have used their war game models of potential nuclear battle to highlight the hazards of darkening the skies precipitately in a nuclear exchange.

The latest is published in the Proceedings of the National Academy of Sciences and calculates that any encounter that uses less than even 1% of the world’s nuclear arsenal could trigger the worst global food losses in modern history, and disrupt harvests and food trade worldwide for about a decade.

“Major breadbasket regions would cut exports, leaving countries worldwide short of supplies. A regional crisis would become global”

The impact of this would turn out to be even worse than the impact of human-made climate change by the end of the century.

“We now know that nuclear conflict would not be just a terrible tragedy in the region where it happens – it is also an underestimated risk for food security,” said Jonas Jägermeyr of Germany’s Potsdam Institute for Climate Impact Research.

“We find severe losses in agricultural production, but more importantly we evaluate trade repercussions affecting local food availability. It turns out that major breadbasket regions would cut exports, leaving countries worldwide short of supplies. A regional crisis would become global, because we all depend on the same climate system.”

The regional crisis, in this case, would be a nuclear exchange involving perhaps 100 Hiroshima-scale warheads over the most densely populated cities of India and Pakistan, neighbouring states with both nuclear weapons and a history of hostility.

The exchange could put five million tonnes of smoke and soot into the upper atmosphere, where the jet stream winds would start to sweep it around the hemisphere. Global average temperatures would drop by 1.8°C, and rainfall would be reduced by 8% for at least five years.

Fossil fuel combustion over the last two centuries has already warmed the planet by around 1°C, to threaten world harvests. But until now, nobody has calculated the cost of a sudden plunge in temperatures.

Four years to zero

The researchers did not factor in the losses in the combatant countries, nor the worldwide damage from radioactive fallout. They just considered the impact on all the other nations that stayed neutral.

In the first year, stocks of maize, wheat, rice and soy in the world’s granaries would buffer the immediate losses. But within four years, global grain stocks would be at almost zero and international trade systems would come to a stop.

Maize and wheat supplies would shrink by at least 20% in more than 70 countries, with about 1.3bn people. By the fourth year, 132 out of 153 countries, home to 5bn people, would experience shortages higher than 10%. Corn production in the US and Canada – source of 40% of all maize – would drop by 17.5% by the fifth year of darkened skies.

The scientists based their calculations on only 5 million tonnes of soot and ash in the stratosphere. In fact, a war between the two nations could yield 16 million tonnes of soot, and be three times as devastating.

And anyone who thinks that at least global warming would have been brought to a halt can think again. After about a decade, the researchers say, global temperatures would again start to surge. – Climate News Network

Vegetation holds key to climate control

New studies shine a light on the intricate relationship in which climate affects vegetation, which in turn impacts on the global climate.

LONDON, 23 March, 2020 − Here’s an easy way to warm the tropics even further: just fell some rainforest, and the local temperatures will soar by at least a degree Celsius, showing the role played by vegetation.

There is also a good way to temper the summer heat of temperate Europe: just abandon some farmland, leave it to go wild and leafy, and the thermometer will drop by perhaps as much as 1°C.

And, paradoxically, there is even a leafy way to warm the Arctic: burn lots of fossil fuels, precipitate a climate crisis, advance the growth of spring foliage by three weeks or so, and check the thermometer. The region will be even warmer, just because the Arctic has become greener.

These apparently contradictory findings are, more than anything else, a reminder that the pas de deux of vegetation and atmosphere is complex, intricate and finely balanced. Nor are they inconsistent, as each study simply takes the measure of vegetation change on local or regional climate.

Reducing heating

In sum, and for the time being, the big picture remains that forests absorb carbon, and more vigorous growth absorbs more carbon to significantly reduce the average rates of global heating across the entire planet.

In effect, all three studies demonstrate that vegetation moderates extremes of temperature in three climate zones.

Brazilian scientists report in the Public Library of Science journal
PLOS One that they subdivided a tract of the Atlantic rainforest in the southeast of the nation into 120-metre squares, measured those segments that had been part-felled or clear-felled, and read the local land surface temperatures.

If even one fourth of a hectare had been cleared, the local temperature went up by 1°C. If the entire hectare had been razed, the rise could be as high as 4°C.

Risk to trees

The Atlantic rainforest is one of the world’s richest ecosystems: it covers 15% of Brazil, but 72% of the population lives there. It holds seven of Brazil’s nine largest drainage basins, delivers water to 130 million people and its dams provide 60% of the nation’s hydroelectric power.

Between 2017 and 2018, around 113 square kilometres of this forest was cleared. As temperatures continue to rise, some tree species could be at risk.

“We don’t have enough data to predict how long it will take, but in the long run, rising temperatures in Atlantic rainforest fragments could certainly influence the survival of tree species in the forest, albeit some species more than others,” says one of the report’s authors, Carlos Joly, professor of plant biology at the University of Campinas in Brazil.

“The forest is extremely important to maintaining milder temperatures on the local and regional scale. Changes in its function could disrupt this type of ecosystem service.

“Abandoned cropland – or land cover change more generally – and its role in regional climate can help us adapt to and mitigate the effects of climate change”

“The Atlantic rainforest doesn’t produce water but it protects the springs and permits the storage of water in reservoirs for consumption, power generation, agricultural irrigation and fishing, among other activities.”

By contrast, Europeans have achieved a local 1°C cooling simply by abandoning farmland that was no longer sufficiently productive.

Between 1992 and 2014, the European Space Agency satellites compiled detailed maps of the continents, measuring the extents of evergreen needle-leaf forest, deciduous broadleaf woodland, open shrubland, crop fields, urban and built-up areas, wetlands, peatlands, grassland and mosaic areas of crops and wilderness.

In those 24 years – partly because of dramatic political changes that followed the collapse of the Soviet Union – around 25 million hectares of farmland was abandoned.

Drying wetlands

Although farmland was colonised elsewhere, the continent was left with 5 million hectares – an area the size of Switzerland – to be colonised by trees and other natural foliage, European scientists report in the journal Nature Communications.

Overall, the loss of cropland in Western Europe was associated with a drop of 1° in spring and summer. In eastern and northeastern Europe, however, temperatures rose by as much as 1°C, partly because what had once been wetlands began to dry.

“We are already at a mean warming of about 1.8°C on the land, and we will be about 3°C on the land even if we are successful at stabilising the average global temperature at 1.5°C,” says one of the report’s authors, Francesco Cherubini, director of the Industrial Ecology Programme at the Norwegian University of Science and Technology.

“That means we take action to adapt to a warming climate, and land use planning is one action that can bring local cooling benefits.”

The Arctic greens

“The message is quite clear. Abandoned cropland – or land cover change more generally – and its role in regional climate can help us adapt to and mitigate the effects of climate change. And by improving agricultural systems, we can free up land for multiple uses.”

But while Europe is changing, and forest in the tropics is being lost, the Arctic is becoming greener: as temperatures rise, vegetation has moved northwards and spring has arrived ever earlier, and growing seasons have lasted longer.

The science of measurement of seasonal change in plant and animal behaviour is called phenology. Chinese and US scientists report in Nature Climate Change that they looked at computer models of vegetation change and factored in the numbers: on average, in the last four decades, leaf-out has advanced by an average of more than four days a decade, and in some cases up to 12 days a decade.

That means snow-covered ground has retreated, and green leaves have moved northwards, and become denser.

Climate feedback

Snow reflects solar radiation, and darker colours absorb it. That means that local landscapes in the north have tended to become even warmer with each decade.

In the Canadian archipelago, the air has been measured at 0.7°C warmer, and parts of Siberia and the Tibetan plateau − far from any leafy canopy − have warmed by 0.4°C and 0.3°C respectively because advanced leaf-out further south means more water vapour, which moves north to change patterns of cloud cover and snowfall.

Climate scientists see this as positive feedback: climate change begets even faster climate change. Global heating tends to accelerate. Climate change affects vegetation, which in turn affects climate yet further.

“Positive feedback loops between climate and spring leaf phenology is likely to amplify in the northern high latitudes,” says Gensuo Jia, one of the researchers from the Chinese Academy of Sciences. “The impact of vegetation change on climate is profound in spring.” − Climate News Network

New studies shine a light on the intricate relationship in which climate affects vegetation, which in turn impacts on the global climate.

LONDON, 23 March, 2020 − Here’s an easy way to warm the tropics even further: just fell some rainforest, and the local temperatures will soar by at least a degree Celsius, showing the role played by vegetation.

There is also a good way to temper the summer heat of temperate Europe: just abandon some farmland, leave it to go wild and leafy, and the thermometer will drop by perhaps as much as 1°C.

And, paradoxically, there is even a leafy way to warm the Arctic: burn lots of fossil fuels, precipitate a climate crisis, advance the growth of spring foliage by three weeks or so, and check the thermometer. The region will be even warmer, just because the Arctic has become greener.

These apparently contradictory findings are, more than anything else, a reminder that the pas de deux of vegetation and atmosphere is complex, intricate and finely balanced. Nor are they inconsistent, as each study simply takes the measure of vegetation change on local or regional climate.

Reducing heating

In sum, and for the time being, the big picture remains that forests absorb carbon, and more vigorous growth absorbs more carbon to significantly reduce the average rates of global heating across the entire planet.

In effect, all three studies demonstrate that vegetation moderates extremes of temperature in three climate zones.

Brazilian scientists report in the Public Library of Science journal
PLOS One that they subdivided a tract of the Atlantic rainforest in the southeast of the nation into 120-metre squares, measured those segments that had been part-felled or clear-felled, and read the local land surface temperatures.

If even one fourth of a hectare had been cleared, the local temperature went up by 1°C. If the entire hectare had been razed, the rise could be as high as 4°C.

Risk to trees

The Atlantic rainforest is one of the world’s richest ecosystems: it covers 15% of Brazil, but 72% of the population lives there. It holds seven of Brazil’s nine largest drainage basins, delivers water to 130 million people and its dams provide 60% of the nation’s hydroelectric power.

Between 2017 and 2018, around 113 square kilometres of this forest was cleared. As temperatures continue to rise, some tree species could be at risk.

“We don’t have enough data to predict how long it will take, but in the long run, rising temperatures in Atlantic rainforest fragments could certainly influence the survival of tree species in the forest, albeit some species more than others,” says one of the report’s authors, Carlos Joly, professor of plant biology at the University of Campinas in Brazil.

“The forest is extremely important to maintaining milder temperatures on the local and regional scale. Changes in its function could disrupt this type of ecosystem service.

“Abandoned cropland – or land cover change more generally – and its role in regional climate can help us adapt to and mitigate the effects of climate change”

“The Atlantic rainforest doesn’t produce water but it protects the springs and permits the storage of water in reservoirs for consumption, power generation, agricultural irrigation and fishing, among other activities.”

By contrast, Europeans have achieved a local 1°C cooling simply by abandoning farmland that was no longer sufficiently productive.

Between 1992 and 2014, the European Space Agency satellites compiled detailed maps of the continents, measuring the extents of evergreen needle-leaf forest, deciduous broadleaf woodland, open shrubland, crop fields, urban and built-up areas, wetlands, peatlands, grassland and mosaic areas of crops and wilderness.

In those 24 years – partly because of dramatic political changes that followed the collapse of the Soviet Union – around 25 million hectares of farmland was abandoned.

Drying wetlands

Although farmland was colonised elsewhere, the continent was left with 5 million hectares – an area the size of Switzerland – to be colonised by trees and other natural foliage, European scientists report in the journal Nature Communications.

Overall, the loss of cropland in Western Europe was associated with a drop of 1° in spring and summer. In eastern and northeastern Europe, however, temperatures rose by as much as 1°C, partly because what had once been wetlands began to dry.

“We are already at a mean warming of about 1.8°C on the land, and we will be about 3°C on the land even if we are successful at stabilising the average global temperature at 1.5°C,” says one of the report’s authors, Francesco Cherubini, director of the Industrial Ecology Programme at the Norwegian University of Science and Technology.

“That means we take action to adapt to a warming climate, and land use planning is one action that can bring local cooling benefits.”

The Arctic greens

“The message is quite clear. Abandoned cropland – or land cover change more generally – and its role in regional climate can help us adapt to and mitigate the effects of climate change. And by improving agricultural systems, we can free up land for multiple uses.”

But while Europe is changing, and forest in the tropics is being lost, the Arctic is becoming greener: as temperatures rise, vegetation has moved northwards and spring has arrived ever earlier, and growing seasons have lasted longer.

The science of measurement of seasonal change in plant and animal behaviour is called phenology. Chinese and US scientists report in Nature Climate Change that they looked at computer models of vegetation change and factored in the numbers: on average, in the last four decades, leaf-out has advanced by an average of more than four days a decade, and in some cases up to 12 days a decade.

That means snow-covered ground has retreated, and green leaves have moved northwards, and become denser.

Climate feedback

Snow reflects solar radiation, and darker colours absorb it. That means that local landscapes in the north have tended to become even warmer with each decade.

In the Canadian archipelago, the air has been measured at 0.7°C warmer, and parts of Siberia and the Tibetan plateau − far from any leafy canopy − have warmed by 0.4°C and 0.3°C respectively because advanced leaf-out further south means more water vapour, which moves north to change patterns of cloud cover and snowfall.

Climate scientists see this as positive feedback: climate change begets even faster climate change. Global heating tends to accelerate. Climate change affects vegetation, which in turn affects climate yet further.

“Positive feedback loops between climate and spring leaf phenology is likely to amplify in the northern high latitudes,” says Gensuo Jia, one of the researchers from the Chinese Academy of Sciences. “The impact of vegetation change on climate is profound in spring.” − Climate News Network

Extreme summer heat puts millions at risk

heat

Summer on much of the planet could get too hot for comfort by the end of the century, with more than a billion people seriously affected by extreme heat.

LONDON, 20 March, 2020 – As many as 1.2 billion people could be at risk of serious medical stress by the year 2100 simply on the basis of the extreme summer temperatures forecast if greenhouse gas emissions continue to rise, according to new research.

The finding is, in essence, a confirmation of earlier studies: researchers looked closely at the threat to health and, indeed, to life in a globally-heating world have already made a calculation that “more than a billion” could be at risk not just from soaring summer temperatures over longer periods, but also from heightened humidity.

Urgent question

One study found that heat extremes can kill in up to 27 different ways. And lethal heat waves in Europe in 2003, Russia in 2010 and Australia in 2012/2013 have confirmed this in the most unwelcome way possible.

But a study published in Environmental Research Letters journal takes a simple statistical approach to this increasingly urgent question and settles on a notional temperature that factors in not just how high the mercury rises but also how much water vapour might be in the air.

This is known to meteorologists as a “wet bulb” temperature. And the consensus is that, for fit, healthy, acclimatised people, a wet bulb temperature of 33°C is about the limit of tolerance – putting the very young, the very old, and the already ill at risk.

“Every bit of global warming makes hot, humid days more frequent and intense”

Humans can survive much higher thermometer readings in dry climates, but are designed to shed surplus body heat through perspiration – something that becomes increasingly difficult as atmospheric humidity begins to rise. Then the risks of heat rash, heat cramps, heat exhaustion and heat stroke begin to multiply.

So researchers in the US looked at how heat and humidity will increase in a warming planet, for the existing population, and played with 40 climate simulations to build up a picture of probabilities as humans burned more fossil fuels, stoked levels of greenhouse gases in the atmosphere, and turned up the planetary thermostat.

They calculated that, by 2100, the numbers at risk of sweltering, gasping and sickening heat extremes will have multiplied.

The planet is already around 1.2°C warmer than it was at the start of the Industrial Revolution. If the temperature notches up to 1.5°C above the long-term average for most of human history, then every year an estimated 500 million could be exposed to unsafe extremes.

If the temperature rises by 2°C – the upper limit the world set itself in an historic Paris climate meeting in 2015 – the numbers at risk would reach 800 million.

And if the planetary average annual temperature rise was by 3°C – and right now the planet is on course to exceed even that figure – then an estimated 1.2 billion would at least once a year be at risk of extended spells of dangerous heat and humidity.

Research leader Dawei Li, once of Rutgers University and now postdoctoral associate in the Department of Geosciences at the University of Massachusetts, says: “Every bit of global warming makes hot, humid days more frequent and intense.

“In New York City, for example, the hottest, most humid day in a typical year already occurs about 11 times more frequently than it would have done in the 19th century.” Climate News Network

Summer on much of the planet could get too hot for comfort by the end of the century, with more than a billion people seriously affected by extreme heat.

LONDON, 20 March, 2020 – As many as 1.2 billion people could be at risk of serious medical stress by the year 2100 simply on the basis of the extreme summer temperatures forecast if greenhouse gas emissions continue to rise, according to new research.

The finding is, in essence, a confirmation of earlier studies: researchers looked closely at the threat to health and, indeed, to life in a globally-heating world have already made a calculation that “more than a billion” could be at risk not just from soaring summer temperatures over longer periods, but also from heightened humidity.

Urgent question

One study found that heat extremes can kill in up to 27 different ways. And lethal heat waves in Europe in 2003, Russia in 2010 and Australia in 2012/2013 have confirmed this in the most unwelcome way possible.

But a study published in Environmental Research Letters journal takes a simple statistical approach to this increasingly urgent question and settles on a notional temperature that factors in not just how high the mercury rises but also how much water vapour might be in the air.

This is known to meteorologists as a “wet bulb” temperature. And the consensus is that, for fit, healthy, acclimatised people, a wet bulb temperature of 33°C is about the limit of tolerance – putting the very young, the very old, and the already ill at risk.

“Every bit of global warming makes hot, humid days more frequent and intense”

Humans can survive much higher thermometer readings in dry climates, but are designed to shed surplus body heat through perspiration – something that becomes increasingly difficult as atmospheric humidity begins to rise. Then the risks of heat rash, heat cramps, heat exhaustion and heat stroke begin to multiply.

So researchers in the US looked at how heat and humidity will increase in a warming planet, for the existing population, and played with 40 climate simulations to build up a picture of probabilities as humans burned more fossil fuels, stoked levels of greenhouse gases in the atmosphere, and turned up the planetary thermostat.

They calculated that, by 2100, the numbers at risk of sweltering, gasping and sickening heat extremes will have multiplied.

The planet is already around 1.2°C warmer than it was at the start of the Industrial Revolution. If the temperature notches up to 1.5°C above the long-term average for most of human history, then every year an estimated 500 million could be exposed to unsafe extremes.

If the temperature rises by 2°C – the upper limit the world set itself in an historic Paris climate meeting in 2015 – the numbers at risk would reach 800 million.

And if the planetary average annual temperature rise was by 3°C – and right now the planet is on course to exceed even that figure – then an estimated 1.2 billion would at least once a year be at risk of extended spells of dangerous heat and humidity.

Research leader Dawei Li, once of Rutgers University and now postdoctoral associate in the Department of Geosciences at the University of Massachusetts, says: “Every bit of global warming makes hot, humid days more frequent and intense.

“In New York City, for example, the hottest, most humid day in a typical year already occurs about 11 times more frequently than it would have done in the 19th century.” 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

Rainforest and reef systems face collapse

rainforest

In less than a human lifetime, the world’s greatest rainforest could become parched grassland and scrub, and the Caribbean coral reef system could collapse completely.

LONDON, 17 March, 2020 – The entire Amazon rainforest could collapse into savannah – dry grassland with scrub and intermittent woodland – within 50 years as a result of human action.

And the study of what it takes to alter an enduring natural ecosystem confirms that, within as little as 15 years, the rich Caribbean coral reef system could be no more.

A new statistical examination of the vulnerability of what had once seemed the eternal forest and the glorious coral reefs confirms that once large ecosystems begin to change, they can reach a point at which the collapse becomes sudden and irreversible.

The research confirms an increasing fear that global heating driven by profligate human use of fossil fuels could tip not just climate but also natural landscapes into a new and potentially catastrophic states.

Dramatic warning

More directly, as reported in an interview with Brazilian scientist Antonio Donato Nobre in Climate News Network yesterday, it confirms a dramatic warning delivered in December last year that the Amazon rainforest – a landscape almost as vast as the entire 48 contiguous states of the US – may already be teetering on the edge of functional disruption.

How this disruption could happen was recently outlined by two scientists, Thomas Lovejoy, professor of biology at George Mason University in Virginia, US, and Carlos Nobre, a leading expert on the Amazon and climate change, who is the brother of Antonio Donato Nobre and is senior researcher at the University of Saõ Paulo’s Institute for Advanced Studies.

Lovejoy and Carlos Nobre point out that most of the rain that keeps the Amazon a rainforest is actually recycled from the dense canopy that covers the region. After rainfall, evapotranspiration from the foliage returns water vapour to the air above the forest and falls anew as rain, again and again.

“Over the whole basin, the air rises, cools and precipitates out close to 20% of the world’s river water in the Amazon river system,” they warn in a Science journal report.

“Current deforestation is substantial and frightening: 17% across the entire Amazon basin and approaching 20% in the Brazilian Amazon.

“Already there are ominous signals of it in nature. Dry seasons in the Amazon are already hotter and longer. Mortality rates of wet-climate species are increased, whereas dry-climate species are showing resilience. The increasing frequency of unprecedented droughts in 2005, 2010 and 2015/16 is signalling that the tipping point is at hand.”

By contrast, the latest study in Nature Communications zeroes in on the rates at which large ecosystems could, in principle, change once the climate has begun to shift and the natural habitat is in some way degraded.

“This is yet another strong argument to avoid degrading our planet’s ecosystems; we need to do more to conserve biodiversity.”

Three scientists in the UK used computer models to test data from four terrestrial landscapes, 25 marine habitats and 13 freshwater ecosystems. They found, not surprisingly, that larger ecosystems tend to undergo regime shifts more slowly than the smaller ones.

However, as the ecosystem gets bigger, the additional time taken for collapse to happen gets briefer, so big ecosystems fail relatively more quickly.

This would mean that it would take 15 years for 20,000 sq km of Caribbean reef system to collapse, once some fatal trigger point had been reached. And the 5.5 million sq km of the Amazon tropical moist forest, once it starts to go, could be gone in just 49 years.

“Unfortunately, what our paper reveals is that humanity needs to prepare for change far sooner than expected,” says Simon Willcock, senior lecturer in environmental geography at Bangor University in Wales.

And his colleague, Dr Gregory Cooper, postdoctoral research fellow at the University of London’s Centre for Development, Environment and Policy, says: “This is yet another strong argument to avoid degrading our planet’s ecosystems; we need to do more to conserve biodiversity.”

Atmospheric carbon

Other researchers have separately found that the Amazon rainforest could be about to become a source of yet more atmospheric carbon – rather than a green machine for absorbing surplus carbon dioxide from the atmosphere – as a result of climate change and environmental destruction.

The Amazon ecosystem took 58 million years to evolve. But the message is that it could unravel in a very short time.

Alexandre Antonelli, director of science at the Royal Botanic Gardens at Kew, London, was not one of the researchers, but he describes the results of the study as “terrifying” and warns that the Amazon could pass the point of no return this year.

He says: “Nature is fragile. Just because an area is big or a species is common, it doesn’t mean they’ll last forever.

“The Sahel – an area south of the Sahara that is six times the size of Spain – went from being vegetated and bountiful to just a desert in a few hundred years.

“The American chestnut – one of the most important trees of eastern North America – almost faced extinction after a fungal disease caused some three to four billion trees to die in the early 1900s.

“Natural ecosystems are usually resilient to change when kept intact, but after decades of disruption, exploitation and climatic stress, it should come as no surprise that they are breaking down.

“In other words, you can’t simply remove huge chunks of a rainforest and hope everything will be fine – it won’t. Based on these results, 2020 is our very last opportunity to stop Amazonian deforestation.” – Climate News Network

In less than a human lifetime, the world’s greatest rainforest could become parched grassland and scrub, and the Caribbean coral reef system could collapse completely.

LONDON, 17 March, 2020 – The entire Amazon rainforest could collapse into savannah – dry grassland with scrub and intermittent woodland – within 50 years as a result of human action.

And the study of what it takes to alter an enduring natural ecosystem confirms that, within as little as 15 years, the rich Caribbean coral reef system could be no more.

A new statistical examination of the vulnerability of what had once seemed the eternal forest and the glorious coral reefs confirms that once large ecosystems begin to change, they can reach a point at which the collapse becomes sudden and irreversible.

The research confirms an increasing fear that global heating driven by profligate human use of fossil fuels could tip not just climate but also natural landscapes into a new and potentially catastrophic states.

Dramatic warning

More directly, as reported in an interview with Brazilian scientist Antonio Donato Nobre in Climate News Network yesterday, it confirms a dramatic warning delivered in December last year that the Amazon rainforest – a landscape almost as vast as the entire 48 contiguous states of the US – may already be teetering on the edge of functional disruption.

How this disruption could happen was recently outlined by two scientists, Thomas Lovejoy, professor of biology at George Mason University in Virginia, US, and Carlos Nobre, a leading expert on the Amazon and climate change, who is the brother of Antonio Donato Nobre and is senior researcher at the University of Saõ Paulo’s Institute for Advanced Studies.

Lovejoy and Carlos Nobre point out that most of the rain that keeps the Amazon a rainforest is actually recycled from the dense canopy that covers the region. After rainfall, evapotranspiration from the foliage returns water vapour to the air above the forest and falls anew as rain, again and again.

“Over the whole basin, the air rises, cools and precipitates out close to 20% of the world’s river water in the Amazon river system,” they warn in a Science journal report.

“Current deforestation is substantial and frightening: 17% across the entire Amazon basin and approaching 20% in the Brazilian Amazon.

“Already there are ominous signals of it in nature. Dry seasons in the Amazon are already hotter and longer. Mortality rates of wet-climate species are increased, whereas dry-climate species are showing resilience. The increasing frequency of unprecedented droughts in 2005, 2010 and 2015/16 is signalling that the tipping point is at hand.”

By contrast, the latest study in Nature Communications zeroes in on the rates at which large ecosystems could, in principle, change once the climate has begun to shift and the natural habitat is in some way degraded.

“This is yet another strong argument to avoid degrading our planet’s ecosystems; we need to do more to conserve biodiversity.”

Three scientists in the UK used computer models to test data from four terrestrial landscapes, 25 marine habitats and 13 freshwater ecosystems. They found, not surprisingly, that larger ecosystems tend to undergo regime shifts more slowly than the smaller ones.

However, as the ecosystem gets bigger, the additional time taken for collapse to happen gets briefer, so big ecosystems fail relatively more quickly.

This would mean that it would take 15 years for 20,000 sq km of Caribbean reef system to collapse, once some fatal trigger point had been reached. And the 5.5 million sq km of the Amazon tropical moist forest, once it starts to go, could be gone in just 49 years.

“Unfortunately, what our paper reveals is that humanity needs to prepare for change far sooner than expected,” says Simon Willcock, senior lecturer in environmental geography at Bangor University in Wales.

And his colleague, Dr Gregory Cooper, postdoctoral research fellow at the University of London’s Centre for Development, Environment and Policy, says: “This is yet another strong argument to avoid degrading our planet’s ecosystems; we need to do more to conserve biodiversity.”

Atmospheric carbon

Other researchers have separately found that the Amazon rainforest could be about to become a source of yet more atmospheric carbon – rather than a green machine for absorbing surplus carbon dioxide from the atmosphere – as a result of climate change and environmental destruction.

The Amazon ecosystem took 58 million years to evolve. But the message is that it could unravel in a very short time.

Alexandre Antonelli, director of science at the Royal Botanic Gardens at Kew, London, was not one of the researchers, but he describes the results of the study as “terrifying” and warns that the Amazon could pass the point of no return this year.

He says: “Nature is fragile. Just because an area is big or a species is common, it doesn’t mean they’ll last forever.

“The Sahel – an area south of the Sahara that is six times the size of Spain – went from being vegetated and bountiful to just a desert in a few hundred years.

“The American chestnut – one of the most important trees of eastern North America – almost faced extinction after a fungal disease caused some three to four billion trees to die in the early 1900s.

“Natural ecosystems are usually resilient to change when kept intact, but after decades of disruption, exploitation and climatic stress, it should come as no surprise that they are breaking down.

“In other words, you can’t simply remove huge chunks of a rainforest and hope everything will be fine – it won’t. Based on these results, 2020 is our very last opportunity to stop Amazonian deforestation.” – Climate News Network

Tropical forests may be heating Earth by 2035

Climate change so far has meant more vigorous forest growth as greenhouse gases rise. The tropical forests may soon change that.

LONDON, 6 March, 2020 – Within about fifteen years, the great tropical forests of Amazonia and Africa could stop absorbing atmospheric carbon, and slowly start to release more carbon than growing trees can fix.

A team of scientists from 100 research institutions has looked at the evidence from pristine tracts of tropical forest to find that – overall – the foliage soaked up the most carbon, most efficiently, more than two decades ago.

Since then, the measured efficiency of the forests as a “sink” in which carbon is sequestered from the atmosphere has been dwindling. By the last decade, the ability of a tropical forest to absorb carbon had dropped by a third.

All plant growth is a balancing act based on sunshine and atmospheric carbon and rainfall. Plants absorb carbon dioxide as they grow, and surrender it as they die.

In a dense, undisturbed wilderness, fallen leaves and even fallen trees are slightly less likely to decompose completely: the atmospheric carbon in leaf and wood form has a better chance of being preserved in flooded forests as peat, or being buried before it can completely decompose.

The forest becomes a bank vault, repository or sink of the extra carbon that humans are now spilling into the atmosphere from car exhausts, factory chimneys and power station furnaces.

Theory and practice

And in theory, as more and more carbon dioxide gets into the atmosphere, plants respond to the more generous fertilisation by growing more vigorously, and absorbing more carbon.

But as more carbon gets into the atmosphere, the temperature rises and weather patterns begin to become more extreme. Summers get hotter, rainfall more capricious. Then trees become vulnerable to drought, forest fire and invasive diseases, and die more often, and decompose more completely.

Wannes Hubau, once of the University of Leeds in the UK and now at the Royal Museum for Central Africa in Belgium, and more than 100 colleagues from around the world, report in the journal Nature that they assembled 30 years of measurement from more than 300,000 trees in 244 undisturbed plots of forest in 11 countries in Africa, and from 321 plots of forest in Amazonia, and did the sums.

In the 1990s, intact tropical forests removed around 46 billion tonnes of carbon dioxide from the atmosphere. By the 2010s, the uptake had fallen to around 25 billion tonnes. This means that 21 billion tons of greenhouse gas that might otherwise have been turned into timber and root had been added to the atmosphere.

This is pretty much what the UK, France, Germany and Canada together spilled into the atmosphere from fossil fuel combustion over a 10-year period.

“We’ve found one of the most worrying impacts of climate change has already begun. This is decades ahead of even the most pessimistic climate models”

“Extra carbon boosts tree growth, but every year this effect is being increasingly countered by the negative impacts of higher temperatures and droughts which slow growth and can kill trees,” said Dr Hubau.

“Our modeling shows a long-term decline in the African sink and that the Amazon sink will continue to rapidly weaken, which we predict will become a carbon source in the mid-2030s.”

Tropical forests are an integral factor in the planetary carbon budget – a crude accounting system that climate scientists rely upon to model the choice of futures that face humankind as the world heats up.

Around half of Earth’s carbon is stored in terrestrial vegetation and the tropical forests account for about a third of the planet’s primary productivity. So how forests respond to a warmer world is vital.

Because the Amazon region is being hit by higher temperatures, and more frequent and prolonged droughts than forests in tropical Africa, Amazonia is weakening at a faster rate.

But decline has also begun in Africa. In the 1990s, the undisturbed tropical forests alone inhaled 17% of human-made carbon dioxide emissions. In the decade just ended, this proportion fell to 6%.

Catastrophic prospect

In roughly the same period, the area of intact forest fell by 19%, and global carbon dioxide emissions rose by 46%. Even so, the tropical forests store 250 billion tonnes of carbon in their trees alone: 90 years of fossil fuel emissions at the present rate. So their sustained loss would be catastrophic.

“Intact tropical forests remain a vital carbon sink but this research reveals that unless policies are put in place to stabilise the Earth’s climate, it is only a matter of time until they are no longer able to sequester carbon,” said Simon Lewis, a geographer at the University of Leeds, and one of the authors.

“One big concern for the future of humanity is when carbon-cycle feedbacks really kick in, with nature switching from slowing climate change to accelerating it.

“After years of work deep in the Congo and Amazon rainforests, we’ve found one of the most worrying impacts of climate change has already begun.

“This is decades ahead of even the most pessimistic climate models. There is no time to lose in tackling climate change.” – Climate News Network

Climate change so far has meant more vigorous forest growth as greenhouse gases rise. The tropical forests may soon change that.

LONDON, 6 March, 2020 – Within about fifteen years, the great tropical forests of Amazonia and Africa could stop absorbing atmospheric carbon, and slowly start to release more carbon than growing trees can fix.

A team of scientists from 100 research institutions has looked at the evidence from pristine tracts of tropical forest to find that – overall – the foliage soaked up the most carbon, most efficiently, more than two decades ago.

Since then, the measured efficiency of the forests as a “sink” in which carbon is sequestered from the atmosphere has been dwindling. By the last decade, the ability of a tropical forest to absorb carbon had dropped by a third.

All plant growth is a balancing act based on sunshine and atmospheric carbon and rainfall. Plants absorb carbon dioxide as they grow, and surrender it as they die.

In a dense, undisturbed wilderness, fallen leaves and even fallen trees are slightly less likely to decompose completely: the atmospheric carbon in leaf and wood form has a better chance of being preserved in flooded forests as peat, or being buried before it can completely decompose.

The forest becomes a bank vault, repository or sink of the extra carbon that humans are now spilling into the atmosphere from car exhausts, factory chimneys and power station furnaces.

Theory and practice

And in theory, as more and more carbon dioxide gets into the atmosphere, plants respond to the more generous fertilisation by growing more vigorously, and absorbing more carbon.

But as more carbon gets into the atmosphere, the temperature rises and weather patterns begin to become more extreme. Summers get hotter, rainfall more capricious. Then trees become vulnerable to drought, forest fire and invasive diseases, and die more often, and decompose more completely.

Wannes Hubau, once of the University of Leeds in the UK and now at the Royal Museum for Central Africa in Belgium, and more than 100 colleagues from around the world, report in the journal Nature that they assembled 30 years of measurement from more than 300,000 trees in 244 undisturbed plots of forest in 11 countries in Africa, and from 321 plots of forest in Amazonia, and did the sums.

In the 1990s, intact tropical forests removed around 46 billion tonnes of carbon dioxide from the atmosphere. By the 2010s, the uptake had fallen to around 25 billion tonnes. This means that 21 billion tons of greenhouse gas that might otherwise have been turned into timber and root had been added to the atmosphere.

This is pretty much what the UK, France, Germany and Canada together spilled into the atmosphere from fossil fuel combustion over a 10-year period.

“We’ve found one of the most worrying impacts of climate change has already begun. This is decades ahead of even the most pessimistic climate models”

“Extra carbon boosts tree growth, but every year this effect is being increasingly countered by the negative impacts of higher temperatures and droughts which slow growth and can kill trees,” said Dr Hubau.

“Our modeling shows a long-term decline in the African sink and that the Amazon sink will continue to rapidly weaken, which we predict will become a carbon source in the mid-2030s.”

Tropical forests are an integral factor in the planetary carbon budget – a crude accounting system that climate scientists rely upon to model the choice of futures that face humankind as the world heats up.

Around half of Earth’s carbon is stored in terrestrial vegetation and the tropical forests account for about a third of the planet’s primary productivity. So how forests respond to a warmer world is vital.

Because the Amazon region is being hit by higher temperatures, and more frequent and prolonged droughts than forests in tropical Africa, Amazonia is weakening at a faster rate.

But decline has also begun in Africa. In the 1990s, the undisturbed tropical forests alone inhaled 17% of human-made carbon dioxide emissions. In the decade just ended, this proportion fell to 6%.

Catastrophic prospect

In roughly the same period, the area of intact forest fell by 19%, and global carbon dioxide emissions rose by 46%. Even so, the tropical forests store 250 billion tonnes of carbon in their trees alone: 90 years of fossil fuel emissions at the present rate. So their sustained loss would be catastrophic.

“Intact tropical forests remain a vital carbon sink but this research reveals that unless policies are put in place to stabilise the Earth’s climate, it is only a matter of time until they are no longer able to sequester carbon,” said Simon Lewis, a geographer at the University of Leeds, and one of the authors.

“One big concern for the future of humanity is when carbon-cycle feedbacks really kick in, with nature switching from slowing climate change to accelerating it.

“After years of work deep in the Congo and Amazon rainforests, we’ve found one of the most worrying impacts of climate change has already begun.

“This is decades ahead of even the most pessimistic climate models. There is no time to lose in tackling climate change.” – Climate News Network