Category Archives: Nature

Greenhouse gases have a puzzling double effect

Lustier plant growth as greenhouse gases climb should counter global heating and atmospheric carbon build-up. But it’s not quite so simple.

LONDON, 21 February, 2020 – The Arctic is getting greener as greenhouse gases abound and the global thermometer rises. The vegetation of the high latitudes is moving further north, growing taller, becoming more substantial, more abundant and budding earlier, according to new studies by 40 scientists from 36 European and US institutions.

And the whole planet is getting greener too, according to a separate study in a second journal, as more carbon dioxide in the atmosphere – the chief cause of global heating – also acts as a fertiliser to stimulate plant growth.

It is as if researchers have finally identified a genuine negative feedback effect: as the world warms because of higher levels of greenhouse gases, the plant world responds by absorbing more of the carbon in the atmosphere and modifying the overall impact.

But both studies identify problems with what might be a comforting conclusion: it isn’t clear why in some Arctic regions the green things are getting greener, while in others the vegetation cover is becoming poorer.

And worldwide, it might be that much of the global greening can be attributed to human action – the advance of industrial-scale agriculture and commercial forest plantation – in which case most of the absorbed carbon dioxide will be returned to the atmosphere sooner or later.

“It is ironic that the very same carbon emissions responsible for harmful changes to climate are also fertilising plant growth, which in turn is somewhat moderating global warming”

Both studies confirm the value of a closer look at the evidence so far – and the need for further study.

In the journal Nature Climate Change, scientists report that they checked the big picture of polar greening based on four decades of data from large-scale satellite observation against more detailed evidence over smaller sample regions collected by sensors mounted on drones and on aircraft, as well as direct examination on the once-frozen ground.

The Arctic is the fastest-warming region of the planet: it is warming twice as fast as the globe as a whole. Snow melts earlier, plants leaf sooner. Shrubs that once stayed close to the slushy snow surface are now taller, and new species are colonising once hostile terrain.

This is expected to destabilise the Arctic tundra, the region of year-round permafrost that masks a vast reservoir of carbon buried in the frozen soils.

Natural response

So botanists and climate scientists in the high latitudes now have to begin some tricky calculations in their pursuit of reliable estimates of the global carbon budget. How much carbon will the new green growth absorb and store? And how much carbon buried for the last 100,000 years or so will escape into the atmosphere with the advance of the northern greenery and the thawing of the soils?

But at least, according to a paper in the journal Nature Reviews Earth and Environment, the observed greening of the Arctic is a natural response to rising average temperatures and greater carbon dioxide fertilisation as a consequence of ever-higher levels of greenhouse gas emissions and consequent climate change.

Svalbard in the high Arctic is almost 2°C warmer in summer than it was in 1986, and at least 30% greener. But the Arctic is a region with limited human settlement and low industrial investment.

A team of researchers from China, the US, France and Norway combed through 250 earlier studies, and revisited satellite data, climate models and field observations, to make sense of the evidence of a planet that has grown a lot greener: half of all the world’s vegetated lands are leafier than they once were.

And they concluded that it was possible that the growth of global greening in the last 40 years may have slowed the rate of global heating by as much as 0.25°C.

Human footprint

But the same greening can be seen as evidence of rapid human impact on the planet as a whole: much of it can be explained by more intensive use of farmland and forest plantation, especially in the world’s most populous countries, India and China.

“It is ironic that the very same carbon emissions responsible for harmful changes to climate are also fertilising plant growth, which in turn is somewhat moderating global warming,” said one author, Jarle Bjerke of the Norwegian Institute for Nature Research.

And his co-author Phillipe Ciais, of France’s Laboratory of Climate and Environmental Sciences, said: “Plants are actively defending against the dangers of carbon pollution by not only sequestering carbon on land but also by wetting the atmosphere through transpiration of ground water and evaporation of precipitation intercepted by their bodies.

“Stopping deforestation and promoting sustainable, ecologically sensible afforestation could be one of the simplest and most cost-effective, though not sufficient, defences against climate change.” – Climate News Network

Lustier plant growth as greenhouse gases climb should counter global heating and atmospheric carbon build-up. But it’s not quite so simple.

LONDON, 21 February, 2020 – The Arctic is getting greener as greenhouse gases abound and the global thermometer rises. The vegetation of the high latitudes is moving further north, growing taller, becoming more substantial, more abundant and budding earlier, according to new studies by 40 scientists from 36 European and US institutions.

And the whole planet is getting greener too, according to a separate study in a second journal, as more carbon dioxide in the atmosphere – the chief cause of global heating – also acts as a fertiliser to stimulate plant growth.

It is as if researchers have finally identified a genuine negative feedback effect: as the world warms because of higher levels of greenhouse gases, the plant world responds by absorbing more of the carbon in the atmosphere and modifying the overall impact.

But both studies identify problems with what might be a comforting conclusion: it isn’t clear why in some Arctic regions the green things are getting greener, while in others the vegetation cover is becoming poorer.

And worldwide, it might be that much of the global greening can be attributed to human action – the advance of industrial-scale agriculture and commercial forest plantation – in which case most of the absorbed carbon dioxide will be returned to the atmosphere sooner or later.

“It is ironic that the very same carbon emissions responsible for harmful changes to climate are also fertilising plant growth, which in turn is somewhat moderating global warming”

Both studies confirm the value of a closer look at the evidence so far – and the need for further study.

In the journal Nature Climate Change, scientists report that they checked the big picture of polar greening based on four decades of data from large-scale satellite observation against more detailed evidence over smaller sample regions collected by sensors mounted on drones and on aircraft, as well as direct examination on the once-frozen ground.

The Arctic is the fastest-warming region of the planet: it is warming twice as fast as the globe as a whole. Snow melts earlier, plants leaf sooner. Shrubs that once stayed close to the slushy snow surface are now taller, and new species are colonising once hostile terrain.

This is expected to destabilise the Arctic tundra, the region of year-round permafrost that masks a vast reservoir of carbon buried in the frozen soils.

Natural response

So botanists and climate scientists in the high latitudes now have to begin some tricky calculations in their pursuit of reliable estimates of the global carbon budget. How much carbon will the new green growth absorb and store? And how much carbon buried for the last 100,000 years or so will escape into the atmosphere with the advance of the northern greenery and the thawing of the soils?

But at least, according to a paper in the journal Nature Reviews Earth and Environment, the observed greening of the Arctic is a natural response to rising average temperatures and greater carbon dioxide fertilisation as a consequence of ever-higher levels of greenhouse gas emissions and consequent climate change.

Svalbard in the high Arctic is almost 2°C warmer in summer than it was in 1986, and at least 30% greener. But the Arctic is a region with limited human settlement and low industrial investment.

A team of researchers from China, the US, France and Norway combed through 250 earlier studies, and revisited satellite data, climate models and field observations, to make sense of the evidence of a planet that has grown a lot greener: half of all the world’s vegetated lands are leafier than they once were.

And they concluded that it was possible that the growth of global greening in the last 40 years may have slowed the rate of global heating by as much as 0.25°C.

Human footprint

But the same greening can be seen as evidence of rapid human impact on the planet as a whole: much of it can be explained by more intensive use of farmland and forest plantation, especially in the world’s most populous countries, India and China.

“It is ironic that the very same carbon emissions responsible for harmful changes to climate are also fertilising plant growth, which in turn is somewhat moderating global warming,” said one author, Jarle Bjerke of the Norwegian Institute for Nature Research.

And his co-author Phillipe Ciais, of France’s Laboratory of Climate and Environmental Sciences, said: “Plants are actively defending against the dangers of carbon pollution by not only sequestering carbon on land but also by wetting the atmosphere through transpiration of ground water and evaporation of precipitation intercepted by their bodies.

“Stopping deforestation and promoting sustainable, ecologically sensible afforestation could be one of the simplest and most cost-effective, though not sufficient, defences against climate change.” – Climate News Network

Many species face threat of insect extinction

Rainforests can get too hot for beetles. Mayflies can succumb to seasonal change, bumblebees to drought. Insect extinction may soon await myriad species.

LONDON, 13 February, 2020 – Humankind could be about to bid farewell to friends it never got to know, as insect extinction overtakes countless species.

Most of the millions of insects that support life on the planet have yet to be named or described. And yet perhaps 500,000 species of beetles, butterflies, bees, ants and other six-legged creatures vital to the efficient working of natural ecosystems and commercial economies could be about to disappear – as a consequence of climate change and other pressures driven by human population growth.

And this note of alarm has been sounded within a few days in which other research groups have separately warned of the climate threats to beetles in the Amazon forest, to the burrowing mayflies of the American mid-west and to the bumblebees of North America and Europe.

Insects pollinate growing plants, dispose of dying ones and serve as lunch or supper for birds, amphibians, reptiles, bats and other mammals. There could be as many as 5.5 million distinct species of insect, of which no more than one in five has been observed, identified and catalogued by entomologists.

A million or more creatures fashioned by aeons of evolution and natural selection could be at imminent risk of extinction because of human advance. A group of 30 experts now urgently warns in the journal Biological Conservation that half of these could be insects.

“From pollination and decomposition, to being resources for new medicines, insects provide essential and irreplaceable services”

“It is surprising how little we know about biodiversity at a global level, when only about 10 to 20% of insect and other invertebrate species have been described and named. And of those with a name, we know little more than a brief morphological description, maybe part of the genetic code and a single site where it was seen some years ago,” said Pedro Cardoso, of the Finnish Museum of Natural History in Helsinki, who led the study.

“With species loss, we lose not only another piece of the complex puzzle that is our living world, but also biomass, essential to feed other animals in the living chain, unique genes and substances that might one day contribute to cure diseases, and ecosystem functions on which humanity depends.”

The researchers argue that insect species are vulnerable to human changes to their natural habitat; to pesticide and fertiliser use; to light pollution, industrial pollution and even noise pollution. Climate change driven by fossil fuel combustion amplifies the hazard: the unfamiliar seasonal temperatures and the advance of spring mean for instance that butterflies have emerged ahead of the nectar plants that normally nourish them.

And a series of separate studies explore some of the impact of human-triggered changes to natural systems. Researchers report in the journal Biotropica that hotter and drier episodes in the Amazon rainforests have led not only to disastrous fires but to a dramatic collapse of dung beetle populations.

Vanishing beetles

These little creatures spread nutrients and seeds, and ecologists see them as evidence of the overall health of an ecosystem, which is why international teams of scientists have been monitoring dung beetles from 98 species across 30 forest plots in the Brazilian state of Pará.

In 2010, they counted 8000 beetles. In 2017, after an El Niño event had brought drought and fire to the region, they found only 2,600.

Mayflies, too, are seen as indicators of the health of rivers, lakes and streams: the more there are, the better the water quality. The burrowing mayfly makes a spectacular emergence each year from US waterways to darken the skies. Researchers have estimated more than 87 billion insects in one swarm, weighing more than 3,000 tonnes of potential bird and fish food.

But researchers report in the Proceedings of the National Academy of Sciences that between 2015 and 2019 scientists used radar to monitor the swarms over Lake Erie and found that as a consequence of a warming climate and other pressures, numbers fell in that four-year sequence by 84%.

And in the journal Science, Canadian and British scientists report that they looked at more than a century of records of 66 species of bumblebee in North America and Europe, to find that, within one human generation, as global heating amplified the frequency of extreme temperatures and droughts, the likelihood of a bumblebee population surviving in a given place had fallen on average by 30%.

Not insects alone

That insects may be in trouble is not news: naturalists have measured huge losses over time in sample locations, often as a consequence of habitat destruction, but also as a consequence of local climate shifts in response to global heating. These losses have been mirrored in bird predator populations and even in changes in insects themselves.

As the authors of the Biological Conservation paper point out, the damage goes beyond the insect world. Other creatures depend on insects, directly or indirectly. So do humans.

“With insect extinctions, we lose much more than species,” Dr Cardoso and his colleagues write. “We lose abundance and biomass of insects, diversity across space and time with consequent homogenisation, large parts of the tree of life, unique ecological functions and traits, and fundamental parts of extensive networks of biotic interactions.

“Such losses lead to the decline of key ecosystem services on which humanity depends. From pollination and decomposition, to being resources for new medicines, habitat quality indication and many others, insects provide essential and irreplaceable services.” – Climate News Network

Rainforests can get too hot for beetles. Mayflies can succumb to seasonal change, bumblebees to drought. Insect extinction may soon await myriad species.

LONDON, 13 February, 2020 – Humankind could be about to bid farewell to friends it never got to know, as insect extinction overtakes countless species.

Most of the millions of insects that support life on the planet have yet to be named or described. And yet perhaps 500,000 species of beetles, butterflies, bees, ants and other six-legged creatures vital to the efficient working of natural ecosystems and commercial economies could be about to disappear – as a consequence of climate change and other pressures driven by human population growth.

And this note of alarm has been sounded within a few days in which other research groups have separately warned of the climate threats to beetles in the Amazon forest, to the burrowing mayflies of the American mid-west and to the bumblebees of North America and Europe.

Insects pollinate growing plants, dispose of dying ones and serve as lunch or supper for birds, amphibians, reptiles, bats and other mammals. There could be as many as 5.5 million distinct species of insect, of which no more than one in five has been observed, identified and catalogued by entomologists.

A million or more creatures fashioned by aeons of evolution and natural selection could be at imminent risk of extinction because of human advance. A group of 30 experts now urgently warns in the journal Biological Conservation that half of these could be insects.

“From pollination and decomposition, to being resources for new medicines, insects provide essential and irreplaceable services”

“It is surprising how little we know about biodiversity at a global level, when only about 10 to 20% of insect and other invertebrate species have been described and named. And of those with a name, we know little more than a brief morphological description, maybe part of the genetic code and a single site where it was seen some years ago,” said Pedro Cardoso, of the Finnish Museum of Natural History in Helsinki, who led the study.

“With species loss, we lose not only another piece of the complex puzzle that is our living world, but also biomass, essential to feed other animals in the living chain, unique genes and substances that might one day contribute to cure diseases, and ecosystem functions on which humanity depends.”

The researchers argue that insect species are vulnerable to human changes to their natural habitat; to pesticide and fertiliser use; to light pollution, industrial pollution and even noise pollution. Climate change driven by fossil fuel combustion amplifies the hazard: the unfamiliar seasonal temperatures and the advance of spring mean for instance that butterflies have emerged ahead of the nectar plants that normally nourish them.

And a series of separate studies explore some of the impact of human-triggered changes to natural systems. Researchers report in the journal Biotropica that hotter and drier episodes in the Amazon rainforests have led not only to disastrous fires but to a dramatic collapse of dung beetle populations.

Vanishing beetles

These little creatures spread nutrients and seeds, and ecologists see them as evidence of the overall health of an ecosystem, which is why international teams of scientists have been monitoring dung beetles from 98 species across 30 forest plots in the Brazilian state of Pará.

In 2010, they counted 8000 beetles. In 2017, after an El Niño event had brought drought and fire to the region, they found only 2,600.

Mayflies, too, are seen as indicators of the health of rivers, lakes and streams: the more there are, the better the water quality. The burrowing mayfly makes a spectacular emergence each year from US waterways to darken the skies. Researchers have estimated more than 87 billion insects in one swarm, weighing more than 3,000 tonnes of potential bird and fish food.

But researchers report in the Proceedings of the National Academy of Sciences that between 2015 and 2019 scientists used radar to monitor the swarms over Lake Erie and found that as a consequence of a warming climate and other pressures, numbers fell in that four-year sequence by 84%.

And in the journal Science, Canadian and British scientists report that they looked at more than a century of records of 66 species of bumblebee in North America and Europe, to find that, within one human generation, as global heating amplified the frequency of extreme temperatures and droughts, the likelihood of a bumblebee population surviving in a given place had fallen on average by 30%.

Not insects alone

That insects may be in trouble is not news: naturalists have measured huge losses over time in sample locations, often as a consequence of habitat destruction, but also as a consequence of local climate shifts in response to global heating. These losses have been mirrored in bird predator populations and even in changes in insects themselves.

As the authors of the Biological Conservation paper point out, the damage goes beyond the insect world. Other creatures depend on insects, directly or indirectly. So do humans.

“With insect extinctions, we lose much more than species,” Dr Cardoso and his colleagues write. “We lose abundance and biomass of insects, diversity across space and time with consequent homogenisation, large parts of the tree of life, unique ecological functions and traits, and fundamental parts of extensive networks of biotic interactions.

“Such losses lead to the decline of key ecosystem services on which humanity depends. From pollination and decomposition, to being resources for new medicines, habitat quality indication and many others, insects provide essential and irreplaceable services.” – Climate News Network

Rare trees saved from Australia’s wildfires

This story originally appeared in the Bulletin of the Atomic Scientists and is republished here as part of Covering Climate Now, a global journalism collaboration to strengthen coverage of the climate story.

Buried amid the horrific news from Australia about climate change and out-of-control wildfire was a positive story: the saving of rare trees.

CHICAGO, 5 February, 2020 − An Associated Press story  titled Firefighters in Australia save unique prehistoric trees brought a scarce gleam of hope: “Firefighters winched from helicopters to reach the cluster of fewer than 200 Wollemi Pines in a remote gorge in the Blue Mountains a week before a massive wildfire bore down… the firefighters set up an irrigation system to keep the so-called dinosaur trees moist, and pumped water daily from the gorge as the blaze that had burned out of control for two months edged closer.”

This news had particular significance to me for a number of reasons. For one thing, the successful protection of this endangered species could hint at things to come − if we play our cards right.

For another, I know the Blue Mountains of New South Wales (though I have not been to that grove of trees − whose exact location has been kept a secret by botanists ever since it was first discovered in 1994.)

I spent four years down-under, first as an American researcher on a Fulbright grant to see what we in the States could learn from looking at the Australian experience, and then as a roving foreign correspondent for science-related US magazines such as International Wildlife, Scientific American, and the journal Science, among others.

My job was to travel over the land down-under, reporting on natural history, the environment, and science in the Great South Land for publications back home in the States − as well as magazines like Australian Geographic.

Easy to miss

Which was how I became acquainted with the Blue Mountains, a lesser-known area about 120 miles west of Sydney. They’re a surprisingly steep, thickly wooded, and easily overlooked mountain chain, much like an Aussie version of our Appalachians. And much like the Appalachians, their deep ravines held up westward exploration and expansion for a long time. But there the parallels end.

Walking in Australia’s Blue Mountains is an unworldly experience. There are no squirrels or chipmunks; instead, parrots occupy that ecological niche. My edition of the Field Guide to the Birds of Australia lists 23 different species of parrots alone.

Just a short list of the formal names of some of the individual species gives an idea of the colorful diversity you can see: Blue-winged, Orange-bellied, Golden-shouldered, Scarlet-chested, Red-rumped, and Turquoise parrots. Not to mention Elegant, Paradise, Superb, and King parrots.

And instead of smelling pine trees, your nose registers the scent of eucalypts. Look up at the stars at night, and there’s not a single familiar constellation; instead you see celestial objects like the Jewel Box Cluster − while hearing the mocking laugh of kookaburras.

Even the food tastes different − in place of pepperoni or sausage, toppings at the Australian Pizza Kitchen in Canberra include emu and kangaroo (I prefer the kangaroo).

“These trees are descendants of individuals that had survived since the era of the dinosaurs”

And some of the trees in parts of the Blueys − as they’re called − resemble nothing so much as short stumps with ferns popping out of their sides willy-nilly; everything looks so primeval you half-expect to see escapees from Jurassic Park poking their snouts out.

Indeed, in far-north Queensland I and my parents were to be stalked by a full-grown, adult male cassowary, defending his mate. We took shelter behind a large tropical tree, trying to keep the trunk between us and the approximately 200-pound, 6-foot-tall creature as it circled around.

This pervasive feeling of encounters with the primeval is appropriate. Australia is a very ancient land, which used to be part of what geologists call Gondwana − when most of the world’s landmasses were linked together in the distant past.

But while the other landforms went on to become continents such as South America and Africa, Australia remained a giant island continent, cut off from the rest of the planet. And species that died out elsewhere continued to thrive, and evolve, here.

(Just why species do so well on islands, and why evolution seems to speed up on them, is something that kept Charles Darwin busy. An entire field of island biogeography has sprung up to delve into its mysteries.)

Human rarities

Even now, some parts of Australia are so isolated that the wildlife has seldom seen humans. So far as researchers can tell, no Aborigines, Melanesians, Micronesians, Polynesians, or Caucasians ever settled on Australia’s Lord Howe Island until 1834; consequently, the wildlife never learned to be afraid of humans.

When I went there, you could stand at the foot of Lord Howe’s tallest mountain, call up to the providence petrels nesting as much as a hundred feet above, and watch the birds glide down to land at your feet. If you’re really good, you may be able to touch them, or at least have one land on your outstretched arm.

Due to these vagaries of isolation, ancient and unique species seem to abound in Australia − though they can be easily overlooked. Drive along the highway outside Shark Bay in the state of Western Australia, and you’ll spot weird dark, mushroom-shaped, rock-like structures in the shallows of the hyper-salty water; they’re actually living mats of blue-green algae known as stromatolites − Greek for “layered rock.”

Stromatolites are one of the oldest forms of life that we know of, essentially unchanged since their ancestors flourished 3.5 billion years ago. They were previously known to us only from fossils, until first discovered in this region in the 1980s.

So it’s not entirely surprising that Wollemi Pines should survive in the wild, undetected, a relatively short drive from Sydney for so many years; after all, these trees are descendants of individuals that had survived since the era of the dinosaurs − though they now exist in the wild in only one place in the world, with fewer than 100 adult specimens known.

Survivors for sale

What was surprising was that these wild specimens were saved from the wildfires, in a complex operation that involved firefighters being lowered from helicopters into the narrow steep-sided ridges where the trees dwell, along with planes strategically bombing the advancing firefront with fire retardant.

And well in advance of events these past months, authorities had covered their bets by doing all they could to increase the species’ chance of survival. Since 2006, a propagation program has made these trees available to botanical gardens so their numbers could be increased; I’ve subsequently run across Aussies who have grown the plants from seeds in their living rooms. (In Australia, seedlings can even be ordered online,  and the Royal Botanic Gardens Sydney offer information on Wollemi care, conservation, and research.)

More than that, when it looked like the wildfires were in imminent danger of destroying the only existing stand of these trees in the wild, leaders had the foresight to rely on the recommendations of scientists, firefighters, and other experts as to how to proceed. They then worked out a plan and put it into action − actively dealing with the problem rather than denying it existed.

In short, in the time since the Wollemi Pines were discovered, government agencies, nonprofit organisations, private enterprise and volunteer efforts successfully worked together over decades to protect the trees from extinction.

Which makes one wonder, once again, what we in the States could learn from observing the Australian experience. − Climate News Network

This story originally appeared in the Bulletin of the Atomic Scientists and is republished here as part of Covering Climate Now, a global journalism collaboration to strengthen coverage of the climate story.

Buried amid the horrific news from Australia about climate change and out-of-control wildfire was a positive story: the saving of rare trees.

CHICAGO, 5 February, 2020 − An Associated Press story  titled Firefighters in Australia save unique prehistoric trees brought a scarce gleam of hope: “Firefighters winched from helicopters to reach the cluster of fewer than 200 Wollemi Pines in a remote gorge in the Blue Mountains a week before a massive wildfire bore down… the firefighters set up an irrigation system to keep the so-called dinosaur trees moist, and pumped water daily from the gorge as the blaze that had burned out of control for two months edged closer.”

This news had particular significance to me for a number of reasons. For one thing, the successful protection of this endangered species could hint at things to come − if we play our cards right.

For another, I know the Blue Mountains of New South Wales (though I have not been to that grove of trees − whose exact location has been kept a secret by botanists ever since it was first discovered in 1994.)

I spent four years down-under, first as an American researcher on a Fulbright grant to see what we in the States could learn from looking at the Australian experience, and then as a roving foreign correspondent for science-related US magazines such as International Wildlife, Scientific American, and the journal Science, among others.

My job was to travel over the land down-under, reporting on natural history, the environment, and science in the Great South Land for publications back home in the States − as well as magazines like Australian Geographic.

Easy to miss

Which was how I became acquainted with the Blue Mountains, a lesser-known area about 120 miles west of Sydney. They’re a surprisingly steep, thickly wooded, and easily overlooked mountain chain, much like an Aussie version of our Appalachians. And much like the Appalachians, their deep ravines held up westward exploration and expansion for a long time. But there the parallels end.

Walking in Australia’s Blue Mountains is an unworldly experience. There are no squirrels or chipmunks; instead, parrots occupy that ecological niche. My edition of the Field Guide to the Birds of Australia lists 23 different species of parrots alone.

Just a short list of the formal names of some of the individual species gives an idea of the colorful diversity you can see: Blue-winged, Orange-bellied, Golden-shouldered, Scarlet-chested, Red-rumped, and Turquoise parrots. Not to mention Elegant, Paradise, Superb, and King parrots.

And instead of smelling pine trees, your nose registers the scent of eucalypts. Look up at the stars at night, and there’s not a single familiar constellation; instead you see celestial objects like the Jewel Box Cluster − while hearing the mocking laugh of kookaburras.

Even the food tastes different − in place of pepperoni or sausage, toppings at the Australian Pizza Kitchen in Canberra include emu and kangaroo (I prefer the kangaroo).

“These trees are descendants of individuals that had survived since the era of the dinosaurs”

And some of the trees in parts of the Blueys − as they’re called − resemble nothing so much as short stumps with ferns popping out of their sides willy-nilly; everything looks so primeval you half-expect to see escapees from Jurassic Park poking their snouts out.

Indeed, in far-north Queensland I and my parents were to be stalked by a full-grown, adult male cassowary, defending his mate. We took shelter behind a large tropical tree, trying to keep the trunk between us and the approximately 200-pound, 6-foot-tall creature as it circled around.

This pervasive feeling of encounters with the primeval is appropriate. Australia is a very ancient land, which used to be part of what geologists call Gondwana − when most of the world’s landmasses were linked together in the distant past.

But while the other landforms went on to become continents such as South America and Africa, Australia remained a giant island continent, cut off from the rest of the planet. And species that died out elsewhere continued to thrive, and evolve, here.

(Just why species do so well on islands, and why evolution seems to speed up on them, is something that kept Charles Darwin busy. An entire field of island biogeography has sprung up to delve into its mysteries.)

Human rarities

Even now, some parts of Australia are so isolated that the wildlife has seldom seen humans. So far as researchers can tell, no Aborigines, Melanesians, Micronesians, Polynesians, or Caucasians ever settled on Australia’s Lord Howe Island until 1834; consequently, the wildlife never learned to be afraid of humans.

When I went there, you could stand at the foot of Lord Howe’s tallest mountain, call up to the providence petrels nesting as much as a hundred feet above, and watch the birds glide down to land at your feet. If you’re really good, you may be able to touch them, or at least have one land on your outstretched arm.

Due to these vagaries of isolation, ancient and unique species seem to abound in Australia − though they can be easily overlooked. Drive along the highway outside Shark Bay in the state of Western Australia, and you’ll spot weird dark, mushroom-shaped, rock-like structures in the shallows of the hyper-salty water; they’re actually living mats of blue-green algae known as stromatolites − Greek for “layered rock.”

Stromatolites are one of the oldest forms of life that we know of, essentially unchanged since their ancestors flourished 3.5 billion years ago. They were previously known to us only from fossils, until first discovered in this region in the 1980s.

So it’s not entirely surprising that Wollemi Pines should survive in the wild, undetected, a relatively short drive from Sydney for so many years; after all, these trees are descendants of individuals that had survived since the era of the dinosaurs − though they now exist in the wild in only one place in the world, with fewer than 100 adult specimens known.

Survivors for sale

What was surprising was that these wild specimens were saved from the wildfires, in a complex operation that involved firefighters being lowered from helicopters into the narrow steep-sided ridges where the trees dwell, along with planes strategically bombing the advancing firefront with fire retardant.

And well in advance of events these past months, authorities had covered their bets by doing all they could to increase the species’ chance of survival. Since 2006, a propagation program has made these trees available to botanical gardens so their numbers could be increased; I’ve subsequently run across Aussies who have grown the plants from seeds in their living rooms. (In Australia, seedlings can even be ordered online,  and the Royal Botanic Gardens Sydney offer information on Wollemi care, conservation, and research.)

More than that, when it looked like the wildfires were in imminent danger of destroying the only existing stand of these trees in the wild, leaders had the foresight to rely on the recommendations of scientists, firefighters, and other experts as to how to proceed. They then worked out a plan and put it into action − actively dealing with the problem rather than denying it existed.

In short, in the time since the Wollemi Pines were discovered, government agencies, nonprofit organisations, private enterprise and volunteer efforts successfully worked together over decades to protect the trees from extinction.

Which makes one wonder, once again, what we in the States could learn from observing the Australian experience. − Climate News Network

Ex-general takes over Brazil’s Amazon protection

Brazil’s president, Jair Bolsonaro, is a former soldier. He’s now appointed an ex-military colleague to oversee Amazon protection, causing widespread dismay.

SÃO PAULO, 31 January, 2020 − Alarmed by warnings that his neglect of the need to protect the Amazon could lead to disinvestment and export bans, Brazil’s President Jair Bolsonaro has turned to his usual solution to problems: call in the army.

He has chosen his vice-president, retired general Hamilton Mourão, to head a new Amazon Council which will co-ordinate “the activities of all the ministries involved in the protection, defence and development and sustainable development of the Amazon”.

He has also decided to create a new environmental police force (in Portuguese) to protect the Amazon. The “Green Police” will recruit agents from local state forces.

The creation of the council is a belated attempt to undo the damage done in the first year of Bolsonaro’s government, when the environment ministry was entrusted to right-wing climate sceptic Ricardo Salles.

Salles, a São Paulo lawyer who had never set foot in the Amazon and faces charges of fraud dating from his term as environment secretary of the local state government, immediately set about dismantling the ministry’s capacity to monitor deforestation, enforce the law and fine offenders, replacing experienced, qualified staff with retired police officers, and blaming Greenpeace and other NGOs for environmental disasters.

“What finally persuaded Bolsonaro that he had to listen to the critics was pressure from Brazilian exporters and foreign investors”

As a result of his unfounded accusations of irregularities among recipients, Norway and Germany suspended their contributions to the billion dollar Amazon Fund, set up in 2000 to finance sustainable development projects and firefighting brigades.

Bolsonaro also gave the go-ahead to wildcat miners and landgrabbers to invade protected areas, with remarks that disparaged indigenous peoples and encouraged economic activities in the rainforest.

The effect of this policy was a huge surge in Amazon forest fires and a big increase in deforestation over the previous year. When confronted with the figures, Bolsonaro’s answer was to accuse the head of Brazil’s internationally respected monitoring agency, INPE, of lying and being in the pay of NGOs, forcing him to resign.

What finally persuaded Bolsonaro that he had to listen to the critics was pressure from Brazilian exporters and foreign investors.

Change of tune

With disinvestment in environmentally unsustainable areas growing, large investment fund managers warned that pressure from shareholders, increasingly worried about the climate crisis, would force them to pull out of Brazil unless the government changed its tune and began protecting the Amazon.

Brazil’s politically powerful agribusiness lobby spelt out the consequences for their grain and meat exports if the government continued to encourage deforestation, because consumers now demand sustainability.

But instead of sacking his environment minister or increasing funds to prevent deforestation and fires, Bolsonaro has appointed Hamilton Mourão, whose Amazon experience is five years as military commander in the region, to sort out the problem.

Scientists, environmentalists and NGOs with years of experience in the Amazon were not consulted before the surprise move. Even Mourão himself, when interviewed, was vague about what he is meant to do or how he will do it.

Ignoring local knowledge

The army’s involvement in the Amazon began in the 1960s when Brazil was at the beginning of a 21-year-long military dictatorship. The key word was development – highways, dams, cattle ranches – ignoring the indigenous and traditional people who already lived there. As a result, thousands were displaced and many died from diseases transmittted by outsiders.

The decision to resort to the military has caused dismay among environmentalists. Suely Araújo, former head of Ibama, the environmental enforcement agency, who resigned in protest (in Portuguese) at the minister’s and Bolsonaro’s comments, said: “The solution is not in militarising environmental policy… military support for operations in critical areas might be necessary, but it should be understood that environmental monitoring has to go way beyond troops on the ground.”

She pointed out that Ibama’s 2020 budget for monitoring work throughout Brazil has been slashed by 25% over the previous year.

The latest figures from INPE show an 85.3% increase in deforestation (in Portuguese) for the year ending in August 2019, compared with the year before. Fires for the same period were 30% higher. − Climate News Network

Brazil’s president, Jair Bolsonaro, is a former soldier. He’s now appointed an ex-military colleague to oversee Amazon protection, causing widespread dismay.

SÃO PAULO, 31 January, 2020 − Alarmed by warnings that his neglect of the need to protect the Amazon could lead to disinvestment and export bans, Brazil’s President Jair Bolsonaro has turned to his usual solution to problems: call in the army.

He has chosen his vice-president, retired general Hamilton Mourão, to head a new Amazon Council which will co-ordinate “the activities of all the ministries involved in the protection, defence and development and sustainable development of the Amazon”.

He has also decided to create a new environmental police force (in Portuguese) to protect the Amazon. The “Green Police” will recruit agents from local state forces.

The creation of the council is a belated attempt to undo the damage done in the first year of Bolsonaro’s government, when the environment ministry was entrusted to right-wing climate sceptic Ricardo Salles.

Salles, a São Paulo lawyer who had never set foot in the Amazon and faces charges of fraud dating from his term as environment secretary of the local state government, immediately set about dismantling the ministry’s capacity to monitor deforestation, enforce the law and fine offenders, replacing experienced, qualified staff with retired police officers, and blaming Greenpeace and other NGOs for environmental disasters.

“What finally persuaded Bolsonaro that he had to listen to the critics was pressure from Brazilian exporters and foreign investors”

As a result of his unfounded accusations of irregularities among recipients, Norway and Germany suspended their contributions to the billion dollar Amazon Fund, set up in 2000 to finance sustainable development projects and firefighting brigades.

Bolsonaro also gave the go-ahead to wildcat miners and landgrabbers to invade protected areas, with remarks that disparaged indigenous peoples and encouraged economic activities in the rainforest.

The effect of this policy was a huge surge in Amazon forest fires and a big increase in deforestation over the previous year. When confronted with the figures, Bolsonaro’s answer was to accuse the head of Brazil’s internationally respected monitoring agency, INPE, of lying and being in the pay of NGOs, forcing him to resign.

What finally persuaded Bolsonaro that he had to listen to the critics was pressure from Brazilian exporters and foreign investors.

Change of tune

With disinvestment in environmentally unsustainable areas growing, large investment fund managers warned that pressure from shareholders, increasingly worried about the climate crisis, would force them to pull out of Brazil unless the government changed its tune and began protecting the Amazon.

Brazil’s politically powerful agribusiness lobby spelt out the consequences for their grain and meat exports if the government continued to encourage deforestation, because consumers now demand sustainability.

But instead of sacking his environment minister or increasing funds to prevent deforestation and fires, Bolsonaro has appointed Hamilton Mourão, whose Amazon experience is five years as military commander in the region, to sort out the problem.

Scientists, environmentalists and NGOs with years of experience in the Amazon were not consulted before the surprise move. Even Mourão himself, when interviewed, was vague about what he is meant to do or how he will do it.

Ignoring local knowledge

The army’s involvement in the Amazon began in the 1960s when Brazil was at the beginning of a 21-year-long military dictatorship. The key word was development – highways, dams, cattle ranches – ignoring the indigenous and traditional people who already lived there. As a result, thousands were displaced and many died from diseases transmittted by outsiders.

The decision to resort to the military has caused dismay among environmentalists. Suely Araújo, former head of Ibama, the environmental enforcement agency, who resigned in protest (in Portuguese) at the minister’s and Bolsonaro’s comments, said: “The solution is not in militarising environmental policy… military support for operations in critical areas might be necessary, but it should be understood that environmental monitoring has to go way beyond troops on the ground.”

She pointed out that Ibama’s 2020 budget for monitoring work throughout Brazil has been slashed by 25% over the previous year.

The latest figures from INPE show an 85.3% increase in deforestation (in Portuguese) for the year ending in August 2019, compared with the year before. Fires for the same period were 30% higher. − Climate News Network

Climate heat means new wine from familiar places

Each great wine is a unique product of place and climate. Rising heat could force new wine into old, prized bottles from famous cellars.

LONDON, 30 January, 2020 – As global average temperatures rise, so does uncertainty for the world’s wine-growers – with new wine the likely result. The great Bordeaux region of France will survive – but only if it stops serving claret.

Burgundy will still value its vines, but these won’t produce the high-priced tipple that the law defines as burgundy. Instead, what comes out of the cellars of Beaune or the Cote d’Or will be more like the output now from the southern Rhone.

That is always supposing that the growers keep up with rising temperatures by choosing grape varieties more likely to flourish with climate heating. A new study by European, Canadian and US scientists suggests that, even if the world’s most prized vineyards do abandon the grape varieties that made them prized in the first place, they will still lose up to a quarter of the space now in cultivation.

And if they don’t, the great wine regions of Europe could say goodbye to half their vineyards altogether. Producers in cool climates – Germany, New Zealand and the Pacific Northwest – could avoid major losses, but they will be tempted to switch to later-ripening varieties.

“Wine is like the canary in the coal mine for climate change impacts on agriculture, because these grapes are so climate-sensitive”

In the United Kingdom, where until very lately any wine harvest has been a gamble, the terrain might become suitable for at least five new varieties. New Zealand’s range of grape choices could double.

But Burgundian growers might have to forego the famously temperamental pinot noir grape and switch to grenache, or mourvedre, known in Spain as monastrell. The vintners of St Emilion, Pomerol and Medoc could see their cabernet sauvignon and merlot varieties replaced by mourvedre, according to research in the Proceedings of the National Academy of Sciences.

In fact, Europe’s growers have already had several warnings: hot and dry summers are now, for France, the norm. Extreme summer temperatures take their toll not just of the yield on the vine, but also of the people who have to pick the grapes, and even of the oak trees that provide the bark for the corks in the finished product.

Temperatures have already risen by more than 1°C worldwide, and the cool region of Champagne could be about to lose its sparkle.

Medieval records

But the new study is about far more than just the high-priced product of high-status wine regions. There are more than 1000 varieties of the grape Vitis vinifera, many of them sensitive to specific temperature and rainfall conditions. Even more helpfully, scientists can call upon harvest records that date back to medieval times.

So the grape seemed a good proxy for all of agriculture: from apples to wheat, from bananas to brassicas, the world’s growers can call on a huge range of crop varieties to buffer them from the shock of climate change driven by ever-increasing use of fossil fuels and ever-greater emissions of greenhouse gases into the atmosphere.

“In some ways, wine is like the canary in the coal mine for climate change impacts on agriculture, because these grapes are so climate-sensitive,” said co-author Benjamin Cook, of the Lamont Doherty Earth Observatory at Columbia University in the US.

The scientists considered 11 kinds of cultivar and dates of budding, flowering and harvest matched to seasonal temperature records, and found that if global temperatures rise by 2°C – and there is every indication that they could rise by more than 3°C – at least 51% of current wine-growing regions could be wiped out.

Higher warmth difficulties

“These estimates however ignore important changes that growers can make,” said Elizabeth Wolkovich, of the University of British Columbia, another author.

“We found that by switching to different varieties, vintners can lessen the damage to just 24% of areas lost. For example, in Burgundy, France, vintners can consider planting more heat-tolerant varieties such as syrah and grenache to replace the dominant pinot noir. And growers in regions such as Bordeaux may swap out cabernet sauvignon and merlot for mourvedre.”

But that’s if warming is limited to just 2°C. “At four degrees, around 77% of all areas may be lost, and planting new varieties will limit this to 58% losses,” said Ignacio Morales-Castilla, of the University of Acalá in Spain, who led the study.

“Wine-growing regions can adapt to a lower level of warming but at higher warming, it’s much harder.” – Climate News Network

Each great wine is a unique product of place and climate. Rising heat could force new wine into old, prized bottles from famous cellars.

LONDON, 30 January, 2020 – As global average temperatures rise, so does uncertainty for the world’s wine-growers – with new wine the likely result. The great Bordeaux region of France will survive – but only if it stops serving claret.

Burgundy will still value its vines, but these won’t produce the high-priced tipple that the law defines as burgundy. Instead, what comes out of the cellars of Beaune or the Cote d’Or will be more like the output now from the southern Rhone.

That is always supposing that the growers keep up with rising temperatures by choosing grape varieties more likely to flourish with climate heating. A new study by European, Canadian and US scientists suggests that, even if the world’s most prized vineyards do abandon the grape varieties that made them prized in the first place, they will still lose up to a quarter of the space now in cultivation.

And if they don’t, the great wine regions of Europe could say goodbye to half their vineyards altogether. Producers in cool climates – Germany, New Zealand and the Pacific Northwest – could avoid major losses, but they will be tempted to switch to later-ripening varieties.

“Wine is like the canary in the coal mine for climate change impacts on agriculture, because these grapes are so climate-sensitive”

In the United Kingdom, where until very lately any wine harvest has been a gamble, the terrain might become suitable for at least five new varieties. New Zealand’s range of grape choices could double.

But Burgundian growers might have to forego the famously temperamental pinot noir grape and switch to grenache, or mourvedre, known in Spain as monastrell. The vintners of St Emilion, Pomerol and Medoc could see their cabernet sauvignon and merlot varieties replaced by mourvedre, according to research in the Proceedings of the National Academy of Sciences.

In fact, Europe’s growers have already had several warnings: hot and dry summers are now, for France, the norm. Extreme summer temperatures take their toll not just of the yield on the vine, but also of the people who have to pick the grapes, and even of the oak trees that provide the bark for the corks in the finished product.

Temperatures have already risen by more than 1°C worldwide, and the cool region of Champagne could be about to lose its sparkle.

Medieval records

But the new study is about far more than just the high-priced product of high-status wine regions. There are more than 1000 varieties of the grape Vitis vinifera, many of them sensitive to specific temperature and rainfall conditions. Even more helpfully, scientists can call upon harvest records that date back to medieval times.

So the grape seemed a good proxy for all of agriculture: from apples to wheat, from bananas to brassicas, the world’s growers can call on a huge range of crop varieties to buffer them from the shock of climate change driven by ever-increasing use of fossil fuels and ever-greater emissions of greenhouse gases into the atmosphere.

“In some ways, wine is like the canary in the coal mine for climate change impacts on agriculture, because these grapes are so climate-sensitive,” said co-author Benjamin Cook, of the Lamont Doherty Earth Observatory at Columbia University in the US.

The scientists considered 11 kinds of cultivar and dates of budding, flowering and harvest matched to seasonal temperature records, and found that if global temperatures rise by 2°C – and there is every indication that they could rise by more than 3°C – at least 51% of current wine-growing regions could be wiped out.

Higher warmth difficulties

“These estimates however ignore important changes that growers can make,” said Elizabeth Wolkovich, of the University of British Columbia, another author.

“We found that by switching to different varieties, vintners can lessen the damage to just 24% of areas lost. For example, in Burgundy, France, vintners can consider planting more heat-tolerant varieties such as syrah and grenache to replace the dominant pinot noir. And growers in regions such as Bordeaux may swap out cabernet sauvignon and merlot for mourvedre.”

But that’s if warming is limited to just 2°C. “At four degrees, around 77% of all areas may be lost, and planting new varieties will limit this to 58% losses,” said Ignacio Morales-Castilla, of the University of Acalá in Spain, who led the study.

“Wine-growing regions can adapt to a lower level of warming but at higher warming, it’s much harder.” – Climate News Network

Wildfire risk can be reduced with agroforestry

As Australia struggles to recover from months of wildfires, farmers and foresters say agroforestry could help to protect the country.

LONDON, 28 January, 2020 – Researchers in Europe have found that simply adopting a way of managing land to support animals, crops and trees – a system known as agroforestry – can help significantly to cut the risk of wildfires breaking out in areas around the Mediterranean.

As uncontrolled wildfires threaten natural vegetation, biodiversity, communities and economies – and lives – and release large amounts of carbon dioxide, contributing to global temperature rise, the pressure to find ways of controlling them is urgent.

Studying ten years’ worth of data, the researchers analysed the relationship between the incidence of fire and several different uses of land (for agroforestry, forests, shrublands and grasslands). Agroforestry, occupying 12% of the land area, was linked to just 6% of the fires, while shrubland, which occupied 16%, suffered from 41% of the fires (these figures are based on two European Union documents – LUCAS, its Land use and land cover survey, and the European Forest Fire Information System, EFFIS, 2008-17.

Paul Burgess, reader in crop ecology and management at Cranfield University, UK, said: “Areas of shrubland were at particular risk of wildfire – where the land is not proactively managed or used, there is a build-up of dry vegetation and shrubs creating fuel.

Work boost

“Agroforestry is shown to reduce wildfire risk by encouraging rural employment and removing part of the dry ground-level vegetation through livestock grazing. Taking into account the effect of climate change in this region, it is a land management option that can successfully reduce fires, protect the environment and improve human well-being.”

Combining livestock and trees on agroforestry land can create habitats rich in a variety of species that provide an annual income for farmers through livestock products. For clearing vegetation, agroforestry uses less machinery and fossil fuel.

Dr Burgess, who is secretary of the Farm Woodland Forum, told the Climate News Network that agroforestry could help countries like Australia and Portugal to cut the extreme fire risk they have been facing.

He said: “Compared with unmanaged shrubland areas, agroforestry can provide three benefits. Firstly, it encourages local employment and management on the ground which can allow for more rapid initial responses. Then, in most agroforestry systems, the understorey, the vegetation between the forest canopy and the floor, is managed, and this reduces the store of fuel. Third, in many agroforestry systems there are breaks between the trees, which can also help to limit fire spread.”

“Agroforestry is a land management option that can successfully reduce fires, protect the environment and improve human well-being”

The proportion of burnt land in the area studied by the team over 10 years ranged from 0.1% of the area of France to 1-2% of the area of Greece, Cyprus, Italy and Spain, and to 14% of the area of Portugal. The researchers report their study in the journal Agroforestry Systems.

Land abandonment is an important element in the risk of wildfires. In many parts of the Mediterranean, an ageing population and the end of traditional farming and forestry activity have led to extensive unmanaged lands.

This results in an increase in decayed biomass, plant material which readily serves as fuel in shrublands that can be easily ignited by natural events such as thunderstorms, or by human activity.

Other suggestions for reducing wildfires include using sunlight to replace fossil fuel-derived kerosene with a synthetic version, and cutting fossil fuel reliance through wide use of new generation batteries. – Climate News Network

As Australia struggles to recover from months of wildfires, farmers and foresters say agroforestry could help to protect the country.

LONDON, 28 January, 2020 – Researchers in Europe have found that simply adopting a way of managing land to support animals, crops and trees – a system known as agroforestry – can help significantly to cut the risk of wildfires breaking out in areas around the Mediterranean.

As uncontrolled wildfires threaten natural vegetation, biodiversity, communities and economies – and lives – and release large amounts of carbon dioxide, contributing to global temperature rise, the pressure to find ways of controlling them is urgent.

Studying ten years’ worth of data, the researchers analysed the relationship between the incidence of fire and several different uses of land (for agroforestry, forests, shrublands and grasslands). Agroforestry, occupying 12% of the land area, was linked to just 6% of the fires, while shrubland, which occupied 16%, suffered from 41% of the fires (these figures are based on two European Union documents – LUCAS, its Land use and land cover survey, and the European Forest Fire Information System, EFFIS, 2008-17.

Paul Burgess, reader in crop ecology and management at Cranfield University, UK, said: “Areas of shrubland were at particular risk of wildfire – where the land is not proactively managed or used, there is a build-up of dry vegetation and shrubs creating fuel.

Work boost

“Agroforestry is shown to reduce wildfire risk by encouraging rural employment and removing part of the dry ground-level vegetation through livestock grazing. Taking into account the effect of climate change in this region, it is a land management option that can successfully reduce fires, protect the environment and improve human well-being.”

Combining livestock and trees on agroforestry land can create habitats rich in a variety of species that provide an annual income for farmers through livestock products. For clearing vegetation, agroforestry uses less machinery and fossil fuel.

Dr Burgess, who is secretary of the Farm Woodland Forum, told the Climate News Network that agroforestry could help countries like Australia and Portugal to cut the extreme fire risk they have been facing.

He said: “Compared with unmanaged shrubland areas, agroforestry can provide three benefits. Firstly, it encourages local employment and management on the ground which can allow for more rapid initial responses. Then, in most agroforestry systems, the understorey, the vegetation between the forest canopy and the floor, is managed, and this reduces the store of fuel. Third, in many agroforestry systems there are breaks between the trees, which can also help to limit fire spread.”

“Agroforestry is a land management option that can successfully reduce fires, protect the environment and improve human well-being”

The proportion of burnt land in the area studied by the team over 10 years ranged from 0.1% of the area of France to 1-2% of the area of Greece, Cyprus, Italy and Spain, and to 14% of the area of Portugal. The researchers report their study in the journal Agroforestry Systems.

Land abandonment is an important element in the risk of wildfires. In many parts of the Mediterranean, an ageing population and the end of traditional farming and forestry activity have led to extensive unmanaged lands.

This results in an increase in decayed biomass, plant material which readily serves as fuel in shrublands that can be easily ignited by natural events such as thunderstorms, or by human activity.

Other suggestions for reducing wildfires include using sunlight to replace fossil fuel-derived kerosene with a synthetic version, and cutting fossil fuel reliance through wide use of new generation batteries. – Climate News Network

New forests mean permanently lower river flows

Planting trees helps to combat the climate crisis by cutting greenhouse gases. But the price can be permanently lower river flows.

LONDON, 20 January, 2020 − New forests are an apparently promising way to tackle global heating: the trees absorb carbon dioxide, the main greenhouse gas from human activities. But there’s a snag, because permanently lower river flows can be an unintended consequence.

A study by scientists at the University of Cambridge, UK, has found that river flow is reduced in areas where forests have been planted − and, significantly, it does not recover over time. Rivers in some regions can disappear completely within 10 years.

This, the researchers say, highlights the need to consider the impact on regional water availability, as well as the wider climate benefit of tree-planting plans.

“Reforestation is an important part of tackling climate change, but we need to carefully consider the best places for it. In some places, changes to water availability will completely change the local cost-benefits of tree-planting programmes”, said Laura Bentley, a plant scientist in the University of Cambridge Conservation Research Institute, and first author of the report.

Age effect missed

Planting large areas of trees has been suggested as one of the best ways of reducing atmospheric carbon dioxide levels, because trees absorb and store the gas as they grow, although uncertainties about the strategy persist. Science has known for a long time that planting trees reduces the amount of water flowing into nearby rivers, but no-one had realised how this effect changes as forests age.

The Cambridge study looked at 43 sites across the world where forests have been established, and used river flow as a measure of water availability in the region. It found that within five years of planting trees, river flow had reduced by an average of 25%.

But 25 years after the trees were planted, rivers had gone down by an average of 40%, or in a few cases had dried up altogether. The biggest percentage reductions in water availability were in parts of Australia and South Africa.

“River flow does not recover after planting trees, even after many years, once disturbances in the catchment and the effects of climate are accounted for,” said Professor David Coomes, director of the Conservation Research Institute, who led the study.

“In some places, changes to water availability will completely change the local cost-benefits of tree-planting programmes”

Published in the journal Global Change Biology, the research showed that the type of land where trees are planted determines the impact they have on local water availability.

Trees planted on natural grassland where the soil is healthy decrease river flow significantly. But on land previously degraded by agriculture, establishing a forest helps to repair the soil so that it can hold more water, and therefore decreases nearby river flow by a smaller amount.

Strangely, the effect of trees on river flow is smaller in drier years than in wetter ones. When trees are drought-stressed they close the pores on their leaves to conserve water, and as a result take up less water from the soil. In wet weather, though, they use more water from the soil, and also catch the rainwater in their leaves.

“Climate change will affect water availability around the world,” said Bentley. “By studying how forestation affects water availability, we can work to minimise any local consequences for people and the environment.” − Climate News Network

Planting trees helps to combat the climate crisis by cutting greenhouse gases. But the price can be permanently lower river flows.

LONDON, 20 January, 2020 − New forests are an apparently promising way to tackle global heating: the trees absorb carbon dioxide, the main greenhouse gas from human activities. But there’s a snag, because permanently lower river flows can be an unintended consequence.

A study by scientists at the University of Cambridge, UK, has found that river flow is reduced in areas where forests have been planted − and, significantly, it does not recover over time. Rivers in some regions can disappear completely within 10 years.

This, the researchers say, highlights the need to consider the impact on regional water availability, as well as the wider climate benefit of tree-planting plans.

“Reforestation is an important part of tackling climate change, but we need to carefully consider the best places for it. In some places, changes to water availability will completely change the local cost-benefits of tree-planting programmes”, said Laura Bentley, a plant scientist in the University of Cambridge Conservation Research Institute, and first author of the report.

Age effect missed

Planting large areas of trees has been suggested as one of the best ways of reducing atmospheric carbon dioxide levels, because trees absorb and store the gas as they grow, although uncertainties about the strategy persist. Science has known for a long time that planting trees reduces the amount of water flowing into nearby rivers, but no-one had realised how this effect changes as forests age.

The Cambridge study looked at 43 sites across the world where forests have been established, and used river flow as a measure of water availability in the region. It found that within five years of planting trees, river flow had reduced by an average of 25%.

But 25 years after the trees were planted, rivers had gone down by an average of 40%, or in a few cases had dried up altogether. The biggest percentage reductions in water availability were in parts of Australia and South Africa.

“River flow does not recover after planting trees, even after many years, once disturbances in the catchment and the effects of climate are accounted for,” said Professor David Coomes, director of the Conservation Research Institute, who led the study.

“In some places, changes to water availability will completely change the local cost-benefits of tree-planting programmes”

Published in the journal Global Change Biology, the research showed that the type of land where trees are planted determines the impact they have on local water availability.

Trees planted on natural grassland where the soil is healthy decrease river flow significantly. But on land previously degraded by agriculture, establishing a forest helps to repair the soil so that it can hold more water, and therefore decreases nearby river flow by a smaller amount.

Strangely, the effect of trees on river flow is smaller in drier years than in wetter ones. When trees are drought-stressed they close the pores on their leaves to conserve water, and as a result take up less water from the soil. In wet weather, though, they use more water from the soil, and also catch the rainwater in their leaves.

“Climate change will affect water availability around the world,” said Bentley. “By studying how forestation affects water availability, we can work to minimise any local consequences for people and the environment.” − Climate News Network

Humans are set to hijack the fossil record

Humans have made an indelible mark on the planet: they may also have erased most of life’s other stories, distorting the fossil record, the narrative of creation.

LONDON, 2 January, 2020 – US scientists have made a prediction that some yet-to-evolve intelligent species a hundred million years into the future can test. One day the fossil record will be more than usually rich in the complete skeletons of a small number of creatures: pigs, sheep, cattle and humans, many of the last arranged seemingly in ranks.

The assemblage from what many scientists now call the Anthropocene – the geological era dominated by Homo sapiens – will be entirely unlike the pattern of preserved relics from all the other geological eras in the last 500 million years.

“Fossil mammals occur in caves, ancient lake beds and river channels, and are usually only teeth and isolated bones,” said Roy Plotnick, a palaeontologist at the University of Illinois in Chicago. “Animals that die on farms or in mass death due to disease often end up as complete corpses in trenches and landfills, far from water.”

Also available for study will be a vast array of undisturbed examples of one species that already far outnumbers all other large wild mammals. “In the far future, the fossil record of today will have a huge number of complete hominid skeletons, all lined up in rows.”

The thesis, outlined in the journal The Anthropocene, is a simple one. The evidence of past life preserved in the rocks is the only key to the story of life on Earth, and it has unfolded until now entirely by caprice.

“The future mammal record will be mostly cows, sheep, goats, pigs, dogs, cats and people themselves”

Animals that died in the Triassic, Jurassic or the Cretaceous were incompletely preserved. Upon death, they were liable to be dismantled by scavengers, swept away by floods, incinerated by fires, buried by lava or demolished entirely by microbes. Preservation of any kind was entirely a matter of geological caprice and bone structure: soft-bodied animals – and most living things have always been boneless – have almost no chance of preservation.

The North American passenger pigeon astonished the first European settlers. It existed by the billion-fold: one flock could be a mile wide and 200 miles long.

The last survivor perished in 1914 and, says Steve Jones in 1999, in his much-recommended examination of evolutionary insight, Almost Like a Whale, without a written record, no-one would now know it had ever existed: no fossil has ever been found.

The argument by Professor Plotnick and a colleague is a simple one. If preservation in fossilised form is a lottery, humankind has now taken over the management and rigged the odds.

Humans evolved from primate ancestors, but no primate species ever flourished in such numbers. Global population has soared almost eightfold in the last two centuries, and with humans the population of domesticated animals has multiplied dramatically: one species now threatens to eliminate many of the other inhabitants of the planet.

Preservation more probable

The mass of humanity, according to one calculation, long ago began to outweigh the gross mass of all other wild mammals on the planet, by at least 10-fold. And in such numbers, humans and their chosen species should stand a much better chance of preservation far into the future.

Homo sapiens has already fashioned cities, industries and constructions that gross up to trillions of tonnes of cement and metal, and in a few decades laid down a stratum of seemingly indestructible polymer material in the form of plastic cups, bottles, nets, cables and containers.

Erosion, earthquakes and time alone may wipe away many of the scars left by most construction work, but some will survive as evidence that at least one intelligent civilisation made it through evolution’s obstacle race before possibly ensuring its own collapse.

The chances of long-term preservation of the bones of the blue whale, the African lion, the mountain gorilla, the emperor penguin or even the jungle fowl, ancestor of the broiler chicken, will remain vanishingly small. But the factory farms and orderly cemeteries of today will dominate the evidence.

“The chance of a wild animal becoming part of the fossil record has become very small,” said Professor Plotnick. “Instead the future mammal record will be mostly cows, sheep, goats, pigs, dogs, cats and people themselves.” – Climate News Network

Humans have made an indelible mark on the planet: they may also have erased most of life’s other stories, distorting the fossil record, the narrative of creation.

LONDON, 2 January, 2020 – US scientists have made a prediction that some yet-to-evolve intelligent species a hundred million years into the future can test. One day the fossil record will be more than usually rich in the complete skeletons of a small number of creatures: pigs, sheep, cattle and humans, many of the last arranged seemingly in ranks.

The assemblage from what many scientists now call the Anthropocene – the geological era dominated by Homo sapiens – will be entirely unlike the pattern of preserved relics from all the other geological eras in the last 500 million years.

“Fossil mammals occur in caves, ancient lake beds and river channels, and are usually only teeth and isolated bones,” said Roy Plotnick, a palaeontologist at the University of Illinois in Chicago. “Animals that die on farms or in mass death due to disease often end up as complete corpses in trenches and landfills, far from water.”

Also available for study will be a vast array of undisturbed examples of one species that already far outnumbers all other large wild mammals. “In the far future, the fossil record of today will have a huge number of complete hominid skeletons, all lined up in rows.”

The thesis, outlined in the journal The Anthropocene, is a simple one. The evidence of past life preserved in the rocks is the only key to the story of life on Earth, and it has unfolded until now entirely by caprice.

“The future mammal record will be mostly cows, sheep, goats, pigs, dogs, cats and people themselves”

Animals that died in the Triassic, Jurassic or the Cretaceous were incompletely preserved. Upon death, they were liable to be dismantled by scavengers, swept away by floods, incinerated by fires, buried by lava or demolished entirely by microbes. Preservation of any kind was entirely a matter of geological caprice and bone structure: soft-bodied animals – and most living things have always been boneless – have almost no chance of preservation.

The North American passenger pigeon astonished the first European settlers. It existed by the billion-fold: one flock could be a mile wide and 200 miles long.

The last survivor perished in 1914 and, says Steve Jones in 1999, in his much-recommended examination of evolutionary insight, Almost Like a Whale, without a written record, no-one would now know it had ever existed: no fossil has ever been found.

The argument by Professor Plotnick and a colleague is a simple one. If preservation in fossilised form is a lottery, humankind has now taken over the management and rigged the odds.

Humans evolved from primate ancestors, but no primate species ever flourished in such numbers. Global population has soared almost eightfold in the last two centuries, and with humans the population of domesticated animals has multiplied dramatically: one species now threatens to eliminate many of the other inhabitants of the planet.

Preservation more probable

The mass of humanity, according to one calculation, long ago began to outweigh the gross mass of all other wild mammals on the planet, by at least 10-fold. And in such numbers, humans and their chosen species should stand a much better chance of preservation far into the future.

Homo sapiens has already fashioned cities, industries and constructions that gross up to trillions of tonnes of cement and metal, and in a few decades laid down a stratum of seemingly indestructible polymer material in the form of plastic cups, bottles, nets, cables and containers.

Erosion, earthquakes and time alone may wipe away many of the scars left by most construction work, but some will survive as evidence that at least one intelligent civilisation made it through evolution’s obstacle race before possibly ensuring its own collapse.

The chances of long-term preservation of the bones of the blue whale, the African lion, the mountain gorilla, the emperor penguin or even the jungle fowl, ancestor of the broiler chicken, will remain vanishingly small. But the factory farms and orderly cemeteries of today will dominate the evidence.

“The chance of a wild animal becoming part of the fossil record has become very small,” said Professor Plotnick. “Instead the future mammal record will be mostly cows, sheep, goats, pigs, dogs, cats and people themselves.” – Climate News Network

Food at risk as third of plants face extinction

More than a third of the world’s plants are so rare they face extinction. In a warmer world, that would leave supplies of food at risk.

LONDON, 17 December, 2019 – Botanists have made a new census of terrestrial plants – only to find that with nearly 40% of them rare, or extremely rare, this may put food at risk.

And a second team of researchers, in a separate study, has established that some of these rare or vanishing species could include the wild relatives of some of the planet’s most popular vegetables.

The two studies matter. The first underlines yet another reason for new and determined conservation strategies to preserve the extraordinary natural variety and richness of life – the shorthand word that scientists use is biodiversity – already under pressure from the explosion in human numbers, the destruction of natural habitats and the looming catastrophe of climate change driven by rapidly rising global temperatures.

And the second study is simply a matter of the next lunch or dinner: many rare plants are survivors with the resources to adapt to change. In a fast-changing world, crop breeders may need to go back to the wild relatives to look for the genes that will keep the commercial carrots, courgettes, pumpkins and chilli peppers on the grocery shelves.

US scientists and international colleagues report in the journal Science Advances that they worked for 10 years and compiled 20 million observational records to establish a simple plant census: the forests, grasslands, scrublands, tundra and swamps of the wild world are home to about 435,000 unique plant species.

“The wild relatives of crops are one of the key tools used to breed crops adapted to difficult conditions. Some of them are sure to disappear from their natural habitats without urgent action”

And of this huge number, a surprising 36.5% are “exceedingly rare.” By this, researchers mean that these species have been observed and recorded no more than five times in the last 300 years of systematic botanical research.

“According to ecological and evolutionary theory, we’d expect many species to be rare, but the actual observed number we found was pretty startling,” said Brian Enquist of the University of Arizona, who led the consortium. “There are many more rare species than we expected.”

The rare species were most likely to be clustered in what ecologists call hotspots: the northern Andes in South America, Costa Rica, South Africa, Madagascar and south-east Asia.

What these places have in common is that, over millions of years, they have maintained stable climates, and as the glaciers retreated at the end of the last Ice Age, these tropical mountains and valleys provided refuge for life’s variety.

But these survivors may not enjoy a stable future, as ever higher levels of greenhouse gases are spilled into the atmosphere from human use of fossil fuels, and global temperatures continue to rise, and as human communities expand into what was once wilderness.

Significant loss ahead

“In many of these regions, there’s increasing human activity such as agriculture, cities and towns, land use and clearing,” said Professor Enquist.

“So that’s not exactly the best of news. If nothing is done, this all indicates that there will be a significant reduction in biodiversity – mainly in rare species – because their low numbers makes them more prone to extinction.”

Humans depend on the natural world for survival: biodiversity – plants, fungi, mammals, birds, fish, amphibians, reptiles and so on – provides all human nourishment, most of the medicines, fuels, fabrics and textiles that warm and shelter 7.7bn people, and at the same time maintains supplies of water, air, crop pollinators and so on.

But new research in the journal Plants, People, Planet confirms once again that many of the wild ancestors and cousins of the crops that nourish billions could be at risk.

And these wild relatives – which have survived climate shifts over millions of years – represent a vital resource for plant breeders anxious to cope with rapid global heating.

Unpreserved

The latest study confirms that 65% of wild pumpkins and more than 95% of wild chilli peppers are not formally preserved in any gene banks protected by conservation scientists.

“The wild relatives of crops are one of the key tools used to breed crops adapted to hotter, colder, drier, wetter, saltier and other difficult conditions,” said Colin Khoury of the International Centre for Tropical Agriculture.

“But they are impacted by habitat destruction, over-harvesting, climate change, pollution, invasive species and more. Some of them are sure to disappear from their natural habitats without urgent action.”

Dr Khoury and his colleagues have prepared a series of detailed maps of the range and distribution of the wild relatives of a range of important food species: the aim is to focus on the most effective kinds of protection for what, literally, could become tomorrow’s lunch in a world of rapid change.

“If they disappear, they are gone,” said Dr Khoury. “Extinction is forever, which is a loss not only in terms of their evolution and persistence on the planet, but also a loss to the future of our food.” – Climate News Network

More than a third of the world’s plants are so rare they face extinction. In a warmer world, that would leave supplies of food at risk.

LONDON, 17 December, 2019 – Botanists have made a new census of terrestrial plants – only to find that with nearly 40% of them rare, or extremely rare, this may put food at risk.

And a second team of researchers, in a separate study, has established that some of these rare or vanishing species could include the wild relatives of some of the planet’s most popular vegetables.

The two studies matter. The first underlines yet another reason for new and determined conservation strategies to preserve the extraordinary natural variety and richness of life – the shorthand word that scientists use is biodiversity – already under pressure from the explosion in human numbers, the destruction of natural habitats and the looming catastrophe of climate change driven by rapidly rising global temperatures.

And the second study is simply a matter of the next lunch or dinner: many rare plants are survivors with the resources to adapt to change. In a fast-changing world, crop breeders may need to go back to the wild relatives to look for the genes that will keep the commercial carrots, courgettes, pumpkins and chilli peppers on the grocery shelves.

US scientists and international colleagues report in the journal Science Advances that they worked for 10 years and compiled 20 million observational records to establish a simple plant census: the forests, grasslands, scrublands, tundra and swamps of the wild world are home to about 435,000 unique plant species.

“The wild relatives of crops are one of the key tools used to breed crops adapted to difficult conditions. Some of them are sure to disappear from their natural habitats without urgent action”

And of this huge number, a surprising 36.5% are “exceedingly rare.” By this, researchers mean that these species have been observed and recorded no more than five times in the last 300 years of systematic botanical research.

“According to ecological and evolutionary theory, we’d expect many species to be rare, but the actual observed number we found was pretty startling,” said Brian Enquist of the University of Arizona, who led the consortium. “There are many more rare species than we expected.”

The rare species were most likely to be clustered in what ecologists call hotspots: the northern Andes in South America, Costa Rica, South Africa, Madagascar and south-east Asia.

What these places have in common is that, over millions of years, they have maintained stable climates, and as the glaciers retreated at the end of the last Ice Age, these tropical mountains and valleys provided refuge for life’s variety.

But these survivors may not enjoy a stable future, as ever higher levels of greenhouse gases are spilled into the atmosphere from human use of fossil fuels, and global temperatures continue to rise, and as human communities expand into what was once wilderness.

Significant loss ahead

“In many of these regions, there’s increasing human activity such as agriculture, cities and towns, land use and clearing,” said Professor Enquist.

“So that’s not exactly the best of news. If nothing is done, this all indicates that there will be a significant reduction in biodiversity – mainly in rare species – because their low numbers makes them more prone to extinction.”

Humans depend on the natural world for survival: biodiversity – plants, fungi, mammals, birds, fish, amphibians, reptiles and so on – provides all human nourishment, most of the medicines, fuels, fabrics and textiles that warm and shelter 7.7bn people, and at the same time maintains supplies of water, air, crop pollinators and so on.

But new research in the journal Plants, People, Planet confirms once again that many of the wild ancestors and cousins of the crops that nourish billions could be at risk.

And these wild relatives – which have survived climate shifts over millions of years – represent a vital resource for plant breeders anxious to cope with rapid global heating.

Unpreserved

The latest study confirms that 65% of wild pumpkins and more than 95% of wild chilli peppers are not formally preserved in any gene banks protected by conservation scientists.

“The wild relatives of crops are one of the key tools used to breed crops adapted to hotter, colder, drier, wetter, saltier and other difficult conditions,” said Colin Khoury of the International Centre for Tropical Agriculture.

“But they are impacted by habitat destruction, over-harvesting, climate change, pollution, invasive species and more. Some of them are sure to disappear from their natural habitats without urgent action.”

Dr Khoury and his colleagues have prepared a series of detailed maps of the range and distribution of the wild relatives of a range of important food species: the aim is to focus on the most effective kinds of protection for what, literally, could become tomorrow’s lunch in a world of rapid change.

“If they disappear, they are gone,” said Dr Khoury. “Extinction is forever, which is a loss not only in terms of their evolution and persistence on the planet, but also a loss to the future of our food.” – Climate News Network

Jet stream changes may hit global breadbaskets

Food shortages and civil disturbances may result from changes in the jet stream winds which circle the Earth, scientists say.

LONDON, 10 December, 2019 − Patterns in the winds of the jet stream that circles the Earth can bring simultaneous heatwaves to breadbasket regions which provide up to a quarter of global crops, scientists have found.

Extreme weather on this scale can significantly harm food production, making prices soar and fuelling social unrest. Western North America, western Europe, western Russia, Ukraine and the Caspian Sea region are especially susceptible.

In a study published in the journal Nature Climate Change the researchers, from Germany, Australia and the US, explain how specific wave patterns in the jet stream strongly increase the chance of heatwaves occurring at the same time in different parts of the globe.

The jet stream is a fast-moving river of air that continuously circles the northern hemisphere from west to east. It generally confines itself to a relatively narrow band, but can meander north or south, due to a feature scientists call Rossby waves.

Among other effects, these atmospheric wobbles may pull frigid air masses from the polar regions, or hot ones from the subtropics, into the populous mid-latitudes.

“We will see more and more heatwaves striking different areas at the same time, and they will become even more severe”

The wobbles strongly influence daily weather. When they grow particularly large they can bring prolonged heatwaves, droughts or floods in summer, or in colder seasons abnormal cold spells.

The waves have hit in 1983, 2003, 2006, 2012 and 2018, when many temperature records fell across the US, Canada, Scandinavia and Siberia. As well as killing crops, the waves have killed thousands of people, especially in Europe and Russia, where air conditioning is far less common than in North America.

The research shows that there has been a significant increase in the probability of multiple global breadbasket failures, particularly for wheat, maize, and soybeans. For soybeans the implications of crop failure in all major breadbaskets associated with climate risk would be at least 12.55 million tons of crop losses, far more than the 7.2 million tons lost in 1988–1989, one of the largest soybean production shocks.

Kai Kornhuber, a doctoral candidate from the Potsdam Institute for Climate Impact Research (PIK) in Germany and the Lamont-Doherty Earth Institute, US, and colleagues found that it is these simultaneous heatwaves that can significantly reduce crop production and create the risk of multiple harvest failures and other far-reaching consequences.

Twentyfold increase

“We found an under-explored vulnerability in the food system: when these global-scale wind patterns are in place, we see a twenty-fold increase in the risk of simultaneous heatwaves in major crop-producing regions ”, said Kornhuber. “During these events there actually is a global structure in the otherwise quite chaotic circulation.”

The atmospheric patterns the team researched mean that heat and drought become locked into one place simultaneously, where they then affect crops’ production yields.

“What makes this particularly relevant: the bell can ring in multiple regions at once, and the impacts of those specific interconnections were not quantified previously,” Kornhuber said.

“Normally low harvests in one region are expected to be balanced out by good harvests elsewhere. But these waves can cause reduced harvests in several important breadbaskets simultaneously, creating risks for global food production”, said co-author Dr Dim Coumou from the Institute for Environmental Studies at VU Amsterdam and PIK.

Remote effects

“We will see more and more heatwaves striking different areas at the same time, and they will become even more severe”, added Dr Jonathan Donges, another co-author at PIK. “This can impact food availability not only in the regions directly affected. Even remoter regions may see scarcities and price spikes as a result.”

“During years in which two or more summer weeks featured the amplified wave pattern, cereal crop production was reduced by more than 10% in individual regions, and by 4% when averaged across all crop regions affected by the pattern”, said Elisabeth Vogel, from Melbourne University.

Ted Shepherd, professor of climate science at the University of Reading, UK, who was not involved in the study, said: “We have strong observational evidence of this wave pattern. What is open for discussion is how it might respond to climate change.”

Professor Shepherd said many consensus scientific statements, including those from the Intergovernmental Panel on Climate Change, had proved to be under-estimates of how fast and far the effects of global warming might move. − Climate News Network

Food shortages and civil disturbances may result from changes in the jet stream winds which circle the Earth, scientists say.

LONDON, 10 December, 2019 − Patterns in the winds of the jet stream that circles the Earth can bring simultaneous heatwaves to breadbasket regions which provide up to a quarter of global crops, scientists have found.

Extreme weather on this scale can significantly harm food production, making prices soar and fuelling social unrest. Western North America, western Europe, western Russia, Ukraine and the Caspian Sea region are especially susceptible.

In a study published in the journal Nature Climate Change the researchers, from Germany, Australia and the US, explain how specific wave patterns in the jet stream strongly increase the chance of heatwaves occurring at the same time in different parts of the globe.

The jet stream is a fast-moving river of air that continuously circles the northern hemisphere from west to east. It generally confines itself to a relatively narrow band, but can meander north or south, due to a feature scientists call Rossby waves.

Among other effects, these atmospheric wobbles may pull frigid air masses from the polar regions, or hot ones from the subtropics, into the populous mid-latitudes.

“We will see more and more heatwaves striking different areas at the same time, and they will become even more severe”

The wobbles strongly influence daily weather. When they grow particularly large they can bring prolonged heatwaves, droughts or floods in summer, or in colder seasons abnormal cold spells.

The waves have hit in 1983, 2003, 2006, 2012 and 2018, when many temperature records fell across the US, Canada, Scandinavia and Siberia. As well as killing crops, the waves have killed thousands of people, especially in Europe and Russia, where air conditioning is far less common than in North America.

The research shows that there has been a significant increase in the probability of multiple global breadbasket failures, particularly for wheat, maize, and soybeans. For soybeans the implications of crop failure in all major breadbaskets associated with climate risk would be at least 12.55 million tons of crop losses, far more than the 7.2 million tons lost in 1988–1989, one of the largest soybean production shocks.

Kai Kornhuber, a doctoral candidate from the Potsdam Institute for Climate Impact Research (PIK) in Germany and the Lamont-Doherty Earth Institute, US, and colleagues found that it is these simultaneous heatwaves that can significantly reduce crop production and create the risk of multiple harvest failures and other far-reaching consequences.

Twentyfold increase

“We found an under-explored vulnerability in the food system: when these global-scale wind patterns are in place, we see a twenty-fold increase in the risk of simultaneous heatwaves in major crop-producing regions ”, said Kornhuber. “During these events there actually is a global structure in the otherwise quite chaotic circulation.”

The atmospheric patterns the team researched mean that heat and drought become locked into one place simultaneously, where they then affect crops’ production yields.

“What makes this particularly relevant: the bell can ring in multiple regions at once, and the impacts of those specific interconnections were not quantified previously,” Kornhuber said.

“Normally low harvests in one region are expected to be balanced out by good harvests elsewhere. But these waves can cause reduced harvests in several important breadbaskets simultaneously, creating risks for global food production”, said co-author Dr Dim Coumou from the Institute for Environmental Studies at VU Amsterdam and PIK.

Remote effects

“We will see more and more heatwaves striking different areas at the same time, and they will become even more severe”, added Dr Jonathan Donges, another co-author at PIK. “This can impact food availability not only in the regions directly affected. Even remoter regions may see scarcities and price spikes as a result.”

“During years in which two or more summer weeks featured the amplified wave pattern, cereal crop production was reduced by more than 10% in individual regions, and by 4% when averaged across all crop regions affected by the pattern”, said Elisabeth Vogel, from Melbourne University.

Ted Shepherd, professor of climate science at the University of Reading, UK, who was not involved in the study, said: “We have strong observational evidence of this wave pattern. What is open for discussion is how it might respond to climate change.”

Professor Shepherd said many consensus scientific statements, including those from the Intergovernmental Panel on Climate Change, had proved to be under-estimates of how fast and far the effects of global warming might move. − Climate News Network