Tag Archives: Biodiversity

Natural forests are best at storing carbon

Natural forests are a global good. Well conserved, they help combat climate change. But as new research confirms, it’s not that simple.

LONDON, 18 May, 2020 – Two new studies have freshly confirmed an argument unchallenged for more than three decades: the best way to absorb and permanently store carbon from the atmosphere is to restore and conserve existing natural forests.

This proposition – successively urged on governments around the world since the first studies of strategy to confront global warming and potentially catastrophic climate change – has more chance of sustained success than any attempts to offset carbon emissions by indiscriminate plantations of new canopy, or even systematic investment in public initiatives such as the Trillion Tree Campaign.

And the argument gets even more support from a closer look at disturbances to natural woodland: these demonstrate that even simple clearings in forests will create unfavourable local microclimates and disturb the species that flourish in stable forests.

Karen Holl is a restoration ecologist at the University of California at Santa Cruz. She and a colleague from São Paulo in Brazil argue in the journal Science that while planting trees can help protect biodiversity, assist in natural water management and increase local shade, the same act can actually also damage local native ecosystems, reduce water supply, dispossess local landholders and increase social inequity.

“We can’t plant our way out of climate change. It is only one piece of the puzzle. Planting trees is not a simple solution”

The point she makes is that the wrong kind of tree on the wrong sort of land helps nobody. Nor does a tree that, once planted, is neglected and left to die, or to change the nature of the land it occupies – not even if there are a trillion of them.

“We can’t plant our way out of climate change. It is only one piece of the puzzle,” she said. “Planting trees is not a simple solution. It’s complicated, and we need to be realistic about what we can and cannot achieve.”

Her argument is that planting trees is not the same as increasing forest cover, and in any case will add up to only a fraction of the carbon reductions needed by 2100 to keep global temperatures from rising to 2°C above the long-term average for most of human history.

And given that increasing drought and temperatures can lead to widespread tree death, some of the effort could be hopelessly wasted.

Leave well alone

“The first thing we can do is keep existing forests standing, and the second is to allow trees to regenerate in areas that were formerly forests,” she said.

“In many cases, trees will recover on their own – just look at the entire eastern United States that was deforested 200 years ago. Much of that has come back without actively planting trees.

“Yes, in some highly degraded lands we will need to plant trees, but that should be the last option since it is the most expensive and often is not successful. I’ve spent my life on this. We need to be thoughtful about how we bring the forest back.”

Just how thoughtful is illuminated by another study, also in Science. European scientists looked at temperatures in 100 forest interiors and matched this with 80 years of data from 2,955 locations in 56 regions to discover that the routine open space temperature measurements collected by climate scientists do not reflect conditions under a mature forest canopy.

Avoid clearings

The denser the leaf cover, the more effectively the forest buffers the wild things that live there from climate change. But as the cover becomes sparser, conditions change and the thermometer goes up by several degrees.

The implication – supported by other recent research – is that any kind of clearing in some way weakens the integrity of a forest, both as a refuge for otherwise threatened biodiversity, and as a potential store of atmospheric carbon.

Global warming is already increasing what researchers have labelled “thermophilisation” – that is, a tendency for warm climate species to flourish at the expense of those already at the limit of their preferred temperature.

The implication is that some species will not be able to adapt swiftly enough to ever more intense extremes of heat and drought, and the nature of forest cover is likely to change. – Climate News Network

Natural forests are a global good. Well conserved, they help combat climate change. But as new research confirms, it’s not that simple.

LONDON, 18 May, 2020 – Two new studies have freshly confirmed an argument unchallenged for more than three decades: the best way to absorb and permanently store carbon from the atmosphere is to restore and conserve existing natural forests.

This proposition – successively urged on governments around the world since the first studies of strategy to confront global warming and potentially catastrophic climate change – has more chance of sustained success than any attempts to offset carbon emissions by indiscriminate plantations of new canopy, or even systematic investment in public initiatives such as the Trillion Tree Campaign.

And the argument gets even more support from a closer look at disturbances to natural woodland: these demonstrate that even simple clearings in forests will create unfavourable local microclimates and disturb the species that flourish in stable forests.

Karen Holl is a restoration ecologist at the University of California at Santa Cruz. She and a colleague from São Paulo in Brazil argue in the journal Science that while planting trees can help protect biodiversity, assist in natural water management and increase local shade, the same act can actually also damage local native ecosystems, reduce water supply, dispossess local landholders and increase social inequity.

“We can’t plant our way out of climate change. It is only one piece of the puzzle. Planting trees is not a simple solution”

The point she makes is that the wrong kind of tree on the wrong sort of land helps nobody. Nor does a tree that, once planted, is neglected and left to die, or to change the nature of the land it occupies – not even if there are a trillion of them.

“We can’t plant our way out of climate change. It is only one piece of the puzzle,” she said. “Planting trees is not a simple solution. It’s complicated, and we need to be realistic about what we can and cannot achieve.”

Her argument is that planting trees is not the same as increasing forest cover, and in any case will add up to only a fraction of the carbon reductions needed by 2100 to keep global temperatures from rising to 2°C above the long-term average for most of human history.

And given that increasing drought and temperatures can lead to widespread tree death, some of the effort could be hopelessly wasted.

Leave well alone

“The first thing we can do is keep existing forests standing, and the second is to allow trees to regenerate in areas that were formerly forests,” she said.

“In many cases, trees will recover on their own – just look at the entire eastern United States that was deforested 200 years ago. Much of that has come back without actively planting trees.

“Yes, in some highly degraded lands we will need to plant trees, but that should be the last option since it is the most expensive and often is not successful. I’ve spent my life on this. We need to be thoughtful about how we bring the forest back.”

Just how thoughtful is illuminated by another study, also in Science. European scientists looked at temperatures in 100 forest interiors and matched this with 80 years of data from 2,955 locations in 56 regions to discover that the routine open space temperature measurements collected by climate scientists do not reflect conditions under a mature forest canopy.

Avoid clearings

The denser the leaf cover, the more effectively the forest buffers the wild things that live there from climate change. But as the cover becomes sparser, conditions change and the thermometer goes up by several degrees.

The implication – supported by other recent research – is that any kind of clearing in some way weakens the integrity of a forest, both as a refuge for otherwise threatened biodiversity, and as a potential store of atmospheric carbon.

Global warming is already increasing what researchers have labelled “thermophilisation” – that is, a tendency for warm climate species to flourish at the expense of those already at the limit of their preferred temperature.

The implication is that some species will not be able to adapt swiftly enough to ever more intense extremes of heat and drought, and the nature of forest cover is likely to change. – Climate News Network

Plastic waste now litters Antarctic shore

From the deep Mediterranean marine mud to the desolate beaches of the Southern Ocean, plastic waste now gets everywhere.

LONDON, 12 May, 2020 – The throwaway society now has a global reach. British and German scientists have found astonishing concentrations of plastic waste in the form of tiny fibres on the sea floor. In just one square metre of marine ooze, they have counted as many as 1.9 million fragments less than a millimetre in length.

And two studies have identified sickening levels of plastic waste in the Southern Ocean that washes around Antarctica. One team reports ever greater counts of debris on the beaches of islands in South Georgia and South Orkney; the other on the increasing quantities ingested by the wandering albatross and the giant petrel, two iconic birds of the south polar seas.

An estimated 10 million tonnes of discarded food wrapping, drinking straws, disposable cups, bottles, carrier bags and fishing gear are tipped into the sea each year: plastic waste has now been found in all the world’s oceans, and even in the polar ice, an indestructible reminder of human impact on the natural world.

Tiny textile particles or microfibres of plastic have been found in every sampled litre of sea water, in the stomachs of seabirds and in the bellies of whales.

In fact the visible debris – the polystyrene cups and drinking straws and carrier bags floating on or near the surface – is thought to account for a tiny proportion of the total. Around 99% is thought to be in the deep oceans.

“Microplastics are not uniformly distributed across the study area; instead they are distributed by powerful seafloor currents that concentrate them in certain areas”

And researchers now report in the journal Science that they have found an indicator as to the final fate of most of it. They collected sediment at depths of up to 900 metres from the floor of the Tyrrhenian Sea to the west of the Italian peninsula and began counting the particles of indestructible polymer material in the marine mud, carried there by deep ocean currents.

“Almost everybody has heard of the infamous ‘garbage patches’ of floating plastic, but we were shocked at the high concentrations of microplastics we found on the sea floor,” said Ian Kane of the University of Manchester, in the UK, one of the authors.

“We discovered that microplastics are not uniformly distributed across the study area; instead they are distributed by powerful seafloor currents that concentrate them in certain areas.”

These same deep currents also carry oxygen-rich water and nutrients, which suggests that toxic microplastics are being carried into vital deep ecosystems. But the surface-borne debris has far-reaching consequences too.

Remedial efforts

British and Australian scientists who made surveys over three decades of beached plastic, metal, glass, paper and rubber at locations in the Southern Ocean report in the journal Environment International that between 1989 and March 2019, they recovered 10,112 items of waste weighing in total more than 100kg from Bird Island off South Georgia, and 1,304 items weighing in all 268 kg from the remote shores of Signy Island in the South Orkney archipelago.

Almost 90% of the total was plastic. The peak of the debris count was in the 1990s, which suggests that some attempts have been made to reduce the levels discarded from shipping and other sources.

And a second study in the same journal reports that in the same 30 years, levels of plastic pollution had been consumed in increasing quantities by two out of three species of albatross, and another sea bird.

Annual intake in Diomedea exulans, the wandering albatross, had increased 14-fold, and in the giant petrel Macronectes giganteus the intake had increased six-fold.

“Our study adds to the growing body of evidence that fishing and other vessels make a major contribution to plastic pollution,” said Richard Phillips of the British Antarctic Survey. “It’s clear that marine plastics are a threat to seabirds and other wildlife, and more needs to be done.” – Climate News Network

From the deep Mediterranean marine mud to the desolate beaches of the Southern Ocean, plastic waste now gets everywhere.

LONDON, 12 May, 2020 – The throwaway society now has a global reach. British and German scientists have found astonishing concentrations of plastic waste in the form of tiny fibres on the sea floor. In just one square metre of marine ooze, they have counted as many as 1.9 million fragments less than a millimetre in length.

And two studies have identified sickening levels of plastic waste in the Southern Ocean that washes around Antarctica. One team reports ever greater counts of debris on the beaches of islands in South Georgia and South Orkney; the other on the increasing quantities ingested by the wandering albatross and the giant petrel, two iconic birds of the south polar seas.

An estimated 10 million tonnes of discarded food wrapping, drinking straws, disposable cups, bottles, carrier bags and fishing gear are tipped into the sea each year: plastic waste has now been found in all the world’s oceans, and even in the polar ice, an indestructible reminder of human impact on the natural world.

Tiny textile particles or microfibres of plastic have been found in every sampled litre of sea water, in the stomachs of seabirds and in the bellies of whales.

In fact the visible debris – the polystyrene cups and drinking straws and carrier bags floating on or near the surface – is thought to account for a tiny proportion of the total. Around 99% is thought to be in the deep oceans.

“Microplastics are not uniformly distributed across the study area; instead they are distributed by powerful seafloor currents that concentrate them in certain areas”

And researchers now report in the journal Science that they have found an indicator as to the final fate of most of it. They collected sediment at depths of up to 900 metres from the floor of the Tyrrhenian Sea to the west of the Italian peninsula and began counting the particles of indestructible polymer material in the marine mud, carried there by deep ocean currents.

“Almost everybody has heard of the infamous ‘garbage patches’ of floating plastic, but we were shocked at the high concentrations of microplastics we found on the sea floor,” said Ian Kane of the University of Manchester, in the UK, one of the authors.

“We discovered that microplastics are not uniformly distributed across the study area; instead they are distributed by powerful seafloor currents that concentrate them in certain areas.”

These same deep currents also carry oxygen-rich water and nutrients, which suggests that toxic microplastics are being carried into vital deep ecosystems. But the surface-borne debris has far-reaching consequences too.

Remedial efforts

British and Australian scientists who made surveys over three decades of beached plastic, metal, glass, paper and rubber at locations in the Southern Ocean report in the journal Environment International that between 1989 and March 2019, they recovered 10,112 items of waste weighing in total more than 100kg from Bird Island off South Georgia, and 1,304 items weighing in all 268 kg from the remote shores of Signy Island in the South Orkney archipelago.

Almost 90% of the total was plastic. The peak of the debris count was in the 1990s, which suggests that some attempts have been made to reduce the levels discarded from shipping and other sources.

And a second study in the same journal reports that in the same 30 years, levels of plastic pollution had been consumed in increasing quantities by two out of three species of albatross, and another sea bird.

Annual intake in Diomedea exulans, the wandering albatross, had increased 14-fold, and in the giant petrel Macronectes giganteus the intake had increased six-fold.

“Our study adds to the growing body of evidence that fishing and other vessels make a major contribution to plastic pollution,” said Richard Phillips of the British Antarctic Survey. “It’s clear that marine plastics are a threat to seabirds and other wildlife, and more needs to be done.” – Climate News Network

Tigers retreat before spreading road networks

The global push to save an iconic species from extinction struggles, as tigers retreat before the relentless growth of roads.

LONDON, 4 May, 2020 − Humans have made inroads into the last territory of the tiger – literally: the inexorable increase in roads is driving the tigers’ retreat.

A new study of the wilderness set aside for the rapidly-dwindling populations of Panthera tigris in 13 countries warns that more than half of all this supposedly untouched reserve is within 5kms of a road.

Altogether, tiger conservation landscapes considered crucial for the recovery of an endangered species are now home to 134,000 kilometres of road. This intrusion alone may have reduced the abundance of both the carnivore and its natural prey by about one fifth.

And by 2050 researchers expect that another 24,000kms of road will have been built through the 1.16 million square kilometres of wilderness officially conserved in Russia, China, India, Myanmar, Nepal, Bangladesh, Thailand, Vietnam, Malaysia, Indonesia, Cambodia, Laos and Bhutan. Many of these will have been built under China’s so-called “belt-and-road initiative” in the developing world.

“Our analysis demonstrates that, overall, tigers face a ubiquitous and mounting threat from road networks across much of their 13-country range,” said Neil Carter, of the University of Michigan in the US, who led the research.

“Tiger habitats have declined by 40% since 2006, underscoring the importance of maintaining roadless areas and resisting road expansion in places where tigers still exist, before it is too late”

He and colleagues report in the journal Science Advances that they calculated road density, distance to the nearest road and average species abundance in all 76 blocks of land set aside for tiger conservation, to confirm conservationists’ worst fears.

Encroaching roads discourage the herbivores that tigers might prey upon; they degrade the habitat for all wildlife in the region; and they provide easier access for poachers, for whom a tiger carcass is a valuable commodity. In the Russian Far East, collisions with road vehicles were enough to reduce tiger survival rates.

The road seems the first enemy of conservation. Researchers have recently established that even the presence of human intrusion – the border of a ranch, a commercial clearing, a palm oil plantation or just a simple road – is enough to weaken and in some way damage the integrity of the 500 metres of wilderness next to the clearing.

The global record for the protection of those areas set aside for the conservation of endemic species is not good: another study found that, worldwide, since 1993, more than 280,000 sq kms of natural reserve had been subjected to “intense human pressure.”

And a third study fingered the road itself as the problem, and a growing problem: roads already fragment the world’s landscapes, and by 2050 governments will have added another 25 million kilometres of asphalt, traffic and settlement, most of it in the developing world.

Numbers still dropping

Thanks to human population growth and climate change, the planet is poised for the extinction of wild creatures and plants on a massive scale. So the tiger study reflects a wider pattern.

The difference is that for more than 50 years conservationists and governments have encouraged international efforts to conserve one of the most iconic and at the same time one of the most endangered of all the big cats, but the numbers are still falling, as roads turn what had been undisturbed habitat into an archipelago of little “tiger islands” in which populations are isolated from each other.

The scientists found that those areas most strictly protected in the tiger conservation were less densely interrupted by roads: however, these densities varied widely across countries. China’s average road density in tiger conservation landscapes was almost eight times greater than, for example, Malaysia’s.

“Tiger habitats have declined by 40% since 2006, underscoring the importance of maintaining roadless areas and resisting road expansion in places where tigers still exist, before it is too late,” Dr Carter said.

“Given that roads will be a pervasive challenge to tiger recovery in the future, we urge decision-makers to make sustainable road development a top priority.” − Climate News Network

The global push to save an iconic species from extinction struggles, as tigers retreat before the relentless growth of roads.

LONDON, 4 May, 2020 − Humans have made inroads into the last territory of the tiger – literally: the inexorable increase in roads is driving the tigers’ retreat.

A new study of the wilderness set aside for the rapidly-dwindling populations of Panthera tigris in 13 countries warns that more than half of all this supposedly untouched reserve is within 5kms of a road.

Altogether, tiger conservation landscapes considered crucial for the recovery of an endangered species are now home to 134,000 kilometres of road. This intrusion alone may have reduced the abundance of both the carnivore and its natural prey by about one fifth.

And by 2050 researchers expect that another 24,000kms of road will have been built through the 1.16 million square kilometres of wilderness officially conserved in Russia, China, India, Myanmar, Nepal, Bangladesh, Thailand, Vietnam, Malaysia, Indonesia, Cambodia, Laos and Bhutan. Many of these will have been built under China’s so-called “belt-and-road initiative” in the developing world.

“Our analysis demonstrates that, overall, tigers face a ubiquitous and mounting threat from road networks across much of their 13-country range,” said Neil Carter, of the University of Michigan in the US, who led the research.

“Tiger habitats have declined by 40% since 2006, underscoring the importance of maintaining roadless areas and resisting road expansion in places where tigers still exist, before it is too late”

He and colleagues report in the journal Science Advances that they calculated road density, distance to the nearest road and average species abundance in all 76 blocks of land set aside for tiger conservation, to confirm conservationists’ worst fears.

Encroaching roads discourage the herbivores that tigers might prey upon; they degrade the habitat for all wildlife in the region; and they provide easier access for poachers, for whom a tiger carcass is a valuable commodity. In the Russian Far East, collisions with road vehicles were enough to reduce tiger survival rates.

The road seems the first enemy of conservation. Researchers have recently established that even the presence of human intrusion – the border of a ranch, a commercial clearing, a palm oil plantation or just a simple road – is enough to weaken and in some way damage the integrity of the 500 metres of wilderness next to the clearing.

The global record for the protection of those areas set aside for the conservation of endemic species is not good: another study found that, worldwide, since 1993, more than 280,000 sq kms of natural reserve had been subjected to “intense human pressure.”

And a third study fingered the road itself as the problem, and a growing problem: roads already fragment the world’s landscapes, and by 2050 governments will have added another 25 million kilometres of asphalt, traffic and settlement, most of it in the developing world.

Numbers still dropping

Thanks to human population growth and climate change, the planet is poised for the extinction of wild creatures and plants on a massive scale. So the tiger study reflects a wider pattern.

The difference is that for more than 50 years conservationists and governments have encouraged international efforts to conserve one of the most iconic and at the same time one of the most endangered of all the big cats, but the numbers are still falling, as roads turn what had been undisturbed habitat into an archipelago of little “tiger islands” in which populations are isolated from each other.

The scientists found that those areas most strictly protected in the tiger conservation were less densely interrupted by roads: however, these densities varied widely across countries. China’s average road density in tiger conservation landscapes was almost eight times greater than, for example, Malaysia’s.

“Tiger habitats have declined by 40% since 2006, underscoring the importance of maintaining roadless areas and resisting road expansion in places where tigers still exist, before it is too late,” Dr Carter said.

“Given that roads will be a pervasive challenge to tiger recovery in the future, we urge decision-makers to make sustainable road development a top priority.” − Climate News Network

Threats to the insect world are growing

The insect world is dwindling. By 2100, half of all insects could be gone. But there could be gainers too.

LONDON, 30 April, 2020 − The butterflies are quietly flying away, the beetles are buzzing off, and the insect world is shrinking. The Earth’s  land-based insects are in steady decline, their numbers falling by around a quarter every three decades.

And although there could be a whole world of reasons for the global loss of a vital class of animals, European scientists have pinpointed at least one, in one location.

Insect food plants are being lost in the Swiss canton of Zurich, and with them, many of the hoverflies, bumblebees, bees and butterflies that depend on them.

Scientists from Germany and Russia report in the journal Science that they examined the bigger story told by data from 166 surveys of insects and arachnids – that is, not just flies but spiders too – across 1,676 sites worldwide, over periods from 1925 to 2018, and many of them of around 20 years.

Largely missed

They found that those insects that based their lives on land rather than water were slipping away at an average of 0.92% per year. “0.92% might not sound like much, but in fact it means 24% fewer insects in 30 years’ time and 50% fewer over 75 years,” said Roel van Klink of the German Centre for Integrative Biodiversity Research and based at the University of Leipzig.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next. It’s like going back to the place where you grew up. It’s only because you haven’t been there for years that you suddenly realise how much has changed, and all too often not for the better.”

He is not the first to draw attention to insect loss: other groups have warned of dramatic instances of decline and imminent extinction, along with the changes in insect populations and the disappearance of the habitat on which so many species depend.

But the researchers found the decline wasn’t uniform. Those insects – midges and mayflies, for example – that are essentially aquatic were actually increasing in number, on average by more than 1% a year. Flying insects overall however are in decline, and ground-dwellers and grassland insects too are slowly losing the battle for survival, while the numbers of insects in the woodland treetops remain about the same.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next”

Insect declines in Europe and the US West and Midwest were marked, but those insects that live for part of their lives in water in northern Europe and the western US showed a 38% increase over 30 years: this may reflect national and international attempts to limit pollution of the waterways. In both decline and revival, the scientists at work see the impact of human handling of natural habitat.

“Insect populations are like logs of wood that are pushed under water,” Dr van Klink said. “They want to come up while we keep pushing them down. But we can reduce the pressure so they rise again.

“The freshwater insects have shown us this is possible. It’s just not always easy to identify the causes of declines, and thus the most effective measures to reverse them. And these may also differ between locations.”

But within a day of the publication of the Science analysis, German and Swiss scientists had identified the cause of decline in one closely-observed area. They report in the journal Ecological Applications that over the past century there had been an overall decline in wild food plants for all kinds of insects in the Zurich canton.

Urban spread

Wetlands had shrunk by around 90%, the cities and towns had expanded, intensive farming had meant the loss of meadows and farmland habitats.
With help from 250 volunteers, researchers had made detailed studies of the 1,719 seed plant species in 1km plots of land at 3km intervals across the whole canton, between 2012 and 2017.

They then identified 966 of those plants visited by daytime pollinators, and compared their findings with highly-detailed data assembled about the vegetation of the canton before 1930.

Some specialised groups of insects evolved in partnership with equally specialised insects. The scientists found that, for instance, greater knapweed or Centaurea scabiosa was in decline, which was bad news for those bumblebees, bees and butterflies with tongues long enough to reach the nectar. The poisonous plant aconite, or Aconitum napellus, is pollinated by a bumblebee impervious to its toxin. Once again, the loss of floral variety and insect life even in one much-occupied place may not have been obvious.

“It’s hard for us to imagine what vegetation looked like 100 years ago,” said Michael Kessler, a botanist at the University of Zurich. “But our data showed that about half of all species have experienced significant decline in their abundance, while only about 10% of the species have increased.” − Climate News Network

The insect world is dwindling. By 2100, half of all insects could be gone. But there could be gainers too.

LONDON, 30 April, 2020 − The butterflies are quietly flying away, the beetles are buzzing off, and the insect world is shrinking. The Earth’s  land-based insects are in steady decline, their numbers falling by around a quarter every three decades.

And although there could be a whole world of reasons for the global loss of a vital class of animals, European scientists have pinpointed at least one, in one location.

Insect food plants are being lost in the Swiss canton of Zurich, and with them, many of the hoverflies, bumblebees, bees and butterflies that depend on them.

Scientists from Germany and Russia report in the journal Science that they examined the bigger story told by data from 166 surveys of insects and arachnids – that is, not just flies but spiders too – across 1,676 sites worldwide, over periods from 1925 to 2018, and many of them of around 20 years.

Largely missed

They found that those insects that based their lives on land rather than water were slipping away at an average of 0.92% per year. “0.92% might not sound like much, but in fact it means 24% fewer insects in 30 years’ time and 50% fewer over 75 years,” said Roel van Klink of the German Centre for Integrative Biodiversity Research and based at the University of Leipzig.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next. It’s like going back to the place where you grew up. It’s only because you haven’t been there for years that you suddenly realise how much has changed, and all too often not for the better.”

He is not the first to draw attention to insect loss: other groups have warned of dramatic instances of decline and imminent extinction, along with the changes in insect populations and the disappearance of the habitat on which so many species depend.

But the researchers found the decline wasn’t uniform. Those insects – midges and mayflies, for example – that are essentially aquatic were actually increasing in number, on average by more than 1% a year. Flying insects overall however are in decline, and ground-dwellers and grassland insects too are slowly losing the battle for survival, while the numbers of insects in the woodland treetops remain about the same.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next”

Insect declines in Europe and the US West and Midwest were marked, but those insects that live for part of their lives in water in northern Europe and the western US showed a 38% increase over 30 years: this may reflect national and international attempts to limit pollution of the waterways. In both decline and revival, the scientists at work see the impact of human handling of natural habitat.

“Insect populations are like logs of wood that are pushed under water,” Dr van Klink said. “They want to come up while we keep pushing them down. But we can reduce the pressure so they rise again.

“The freshwater insects have shown us this is possible. It’s just not always easy to identify the causes of declines, and thus the most effective measures to reverse them. And these may also differ between locations.”

But within a day of the publication of the Science analysis, German and Swiss scientists had identified the cause of decline in one closely-observed area. They report in the journal Ecological Applications that over the past century there had been an overall decline in wild food plants for all kinds of insects in the Zurich canton.

Urban spread

Wetlands had shrunk by around 90%, the cities and towns had expanded, intensive farming had meant the loss of meadows and farmland habitats.
With help from 250 volunteers, researchers had made detailed studies of the 1,719 seed plant species in 1km plots of land at 3km intervals across the whole canton, between 2012 and 2017.

They then identified 966 of those plants visited by daytime pollinators, and compared their findings with highly-detailed data assembled about the vegetation of the canton before 1930.

Some specialised groups of insects evolved in partnership with equally specialised insects. The scientists found that, for instance, greater knapweed or Centaurea scabiosa was in decline, which was bad news for those bumblebees, bees and butterflies with tongues long enough to reach the nectar. The poisonous plant aconite, or Aconitum napellus, is pollinated by a bumblebee impervious to its toxin. Once again, the loss of floral variety and insect life even in one much-occupied place may not have been obvious.

“It’s hard for us to imagine what vegetation looked like 100 years ago,” said Michael Kessler, a botanist at the University of Zurich. “But our data showed that about half of all species have experienced significant decline in their abundance, while only about 10% of the species have increased.” − Climate News Network

Tropical deforestation releases deadly infections

Brazil’s burning forests are bad news for the global climate. Now scientists say the trees harbour deadly infections too.

SÃO PAULO, 29 April, 2020 − As forest destruction continues unabated in Brazil, scientists are alarmed that, as well as spurring climate change, it may unleash new and deadly infections on humankind.

There is growing awareness that large-scale tropical deforestation, as in the Amazon, not only brings disastrous consequences for the climate, but releases new diseases like Covid-19 by enabling infections to pass from wild animals to human beings.

As one well-known Amazon scientist, biologist Philip Fearnside, puts it: “Amazon deforestation facilitates transmission both of new diseases and of old ones like malaria.

“The connection between deforestation and infectious diseases is just one more impact of deforestation, added to impacts of losing both Amazonia’s biodiversity and the forest’s vital climate functions in avoiding global warming and in recycling water.”

He is one of the co-authors of a paper by a team led by Joel Henrique Ellwanger on the impacts of Amazon deforestation on infectious diseases and public health, which has just been published in the Annals of the Brazilian Academy.

Dr Fearnside adds: “Many ‘new’ human diseases originate from pathogens transferred from wild animals, as occurred with the Covid-19 coronavirus. Amazonia contains a vast number of animal species and their associated pathogens with the potential to be transferred to humans.”

No surprise

The warnings are not new. Ana Lúcia Tourinho, with a Ph.D in ecology at the Federal University of Mato Grosso (UFMT), interviewed by Deutsche Welle, said: “For at least two decades scientists have repeated the warning: as populations advance on the forests, the risk grows of micro-organisms – up till then in equilibrium – migrating to humans and causing victims.

“That is why news of the propagation of the new coronavirus detected in China, which has spread throughout the world, was not a surprise.

“When a vírus which is not part of our evolutionary history leaves its natural host and enters our body it brings chaos”, she said.

Isolated and in equilibrium with their habitats, like dense forests, this sort of vírus would not be a threat to humans. The problem comes when this natural reservoir is destroyed and occupied (by other species).

Scientific studies published years before the present pandemic already showed the connection between the loss of forest, proliferation of bats in the degraded areas, and the coronavirus.

One example is the study by Dr Aneta Afelt, a researcher at the University of Warsaw, who concluded that the high rates of forest destruction in the last 40 years in Asia were an indication that the next serious infectious disease could come from there.

“For at least two decades scientists have repeated the warning: as populations advance on the forests, the risk grows of micro-organisms migrating to humans”

To reach this conclusion, she followed the trail of previous pandemics triggered by other coronaviruses like Sars in 2002 and 2003, and Mers in 2012.

“Because it’s one of the regions where population growth is most intense, where sanitary conditions remain bad and where the rate of deforestation is high, south-east Asia has all the conditions for becoming the place where infectious diseases emerge or re-emerge”, she wrote in 2018.

If destruction of the Amazon continues at the present accelerated pace, Dr Tourinho says, and it is turned into an area of savannah, “we cannot imagine what might come out of there in terms of diseases.”

The relationship between deforestation and the increase of diseases in the Amazon has been studied by Brazil’s Institute of Applied Economic Research (IPEA).

A 2015 survey in 773 Amazon towns showed that for each 1% of forest destroyed, malaria cases increased by 23%. The incidence of leishmaniasis, a disease spread by the bite of sand flies, which causes skin sores, disfigurement and can kill, also increased.

Since Jair Bolsonaro, an extreme right-wing climate denier, became president of Brazil in January 2019, the rate of deforestation, followed by forest fires, has exploded.

Officially-sanctioned illegality

This year the Institute of People and the Environment of the Amazon (Imazon)’s deforestation alert system (SAD) reports that an area of 254 sq km in the Amazon region was deforested in March, a increase of 279% over the same month last year.

This is even more alarming because traditionally deforestation begins in June, at the end of the rainy season. This year it has begun three months earlier.

The illegal clearing of the forest, much of it in indigenous reserves or conservation areas, by land grabbers, for cattle, soy, and logging projects, and by miners panning for gold, has been openly encouraged by Bolsonaro and his so-called Environment Minister, Ricardo Salles.

The Amazon Council set up by the president to coordinate action in the region does not include a single scientist, environmentalist or Amazon researcher, or even any experts from the government agencies for the environment and indigenous affairs, Ibama and Funai.

Instead, all its members are officers of the armed forces or the police. The likelihood that it will do anything serious to stop deforestation is zero.

Yet the destruction of the Amazon is a disaster not only for the world’s climate but also for its health, and Brazil is set to become one of the worst-affected countries. Climate News Network

Brazil’s burning forests are bad news for the global climate. Now scientists say the trees harbour deadly infections too.

SÃO PAULO, 29 April, 2020 − As forest destruction continues unabated in Brazil, scientists are alarmed that, as well as spurring climate change, it may unleash new and deadly infections on humankind.

There is growing awareness that large-scale tropical deforestation, as in the Amazon, not only brings disastrous consequences for the climate, but releases new diseases like Covid-19 by enabling infections to pass from wild animals to human beings.

As one well-known Amazon scientist, biologist Philip Fearnside, puts it: “Amazon deforestation facilitates transmission both of new diseases and of old ones like malaria.

“The connection between deforestation and infectious diseases is just one more impact of deforestation, added to impacts of losing both Amazonia’s biodiversity and the forest’s vital climate functions in avoiding global warming and in recycling water.”

He is one of the co-authors of a paper by a team led by Joel Henrique Ellwanger on the impacts of Amazon deforestation on infectious diseases and public health, which has just been published in the Annals of the Brazilian Academy.

Dr Fearnside adds: “Many ‘new’ human diseases originate from pathogens transferred from wild animals, as occurred with the Covid-19 coronavirus. Amazonia contains a vast number of animal species and their associated pathogens with the potential to be transferred to humans.”

No surprise

The warnings are not new. Ana Lúcia Tourinho, with a Ph.D in ecology at the Federal University of Mato Grosso (UFMT), interviewed by Deutsche Welle, said: “For at least two decades scientists have repeated the warning: as populations advance on the forests, the risk grows of micro-organisms – up till then in equilibrium – migrating to humans and causing victims.

“That is why news of the propagation of the new coronavirus detected in China, which has spread throughout the world, was not a surprise.

“When a vírus which is not part of our evolutionary history leaves its natural host and enters our body it brings chaos”, she said.

Isolated and in equilibrium with their habitats, like dense forests, this sort of vírus would not be a threat to humans. The problem comes when this natural reservoir is destroyed and occupied (by other species).

Scientific studies published years before the present pandemic already showed the connection between the loss of forest, proliferation of bats in the degraded areas, and the coronavirus.

One example is the study by Dr Aneta Afelt, a researcher at the University of Warsaw, who concluded that the high rates of forest destruction in the last 40 years in Asia were an indication that the next serious infectious disease could come from there.

“For at least two decades scientists have repeated the warning: as populations advance on the forests, the risk grows of micro-organisms migrating to humans”

To reach this conclusion, she followed the trail of previous pandemics triggered by other coronaviruses like Sars in 2002 and 2003, and Mers in 2012.

“Because it’s one of the regions where population growth is most intense, where sanitary conditions remain bad and where the rate of deforestation is high, south-east Asia has all the conditions for becoming the place where infectious diseases emerge or re-emerge”, she wrote in 2018.

If destruction of the Amazon continues at the present accelerated pace, Dr Tourinho says, and it is turned into an area of savannah, “we cannot imagine what might come out of there in terms of diseases.”

The relationship between deforestation and the increase of diseases in the Amazon has been studied by Brazil’s Institute of Applied Economic Research (IPEA).

A 2015 survey in 773 Amazon towns showed that for each 1% of forest destroyed, malaria cases increased by 23%. The incidence of leishmaniasis, a disease spread by the bite of sand flies, which causes skin sores, disfigurement and can kill, also increased.

Since Jair Bolsonaro, an extreme right-wing climate denier, became president of Brazil in January 2019, the rate of deforestation, followed by forest fires, has exploded.

Officially-sanctioned illegality

This year the Institute of People and the Environment of the Amazon (Imazon)’s deforestation alert system (SAD) reports that an area of 254 sq km in the Amazon region was deforested in March, a increase of 279% over the same month last year.

This is even more alarming because traditionally deforestation begins in June, at the end of the rainy season. This year it has begun three months earlier.

The illegal clearing of the forest, much of it in indigenous reserves or conservation areas, by land grabbers, for cattle, soy, and logging projects, and by miners panning for gold, has been openly encouraged by Bolsonaro and his so-called Environment Minister, Ricardo Salles.

The Amazon Council set up by the president to coordinate action in the region does not include a single scientist, environmentalist or Amazon researcher, or even any experts from the government agencies for the environment and indigenous affairs, Ibama and Funai.

Instead, all its members are officers of the armed forces or the police. The likelihood that it will do anything serious to stop deforestation is zero.

Yet the destruction of the Amazon is a disaster not only for the world’s climate but also for its health, and Brazil is set to become one of the worst-affected countries. Climate News Network

Halve the farmland, save nature, feed the world

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

If we farm efficiently, scientists say, we can cut climate change, slow extinction and feed the world even as it asks for more.

LONDON, 21 April, 2020 – Forget about organic farming: get the best out of the best cropland, return the rest to nature and still feed the world. It could work, say researchers.

Once again, scientists have demonstrated that humans could restore roughly half the planet as a natural home for all the other wild things, while at the same time feeding a growing population and limiting climate change.

That doesn’t mean it will happen, or could be made to happen easily. But it does yet again address one of the enduring challenges of population growth and the potentially devastating loss of the biodiversity upon which all individual species – humans more than most – depend to survive.

The answer? Simply to farm more efficiently and more intensively, to maximise the yield from those tracts of land most suitable for crops, and let nature reclaim the no-longer so productive hectares.

Even more effective would be to release as much land as possible in those regions that ecologists and biologists like to call “biodiversity hotspots”, among them the forests where concentrations of species are at their peak.

European researchers argue, in a study in the journal Nature Sustainability, that as less land was cultivated, but more intensively, the greenhouse gas emissions from farming would be reduced: so too would water use.

“Cropland expansion is not inevitable and there is significant potential for improving present land use efficiency”

“The main questions we wanted to address were how much cropland could be spared if attainable crop yields were achieved globally and crops were grown where they are most productive,” said Christian Folberth, a scientist with the International Institute for Applied Systems Analysis (IIASA) in Austria, who led the study.

“In addition, we wanted to determine what the implications would be for other factors related to the agricultural sector, including fertiliser and irrigation water requirements, greenhouse gas emissions, carbon sequestration potential, and wildlife habitat for threatened species.”

The problem is enormous, and enormously complex. Cropland farming alone – forget about methane from cattle and sheep – accounts for 5% of all greenhouse gas emissions from human activity. Worldwide, about 70% of all the freshwater taken from rivers and aquifers goes into irrigation.

Human populations continue to soar, while cities continue to expand  across the countryside. By the end of this century, there could be more than 9bn people to be fed.

Global heating driven by fossil fuel investment continues to increase, and this in turn threatens to diminish harvest yields across a wide range of crops, along with the nutritive value of the staples themselves.

Nature under threat

At the same time, both climate change driven by global warming and the expansion of the cities and the surrounding farmlands continue to amplify the threat to natural habitats and the millions of species – many yet to be identified and named by science – that depend upon them.

And this in turn poses a threat to human economies and even human life: almost every resource – antibiotic medicines and drugs, food, waste disposal, fabrics, building materials and even fresh air and water – evolved in undisturbed ecosystems long before Homo sapiens arrived, and the services each element provides depend ultimately on the survival of those ecosystems.

So the challenge is to restore and return to nature around half the land humans already use, while at the same time feeding what could be an additional 2bn people, while reducing greenhouse gas emissions but still sustaining development in the poorest nations.

Dr Folberth and his colleagues from Slovakia, France, Belgium, Spain and the UK are not the first to argue that it can be done, and not just by changing the planetary lunch menu.

The scientists looked at the data for 16 major crop species around the world to calculate that at least in theory – with careful use of the right crops on the most suitable soils, and with high fertiliser use – about half of the present cropland now cultivated could still deliver the present output.

That is, the land humans occupy is not being managed efficiently. If it were, the other half could be returned to wilderness, and conserved as natural forest, grassland or wetland.

Climate benefits

If humans then thought about how best to slow biodiversity loss, they would do almost as well by abandoning farmland in those places where there was the greatest concentration of wild things – tropical rain forests, estuary floodplains and mangrove swamps, for instance. And just returning 20% of farmland to nature everywhere else would still reduce human farmland use by 40%.

In return, fertiliser use would remain about the same, but greenhouse gas emissions and water use would fall, while more land would become free to sequester atmospheric carbon.

There would be costs – nitrogen pollution would go up in some places, and many rural farmers would become even poorer – so more thinking needs to be done. The point the European researchers want to make is that, in principle, it should be possible to feed people, abandon farmland to the natural world and reduce emissions all at the same time.

“It shows that cropland expansion is not inevitable and there is significant potential for improving present land use efficiency,” said Michael Obersteiner, another author, now at the Environmental Change Institute at Oxford.

“If the right policies are implemented, measures such as improved production technologies can be just as effective as demand-side measures like dietary changes. However, in all cases, such a process would need to be steered by policies to avoid unwanted outcomes.” – Climate News Network

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

If we farm efficiently, scientists say, we can cut climate change, slow extinction and feed the world even as it asks for more.

LONDON, 21 April, 2020 – Forget about organic farming: get the best out of the best cropland, return the rest to nature and still feed the world. It could work, say researchers.

Once again, scientists have demonstrated that humans could restore roughly half the planet as a natural home for all the other wild things, while at the same time feeding a growing population and limiting climate change.

That doesn’t mean it will happen, or could be made to happen easily. But it does yet again address one of the enduring challenges of population growth and the potentially devastating loss of the biodiversity upon which all individual species – humans more than most – depend to survive.

The answer? Simply to farm more efficiently and more intensively, to maximise the yield from those tracts of land most suitable for crops, and let nature reclaim the no-longer so productive hectares.

Even more effective would be to release as much land as possible in those regions that ecologists and biologists like to call “biodiversity hotspots”, among them the forests where concentrations of species are at their peak.

European researchers argue, in a study in the journal Nature Sustainability, that as less land was cultivated, but more intensively, the greenhouse gas emissions from farming would be reduced: so too would water use.

“Cropland expansion is not inevitable and there is significant potential for improving present land use efficiency”

“The main questions we wanted to address were how much cropland could be spared if attainable crop yields were achieved globally and crops were grown where they are most productive,” said Christian Folberth, a scientist with the International Institute for Applied Systems Analysis (IIASA) in Austria, who led the study.

“In addition, we wanted to determine what the implications would be for other factors related to the agricultural sector, including fertiliser and irrigation water requirements, greenhouse gas emissions, carbon sequestration potential, and wildlife habitat for threatened species.”

The problem is enormous, and enormously complex. Cropland farming alone – forget about methane from cattle and sheep – accounts for 5% of all greenhouse gas emissions from human activity. Worldwide, about 70% of all the freshwater taken from rivers and aquifers goes into irrigation.

Human populations continue to soar, while cities continue to expand  across the countryside. By the end of this century, there could be more than 9bn people to be fed.

Global heating driven by fossil fuel investment continues to increase, and this in turn threatens to diminish harvest yields across a wide range of crops, along with the nutritive value of the staples themselves.

Nature under threat

At the same time, both climate change driven by global warming and the expansion of the cities and the surrounding farmlands continue to amplify the threat to natural habitats and the millions of species – many yet to be identified and named by science – that depend upon them.

And this in turn poses a threat to human economies and even human life: almost every resource – antibiotic medicines and drugs, food, waste disposal, fabrics, building materials and even fresh air and water – evolved in undisturbed ecosystems long before Homo sapiens arrived, and the services each element provides depend ultimately on the survival of those ecosystems.

So the challenge is to restore and return to nature around half the land humans already use, while at the same time feeding what could be an additional 2bn people, while reducing greenhouse gas emissions but still sustaining development in the poorest nations.

Dr Folberth and his colleagues from Slovakia, France, Belgium, Spain and the UK are not the first to argue that it can be done, and not just by changing the planetary lunch menu.

The scientists looked at the data for 16 major crop species around the world to calculate that at least in theory – with careful use of the right crops on the most suitable soils, and with high fertiliser use – about half of the present cropland now cultivated could still deliver the present output.

That is, the land humans occupy is not being managed efficiently. If it were, the other half could be returned to wilderness, and conserved as natural forest, grassland or wetland.

Climate benefits

If humans then thought about how best to slow biodiversity loss, they would do almost as well by abandoning farmland in those places where there was the greatest concentration of wild things – tropical rain forests, estuary floodplains and mangrove swamps, for instance. And just returning 20% of farmland to nature everywhere else would still reduce human farmland use by 40%.

In return, fertiliser use would remain about the same, but greenhouse gas emissions and water use would fall, while more land would become free to sequester atmospheric carbon.

There would be costs – nitrogen pollution would go up in some places, and many rural farmers would become even poorer – so more thinking needs to be done. The point the European researchers want to make is that, in principle, it should be possible to feed people, abandon farmland to the natural world and reduce emissions all at the same time.

“It shows that cropland expansion is not inevitable and there is significant potential for improving present land use efficiency,” said Michael Obersteiner, another author, now at the Environmental Change Institute at Oxford.

“If the right policies are implemented, measures such as improved production technologies can be just as effective as demand-side measures like dietary changes. However, in all cases, such a process would need to be steered by policies to avoid unwanted outcomes.” – Climate News Network

Entire wild systems at risk from rising global heat

Rising global heat raises risks to the creatures and ecosystems that sustain human society. Collapse could be sudden and near-total.

LONDON, 14 April, 2020 – Worldwide, entire ecosystems could collapse as the planetary thermometer soars: rising global heat could see the Earth’s average temperature rise by 4°C (right now the world is heading for a rise of more than three degrees).

And then one in six of the complex communities of plants and animals in wetlands, grasslands, forests or oceans could drastically alter or fail.

That is because at such temperatures more than one in five of the creatures in that network of co-dependencies would in the same decade experience temperatures beyond their normal tolerance levels.

The prediction is based on data that pinpoint the geographical ranges of 30,652 birds, mammals, reptiles, amphibians, fish and plants, and climate data from 1850 to 2005.

“We found that climate change risks to biodiversity don’t increase gradually,” said Alex Pigot of Imperial College London, in the UK, who led the research.

Abrupt change

“Instead, as the climate warms, within a certain area most species will be able to cope for a while, before crossing a temperature threshold, when a large proportion of the species will suddenly face conditions they’ve never experienced before.

“It’s not a slippery slope, but a series of cliff edges, hitting different areas at different times.”

The finding – published in the journal Nature – should come as no great surprise to the world’s zoologists, botanists, ecologists, foresters, marine scientists and conservationists.

They have repeatedly warned that as global temperatures rise, and climate patterns become increasingly unstable, in response to ever-higher greenhouse gas emissions from power stations and car exhausts, and forest destruction, both individual species and even whole habitats could be exposed to loss and species extinction.

Such threats can be prefigured even in subtle changes in species behaviour. Within this month, Spanish ornithologists who have studied the nightingale Luscinia megarhynchos since 1995 report in the journal The Auk: Ornithological Advances that in two decades, as Spanish summers became hotter and more parched, the wings of each new generation of birds have become progressively shorter.

“Our findings highlight the urgent need for climate change mitigation, by immediately and drastically reducing emissions, which could help save thousands of species from extinction”

A shorter wingspan in proportion to body length creates potential survival problems for a species that breeds in Europe but prefers to fly to sub-Saharan Africa for the winter.

And across the Atlantic, another species, the American robin Turdus migratorius now takes wing 12 days earlier each spring in Mexico and the US to fly to its summer breeding grounds in Canada and Alaska.

The ornithologists report in the journal Environmental Research Letters that GPS tracking of 55 individual birds confirms that the bird may be timing its migration to the snow melt and the first arrival of insects in the high latitudes nearer the fast-warming Arctic.

So far, the planet on average has warmed around only 1°C above the long-term average for most of human history. But Dr Pigot and colleagues in the US and South Africa wanted to look at the big picture of potential change in species everywhere as global heating reaches 2°C – the upper limits that the world’s nations promised in a key international agreement reached in Paris in 2015 – and then goes on soaring.

So they took their species data, and mapped it onto a global grid divided into 100-km-square cells, and then fine-tuned the temperature predicted by climate scientists to see where species and their habitats would experience ever-rising heat beyond their comfort zone.

Unprecedented ocean heat

Any ecosystem is a network of interdependencies: insects pollinate flowers, animals disperse seed and prey upon pests and each other in an intricate set of arrangements that have evolved over tens of thousands of years in a particular pattern of temperature and precipitation. Any disturbance ripples through the entire habitat.

The scientists’ atlas of potential ecological disruption included isolated bits of the world such as the Cayman Islands in the Caribbean and the Gobi Desert in Mongolia as well as the Amazon basin and the forests and clearings in the Congo, and one of the world’s richest marine habitats, the so-called Coral Triangle bounded by the Philippines, Malaysia, Papua New Guinea and the islands of the Western Pacific.

They found that if warming could be contained to 2°C or less, only about one community in 50 would be faced with exposure to such disruption: they warn however that even this 2% includes some of the richest habitats on the planet.

They also warn that by 2030, the tropical oceans will start to experience temperature regimes that have no precedent in human history. The tropical forests could be at risk by 2050. Ominously, almost three-fourths of all the species to face unprecedented temperatures before the end of this century will all do so more or less at the same time.

“Our findings highlight the urgent need for climate change mitigation, by immediately and drastically reducing emissions, which could help save thousands of species from extinction,” Dr Pigot said. – Climate News Network

Rising global heat raises risks to the creatures and ecosystems that sustain human society. Collapse could be sudden and near-total.

LONDON, 14 April, 2020 – Worldwide, entire ecosystems could collapse as the planetary thermometer soars: rising global heat could see the Earth’s average temperature rise by 4°C (right now the world is heading for a rise of more than three degrees).

And then one in six of the complex communities of plants and animals in wetlands, grasslands, forests or oceans could drastically alter or fail.

That is because at such temperatures more than one in five of the creatures in that network of co-dependencies would in the same decade experience temperatures beyond their normal tolerance levels.

The prediction is based on data that pinpoint the geographical ranges of 30,652 birds, mammals, reptiles, amphibians, fish and plants, and climate data from 1850 to 2005.

“We found that climate change risks to biodiversity don’t increase gradually,” said Alex Pigot of Imperial College London, in the UK, who led the research.

Abrupt change

“Instead, as the climate warms, within a certain area most species will be able to cope for a while, before crossing a temperature threshold, when a large proportion of the species will suddenly face conditions they’ve never experienced before.

“It’s not a slippery slope, but a series of cliff edges, hitting different areas at different times.”

The finding – published in the journal Nature – should come as no great surprise to the world’s zoologists, botanists, ecologists, foresters, marine scientists and conservationists.

They have repeatedly warned that as global temperatures rise, and climate patterns become increasingly unstable, in response to ever-higher greenhouse gas emissions from power stations and car exhausts, and forest destruction, both individual species and even whole habitats could be exposed to loss and species extinction.

Such threats can be prefigured even in subtle changes in species behaviour. Within this month, Spanish ornithologists who have studied the nightingale Luscinia megarhynchos since 1995 report in the journal The Auk: Ornithological Advances that in two decades, as Spanish summers became hotter and more parched, the wings of each new generation of birds have become progressively shorter.

“Our findings highlight the urgent need for climate change mitigation, by immediately and drastically reducing emissions, which could help save thousands of species from extinction”

A shorter wingspan in proportion to body length creates potential survival problems for a species that breeds in Europe but prefers to fly to sub-Saharan Africa for the winter.

And across the Atlantic, another species, the American robin Turdus migratorius now takes wing 12 days earlier each spring in Mexico and the US to fly to its summer breeding grounds in Canada and Alaska.

The ornithologists report in the journal Environmental Research Letters that GPS tracking of 55 individual birds confirms that the bird may be timing its migration to the snow melt and the first arrival of insects in the high latitudes nearer the fast-warming Arctic.

So far, the planet on average has warmed around only 1°C above the long-term average for most of human history. But Dr Pigot and colleagues in the US and South Africa wanted to look at the big picture of potential change in species everywhere as global heating reaches 2°C – the upper limits that the world’s nations promised in a key international agreement reached in Paris in 2015 – and then goes on soaring.

So they took their species data, and mapped it onto a global grid divided into 100-km-square cells, and then fine-tuned the temperature predicted by climate scientists to see where species and their habitats would experience ever-rising heat beyond their comfort zone.

Unprecedented ocean heat

Any ecosystem is a network of interdependencies: insects pollinate flowers, animals disperse seed and prey upon pests and each other in an intricate set of arrangements that have evolved over tens of thousands of years in a particular pattern of temperature and precipitation. Any disturbance ripples through the entire habitat.

The scientists’ atlas of potential ecological disruption included isolated bits of the world such as the Cayman Islands in the Caribbean and the Gobi Desert in Mongolia as well as the Amazon basin and the forests and clearings in the Congo, and one of the world’s richest marine habitats, the so-called Coral Triangle bounded by the Philippines, Malaysia, Papua New Guinea and the islands of the Western Pacific.

They found that if warming could be contained to 2°C or less, only about one community in 50 would be faced with exposure to such disruption: they warn however that even this 2% includes some of the richest habitats on the planet.

They also warn that by 2030, the tropical oceans will start to experience temperature regimes that have no precedent in human history. The tropical forests could be at risk by 2050. Ominously, almost three-fourths of all the species to face unprecedented temperatures before the end of this century will all do so more or less at the same time.

“Our findings highlight the urgent need for climate change mitigation, by immediately and drastically reducing emissions, which could help save thousands of species from extinction,” Dr Pigot said. – Climate News Network

Ancient ice-free polar forest could soon return

An ice-free polar forest once flourished, helped by enough heat and ample greenhouse gas. It could come back.

LONDON, 10 April, 2020 – Many millions of years ago, the southern continent wasn’t frozen at all, but basked in heat balmy enough for an ice-free polar forest to thrive. And ancient pre-history could repeat itself.

Climate scientists can tell you what the world could be like were today’s greenhouse gas concentrations to triple – which they could do if humans go on clearing tropical forests and burning fossil fuels.

They know because, 90 million years ago, the last time when carbon dioxide levels in the atmosphere went past the 1200 ppm (parts per million) mark, sea levels were 170 metres higher than today and the world was so warm that dense forests grew in what is now Antarctica.

At latitude 82 South, a region where the polar night lasts for four months, there was no icecap. Instead, the continental rocks were colonised by conifer forest, with a mix of tree ferns and an understorey of flowering shrubs.

Even though at that latitude the midday sun would have been relatively low in the sky, and the forests would have had to survive sustained winter darkness for a dozen weeks or more, average temperatures would have been that of modern day Tasmania, and a good 2C° warmer than modern Germany.

“Even during months of darkness, swampy temperate forests were able to grow close to the South Pole, revealing an even warmer climate than we expected”

German and British researchers report in the journal Nature that they took a closer look at a sequence of strangely-coloured mudstone in a core drilled 30 metres below the bottom of the sea floor, off West Antarctica.

The section of sediment had been preserved from the mid-Cretaceous, around 90 million years ago, in a world dominated by dinosaurs. By then, the first mammals may have evolved, the grasses were about to emerge, and seasonal flowering plants had begun to colonise a planet dominated for aeons by evergreens.

And in the preserved silt were pollens, spores, tangled roots and other plant material so well preserved that the researchers could not just identify the plant families, but even take a guess at parallels with modern forests. Before their eyes was evidence of something like the modern rainforests of New Zealand’s South Island, but deep inside the Antarctic Circle.

“The preservation of this 90 million-year-old forest is exceptional, but even more surprising is the world it reveals,” said Tina van de Flierdt, of Imperial College London.

“Even during months of darkness, swampy temperate forests were able to grow close to the South Pole, revealing an even warmer climate than we expected.”

British rain levels

Somewhere between 115 and 85 million years ago, the whole world was a lot hotter: in the tropics temperatures reached 35°C and the average temperature of that part of the Antarctic was 13°C. This is at least two degrees higher than the average temperature for modern Germany.

Average temperatures in summer went up to 18.5°C, and the water temperatures in the swamps and rivers tipped 20°C, only 900 kms from the then South Pole. Modern Antarctica is classed as desert, with minimal precipitation: then it would have seen 1120 mm a year. People from southwestern Scotland or parts of Wales would have felt at home.

It is an axiom of earth science that the present is key to the past: if such forests today can flourish at existing temperatures, then the same must have been true in the deep past.

So climate scientists from the start have taken a close interest in the evidence of intensely warm periods in the fossil record: a mix of plant and animal remains, the ratio of chemical isotopes preserved in rock, and even the air bubbles trapped in deep ice cores can help them reconstruct the temperatures, the composition of the atmosphere and the rainfall of, for example, the warmest periods of the Pliocene, when carbon dioxide levels in the atmosphere tipped the 1000 ppm mark, and average planetary temperatures rose by 9°C.

Prehistoric encore approaching?

In the past century, atmospheric CO2 levels have swollen from 285 ppm to more than 400 ppm, and the planetary thermometer has already crept up by 1°C above the level for most of human history. If human economies continue burning fossil fuels at an ever-increasing rate, the conditions that prevailed 56 million years ago could return by 2159.

The Cretaceous evidence will help climate scientists calibrate their models of a world in which greenhouse gas emissions go on rising.

“Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm,” said Johann Klages, of the Alfred Wegener Institute centre for polar and marine research in Germany, who led the study.

“But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in Antarctica.” – Climate News Network

An ice-free polar forest once flourished, helped by enough heat and ample greenhouse gas. It could come back.

LONDON, 10 April, 2020 – Many millions of years ago, the southern continent wasn’t frozen at all, but basked in heat balmy enough for an ice-free polar forest to thrive. And ancient pre-history could repeat itself.

Climate scientists can tell you what the world could be like were today’s greenhouse gas concentrations to triple – which they could do if humans go on clearing tropical forests and burning fossil fuels.

They know because, 90 million years ago, the last time when carbon dioxide levels in the atmosphere went past the 1200 ppm (parts per million) mark, sea levels were 170 metres higher than today and the world was so warm that dense forests grew in what is now Antarctica.

At latitude 82 South, a region where the polar night lasts for four months, there was no icecap. Instead, the continental rocks were colonised by conifer forest, with a mix of tree ferns and an understorey of flowering shrubs.

Even though at that latitude the midday sun would have been relatively low in the sky, and the forests would have had to survive sustained winter darkness for a dozen weeks or more, average temperatures would have been that of modern day Tasmania, and a good 2C° warmer than modern Germany.

“Even during months of darkness, swampy temperate forests were able to grow close to the South Pole, revealing an even warmer climate than we expected”

German and British researchers report in the journal Nature that they took a closer look at a sequence of strangely-coloured mudstone in a core drilled 30 metres below the bottom of the sea floor, off West Antarctica.

The section of sediment had been preserved from the mid-Cretaceous, around 90 million years ago, in a world dominated by dinosaurs. By then, the first mammals may have evolved, the grasses were about to emerge, and seasonal flowering plants had begun to colonise a planet dominated for aeons by evergreens.

And in the preserved silt were pollens, spores, tangled roots and other plant material so well preserved that the researchers could not just identify the plant families, but even take a guess at parallels with modern forests. Before their eyes was evidence of something like the modern rainforests of New Zealand’s South Island, but deep inside the Antarctic Circle.

“The preservation of this 90 million-year-old forest is exceptional, but even more surprising is the world it reveals,” said Tina van de Flierdt, of Imperial College London.

“Even during months of darkness, swampy temperate forests were able to grow close to the South Pole, revealing an even warmer climate than we expected.”

British rain levels

Somewhere between 115 and 85 million years ago, the whole world was a lot hotter: in the tropics temperatures reached 35°C and the average temperature of that part of the Antarctic was 13°C. This is at least two degrees higher than the average temperature for modern Germany.

Average temperatures in summer went up to 18.5°C, and the water temperatures in the swamps and rivers tipped 20°C, only 900 kms from the then South Pole. Modern Antarctica is classed as desert, with minimal precipitation: then it would have seen 1120 mm a year. People from southwestern Scotland or parts of Wales would have felt at home.

It is an axiom of earth science that the present is key to the past: if such forests today can flourish at existing temperatures, then the same must have been true in the deep past.

So climate scientists from the start have taken a close interest in the evidence of intensely warm periods in the fossil record: a mix of plant and animal remains, the ratio of chemical isotopes preserved in rock, and even the air bubbles trapped in deep ice cores can help them reconstruct the temperatures, the composition of the atmosphere and the rainfall of, for example, the warmest periods of the Pliocene, when carbon dioxide levels in the atmosphere tipped the 1000 ppm mark, and average planetary temperatures rose by 9°C.

Prehistoric encore approaching?

In the past century, atmospheric CO2 levels have swollen from 285 ppm to more than 400 ppm, and the planetary thermometer has already crept up by 1°C above the level for most of human history. If human economies continue burning fossil fuels at an ever-increasing rate, the conditions that prevailed 56 million years ago could return by 2159.

The Cretaceous evidence will help climate scientists calibrate their models of a world in which greenhouse gas emissions go on rising.

“Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm,” said Johann Klages, of the Alfred Wegener Institute centre for polar and marine research in Germany, who led the study.

“But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in Antarctica.” – Climate News Network

Tropical forests’ damage spreads catastrophically

Human inroads into tropical forests stretch far beyond oil plantations or the edge of cattle ranches and are a wider threat to conservation.

LONDON, 7 April, 2020 – Tropical forests are vital in the campaign to limit global heating. Here’s how to blunt them as a force – just put a clearing, or a plantation, a road or a ranch in the pristine wilderness. And then, as absorbers of atmospheric carbon, the trees up to 100 metres deep into the jungle will lose their edge.

Along that 100 metre width, the canopy height, leaf mass and phosphorus levels per square metre will begin to change. All three are measures of a tree’s capacity to grow vigorously and store carbon.

Researchers call this the edge effect. It matters. The world now has 1.2bn hectares of remaining tropical forest. This is an area far bigger than Canada.

But invasion of what, just one lifetime ago, were still unmapped wildernesses is now so aggressive that almost one fifth of the area of the world’s tropical forest is within 100 metres of a non-forest edge.

And about half of all the forest is within 500 metres of a ranch, road, settlement or plantation.

“The importance of this discovery trickles all the way down to how conservation managers work to mitigate biodiversity losses associated with agricultural expansion”

Scientists from the US report in the Proceedings of the National Academy of Sciences that they mapped change in the forests of Malaysian Borneo, looking closely at the sites where forest and commercial palm oil plantation co-exist.

They report that the levels of carbon stored “above ground” – that is, in the trunk and canopy – fell by an average of 22% along the forest edges, to a depth of 100 metres. The older this forest edge, the greater the fall in stored carbon.

There are already reports that degradation of the rainforest in the Amazon and Congo, amplified by the impact of climate change in the form of extreme heat and drought, is so advanced that within a decade or two these forests could cease to be “sinks” for atmospheric carbon, and instead start adding to the world’s burden of greenhouse gases that threaten to accelerate climate change, with potentially catastrophic consequences.

The world’s forests are vital in the global plans to contain or limit climate change driven by profligate combustion of fossil fuels that release carbon dioxide and other greenhouse gases.

Research has repeatedly confirmed that undisturbed forest is an efficient absorber and permanent store of atmospheric carbon and that almost any human transgression could damage the capacity of the rainforest to absorb carbon.

Road web spreads

And yet all the signs are ominous: humans will go on making inroads into natural wilderness, in the most literal sense: by 2050, there could be 25 million km new road lanes, most of them in the developing world, to carry timber trucks, livestock and minerals through the world’s forests.

There is an argument that “smart” roads can limit the damage to the environment and society caused by indiscriminate engineering: one group advocating this approach is the Centre for Tropical Environmental and Sustainability Science (TESS), based at James Cook University in Australia.

But the threat to the remaining forests is now so pronounced that many researchers simply point out, in the kind of understatement that comes naturally to scientists, that such changes have “far-reaching implications” for the conservation of forest biodiversity and carbon stocks.

They see their research as a potential guide to government and local authorities on the management of the remaining wild woodland.

“Not all forest-agriculture boundaries are created equal, and most remaining forests change for many years following the original land conversion that takes place nearby,” said Greg Asner of Arizona State University, one of the researchers.

“The importance of this discovery trickles all the way down to how conservation managers work to mitigate biodiversity losses associated with agricultural expansion.” – Climate News Network

Human inroads into tropical forests stretch far beyond oil plantations or the edge of cattle ranches and are a wider threat to conservation.

LONDON, 7 April, 2020 – Tropical forests are vital in the campaign to limit global heating. Here’s how to blunt them as a force – just put a clearing, or a plantation, a road or a ranch in the pristine wilderness. And then, as absorbers of atmospheric carbon, the trees up to 100 metres deep into the jungle will lose their edge.

Along that 100 metre width, the canopy height, leaf mass and phosphorus levels per square metre will begin to change. All three are measures of a tree’s capacity to grow vigorously and store carbon.

Researchers call this the edge effect. It matters. The world now has 1.2bn hectares of remaining tropical forest. This is an area far bigger than Canada.

But invasion of what, just one lifetime ago, were still unmapped wildernesses is now so aggressive that almost one fifth of the area of the world’s tropical forest is within 100 metres of a non-forest edge.

And about half of all the forest is within 500 metres of a ranch, road, settlement or plantation.

“The importance of this discovery trickles all the way down to how conservation managers work to mitigate biodiversity losses associated with agricultural expansion”

Scientists from the US report in the Proceedings of the National Academy of Sciences that they mapped change in the forests of Malaysian Borneo, looking closely at the sites where forest and commercial palm oil plantation co-exist.

They report that the levels of carbon stored “above ground” – that is, in the trunk and canopy – fell by an average of 22% along the forest edges, to a depth of 100 metres. The older this forest edge, the greater the fall in stored carbon.

There are already reports that degradation of the rainforest in the Amazon and Congo, amplified by the impact of climate change in the form of extreme heat and drought, is so advanced that within a decade or two these forests could cease to be “sinks” for atmospheric carbon, and instead start adding to the world’s burden of greenhouse gases that threaten to accelerate climate change, with potentially catastrophic consequences.

The world’s forests are vital in the global plans to contain or limit climate change driven by profligate combustion of fossil fuels that release carbon dioxide and other greenhouse gases.

Research has repeatedly confirmed that undisturbed forest is an efficient absorber and permanent store of atmospheric carbon and that almost any human transgression could damage the capacity of the rainforest to absorb carbon.

Road web spreads

And yet all the signs are ominous: humans will go on making inroads into natural wilderness, in the most literal sense: by 2050, there could be 25 million km new road lanes, most of them in the developing world, to carry timber trucks, livestock and minerals through the world’s forests.

There is an argument that “smart” roads can limit the damage to the environment and society caused by indiscriminate engineering: one group advocating this approach is the Centre for Tropical Environmental and Sustainability Science (TESS), based at James Cook University in Australia.

But the threat to the remaining forests is now so pronounced that many researchers simply point out, in the kind of understatement that comes naturally to scientists, that such changes have “far-reaching implications” for the conservation of forest biodiversity and carbon stocks.

They see their research as a potential guide to government and local authorities on the management of the remaining wild woodland.

“Not all forest-agriculture boundaries are created equal, and most remaining forests change for many years following the original land conversion that takes place nearby,” said Greg Asner of Arizona State University, one of the researchers.

“The importance of this discovery trickles all the way down to how conservation managers work to mitigate biodiversity losses associated with agricultural expansion.” – Climate News Network

Poles attract marine life avoiding rising heat

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

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

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

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

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

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

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

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

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

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

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

Winners and losers

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Winners and losers

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

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

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

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

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