Category Archives: Nature

Save wildlife, save forests, and avoid pandemics

Covid-19 emerged from the wilderness. That alone is reason to protect the forests, control trade in wildlife – and avoid pandemics.

LONDON, 5 August, 2020 – If the world wants to avoid pandemics like Covid-19 in future, it has a lot to learn. This coronavirus outbreak is likely to cost the world somewhere between $8 trillion and $15 trillion.

It might have been 500 times cheaper, say US scientists, simply to have done what conservationists have sought for years: control trade in wildlife and stop destroying tropical forests.

The SARS-CoV-2 virus – also known as Covid-19 – is a new human infection that has been traced back to bats apparently traded as food in China. It has so far infected 15 million people around the planet and caused nearly 700,000 deaths.

But it is just one of a series of viruses that have emerged from creatures in the wilderness, to cause a series of local or global epidemics: among them HIV, Ebola, MERS, SARS and H1N1.

Researchers calculate that, for the last century, at least two new viruses each year have spilled from their natural hosts into the human population.

“Nothing seems more prudent than to give ourselves time to deal with this pandemic before the next one comes”

And this has happened, they argue in the journal Science, most often directly after people have handled live primates, bats and other mammals, or butchered them for meat, or indirectly after such viruses have infected farm animals such as chickens or pigs.

These infections are now so familiar they have acquired their own medical classification: they are zoonotic viruses.

And human exploitation of the world’s last remaining wildernesses – the tropical forests – and pursuit of exotic creatures for trophies, medicines or food can be linked to the emergence of most of them.

“All this traces back to our indifference about what has been happening at the edge of the tropical forests,” said Les Kaufman, an ecologist at Boston University.

He and 17 other experts argue that at a cost of somewhere between $22 billion and $30 billion a year, the transmission of unknown and unexpected diseases could be significantly reduced: chiefly by controlling logging and conversion of rainforest into ranch land, and limiting the trade in wild meat and exotic animals.

Clear argument

The sums are large. But the cost of the COVID-19 pandemic so far is likely to prove at least 500 times more costly.

Professor Kaufman and his colleagues did the calculations. They added up the annual costs of monitoring the world’s wildlife trade; of active programmes to prevent what they call “spillovers” from wild creatures; of efforts to detect and control outbreaks; the cost of reducing infection to human populations and farmed livestock; the cost of reducing deforestation each year by half, and the cost of ending the trade in wild meat in China. Their highest estimate was $31.2bn a year, their lowest $22bn.

They offset this with the benefits simply in the reduction of carbon dioxide emissions linked to forest destruction, and then matched the total against the global loss of gross domestic product, the cost of the estimated 590,000 dead from the virus at the end of July, and so on, to arrive at a minimum cost of $8.1 trillion, and a maximum of $15.8tn.

The researchers see this balance of costs as a clear argument for international and concerted action from governments around the world to reduce an enduring hazard.

“The pandemic gives an incentive to do something addressing concerns that are immediate and threatening to individuals, and that’s what moves people,” Professor Kaufman said. “Nothing seems more prudent than to give ourselves time to deal with this pandemic before the next one comes.” – Climate News Network

Covid-19 emerged from the wilderness. That alone is reason to protect the forests, control trade in wildlife – and avoid pandemics.

LONDON, 5 August, 2020 – If the world wants to avoid pandemics like Covid-19 in future, it has a lot to learn. This coronavirus outbreak is likely to cost the world somewhere between $8 trillion and $15 trillion.

It might have been 500 times cheaper, say US scientists, simply to have done what conservationists have sought for years: control trade in wildlife and stop destroying tropical forests.

The SARS-CoV-2 virus – also known as Covid-19 – is a new human infection that has been traced back to bats apparently traded as food in China. It has so far infected 15 million people around the planet and caused nearly 700,000 deaths.

But it is just one of a series of viruses that have emerged from creatures in the wilderness, to cause a series of local or global epidemics: among them HIV, Ebola, MERS, SARS and H1N1.

Researchers calculate that, for the last century, at least two new viruses each year have spilled from their natural hosts into the human population.

“Nothing seems more prudent than to give ourselves time to deal with this pandemic before the next one comes”

And this has happened, they argue in the journal Science, most often directly after people have handled live primates, bats and other mammals, or butchered them for meat, or indirectly after such viruses have infected farm animals such as chickens or pigs.

These infections are now so familiar they have acquired their own medical classification: they are zoonotic viruses.

And human exploitation of the world’s last remaining wildernesses – the tropical forests – and pursuit of exotic creatures for trophies, medicines or food can be linked to the emergence of most of them.

“All this traces back to our indifference about what has been happening at the edge of the tropical forests,” said Les Kaufman, an ecologist at Boston University.

He and 17 other experts argue that at a cost of somewhere between $22 billion and $30 billion a year, the transmission of unknown and unexpected diseases could be significantly reduced: chiefly by controlling logging and conversion of rainforest into ranch land, and limiting the trade in wild meat and exotic animals.

Clear argument

The sums are large. But the cost of the COVID-19 pandemic so far is likely to prove at least 500 times more costly.

Professor Kaufman and his colleagues did the calculations. They added up the annual costs of monitoring the world’s wildlife trade; of active programmes to prevent what they call “spillovers” from wild creatures; of efforts to detect and control outbreaks; the cost of reducing infection to human populations and farmed livestock; the cost of reducing deforestation each year by half, and the cost of ending the trade in wild meat in China. Their highest estimate was $31.2bn a year, their lowest $22bn.

They offset this with the benefits simply in the reduction of carbon dioxide emissions linked to forest destruction, and then matched the total against the global loss of gross domestic product, the cost of the estimated 590,000 dead from the virus at the end of July, and so on, to arrive at a minimum cost of $8.1 trillion, and a maximum of $15.8tn.

The researchers see this balance of costs as a clear argument for international and concerted action from governments around the world to reduce an enduring hazard.

“The pandemic gives an incentive to do something addressing concerns that are immediate and threatening to individuals, and that’s what moves people,” Professor Kaufman said. “Nothing seems more prudent than to give ourselves time to deal with this pandemic before the next one comes.” – Climate News Network

Rising heat affects Europe’s floods and droughts

Patterns of Europe’s floods and droughts are starting to change: each could be more extreme, and far likelier with rising heat.

LONDON, 27 July, 2020 − Climate change has begun to affect the pattern of Europe’s floods. The past three decades have seen “exceptional” flooding, say Austrian scientists who have worked their way through documentary records for the last 500 years.

At the same time, heat and drought affecting the continent are on the increase. The summer of 2018 broke all records for Germany, Austria and Switzerland, and by 2019 many trees in Europe’s forests were partly or entirely dead. And by 2085 rainfall could decline by a fifth, Swiss ecologists report, to alter the make-up of the forests dramatically.

Both findings are consistent with the big picture of climate change worldwide: wet seasons will become ever wetter; dry seasons too will become more extreme, according to US researchers in a third separate study.

All attempts to establish climate records involve careful interrogation of the past. Günter Blöschl of Vienna’s University of Technology and colleagues report in Nature that they sifted evidence from mountain lake beds, floodplains and 500 years of contemporary documents to identify decades more than usually rich in floods.

The floods of 1990 to 2016 in Western and Central Europe have been among the worst in history. To make sure of such a claim, the researchers identified periods of calamitous inundation across the whole region in the late 16th century and again in the 17th; and in the 18th and early 19th centuries.

“We should be preparing for the future by improving the technology to efficiently use water for crops”

If these episodes had anything in common, bygone floods happened when air temperatures were lower: fewer of them, too, happened in the summer.

“This finding seems to contradict the observation that, in some areas such as in the northwest of Europe, the recent warmer climate is aligned with larger floods,” Professor Blöschl said. “Our study shows for the first time that the underlying mechanisms have changed.

“While in the past floods have occurred more frequently under colder conditions, the opposite is the case now. The hydrological conditions of the present are very different from those in the past.”

Now, 55% of Central European floods happen in the summer, compared with 41% in previous centuries. It’s a message for planners, city chiefs and governments across the region: flood management is going to have to adapt.

So, too, is forest and woodland management, say scientists in Switzerland and Germany, who have been measuring changes in the canopies of their forests.

Growing vulnerability

For most of Europe, the single most extreme heatwave has been that of 2003: that is, until 2018. The sustained heat and aridity made temperatures in the growing season of 2018 on average 1.2°C higher than 2003, and 3.3°C higher than the average from 1961-1990.

Woodland foliage showed signs of drought stress. Leaves wilted, aged and dropped much earlier, and by 2019 many trees were dead, or partly dead. Those that survived were more vulnerable to beetle or fungal pests. Losses included beech, long considered the most drought-resistant.

Ten out of the 12 hottest growing seasons in the last 120 years have all happened this century. Climate forecasts already predict more of the same, with precipitation falling by a fifth by 2085. Foresters will have to think again about woodland design.

“Spruce was most heavily affected. But it was a surprise for us that beech, silver fir and pine were also damaged to this extent,” said Ansgar Kahmen of the University of Basel in Switzerland.

“We still need to study which tree species are good in which combinations, including from a forestry perspective. That will take time.”

Keeping Paris promise

And worldwide, farmers, foresters and water managers can also expect more of the same. As temperatures rise worldwide, dry seasons will tend to become drier, and wet seasons wetter.

US researchers report in the journal Nature Communications that they divided the world into nine land regions, and looked at annual rain or snowfall and how this fluctuated through the seasons in each of the nine from 1971 to 2000. They then looked at future temperature predictions for the rest of the century to see what happened to water availability.

The best outcome for relatively stable water supplies would be if nations could act to limit the planet’s average global temperature rise to no more than 2°C by 2100, in line with a promise made by 195 governments in Paris in 2015.

At higher temperatures the predicted scatter of flood and drought became more extreme. Once again, the message is: start planning. “We need to take precautions to optimally use how much water we have,” said Ashok Mishra of Clemson University in South Carolina.

“As the climate changes and population increases, we should be preparing for the future by improving the technology to efficiently use water for crops.” − Climate News Network

Patterns of Europe’s floods and droughts are starting to change: each could be more extreme, and far likelier with rising heat.

LONDON, 27 July, 2020 − Climate change has begun to affect the pattern of Europe’s floods. The past three decades have seen “exceptional” flooding, say Austrian scientists who have worked their way through documentary records for the last 500 years.

At the same time, heat and drought affecting the continent are on the increase. The summer of 2018 broke all records for Germany, Austria and Switzerland, and by 2019 many trees in Europe’s forests were partly or entirely dead. And by 2085 rainfall could decline by a fifth, Swiss ecologists report, to alter the make-up of the forests dramatically.

Both findings are consistent with the big picture of climate change worldwide: wet seasons will become ever wetter; dry seasons too will become more extreme, according to US researchers in a third separate study.

All attempts to establish climate records involve careful interrogation of the past. Günter Blöschl of Vienna’s University of Technology and colleagues report in Nature that they sifted evidence from mountain lake beds, floodplains and 500 years of contemporary documents to identify decades more than usually rich in floods.

The floods of 1990 to 2016 in Western and Central Europe have been among the worst in history. To make sure of such a claim, the researchers identified periods of calamitous inundation across the whole region in the late 16th century and again in the 17th; and in the 18th and early 19th centuries.

“We should be preparing for the future by improving the technology to efficiently use water for crops”

If these episodes had anything in common, bygone floods happened when air temperatures were lower: fewer of them, too, happened in the summer.

“This finding seems to contradict the observation that, in some areas such as in the northwest of Europe, the recent warmer climate is aligned with larger floods,” Professor Blöschl said. “Our study shows for the first time that the underlying mechanisms have changed.

“While in the past floods have occurred more frequently under colder conditions, the opposite is the case now. The hydrological conditions of the present are very different from those in the past.”

Now, 55% of Central European floods happen in the summer, compared with 41% in previous centuries. It’s a message for planners, city chiefs and governments across the region: flood management is going to have to adapt.

So, too, is forest and woodland management, say scientists in Switzerland and Germany, who have been measuring changes in the canopies of their forests.

Growing vulnerability

For most of Europe, the single most extreme heatwave has been that of 2003: that is, until 2018. The sustained heat and aridity made temperatures in the growing season of 2018 on average 1.2°C higher than 2003, and 3.3°C higher than the average from 1961-1990.

Woodland foliage showed signs of drought stress. Leaves wilted, aged and dropped much earlier, and by 2019 many trees were dead, or partly dead. Those that survived were more vulnerable to beetle or fungal pests. Losses included beech, long considered the most drought-resistant.

Ten out of the 12 hottest growing seasons in the last 120 years have all happened this century. Climate forecasts already predict more of the same, with precipitation falling by a fifth by 2085. Foresters will have to think again about woodland design.

“Spruce was most heavily affected. But it was a surprise for us that beech, silver fir and pine were also damaged to this extent,” said Ansgar Kahmen of the University of Basel in Switzerland.

“We still need to study which tree species are good in which combinations, including from a forestry perspective. That will take time.”

Keeping Paris promise

And worldwide, farmers, foresters and water managers can also expect more of the same. As temperatures rise worldwide, dry seasons will tend to become drier, and wet seasons wetter.

US researchers report in the journal Nature Communications that they divided the world into nine land regions, and looked at annual rain or snowfall and how this fluctuated through the seasons in each of the nine from 1971 to 2000. They then looked at future temperature predictions for the rest of the century to see what happened to water availability.

The best outcome for relatively stable water supplies would be if nations could act to limit the planet’s average global temperature rise to no more than 2°C by 2100, in line with a promise made by 195 governments in Paris in 2015.

At higher temperatures the predicted scatter of flood and drought became more extreme. Once again, the message is: start planning. “We need to take precautions to optimally use how much water we have,” said Ashok Mishra of Clemson University in South Carolina.

“As the climate changes and population increases, we should be preparing for the future by improving the technology to efficiently use water for crops.” − Climate News Network

Food shortage may finish polar bears by 2100

How long polar bears can survive depends on how long they can last without food. And that may be: not long enough.

LONDON, 24 July, 2020 − As the Arctic sea ice dwindles, so will hope for the region’s most dramatic predator, its polar bears. A creature fashioned by evolution to fast a whole summer and gorge through the autumn and winter may not last, as the ice melts ever earlier and forms ever later.

That is because Ursus maritimus can find the food for the next generation of its cubs only by prowling the firm sea ice for a high-calorie diet of seal flesh and blubber.

And now a team of Canadian and US scientists has begun to establish the unknown of polar bear survival: how many days the creature can survive without food and still nourish its young and sustain life.

They call this the “fasting impact threshold” and the answer, they report in the journal Nature Climate Change, is not encouraging.

“Polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist”

If warming continues at the present rate, then by the century’s end most of the sub-populations of this charismatic animal will not survive.

“The challenge is that the Arctic ice will keep disappearing as the world continues to warm,” said Péter Molnár, of the University of Toronto Scarborough, who led the research.

“This means polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist as healthy populations.”

The researchers had to start with one big uncertainty: how much stored energy the bear has when the fasting season begins. Because the shelf ice has been thinning and shrinking for more than 40 years, hunting seasons have become shorter and bears now spend longer and longer on land.

Natural variability

That raised a second factor: some parts of the Arctic lose ice earlier than others. The third unknown is the health of the 19 sub-populations of Ursus maritimus, spread over four distinct eco-regions within the Arctic Circle, and how these separate populations would consider a “good” hunting season and a happy period of fasting.

In the southern Beaufort Sea, fewer than 127 ice-free days could be considered “good”, but even this seemingly assured number was based on only five years of systematic demographic data.

And then the researchers had to calculate the demands placed on individual bears: an adult male might be able to last 200 days; a solitary adult female up to 255 days. But a mother bear might begin to lose what it takes to get cubs through to maturity as early as 117 days, and certainly after 228 days.

But however incomplete, the scientists had data for about 80% of the polar bear populations, collected between 1979 and 2016, and report that what they politely call “recruitment and survival impact thresholds” may have already been exceeded in some populations.

Too hopeful?

That is, there are increasing numbers of bears in the Arctic no longer sure of having cubs or keeping them alive. That includes the polar bears of Hudson Bay and the Davis Strait in northern Canada: perhaps the most photographed bears in the world.

And if the world goes on warming, only a few creatures in the very high Arctic will see the next century.

“While our projections for the future of polar bears seem dire, the unfortunate thing is they might even be too optimistic. For example, we assumed that polar bears will use their available body energy in optimal ways when fasting. If that isn’t the case, the reality could be worse than our projections,” Dr Molnár said.

“What we do know is that becoming fat before a fasting season will be more difficult for polar bears as on-ice hunting seasons become shorter, so it’s likely that fasting impact thresholds will be crossed in the early years of our projected range.” − Climate News Network

How long polar bears can survive depends on how long they can last without food. And that may be: not long enough.

LONDON, 24 July, 2020 − As the Arctic sea ice dwindles, so will hope for the region’s most dramatic predator, its polar bears. A creature fashioned by evolution to fast a whole summer and gorge through the autumn and winter may not last, as the ice melts ever earlier and forms ever later.

That is because Ursus maritimus can find the food for the next generation of its cubs only by prowling the firm sea ice for a high-calorie diet of seal flesh and blubber.

And now a team of Canadian and US scientists has begun to establish the unknown of polar bear survival: how many days the creature can survive without food and still nourish its young and sustain life.

They call this the “fasting impact threshold” and the answer, they report in the journal Nature Climate Change, is not encouraging.

“Polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist”

If warming continues at the present rate, then by the century’s end most of the sub-populations of this charismatic animal will not survive.

“The challenge is that the Arctic ice will keep disappearing as the world continues to warm,” said Péter Molnár, of the University of Toronto Scarborough, who led the research.

“This means polar bears everywhere will face longer periods without food, and this will affect their ability to reproduce, survive and persist as healthy populations.”

The researchers had to start with one big uncertainty: how much stored energy the bear has when the fasting season begins. Because the shelf ice has been thinning and shrinking for more than 40 years, hunting seasons have become shorter and bears now spend longer and longer on land.

Natural variability

That raised a second factor: some parts of the Arctic lose ice earlier than others. The third unknown is the health of the 19 sub-populations of Ursus maritimus, spread over four distinct eco-regions within the Arctic Circle, and how these separate populations would consider a “good” hunting season and a happy period of fasting.

In the southern Beaufort Sea, fewer than 127 ice-free days could be considered “good”, but even this seemingly assured number was based on only five years of systematic demographic data.

And then the researchers had to calculate the demands placed on individual bears: an adult male might be able to last 200 days; a solitary adult female up to 255 days. But a mother bear might begin to lose what it takes to get cubs through to maturity as early as 117 days, and certainly after 228 days.

But however incomplete, the scientists had data for about 80% of the polar bear populations, collected between 1979 and 2016, and report that what they politely call “recruitment and survival impact thresholds” may have already been exceeded in some populations.

Too hopeful?

That is, there are increasing numbers of bears in the Arctic no longer sure of having cubs or keeping them alive. That includes the polar bears of Hudson Bay and the Davis Strait in northern Canada: perhaps the most photographed bears in the world.

And if the world goes on warming, only a few creatures in the very high Arctic will see the next century.

“While our projections for the future of polar bears seem dire, the unfortunate thing is they might even be too optimistic. For example, we assumed that polar bears will use their available body energy in optimal ways when fasting. If that isn’t the case, the reality could be worse than our projections,” Dr Molnár said.

“What we do know is that becoming fat before a fasting season will be more difficult for polar bears as on-ice hunting seasons become shorter, so it’s likely that fasting impact thresholds will be crossed in the early years of our projected range.” − Climate News Network

Heat may leave tropical trees unable to germinate

If a plant can’t germinate, it’s heading for extinction. For many tropical trees, conditions could soon become too hot to procreate.

LONDON, 14 July, 2020 – There could soon be real trouble for tropical trees and other plants. As global average temperatures rise, in response to ever more profligate use of fossil fuels, it may for some species become too hot to successfully germinate.

The foliage most at risk from this thermal barrier to reproduction is certain to be in the tropics, where tens of thousands of plant species have already adapted to very nearly the limits of their tolerance.

Australian researchers report in the journal Global Ecology and Biogeography that they looked at 9,737 records for 1,312 species worldwide from the Kew Gardens’ global germination database, to work out the temperature ranges that suit germination.

They report that the closer to the equator, the more the risk that by 2070 temperatures could rise high enough to exceed the ceiling below which germination is possible.

More than half of all the tropical seedlings tested – 79 out of 142 – would experience temperatures higher than the optimum for breeding. And 41 out of 190 would meet temperatures that would be higher than the maximum at which seeds would germinate.

Survival impossible

“These plants are more at risk because they are near their upper limits. So even a small increase in temperature from climate change could push them over the edge,” said Alexander Sentinella, of the University of New South Wales, who led the study.

“The figures are quite shocking because by 2070 more than 20% of tropical plant species, we predict, will face temperatures above their upper limit, which means they won’t germinate, and so can’t survive.”

The world’s tropical forests are already in trouble. Altogether there could be three trillion trees on the planet, and humans are already removing 15 billion a year. The richest habitats are in the tropics.

There could be 40,000 species of tree that flourish in the equatorial forests, and half of these have already been pronounced threatened. The hot moist forests provide cover for myriad smaller shrubs and plants under the canopy, and they flourish alongside a mosaic of wetland and grassland habitats to support some of the richest biodiversity on the planet.

The forests and the plants in them absorb a high proportion of the extra carbon dioxide emitted from power station and vehicle exhausts, they serve as a sponge to store rainy season water, and they recycle the planet’s oxygen. They are under increasing stress from human exploitation and climate change.

“These plants are more at risk because they are near their upper limits. So even a small increase in temperature from climate change could push them over the edge”

Higher temperatures mean greater extremes of windstorm that can severely damage whole forests; higher temperatures mean more intense droughts and greater fire hazard; climate change has begun to alter the mix, variety and abundance of tree species both in the tropics and worldwide; and where they can, tropical species have already begun to colonise higher ground to stay within suitable temperature boundaries.

So the realisation that plant species – like animals on land and fish in the oceans – may be most vulnerable at a key moment of the life cycle is even more bad news. Many species will still be able to reproduce, but if they have already gone beyond the optimum for germination, then the success rate will be smaller.

The news on a global scale is more encouraging: the researchers found that 95% of species at latitudes higher than 45° could actually benefit from global warming, because temperatures could shift more closely to the optimum for many temperate and cool zone plants. And some plant species may evolve as temperatures rise. But many will not adapt in time to rapidly-rising global temperatures.

“There are almost 400,000 plant species worldwide – so we would expect a number of them to fail to germinate between now and 2070,” Sentinella said.

“Humans have known about the dangers of climate change for decades, and we already have the answers to tackle it. Hopefully, our study will encourage people and policymakers to take action now.” – Climate News Network

If a plant can’t germinate, it’s heading for extinction. For many tropical trees, conditions could soon become too hot to procreate.

LONDON, 14 July, 2020 – There could soon be real trouble for tropical trees and other plants. As global average temperatures rise, in response to ever more profligate use of fossil fuels, it may for some species become too hot to successfully germinate.

The foliage most at risk from this thermal barrier to reproduction is certain to be in the tropics, where tens of thousands of plant species have already adapted to very nearly the limits of their tolerance.

Australian researchers report in the journal Global Ecology and Biogeography that they looked at 9,737 records for 1,312 species worldwide from the Kew Gardens’ global germination database, to work out the temperature ranges that suit germination.

They report that the closer to the equator, the more the risk that by 2070 temperatures could rise high enough to exceed the ceiling below which germination is possible.

More than half of all the tropical seedlings tested – 79 out of 142 – would experience temperatures higher than the optimum for breeding. And 41 out of 190 would meet temperatures that would be higher than the maximum at which seeds would germinate.

Survival impossible

“These plants are more at risk because they are near their upper limits. So even a small increase in temperature from climate change could push them over the edge,” said Alexander Sentinella, of the University of New South Wales, who led the study.

“The figures are quite shocking because by 2070 more than 20% of tropical plant species, we predict, will face temperatures above their upper limit, which means they won’t germinate, and so can’t survive.”

The world’s tropical forests are already in trouble. Altogether there could be three trillion trees on the planet, and humans are already removing 15 billion a year. The richest habitats are in the tropics.

There could be 40,000 species of tree that flourish in the equatorial forests, and half of these have already been pronounced threatened. The hot moist forests provide cover for myriad smaller shrubs and plants under the canopy, and they flourish alongside a mosaic of wetland and grassland habitats to support some of the richest biodiversity on the planet.

The forests and the plants in them absorb a high proportion of the extra carbon dioxide emitted from power station and vehicle exhausts, they serve as a sponge to store rainy season water, and they recycle the planet’s oxygen. They are under increasing stress from human exploitation and climate change.

“These plants are more at risk because they are near their upper limits. So even a small increase in temperature from climate change could push them over the edge”

Higher temperatures mean greater extremes of windstorm that can severely damage whole forests; higher temperatures mean more intense droughts and greater fire hazard; climate change has begun to alter the mix, variety and abundance of tree species both in the tropics and worldwide; and where they can, tropical species have already begun to colonise higher ground to stay within suitable temperature boundaries.

So the realisation that plant species – like animals on land and fish in the oceans – may be most vulnerable at a key moment of the life cycle is even more bad news. Many species will still be able to reproduce, but if they have already gone beyond the optimum for germination, then the success rate will be smaller.

The news on a global scale is more encouraging: the researchers found that 95% of species at latitudes higher than 45° could actually benefit from global warming, because temperatures could shift more closely to the optimum for many temperate and cool zone plants. And some plant species may evolve as temperatures rise. But many will not adapt in time to rapidly-rising global temperatures.

“There are almost 400,000 plant species worldwide – so we would expect a number of them to fail to germinate between now and 2070,” Sentinella said.

“Humans have known about the dangers of climate change for decades, and we already have the answers to tackle it. Hopefully, our study will encourage people and policymakers to take action now.” – Climate News Network

Warming oceans deter more fish from spawning

When the moment to mate arrives, fish like to play it cool. So warming oceans create special problems for the generation game.

LONDON, 9 July, 2020 – German scientists now know why so many fish are so vulnerable to ever-warming oceans. Global heating imposes a harsh cost at the most critical time of all: the moment of spawning.

“Our findings show that, both as embryos in eggs and as adults ready to mate, fish are far more sensitive to heat than in their larval stage or as sexually mature adults outside the mating season,” said Flemming Dahlke, a marine biologist with the Alfred Wegener Institute at Bremerhaven.

“On the global average, for example, adults outside the mating season can survive in water that’s up to 10°C warmer than adults ready to mate, or fish eggs, can.”

The finding – if it is confirmed by other research – should clear up some of the puzzles associated with fish numbers. There is clear evidence, established repeatedly over the decades, that fish are responding to climate change.

But almost three fourths of the planet is blue ocean, and at depth is responding far more slowly than the land surface to global heating fuelled by fossil fuel exploitation that releases greenhouse gases.

Nearing the brink

Since fish in the temperate zones already experience a wide variation in seasonal water temperatures, it hasn’t been obvious why species such as cod have shifted nearer the Arctic, and sardines have migrated to the North Sea.

But marine creatures are on the move, and although there are other factors at work, including overfishing and the increasingly alarming changes in ocean chemistry, thanks to ever-higher levels of dissolved carbon dioxide, temperature change is part of the problem.

The latest answer, Dr Dahlke and his colleagues report in the journal Science, is that many fish may already be living near the limits of their thermal tolerance.

The temperature safety margins during the moments of spawning and embryo might be very precise, and over hundreds of thousands of years of evolution, marine and freshwater species have worked out just what is best for the next generation. Rapid global warming upsets this equilibrium.

“Adults outside the mating season can survive in water that’s up to 10°C warmer than adults ready to mate, or fish eggs, can”

The Bremerhaven scientists looked at experiments, observations and recorded data for the life cycles of 694 marine and freshwater species, to decide that oxygen supply is the key decider of reproductive success. Warmer waters carry less dissolved oxygen. Embryo fish have no gills: they cannot simply take in deeper breaths.

Fish about to mate are busy producing extra mass in the form of sperm and egg cells: this additional body mass also needs oxygen. Even at lower temperatures, piscine cardiovascular systems are under stress.

So the reasoning follows that, if global heating continues, climate change and rising water temperatures are likely to affect the reproduction of perhaps 60% of all fish species.

“Some species might successfully manage this change,” Dr Dahlke said.
“But if you consider the fact that fish have adapted their mating patterns to specific habitats over extremely long timeframes, and have tailored their mating cycles of specific ocean currents and food sources, it has to be assumed that being forced to abandon their normal spawning areas will mean major problems for them.” – Climate News Network

When the moment to mate arrives, fish like to play it cool. So warming oceans create special problems for the generation game.

LONDON, 9 July, 2020 – German scientists now know why so many fish are so vulnerable to ever-warming oceans. Global heating imposes a harsh cost at the most critical time of all: the moment of spawning.

“Our findings show that, both as embryos in eggs and as adults ready to mate, fish are far more sensitive to heat than in their larval stage or as sexually mature adults outside the mating season,” said Flemming Dahlke, a marine biologist with the Alfred Wegener Institute at Bremerhaven.

“On the global average, for example, adults outside the mating season can survive in water that’s up to 10°C warmer than adults ready to mate, or fish eggs, can.”

The finding – if it is confirmed by other research – should clear up some of the puzzles associated with fish numbers. There is clear evidence, established repeatedly over the decades, that fish are responding to climate change.

But almost three fourths of the planet is blue ocean, and at depth is responding far more slowly than the land surface to global heating fuelled by fossil fuel exploitation that releases greenhouse gases.

Nearing the brink

Since fish in the temperate zones already experience a wide variation in seasonal water temperatures, it hasn’t been obvious why species such as cod have shifted nearer the Arctic, and sardines have migrated to the North Sea.

But marine creatures are on the move, and although there are other factors at work, including overfishing and the increasingly alarming changes in ocean chemistry, thanks to ever-higher levels of dissolved carbon dioxide, temperature change is part of the problem.

The latest answer, Dr Dahlke and his colleagues report in the journal Science, is that many fish may already be living near the limits of their thermal tolerance.

The temperature safety margins during the moments of spawning and embryo might be very precise, and over hundreds of thousands of years of evolution, marine and freshwater species have worked out just what is best for the next generation. Rapid global warming upsets this equilibrium.

“Adults outside the mating season can survive in water that’s up to 10°C warmer than adults ready to mate, or fish eggs, can”

The Bremerhaven scientists looked at experiments, observations and recorded data for the life cycles of 694 marine and freshwater species, to decide that oxygen supply is the key decider of reproductive success. Warmer waters carry less dissolved oxygen. Embryo fish have no gills: they cannot simply take in deeper breaths.

Fish about to mate are busy producing extra mass in the form of sperm and egg cells: this additional body mass also needs oxygen. Even at lower temperatures, piscine cardiovascular systems are under stress.

So the reasoning follows that, if global heating continues, climate change and rising water temperatures are likely to affect the reproduction of perhaps 60% of all fish species.

“Some species might successfully manage this change,” Dr Dahlke said.
“But if you consider the fact that fish have adapted their mating patterns to specific habitats over extremely long timeframes, and have tailored their mating cycles of specific ocean currents and food sources, it has to be assumed that being forced to abandon their normal spawning areas will mean major problems for them.” – Climate News Network

Drought-hit forests may worsen climate change

Forests help to slow the challenge of climate change, don’t they? Only if climate change doesn’t fell the forests first.

LONDON, 7 July, 2020 − There could be big problems with national and international plans to plant forests to deal with climate change. One of them is uncertainty about how climate change is going to deal with the forests.

In six new studies of what might be called the plantation carbon conundrum, independent groups of researchers warn that:

That the loss of natural forests worldwide is a driver of global heating and climate change has never been in doubt. And climate scientists continue to count tomorrow’s forests as part of the answer to the threat of catastrophic climate change.

But researchers have already warned that a vow to plant one trillion trees is not of itself a readymade answer, and that national plans to conserve existing forest are less than effective.

So the challenge for foresters and ecologists is to decide what works best – and what would not. Researchers in the US argue in the journal Science that governments and policymakers need a masterplan to confront the risks forests face from the consequences of rising temperatures: drought, fire and insect disturbance.

Flying blind

Forests and other natural ecosystems absorb about one-third of all the greenhouse gas emissions that human actions release each year. New forests must be part of the answer, but only if the new timber goes on and on absorbing carbon.

“There’s a very real chance that many of those forest projects could go up in flames or to bugs or drought stress or hurricanes in the coming decades,” said William Anderegg of the University of Utah, who led the study. “Without good science to tell us what the risks are, we’re flying blind and not making the best policy decisions.”

The other papers look at aspects of the hazard, and of well-intentioned policies to combat climate change. The Bonn Challenge aims to restore an area of forest eight times the size of California, but 80% of the commitments so far involve plantations of single species or of exploitable species: fruit, for instance, and rubber on what might have been natural forest land, grassland or savannahs that support biodiversity.

Californian and Chilean researchers report in the journal Nature Sustainability that they looked at the role of long-running Chilean government subsidies in afforestation and found an uncomfortable result: exotic species flourished at the expense of native wilderness.

“Chile’s forest subsidies probably decreased biodiversity without increasing total carbon stored in aboveground biomass,” they conclude, bluntly. And one of the paper’s authors, Eric Lambin of Stanford University, spelled it out: “That’s the exact opposite of what these policies are aiming for.”

“Up until now, forests have stabilised the climate, but as they become more drought-stressed, they could become a destabilising carbon source”

German scientists report in the journal Basic and Applied Ecology that a warmer world has already delivered dramatic consequences for the forests of Germany, Austria and Switzerland.

The past five years have been the warmest in the region since records began, and 2018’s summer was the most extreme – 3.3°C above the long-term average. For spruce and other species that was the limit, and by 2019 even beech trees had died.

Since extreme drought and heat will become ever more likely, researchers need to decide what mix of species is going to survive and provide cover for threatened species. “This is going to take some time,” said Bernhard Schuldt, of the University of Würzburg.

Chinese and US researchers report in Nature Sustainability that they examined the same problems using a ground-up approach. They looked at 11,000 soil samples taken across 163 control and forested plots in northern China, to find that the carbon capture potential of afforestation schemes may have been overestimated. In soils low in carbon, plantation did increase the density of organic carbon. In those soils already rich in organic carbon, the planting seemed to lower carbon density.

European researchers, too, report in Science that they looked at data collected over 150 years at 6,000 locations to work out what happened to plants and animals as climate change and human intrusion transformed the world’s forests. Again, the answers are not simple.

No guarantee

“Surprisingly, we found that forest loss doesn’t always lead to biodiversity declines,” said Gergana Daskalova of the University of Edinburgh in Scotland. “Instead, when we lose forest cover, this can amplify the ongoing biodiversity change. For example, if a plant or animal species was declining before forest loss, its decline becomes even more severe.” Species already doing well, however, seemed to do better.

But there’s little guarantee that what works now will go on working, according to Arizona scientists writing in the journal Global Change Biology. So far, forests have helped contain climate change. But they found that North America’s most prolific tree, the Douglas fir, will absorb less carbon in future and do less to slow climate change.

They based their finding on examination of 2.7 million tree rings from 2,700 sites in the fir’s enormous ecological range. At the southern and warmest and driest end of this range, the decline in annual growth could be as high as 30%.

“More warming for trees could mean more stress, more tree death and less capacity to slow global warming,” said Margaret Evans, of the University of Arizona.

“Up until now, forests have stabilised the climate, but as they become more drought-stressed, they could become a destabilising carbon source.” − Climate News Network

Forests help to slow the challenge of climate change, don’t they? Only if climate change doesn’t fell the forests first.

LONDON, 7 July, 2020 − There could be big problems with national and international plans to plant forests to deal with climate change. One of them is uncertainty about how climate change is going to deal with the forests.

In six new studies of what might be called the plantation carbon conundrum, independent groups of researchers warn that:

That the loss of natural forests worldwide is a driver of global heating and climate change has never been in doubt. And climate scientists continue to count tomorrow’s forests as part of the answer to the threat of catastrophic climate change.

But researchers have already warned that a vow to plant one trillion trees is not of itself a readymade answer, and that national plans to conserve existing forest are less than effective.

So the challenge for foresters and ecologists is to decide what works best – and what would not. Researchers in the US argue in the journal Science that governments and policymakers need a masterplan to confront the risks forests face from the consequences of rising temperatures: drought, fire and insect disturbance.

Flying blind

Forests and other natural ecosystems absorb about one-third of all the greenhouse gas emissions that human actions release each year. New forests must be part of the answer, but only if the new timber goes on and on absorbing carbon.

“There’s a very real chance that many of those forest projects could go up in flames or to bugs or drought stress or hurricanes in the coming decades,” said William Anderegg of the University of Utah, who led the study. “Without good science to tell us what the risks are, we’re flying blind and not making the best policy decisions.”

The other papers look at aspects of the hazard, and of well-intentioned policies to combat climate change. The Bonn Challenge aims to restore an area of forest eight times the size of California, but 80% of the commitments so far involve plantations of single species or of exploitable species: fruit, for instance, and rubber on what might have been natural forest land, grassland or savannahs that support biodiversity.

Californian and Chilean researchers report in the journal Nature Sustainability that they looked at the role of long-running Chilean government subsidies in afforestation and found an uncomfortable result: exotic species flourished at the expense of native wilderness.

“Chile’s forest subsidies probably decreased biodiversity without increasing total carbon stored in aboveground biomass,” they conclude, bluntly. And one of the paper’s authors, Eric Lambin of Stanford University, spelled it out: “That’s the exact opposite of what these policies are aiming for.”

“Up until now, forests have stabilised the climate, but as they become more drought-stressed, they could become a destabilising carbon source”

German scientists report in the journal Basic and Applied Ecology that a warmer world has already delivered dramatic consequences for the forests of Germany, Austria and Switzerland.

The past five years have been the warmest in the region since records began, and 2018’s summer was the most extreme – 3.3°C above the long-term average. For spruce and other species that was the limit, and by 2019 even beech trees had died.

Since extreme drought and heat will become ever more likely, researchers need to decide what mix of species is going to survive and provide cover for threatened species. “This is going to take some time,” said Bernhard Schuldt, of the University of Würzburg.

Chinese and US researchers report in Nature Sustainability that they examined the same problems using a ground-up approach. They looked at 11,000 soil samples taken across 163 control and forested plots in northern China, to find that the carbon capture potential of afforestation schemes may have been overestimated. In soils low in carbon, plantation did increase the density of organic carbon. In those soils already rich in organic carbon, the planting seemed to lower carbon density.

European researchers, too, report in Science that they looked at data collected over 150 years at 6,000 locations to work out what happened to plants and animals as climate change and human intrusion transformed the world’s forests. Again, the answers are not simple.

No guarantee

“Surprisingly, we found that forest loss doesn’t always lead to biodiversity declines,” said Gergana Daskalova of the University of Edinburgh in Scotland. “Instead, when we lose forest cover, this can amplify the ongoing biodiversity change. For example, if a plant or animal species was declining before forest loss, its decline becomes even more severe.” Species already doing well, however, seemed to do better.

But there’s little guarantee that what works now will go on working, according to Arizona scientists writing in the journal Global Change Biology. So far, forests have helped contain climate change. But they found that North America’s most prolific tree, the Douglas fir, will absorb less carbon in future and do less to slow climate change.

They based their finding on examination of 2.7 million tree rings from 2,700 sites in the fir’s enormous ecological range. At the southern and warmest and driest end of this range, the decline in annual growth could be as high as 30%.

“More warming for trees could mean more stress, more tree death and less capacity to slow global warming,” said Margaret Evans, of the University of Arizona.

“Up until now, forests have stabilised the climate, but as they become more drought-stressed, they could become a destabilising carbon source.” − Climate News Network

The wetter world ahead will suffer worse droughts

Things are bad now, but worse droughts are coming. More rain will fall in a warmer world, but not where and when we need it.

LONDON, 26 June, 2020 – Australian scientists have bad news for drought-stricken and fire-ravaged fellow-citizens: still worse droughts are in store.

Even though the world will grow wetter as greenhouse gas emissions rise and planetary average temperatures soar, the droughts will endure for longer and become more intense.

And this will be true not just for a country with a government that seems anxious not to acknowledge the role of climate change in a procession of disasters. It will be true for California and much of the US West. It will be true for the Mediterranean and parts of Africa, and for any areas that lie within the drylands zone.

It could be true even for the tropical rainforests. Wherever average rainfall seems to be in decline, droughts will become more devastating. And that includes Central America and the Amazon.

“The earlier we act on reducing our emissions, the less economic and social pain we will feel in the future”

And even in the rainy zones where precipitation seems to be on the rise, and floods more frequent, when droughts happen they will be more intense, according to new research in the journal Geophysical Research Letters.

The conclusion, although alarming, is not new. It reinforces decades of earlier research predicting that as the world warms floods, superstorms and megadroughts could all increase.

Every rise of 1°C in planetary average temperatures means that the atmosphere’s capacity to absorb water vapour also increases: for every 1°C rise, rainfall will increase by 2%, and with every average increase the extremes will become ever more extreme.

The latest finding is a test of new climate models to be used by the Intergovernmental Panel on Climate Change (IPCC). Between 1998 and 2017, according to UN data, droughts have afflicted 1.5bn people and accounted for a third of all natural disaster impacts.

Search for precision

What will happen as humans go on burning ever more fossil fuels to raise planetary average temperatures ever higher will mean ever more severe tests for farmers, pastoralists, industry, natural ecosystems and national economies.

The latest study is an attempt to be a little more precise about the shape of the future in a warming world.

“We found the new models produced the most robust results for future droughts to date and that the degree of increase in drought duration and intensity was directly linked to the amounts of greenhouse gases emitted into the atmosphere,” said Anna Ukkola of the Australian National University in Canberra, who led the study.

“However, while these insights grow clearer with each advance, the message they deliver remains the same – the earlier we act on reducing our emissions, the less economic and social pain we will feel in the future.” – Climate News Network

Things are bad now, but worse droughts are coming. More rain will fall in a warmer world, but not where and when we need it.

LONDON, 26 June, 2020 – Australian scientists have bad news for drought-stricken and fire-ravaged fellow-citizens: still worse droughts are in store.

Even though the world will grow wetter as greenhouse gas emissions rise and planetary average temperatures soar, the droughts will endure for longer and become more intense.

And this will be true not just for a country with a government that seems anxious not to acknowledge the role of climate change in a procession of disasters. It will be true for California and much of the US West. It will be true for the Mediterranean and parts of Africa, and for any areas that lie within the drylands zone.

It could be true even for the tropical rainforests. Wherever average rainfall seems to be in decline, droughts will become more devastating. And that includes Central America and the Amazon.

“The earlier we act on reducing our emissions, the less economic and social pain we will feel in the future”

And even in the rainy zones where precipitation seems to be on the rise, and floods more frequent, when droughts happen they will be more intense, according to new research in the journal Geophysical Research Letters.

The conclusion, although alarming, is not new. It reinforces decades of earlier research predicting that as the world warms floods, superstorms and megadroughts could all increase.

Every rise of 1°C in planetary average temperatures means that the atmosphere’s capacity to absorb water vapour also increases: for every 1°C rise, rainfall will increase by 2%, and with every average increase the extremes will become ever more extreme.

The latest finding is a test of new climate models to be used by the Intergovernmental Panel on Climate Change (IPCC). Between 1998 and 2017, according to UN data, droughts have afflicted 1.5bn people and accounted for a third of all natural disaster impacts.

Search for precision

What will happen as humans go on burning ever more fossil fuels to raise planetary average temperatures ever higher will mean ever more severe tests for farmers, pastoralists, industry, natural ecosystems and national economies.

The latest study is an attempt to be a little more precise about the shape of the future in a warming world.

“We found the new models produced the most robust results for future droughts to date and that the degree of increase in drought duration and intensity was directly linked to the amounts of greenhouse gases emitted into the atmosphere,” said Anna Ukkola of the Australian National University in Canberra, who led the study.

“However, while these insights grow clearer with each advance, the message they deliver remains the same – the earlier we act on reducing our emissions, the less economic and social pain we will feel in the future.” – Climate News Network

Nature’s accounts show what the world does for us

People go on getting richer, and the planet pays a mounting price. There’s a better way to balance nature’s accounts.

LONDON, 24 June, 2020 – It may take a while to catch on, but one day the financial pages of the daily newspaper could be quoting a new register of national wealth: called gross ecosystem product, this way of balancing nature’s accounts makes clear how much we really depend on the Earth.

And it would be a real-world indicator of prosperity you could have confidence in: a measure in cash terms of the health of the forests, rivers, lakes and wildlife of both nations and regions and – more precisely – of the benefits heedless humans take for granted.

These include the insect pollination of crops; the control of insect pests by birds and bats; the supply of fresh, safe water from mountain streams, rivers, springs and lakes; the management of waste by scavengers and microbes; the recycling of nutrients; and all the myriad services provided by plants, animals and topography. This is sometimes called “natural capital.”

The measure has already formally been tested in one province in China and matched with the more familiar indicator: Gross Domestic Product, or GDP.

Flying blind

Chinese scientists report in the Proceedings of the National Academy of Sciences that in the year 2000, the gross ecosystem product or GEP of Qinghai province was greater than its GDP.

By 2015, after phenomenal economic growth, it was still three-fourths the size of its GDP. And the form this natural wealth took? Mostly water supplies to other crowded regions: Qinghai is where the Mekong, the Yangtze and the Yellow Rivers rise.

“We’re basically flying blind when it comes to knowing where and how much nature to protect,” said Gretchen Daily, an environmental scientist at Stanford’s School of Humanities and Sciences in California, and one of the report’s authors.

“GEP tracks the vital contributions of nature to society, informs investments in securing them and helps evaluate the performance of leaders and policies.”

And her British co-author, Ian Bateman, an economist at the University of Exeter, said: “The global economy as conventionally measured by GDP more than doubled between 1990 and 2015. However, at the same time our stocks of ‘ecosystem assets’ – such as forests, grasslands, wetlands, fertile soils and biodiversity – have come under increasing pressure.”

“We were able to place a value on important ecosystem services, especially water supply, that Qinghai currently exports to other provinces but receives no credit for in the GDP calculation”

He continued: “These things are obviously valuable in many ways – including to human wellbeing. However, in this study we examine the benefits they bring us measured in a way that governments and business can understand.”

Naturalists, conservationists and economists have repeatedly argued that it makes better economic sense to conserve nature rather than to exploit it: untouched natural forest or grassland contributes more to everybody’s wealth than any clear-felling project or conversion to cattle-grazing.

Scientists and economists have again and again tried to calculate the cash value to humankind of nature’s goods and services, and to steer development in a sustainable fashion.

They have repeatedly warned that global heating driven by profligate use of fossil fuels is almost certain to hit the pockets of the poorest most cruelly.

And they have warned that uncontrolled exploitation of once untouched natural forests, mangrove estuaries, grasslands, wetlands and coral reefs that precipitates mass extinction of species is certain to impoverish billions in the long run.

Direct test

But to persuade governments that natural capital represents an investment with measurable returns, economists need a standard global measure. GEP could be it.

The measure was tested directly in what is sometimes called the “water tower” of Asia. The logic is that if the people of that region care for their natural habitat, and people downstream benefit directly from that care, then those downstream should also contribute to the costs of care.

“Qinghai is rich in natural capital but its GDP alone does not reflect that value”, said the study’s lead author, Zhiyun Ouyang, of the Chinese Academy of Sciences.

“Using this new metric we were able to place a value on important ecosystem services, especially water supply, that Qinghai currently exports to other provinces but receives no credit for in the GDP calculation.” – Climate News Network

People go on getting richer, and the planet pays a mounting price. There’s a better way to balance nature’s accounts.

LONDON, 24 June, 2020 – It may take a while to catch on, but one day the financial pages of the daily newspaper could be quoting a new register of national wealth: called gross ecosystem product, this way of balancing nature’s accounts makes clear how much we really depend on the Earth.

And it would be a real-world indicator of prosperity you could have confidence in: a measure in cash terms of the health of the forests, rivers, lakes and wildlife of both nations and regions and – more precisely – of the benefits heedless humans take for granted.

These include the insect pollination of crops; the control of insect pests by birds and bats; the supply of fresh, safe water from mountain streams, rivers, springs and lakes; the management of waste by scavengers and microbes; the recycling of nutrients; and all the myriad services provided by plants, animals and topography. This is sometimes called “natural capital.”

The measure has already formally been tested in one province in China and matched with the more familiar indicator: Gross Domestic Product, or GDP.

Flying blind

Chinese scientists report in the Proceedings of the National Academy of Sciences that in the year 2000, the gross ecosystem product or GEP of Qinghai province was greater than its GDP.

By 2015, after phenomenal economic growth, it was still three-fourths the size of its GDP. And the form this natural wealth took? Mostly water supplies to other crowded regions: Qinghai is where the Mekong, the Yangtze and the Yellow Rivers rise.

“We’re basically flying blind when it comes to knowing where and how much nature to protect,” said Gretchen Daily, an environmental scientist at Stanford’s School of Humanities and Sciences in California, and one of the report’s authors.

“GEP tracks the vital contributions of nature to society, informs investments in securing them and helps evaluate the performance of leaders and policies.”

And her British co-author, Ian Bateman, an economist at the University of Exeter, said: “The global economy as conventionally measured by GDP more than doubled between 1990 and 2015. However, at the same time our stocks of ‘ecosystem assets’ – such as forests, grasslands, wetlands, fertile soils and biodiversity – have come under increasing pressure.”

“We were able to place a value on important ecosystem services, especially water supply, that Qinghai currently exports to other provinces but receives no credit for in the GDP calculation”

He continued: “These things are obviously valuable in many ways – including to human wellbeing. However, in this study we examine the benefits they bring us measured in a way that governments and business can understand.”

Naturalists, conservationists and economists have repeatedly argued that it makes better economic sense to conserve nature rather than to exploit it: untouched natural forest or grassland contributes more to everybody’s wealth than any clear-felling project or conversion to cattle-grazing.

Scientists and economists have again and again tried to calculate the cash value to humankind of nature’s goods and services, and to steer development in a sustainable fashion.

They have repeatedly warned that global heating driven by profligate use of fossil fuels is almost certain to hit the pockets of the poorest most cruelly.

And they have warned that uncontrolled exploitation of once untouched natural forests, mangrove estuaries, grasslands, wetlands and coral reefs that precipitates mass extinction of species is certain to impoverish billions in the long run.

Direct test

But to persuade governments that natural capital represents an investment with measurable returns, economists need a standard global measure. GEP could be it.

The measure was tested directly in what is sometimes called the “water tower” of Asia. The logic is that if the people of that region care for their natural habitat, and people downstream benefit directly from that care, then those downstream should also contribute to the costs of care.

“Qinghai is rich in natural capital but its GDP alone does not reflect that value”, said the study’s lead author, Zhiyun Ouyang, of the Chinese Academy of Sciences.

“Using this new metric we were able to place a value on important ecosystem services, especially water supply, that Qinghai currently exports to other provinces but receives no credit for in the GDP calculation.” – Climate News Network

Forest trees are growing shorter and dying younger

Temperatures could get too high for tropical forests, and forest trees everywhere are changing in response to human action.

LONDON, 9 June, 2020 – There are limits to what forest trees will tolerate; many tropical forests, for instance, can cope with climate change – but only up to a point. Again, they will go on storing carbon from human greenhouse gas emissions – but only to a degree.

But at around the 32°C threshold, tree growth halts and trees start to die more frequently, putting carbon back into the atmosphere, to accelerate more global heating, according to a detailed study of trees in more than 800 tropical forests.

And a second, unrelated study of forests worldwide finds separate evidence of the impact of climate change. Thanks to human action, forest trees are now younger – and shorter.

The point of the first study is that, in their natural and undisturbed state, the world’s tropical forests can take the heat, but there may be a limit to their capacity for change, and that limit is a daytime maximum of 32.2°C.

A collective of 225 researchers in South America, Africa and Asia report in the journal Science that they made 2 million measurements of 10,000 tropical tree species in sample plots in 24 countries to examine the capacity of forests to absorb atmospheric carbon in a rapidly heating world.

Safety zone

“Our analysis reveals that up to a certain point of heating, tropical forests are surprisingly resistant to small temperature differences. If we limit climate change they can continue to store a large amount of carbon in a warmer world,” said Martin Sullivan, a geographer at the University of Leeds, and at Manchester Metropolitan University, who led the study.

“The 32-degree threshold highlights the critical importance of cutting our emissions to avoid pushing too many forests beyond the safety zone.

“For example, if we limit global average temperatures to a 2°C increase above pre-industrial levels, this pushes nearly three-quarters of tropical forests above the heat threshold we identified. Any further increases in temperature will lead to rapid losses of forest carbon.”

The finding suggests that overall, and independently of species of tree, tropical forest carbon declines with higher temperatures. In all forests, trees flourish and absorb carbon, die back and release it again. But at their best, forests on balance absorb and store away for centuries more carbon than they release – until the thermometer starts to rise and goes on rising.

“Reductions in forest age and height are already happening, and they’re likely to continue to happen”

A co-author, Beatriz Marimon of the State University of Matto Grosso in Brazil, said: “Each degree increase above this 32-degree threshold releases four times as much carbon as would have been released below the threshold.”

The message is that tropical forests need to be protected from climate change, deforestation and wildlife exploitation: that way, they protect  biodiversity, protect themselves, and protect humankind, for future generations. They can adapt to warming temperatures, but this takes decades, perhaps centuries.

But according to another study, also in Science, forest trees the world over are now changing. They are responding to ever higher levels of atmospheric carbon – in effect, they are being fertilised – but also wildfire, drought, windstorm damage, insect attack and disease have become more frequent and more severe with climate change.

And then there has been the direct impact of human economic demand: clearance, disturbance and economic exploitation.

In consequence, US and European scientists conclude, from detailed satellite data and from reviews of more than 160 previous studies, that there has been a “pervasive shift” in forest dynamics, and a dramatic decrease in the age and stature of the forests. The world’s trees on average are younger, and shorter.

Drastic change

“This trend is likely to continue with global warming,” said Nate McDowell,  of the Pacific Northwest National Laboratory, who led the research.

“A future planet with fewer large, old forests will be very different than what we have grown accustomed to. Older forests often host much higher biodiversity than young forests, and they store more carbon than young forests.”

So direct and indirect human action have – in the big picture – affected the way forests shelter new seedlings, the growth of all trees, and the rate of death of those trees. Mortality is going up, while recruitment and growth are faltering.

“Unfortunately, mortality drivers like rising temperature and disturbances are on the rise and are expected to continue increasing in frequency over the next century,” Dr McDowell said.

“So reductions in forest age and height are already happening, and they’re likely to continue to happen.” – Climate News Network

Temperatures could get too high for tropical forests, and forest trees everywhere are changing in response to human action.

LONDON, 9 June, 2020 – There are limits to what forest trees will tolerate; many tropical forests, for instance, can cope with climate change – but only up to a point. Again, they will go on storing carbon from human greenhouse gas emissions – but only to a degree.

But at around the 32°C threshold, tree growth halts and trees start to die more frequently, putting carbon back into the atmosphere, to accelerate more global heating, according to a detailed study of trees in more than 800 tropical forests.

And a second, unrelated study of forests worldwide finds separate evidence of the impact of climate change. Thanks to human action, forest trees are now younger – and shorter.

The point of the first study is that, in their natural and undisturbed state, the world’s tropical forests can take the heat, but there may be a limit to their capacity for change, and that limit is a daytime maximum of 32.2°C.

A collective of 225 researchers in South America, Africa and Asia report in the journal Science that they made 2 million measurements of 10,000 tropical tree species in sample plots in 24 countries to examine the capacity of forests to absorb atmospheric carbon in a rapidly heating world.

Safety zone

“Our analysis reveals that up to a certain point of heating, tropical forests are surprisingly resistant to small temperature differences. If we limit climate change they can continue to store a large amount of carbon in a warmer world,” said Martin Sullivan, a geographer at the University of Leeds, and at Manchester Metropolitan University, who led the study.

“The 32-degree threshold highlights the critical importance of cutting our emissions to avoid pushing too many forests beyond the safety zone.

“For example, if we limit global average temperatures to a 2°C increase above pre-industrial levels, this pushes nearly three-quarters of tropical forests above the heat threshold we identified. Any further increases in temperature will lead to rapid losses of forest carbon.”

The finding suggests that overall, and independently of species of tree, tropical forest carbon declines with higher temperatures. In all forests, trees flourish and absorb carbon, die back and release it again. But at their best, forests on balance absorb and store away for centuries more carbon than they release – until the thermometer starts to rise and goes on rising.

“Reductions in forest age and height are already happening, and they’re likely to continue to happen”

A co-author, Beatriz Marimon of the State University of Matto Grosso in Brazil, said: “Each degree increase above this 32-degree threshold releases four times as much carbon as would have been released below the threshold.”

The message is that tropical forests need to be protected from climate change, deforestation and wildlife exploitation: that way, they protect  biodiversity, protect themselves, and protect humankind, for future generations. They can adapt to warming temperatures, but this takes decades, perhaps centuries.

But according to another study, also in Science, forest trees the world over are now changing. They are responding to ever higher levels of atmospheric carbon – in effect, they are being fertilised – but also wildfire, drought, windstorm damage, insect attack and disease have become more frequent and more severe with climate change.

And then there has been the direct impact of human economic demand: clearance, disturbance and economic exploitation.

In consequence, US and European scientists conclude, from detailed satellite data and from reviews of more than 160 previous studies, that there has been a “pervasive shift” in forest dynamics, and a dramatic decrease in the age and stature of the forests. The world’s trees on average are younger, and shorter.

Drastic change

“This trend is likely to continue with global warming,” said Nate McDowell,  of the Pacific Northwest National Laboratory, who led the research.

“A future planet with fewer large, old forests will be very different than what we have grown accustomed to. Older forests often host much higher biodiversity than young forests, and they store more carbon than young forests.”

So direct and indirect human action have – in the big picture – affected the way forests shelter new seedlings, the growth of all trees, and the rate of death of those trees. Mortality is going up, while recruitment and growth are faltering.

“Unfortunately, mortality drivers like rising temperature and disturbances are on the rise and are expected to continue increasing in frequency over the next century,” Dr McDowell said.

“So reductions in forest age and height are already happening, and they’re likely to continue to happen.” – Climate News Network

Millions of species face extinction emergency

An extinction emergency unparalleled in the history of life on Earth could soon overtake millions of species – thanks to us.

LONDON, 8 June, 2020 – More than 500 terrestrial vertebrate species – birds, amphibians, mammals, reptiles – are on the brink of a worldwide extinction emergency. These are animal species with surviving populations of fewer than 1,000 individuals. They are to be found in tropical and subtropical regions and, significantly, they are concentrated in regions heavily affected by human activities.

Extinction is a natural part of the evolutionary process. But the number of simultaneously threatened species, and the link to direct human pressure, adds support for the argument that humanity is now witnessing the sixth, and possibly greatest, mass extinction in the history of life.

The same research has identified 388 vertebrate species with fewer than 5000 individuals in the surviving populations. Of these, more than four-fifths cling to survival in the same threatened regions, and may therefore also be heading for the brink of extinction.

Three distinguished scientists report in the Proceedings of the National Academy of Sciences that they analysed the International Union for the Conservation of Nature’s list of threatened species to identify 29,400 terrestrial vertebrates, 1.7% of which had fewer than 1,000 remaining individuals anywhere in the world.

There are many cases of local extinction: for a mix of reasons, birds or butterflies might disappear from places where they once were many, but continue to flourish in other zones. But too many local extinctions soon amount to global obliteration: the researchers identified 237,000 populations of vertebrates that had vanished since 1900.

Massive impact ahead

They see an ecological catastrophe in the making, and they urge governments and international agencies to act.

“What we do to deal with the current extinction crisis in the next two decades will define the fate of millions of species,” said study lead author Gerardo Ceballos, a senior researcher at the National Autonomous University of Mexico’s Institute of Ecology.

“We are facing our final opportunity to ensure that the many services nature provides us do not get irretrievably sabotaged.”

And his co-author Paul Ehrlich of Stanford University in California said: “When humanity exterminates populations and species of other creatures, it is sawing off the limb on which it is sitting, destroying working parts of our own life-support system.

“The conservation of endangered species should be elevated to a national and global emergency for governments and institutions, equal to climate disruption, to which it is linked.”

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes”

Nearly a fourth of all species on the planet could face extinction. In the course of the 11,000 years since the invention of agriculture human numbers have multiplied from about one million to 7.7 billion, and are rising fast. In the last 450 million years there have been at least five major extinctions, each destroying 70% to 90% of all life on Earth.

Although creatures alive on Earth today account for only 2% of all the creatures that have ever lived, the absolute number of species is greater now than ever before. “It is into such a biologically diverse world that we humans evolved, and such a world that we are destroying,” the authors write.

Extinction may be the greatest environmental problem, because it is irreversible. It is now happening at rates perhaps a thousand times faster than the “background rate” over the last tens of millions of years.

When a species disappears, it takes with it a unique set of biological riches, and – perhaps more dangerously – it creates a loss for other species that may in some way depend upon it. Extinction breeds extinction, the authors argue.

And as plants and animals vanish into oblivion, the biosphere’s capacity to recycle atmosphere, water and nutrients, to pollinate and fertilise, and to dispose of the dead and the waste, is diminished.

‘Ecological zombies’

Ecosystems that support and enrich all life also support and enrich humanity. At one stage 60 million bison maintained the prairie ecosystems of North America and in the course of doing so supported the then Native American population.

By 1884 only 325 individuals were left. The prairies are now largely farmland, and the 4000 surviving wild bison can be considered, the authors say, as “ecological zombies.”

Among other steps, they want to see a halt to the trade in wildlife – thought to be linked to the origins of the Covid-19 pandemic. All three have considerable reputations within science and they have all been making much the same argument for many years.

They calculate that in the last century 543 species of land vertebrate were extinguished. The same number could go in the next two decades. Human action created the problem: only human action can repair the damage.

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes,” said Peter Raven, president emeritus of the Missouri Botanical Garden, the third of the signatories. – Climate News Network

An extinction emergency unparalleled in the history of life on Earth could soon overtake millions of species – thanks to us.

LONDON, 8 June, 2020 – More than 500 terrestrial vertebrate species – birds, amphibians, mammals, reptiles – are on the brink of a worldwide extinction emergency. These are animal species with surviving populations of fewer than 1,000 individuals. They are to be found in tropical and subtropical regions and, significantly, they are concentrated in regions heavily affected by human activities.

Extinction is a natural part of the evolutionary process. But the number of simultaneously threatened species, and the link to direct human pressure, adds support for the argument that humanity is now witnessing the sixth, and possibly greatest, mass extinction in the history of life.

The same research has identified 388 vertebrate species with fewer than 5000 individuals in the surviving populations. Of these, more than four-fifths cling to survival in the same threatened regions, and may therefore also be heading for the brink of extinction.

Three distinguished scientists report in the Proceedings of the National Academy of Sciences that they analysed the International Union for the Conservation of Nature’s list of threatened species to identify 29,400 terrestrial vertebrates, 1.7% of which had fewer than 1,000 remaining individuals anywhere in the world.

There are many cases of local extinction: for a mix of reasons, birds or butterflies might disappear from places where they once were many, but continue to flourish in other zones. But too many local extinctions soon amount to global obliteration: the researchers identified 237,000 populations of vertebrates that had vanished since 1900.

Massive impact ahead

They see an ecological catastrophe in the making, and they urge governments and international agencies to act.

“What we do to deal with the current extinction crisis in the next two decades will define the fate of millions of species,” said study lead author Gerardo Ceballos, a senior researcher at the National Autonomous University of Mexico’s Institute of Ecology.

“We are facing our final opportunity to ensure that the many services nature provides us do not get irretrievably sabotaged.”

And his co-author Paul Ehrlich of Stanford University in California said: “When humanity exterminates populations and species of other creatures, it is sawing off the limb on which it is sitting, destroying working parts of our own life-support system.

“The conservation of endangered species should be elevated to a national and global emergency for governments and institutions, equal to climate disruption, to which it is linked.”

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes”

Nearly a fourth of all species on the planet could face extinction. In the course of the 11,000 years since the invention of agriculture human numbers have multiplied from about one million to 7.7 billion, and are rising fast. In the last 450 million years there have been at least five major extinctions, each destroying 70% to 90% of all life on Earth.

Although creatures alive on Earth today account for only 2% of all the creatures that have ever lived, the absolute number of species is greater now than ever before. “It is into such a biologically diverse world that we humans evolved, and such a world that we are destroying,” the authors write.

Extinction may be the greatest environmental problem, because it is irreversible. It is now happening at rates perhaps a thousand times faster than the “background rate” over the last tens of millions of years.

When a species disappears, it takes with it a unique set of biological riches, and – perhaps more dangerously – it creates a loss for other species that may in some way depend upon it. Extinction breeds extinction, the authors argue.

And as plants and animals vanish into oblivion, the biosphere’s capacity to recycle atmosphere, water and nutrients, to pollinate and fertilise, and to dispose of the dead and the waste, is diminished.

‘Ecological zombies’

Ecosystems that support and enrich all life also support and enrich humanity. At one stage 60 million bison maintained the prairie ecosystems of North America and in the course of doing so supported the then Native American population.

By 1884 only 325 individuals were left. The prairies are now largely farmland, and the 4000 surviving wild bison can be considered, the authors say, as “ecological zombies.”

Among other steps, they want to see a halt to the trade in wildlife – thought to be linked to the origins of the Covid-19 pandemic. All three have considerable reputations within science and they have all been making much the same argument for many years.

They calculate that in the last century 543 species of land vertebrate were extinguished. The same number could go in the next two decades. Human action created the problem: only human action can repair the damage.

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes,” said Peter Raven, president emeritus of the Missouri Botanical Garden, the third of the signatories. – Climate News Network