Tag Archives: Agriculture

South Asia’s twin threat: extreme heat and foul air

Climate change means many health risks. Any one of them raises the danger. What happens when extreme heat meets bad air?

LONDON, 29 May, 2020 – Extreme heat can kill. Air pollution can seriously shorten human lives. By 2050, extreme summer heat will threaten about 2 billion people on and around the Indian sub-continent for around 78 days every year. And the chances of unbearable heat waves and choking atmospheric chemistry at the same time will rise by 175%.

Climate scientists have been warning for decades that what were once rare events – for instance the 2003 heat wave that claimed tens of thousands of lives in Europe – will, as global average temperatures rise, become the new normal.

And they have repeatedly warned that in step with extreme summer temperatures, extreme humidity is also likely to increase in some regions, and to levels that could prove potentially fatal for outdoor workers and people in crowded cities.

The link between air pollution and ill health was established 60 or more years ago and has been confirmed again and again with mortality statistics.

Risk to megacities

Now a team from China and the US confirms once more in the journal  AGU Advances, published by the American Geophysical Union, that the danger is real, and that they can tell where it is becoming immediate: in seven nations that stretch from Afghanistan to Myanmar, and from Nepal to the tip of southern India.

Around 1.5bn people live there now, and they are already learning to live with around 45 days of extreme heat every year. By 2050, there will be 2bn people, most of them crammed into megacities in Afghanistan, Bangladesh, Bhutan, India, Myanmar, Nepal and Pakistan, and climate models confirm that the number of days of extreme heat could rise to 78 a year.

The number of days on which cities – already blighted by air pollution – reach health-threatening levels of high particulate matter will also rise. When heat and choking air chemistry become too much, lives will be at risk.

That extremes of summer heat are on the increase is now a given. That the intensity, duration and frequency of heat waves will go on rising has also been established. Extremes of heat are a threat to crops and a particular hazard in cities already much hotter than their surrounding landscapes.

“South Asia is a hotspot for future climate change impacts. Much research is needed over other parts of the world on  the risks they pose, and their potential human health effects”

One research group has identified 27 ways in which high temperatures can kill. Others have repeatedly warned of the dangerous mix of high temperatures and high humidity (climate scientists call it the “wet bulb” temperature), and one team of scientists has already argued that such conditions have already arrived, albeit so far for short periods and in limited locations.

The researchers chose the so-called wet-bulb temperature of 25°C as their threshold for an unhealthy extreme, and then worked out the number of days a year that such conditions happened in South Asia: between 1994 and 2006, these arrived at an average of between 40 and 50 days a year.

They then looked at the likely rise with forecast increases in average planetary temperature, depending on how vigorously or feebly the world’s nations tried to switch from fossil fuels to renewable energy sources. The probability increased by 75%.

They then chose widely-agreed dangerous thresholds for air pollution with soot, and sulphate aerosols, usually from fossil fuel combustion, to find that extremes of pollution would happen by 2050 on around 132 days a year.

Tenfold risk increase

Then they tried to estimate the probabilities that extreme pollution and extreme heat would coincide. They judged that the frequency of these more than usually hazardous days would rise by 175%, and they would last an estimated 79% longer. The area of land exposed to this double assault on human health would by then have increased tenfold.

Scientific publications usually avoid emotional language, but the researchers call their own finding “alarming.”

“South Asia is a hotspot for future climate change impacts,” said Yangyang Xu, of Texas A&M University, the first author.

“I think this study raises a lot of important concerns, and much research is needed over other parts of the world on these compounded extremes, the risks they pose, and their potential human health effects.” – Climate News Network

Climate change means many health risks. Any one of them raises the danger. What happens when extreme heat meets bad air?

LONDON, 29 May, 2020 – Extreme heat can kill. Air pollution can seriously shorten human lives. By 2050, extreme summer heat will threaten about 2 billion people on and around the Indian sub-continent for around 78 days every year. And the chances of unbearable heat waves and choking atmospheric chemistry at the same time will rise by 175%.

Climate scientists have been warning for decades that what were once rare events – for instance the 2003 heat wave that claimed tens of thousands of lives in Europe – will, as global average temperatures rise, become the new normal.

And they have repeatedly warned that in step with extreme summer temperatures, extreme humidity is also likely to increase in some regions, and to levels that could prove potentially fatal for outdoor workers and people in crowded cities.

The link between air pollution and ill health was established 60 or more years ago and has been confirmed again and again with mortality statistics.

Risk to megacities

Now a team from China and the US confirms once more in the journal  AGU Advances, published by the American Geophysical Union, that the danger is real, and that they can tell where it is becoming immediate: in seven nations that stretch from Afghanistan to Myanmar, and from Nepal to the tip of southern India.

Around 1.5bn people live there now, and they are already learning to live with around 45 days of extreme heat every year. By 2050, there will be 2bn people, most of them crammed into megacities in Afghanistan, Bangladesh, Bhutan, India, Myanmar, Nepal and Pakistan, and climate models confirm that the number of days of extreme heat could rise to 78 a year.

The number of days on which cities – already blighted by air pollution – reach health-threatening levels of high particulate matter will also rise. When heat and choking air chemistry become too much, lives will be at risk.

That extremes of summer heat are on the increase is now a given. That the intensity, duration and frequency of heat waves will go on rising has also been established. Extremes of heat are a threat to crops and a particular hazard in cities already much hotter than their surrounding landscapes.

“South Asia is a hotspot for future climate change impacts. Much research is needed over other parts of the world on  the risks they pose, and their potential human health effects”

One research group has identified 27 ways in which high temperatures can kill. Others have repeatedly warned of the dangerous mix of high temperatures and high humidity (climate scientists call it the “wet bulb” temperature), and one team of scientists has already argued that such conditions have already arrived, albeit so far for short periods and in limited locations.

The researchers chose the so-called wet-bulb temperature of 25°C as their threshold for an unhealthy extreme, and then worked out the number of days a year that such conditions happened in South Asia: between 1994 and 2006, these arrived at an average of between 40 and 50 days a year.

They then looked at the likely rise with forecast increases in average planetary temperature, depending on how vigorously or feebly the world’s nations tried to switch from fossil fuels to renewable energy sources. The probability increased by 75%.

They then chose widely-agreed dangerous thresholds for air pollution with soot, and sulphate aerosols, usually from fossil fuel combustion, to find that extremes of pollution would happen by 2050 on around 132 days a year.

Tenfold risk increase

Then they tried to estimate the probabilities that extreme pollution and extreme heat would coincide. They judged that the frequency of these more than usually hazardous days would rise by 175%, and they would last an estimated 79% longer. The area of land exposed to this double assault on human health would by then have increased tenfold.

Scientific publications usually avoid emotional language, but the researchers call their own finding “alarming.”

“South Asia is a hotspot for future climate change impacts,” said Yangyang Xu, of Texas A&M University, the first author.

“I think this study raises a lot of important concerns, and much research is needed over other parts of the world on these compounded extremes, the risks they pose, and their potential human health effects.” – Climate News Network

US farm workers face worsening lethal heat

By 2100, US farmers can expect more lethal heat, the equivalent of two months when it’s unsafe to pick crops.

LONDON, 6 May, 2020 – Life is already bad enough for underpaid and overworked crop pickers in the US, but as lethal heat levels rise they will render outdoor labour in the harvest season increasingly impossible.

The men and women who gather melons and strawberries, nuts and grapes, onions and lettuce already find conditions too hot to handle on at least 21 days a year.

By 2050, US agricultural workers will meet unsafe daytime summer temperatures on 39 days each harvest season. And by 2100, this number could triple to 62 unsafe days, according to new research.

Unsafe means that the levels of high thermometer readings and high humidity outdoors could put field workers at risk of heat exhaustion, heat stroke, heat cramps, dehydration, potential kidney injury and even death.

There are roughly one million people in the US officially employed picking crops in states such as Oregon, California, Washington and Florida. The actual number however is estimated to be two million.

“You don’t have to go to the global south to find people who will get hurt with even modest amounts of global warming – you just have to look in your own backyard”

More than three-quarters of them are foreign-born, many from Mexico. Only about half of these have lawful authority to work in the US. Of these, 71% do not speak English well, and on average educational levels are low. Fewer than half have medical insurance, and one third of the families of agricultural workers live below the poverty line.

Their housing and sanitary conditions are often not good, they are often paid on the basis of crops picked, so that to survive they must neglect breaks and work for longer, and they are often deprived of shade, according to data compiled in the journal Environmental Research Letters.

High summer extremes are a hazard, and can cause death on a significant scale. Climate scientists have established that by the century’s end, more than a billion people worldwide will be placed in danger of summer extremes, and the risks are growing.

One enterprising group has even numbered 27 ways in which high temperatures and high humidity can kill. Economists have already counted the price paid in falling productivity in severe conditions in Australia, and – since fruit tends to ripen as the thermometer rises and must be picked at the right moment – the hazards faced by grape-pickers in the world’s vineyards.

When Michelle Tigchelaar began her study of the climate impacts, she was at the University of Washington. She is now at Stanford University in California.

Low estimate

She and colleagues simply followed the climate projections and the impact rising global average temperatures will have on the intensity, frequency and duration of heat waves, and found that with a 2°C rise, expected by 2050, the level of unsafe days leapt from 21 to 39. At 4°C – and there is a high risk on present trends – then unsafe conditions could by 2100 reach 62 days.

“I was surprised by the scale of the change – seeing a doubling of unsafe days by mid-century, then a tripling by 2100. And we think that’s a low estimate,” Dr Tigchelaar said.

“The people who are the most vulnerable are asked to take the highest risk so that we, as consumers, can eat a healthy nutritious diet.”

And her co-author David Battisti of the University of Washington said: “The climate science community has long been pointing to the global south, the developing countries, as places that will be disproportionately affected by climate change.

“This shows that you don’t have to go to the global south to find people who will get hurt with even modest amounts of global warming – you just have to look in your own backyard.” – Climate News Network

By 2100, US farmers can expect more lethal heat, the equivalent of two months when it’s unsafe to pick crops.

LONDON, 6 May, 2020 – Life is already bad enough for underpaid and overworked crop pickers in the US, but as lethal heat levels rise they will render outdoor labour in the harvest season increasingly impossible.

The men and women who gather melons and strawberries, nuts and grapes, onions and lettuce already find conditions too hot to handle on at least 21 days a year.

By 2050, US agricultural workers will meet unsafe daytime summer temperatures on 39 days each harvest season. And by 2100, this number could triple to 62 unsafe days, according to new research.

Unsafe means that the levels of high thermometer readings and high humidity outdoors could put field workers at risk of heat exhaustion, heat stroke, heat cramps, dehydration, potential kidney injury and even death.

There are roughly one million people in the US officially employed picking crops in states such as Oregon, California, Washington and Florida. The actual number however is estimated to be two million.

“You don’t have to go to the global south to find people who will get hurt with even modest amounts of global warming – you just have to look in your own backyard”

More than three-quarters of them are foreign-born, many from Mexico. Only about half of these have lawful authority to work in the US. Of these, 71% do not speak English well, and on average educational levels are low. Fewer than half have medical insurance, and one third of the families of agricultural workers live below the poverty line.

Their housing and sanitary conditions are often not good, they are often paid on the basis of crops picked, so that to survive they must neglect breaks and work for longer, and they are often deprived of shade, according to data compiled in the journal Environmental Research Letters.

High summer extremes are a hazard, and can cause death on a significant scale. Climate scientists have established that by the century’s end, more than a billion people worldwide will be placed in danger of summer extremes, and the risks are growing.

One enterprising group has even numbered 27 ways in which high temperatures and high humidity can kill. Economists have already counted the price paid in falling productivity in severe conditions in Australia, and – since fruit tends to ripen as the thermometer rises and must be picked at the right moment – the hazards faced by grape-pickers in the world’s vineyards.

When Michelle Tigchelaar began her study of the climate impacts, she was at the University of Washington. She is now at Stanford University in California.

Low estimate

She and colleagues simply followed the climate projections and the impact rising global average temperatures will have on the intensity, frequency and duration of heat waves, and found that with a 2°C rise, expected by 2050, the level of unsafe days leapt from 21 to 39. At 4°C – and there is a high risk on present trends – then unsafe conditions could by 2100 reach 62 days.

“I was surprised by the scale of the change – seeing a doubling of unsafe days by mid-century, then a tripling by 2100. And we think that’s a low estimate,” Dr Tigchelaar said.

“The people who are the most vulnerable are asked to take the highest risk so that we, as consumers, can eat a healthy nutritious diet.”

And her co-author David Battisti of the University of Washington said: “The climate science community has long been pointing to the global south, the developing countries, as places that will be disproportionately affected by climate change.

“This shows that you don’t have to go to the global south to find people who will get hurt with even modest amounts of global warming – you just have to look in your own backyard.” – 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

London’s Kew Gardens teach respect for nature

This story originally appeared on CBS News, and is republished here as part of Covering Climate Now, a global journalism collaboration strengthening coverage of the climate story.

 

Kew Gardens in London are a cherished corner of the UK capital − with a life-giving lesson for humanity.

LONDON, 26 April, 2020 − Kew Gardens more formally the United Kingdom’s Royal Botanic Gardens, Kew in London have been a place of reflection and natural refuge for about 250 years, though now they sit empty because of the country’s coronavirus pandemic lockdown.

On April 22, as we celebrated the 50th anniversary of Earth Day, Kew Gardens’ director Richard Deverell warned that more “fundamental challenges” could lie ahead for humankind “unless we start to treat the natural world better.”

“It’s exceptionally beautiful, but it’s tragic to see these beautiful gardens, 330 acres here at Kew − a world heritage site − to see them empty,” he told CBS News’ Mark Phillips.

Deverell, who lives on the property, said he “hopes” the current situation could help people understand the importance of respecting nature.

“We’ve got a situation today where four and half billion people are in lockdown, that’s extraordinary,” he said. “So I hope, if nothing else, this Covid experience has given us a dose of humility… we are just one species of many, many millions.”

He added that we “need to play our role” alongside Earth’s other species “in a responsible way.”

“I hope, if nothing else, this Covid experience has given us a dose of humility… we are just one species of many, many millions”

“And I hope too, that we’ll realise that actually the cost of pre-empting a problem, of mitigating it, is a fraction of the cost of dealing with it when it engulfs you,” he said. “If you abuse the natural world, bad things happen, including bad things to people.”

Researchers at the gardens are already working on these mitigation efforts. With new specimens arriving from all over the world, scientists are studying ways to help plants cope with a warming globe.

Among other projects, researchers are studying how to deal with coffee beans that are not getting enough rain and getting too much sunshine. The team is working to find varieties that are more tolerant to the changing conditions.

“Perhaps some have greater heat tolerance or aridity tolerance that can be bred into the commercial crop to safeguard future supplies of coffee,” Deverell explained.

He highlighted the importance of keeping nature safe and intact, not just for the natural world, but for humanity itself.

“At the simplest level, of course, plants provide us with oxygen,” he said. “About a quarter of all cancer medicines derive from plants and fungi, so they deliver many, many beneficial things to humans.”

This story originally appeared on CBS News, and is republished here as part of Covering Climate Now, a global journalism collaboration strengthening coverage of the climate story.

 

Kew Gardens in London are a cherished corner of the UK capital − with a life-giving lesson for humanity.

LONDON, 26 April, 2020 − Kew Gardens more formally the United Kingdom’s Royal Botanic Gardens, Kew in London have been a place of reflection and natural refuge for about 250 years, though now they sit empty because of the country’s coronavirus pandemic lockdown.

On April 22, as we celebrated the 50th anniversary of Earth Day, Kew Gardens’ director Richard Deverell warned that more “fundamental challenges” could lie ahead for humankind “unless we start to treat the natural world better.”

“It’s exceptionally beautiful, but it’s tragic to see these beautiful gardens, 330 acres here at Kew − a world heritage site − to see them empty,” he told CBS News’ Mark Phillips.

Deverell, who lives on the property, said he “hopes” the current situation could help people understand the importance of respecting nature.

“We’ve got a situation today where four and half billion people are in lockdown, that’s extraordinary,” he said. “So I hope, if nothing else, this Covid experience has given us a dose of humility… we are just one species of many, many millions.”

He added that we “need to play our role” alongside Earth’s other species “in a responsible way.”

“I hope, if nothing else, this Covid experience has given us a dose of humility… we are just one species of many, many millions”

“And I hope too, that we’ll realise that actually the cost of pre-empting a problem, of mitigating it, is a fraction of the cost of dealing with it when it engulfs you,” he said. “If you abuse the natural world, bad things happen, including bad things to people.”

Researchers at the gardens are already working on these mitigation efforts. With new specimens arriving from all over the world, scientists are studying ways to help plants cope with a warming globe.

Among other projects, researchers are studying how to deal with coffee beans that are not getting enough rain and getting too much sunshine. The team is working to find varieties that are more tolerant to the changing conditions.

“Perhaps some have greater heat tolerance or aridity tolerance that can be bred into the commercial crop to safeguard future supplies of coffee,” Deverell explained.

He highlighted the importance of keeping nature safe and intact, not just for the natural world, but for humanity itself.

“At the simplest level, of course, plants provide us with oxygen,” he said. “About a quarter of all cancer medicines derive from plants and fungi, so they deliver many, many beneficial things to humans.”

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

Rising urban space demands squeeze out farmers

More people than ever now live in cities. Their growing urban space demands devour farmland, bad news for tomorrow’s hungry world.

LONDON, 9 April, 2020 – Even as people crowd into the cities, they don’t crowd the way they used to, and urban space demands are increasing. Even in some of the developing nations, townspeople are demanding more elbow-room.

And in the last four decades, worldwide, humans have claimed around 125,000 square kilometres of farmland or wilderness more than would have been necessary if urban densities had stayed at the 1970 level.

That is: to accommodate today’s city-dwellers with more space than their parents and grandparents ever expected to enjoy, an additional area almost the size of Greece has been covered by asphalt, brick, concrete, tile and glass.

In the US, urban settlements have always been fringed by more roomy suburban developments. Now in China, India and Nigeria, the cities are expanding and the population densities are decreasing.

Risk to farmers

“These three countries are expected to account for more than a third of the projected increase in the world’s urban population by 2050,” said Burak Güneralp, a geographer at Texas A&M University in the US.

“They also still have many millions of small farmers earning their livelihoods working fertile lands on the outskirts of cities. Thus any loss of these high-quality lands to urban expansion has huge implications for the livelihoods of these farmers.”

Dr Güneralp and colleagues report in the journal Environmental Research Letters that they looked at 611 case studies of 330 urban centres to calculate population growth, urban expansion and urban population densities between 1970 – the earliest moment for reliable statistics – and 2010.

They also factored in the size of cities, to distinguish different rates of change in centres with more and with fewer than two million citizens.

“Decreasing urban population densities in India and Nigeria since 1970 caused 85% and 30% more land, respectively, to be converted to urban”

Once most of humanity lived in rural areas. Now more than half the planet is crowded into cities and townships, and in a few decades the proportion could reach two-thirds.

But this crowding creates new problems. Cities are always significantly hotter than the surrounding landscape, and as global average temperatures rise, this in turn is likely to accelerate energy demand and global heating as people are forced to install air-conditioning.

The concentration of people in cities is likely to create new demands on sometimes precarious water supplies, and in any case the combination of climate change and population growth means ever greater numbers are at hazard from drought or flood.

All of this in turn increases the pressure for green spaces within the new cities and a more spacious lifestyle.

Cheek by jowl

But civilised city life comes at an environmental price. About half of India’s land is already classified as “degraded”, while India has the largest rural population but also the steepest fall in what geographers call urban land use efficiency, and the rest of the world calls living on top of your neighbours.

“Our findings suggest that decreasing urban population densities in India and Nigeria since 1970 caused 85% and 30% more land, respectively, to be converted to urban,” Dr Güneralp said.

“Furthermore, small-medium cities in India, China, South-east Asia, Africa and Europe are following in the footsteps of the United States in declines in urban densities.

“These findings are important, because globally, it is these small-medium-sized cities with limited institutional and financial capacity that are growing the fastest.” – Climate News Network

More people than ever now live in cities. Their growing urban space demands devour farmland, bad news for tomorrow’s hungry world.

LONDON, 9 April, 2020 – Even as people crowd into the cities, they don’t crowd the way they used to, and urban space demands are increasing. Even in some of the developing nations, townspeople are demanding more elbow-room.

And in the last four decades, worldwide, humans have claimed around 125,000 square kilometres of farmland or wilderness more than would have been necessary if urban densities had stayed at the 1970 level.

That is: to accommodate today’s city-dwellers with more space than their parents and grandparents ever expected to enjoy, an additional area almost the size of Greece has been covered by asphalt, brick, concrete, tile and glass.

In the US, urban settlements have always been fringed by more roomy suburban developments. Now in China, India and Nigeria, the cities are expanding and the population densities are decreasing.

Risk to farmers

“These three countries are expected to account for more than a third of the projected increase in the world’s urban population by 2050,” said Burak Güneralp, a geographer at Texas A&M University in the US.

“They also still have many millions of small farmers earning their livelihoods working fertile lands on the outskirts of cities. Thus any loss of these high-quality lands to urban expansion has huge implications for the livelihoods of these farmers.”

Dr Güneralp and colleagues report in the journal Environmental Research Letters that they looked at 611 case studies of 330 urban centres to calculate population growth, urban expansion and urban population densities between 1970 – the earliest moment for reliable statistics – and 2010.

They also factored in the size of cities, to distinguish different rates of change in centres with more and with fewer than two million citizens.

“Decreasing urban population densities in India and Nigeria since 1970 caused 85% and 30% more land, respectively, to be converted to urban”

Once most of humanity lived in rural areas. Now more than half the planet is crowded into cities and townships, and in a few decades the proportion could reach two-thirds.

But this crowding creates new problems. Cities are always significantly hotter than the surrounding landscape, and as global average temperatures rise, this in turn is likely to accelerate energy demand and global heating as people are forced to install air-conditioning.

The concentration of people in cities is likely to create new demands on sometimes precarious water supplies, and in any case the combination of climate change and population growth means ever greater numbers are at hazard from drought or flood.

All of this in turn increases the pressure for green spaces within the new cities and a more spacious lifestyle.

Cheek by jowl

But civilised city life comes at an environmental price. About half of India’s land is already classified as “degraded”, while India has the largest rural population but also the steepest fall in what geographers call urban land use efficiency, and the rest of the world calls living on top of your neighbours.

“Our findings suggest that decreasing urban population densities in India and Nigeria since 1970 caused 85% and 30% more land, respectively, to be converted to urban,” Dr Güneralp said.

“Furthermore, small-medium cities in India, China, South-east Asia, Africa and Europe are following in the footsteps of the United States in declines in urban densities.

“These findings are important, because globally, it is these small-medium-sized cities with limited institutional and financial capacity that are growing the fastest.” – 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

A second US Dust Bowl would hit world food stocks

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

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

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

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

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

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

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

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

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

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

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

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

Yields and nutrition affected

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Yields and nutrition affected

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

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

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

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

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

Regional nuclear war could bring global hunger

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

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

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

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

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

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

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

No winners

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

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

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

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

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

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

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

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

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

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

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

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

Four years to zero

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

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

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

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

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

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

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

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

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

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

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

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

No winners

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

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

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

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

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

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

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

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

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

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

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

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

Four years to zero

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

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

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

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

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