Author: Tim Radford

About Tim Radford

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

Polar link unites far extremes of north and south

They are different worlds, one an ocean, the other a continent. But a polar link keeps them in touch with each other.

LONDON, 30 November, 2020 − The Arctic and Antarctica are literally a world apart, but for an unlikely polar link. Change in the mass of ice in the north can and does precipitate change in the furthest reaches of the southern hemisphere.

According to 40,000 years of geological evidence, when the Arctic Ocean ice retreats, global sea levels rise to start washing away the sea ice around the shelf of the vast frozen continent at the other extreme of the planet.

This pattern of action at a distance is confirmed by computer simulations: the planet’s two hemispheres are in a kind of conversation, according to a new study in the journal Nature.

“Our results highlight how interconnected the Earth system is, with changes in one part of the planet driving changes in another,” said Natalya Gomez, of McGill University in Canada, who led the study.

“In the modern era, we haven’t seen the kind of large ice sheet retreat that we might see in our future warming world. Looking to records and models of change in Earth’s history can inform us about this.”

“Ice sheets can influence each other over great distances. It’s as though they were talking to one another about sea level changes”

The Arctic is one of the fastest-warming places on the planet: what happens in the far north has reverberations throughout the hemisphere. And Antarctica, too, is changing swiftly.

Although both extremes of cold are vulnerable to global heating driven by profligate fossil fuel use and global-scale loss of forests, climate scientists have tended to consider them as separate cases.

But a closer look at geological records − ice cores and samples from the ocean bottom that offer evidence of iceberg drift across the millennia − revealed a connection. The polar link is real.

At the height of the last ice age more than 20,000 years ago, the mass of ice in the north lowered global sea levels and the Antarctic ice shelf advanced. As the world began to warm again, ice in the north began to flow into the sea. Sea levels rose in the southern hemisphere and this began to force a retreat of the Antarctic ice.

“Ice sheets can influence each other over great distances due to the water that flows between them. It’s as though they were talking to one another about sea level changes,” Dr Gomez said.

Dynamic ice

“Polar ice sheets are not just large static mounds of ice. They evolve on various different time scales and are in constant flux, with ice growing and retreating, depending on the climate and the surrounding water levels.

“They gain ice as snow piles up on top of them, then spread outwards under their own weight, and stream out into the surrounding ocean where their edges break off into icebergs.”

The evidence showed that sea level change in Antarctica and ice mass loss in the Arctic were linked, over a sequence of at least 40,000 years.

“These ice sheets are really dynamic, exciting and intriguing parts of the Earth’s climate system. It’s staggering to think of ice that is several kilometres thick, that covers an entire continent, and that is evolving on all of these different timescales with global consequences,” Dr Gomez said.

“It’s just motivation for trying to better understand these really massive systems that are so far away from us.” − Climate News Network

They are different worlds, one an ocean, the other a continent. But a polar link keeps them in touch with each other.

LONDON, 30 November, 2020 − The Arctic and Antarctica are literally a world apart, but for an unlikely polar link. Change in the mass of ice in the north can and does precipitate change in the furthest reaches of the southern hemisphere.

According to 40,000 years of geological evidence, when the Arctic Ocean ice retreats, global sea levels rise to start washing away the sea ice around the shelf of the vast frozen continent at the other extreme of the planet.

This pattern of action at a distance is confirmed by computer simulations: the planet’s two hemispheres are in a kind of conversation, according to a new study in the journal Nature.

“Our results highlight how interconnected the Earth system is, with changes in one part of the planet driving changes in another,” said Natalya Gomez, of McGill University in Canada, who led the study.

“In the modern era, we haven’t seen the kind of large ice sheet retreat that we might see in our future warming world. Looking to records and models of change in Earth’s history can inform us about this.”

“Ice sheets can influence each other over great distances. It’s as though they were talking to one another about sea level changes”

The Arctic is one of the fastest-warming places on the planet: what happens in the far north has reverberations throughout the hemisphere. And Antarctica, too, is changing swiftly.

Although both extremes of cold are vulnerable to global heating driven by profligate fossil fuel use and global-scale loss of forests, climate scientists have tended to consider them as separate cases.

But a closer look at geological records − ice cores and samples from the ocean bottom that offer evidence of iceberg drift across the millennia − revealed a connection. The polar link is real.

At the height of the last ice age more than 20,000 years ago, the mass of ice in the north lowered global sea levels and the Antarctic ice shelf advanced. As the world began to warm again, ice in the north began to flow into the sea. Sea levels rose in the southern hemisphere and this began to force a retreat of the Antarctic ice.

“Ice sheets can influence each other over great distances due to the water that flows between them. It’s as though they were talking to one another about sea level changes,” Dr Gomez said.

Dynamic ice

“Polar ice sheets are not just large static mounds of ice. They evolve on various different time scales and are in constant flux, with ice growing and retreating, depending on the climate and the surrounding water levels.

“They gain ice as snow piles up on top of them, then spread outwards under their own weight, and stream out into the surrounding ocean where their edges break off into icebergs.”

The evidence showed that sea level change in Antarctica and ice mass loss in the Arctic were linked, over a sequence of at least 40,000 years.

“These ice sheets are really dynamic, exciting and intriguing parts of the Earth’s climate system. It’s staggering to think of ice that is several kilometres thick, that covers an entire continent, and that is evolving on all of these different timescales with global consequences,” Dr Gomez said.

“It’s just motivation for trying to better understand these really massive systems that are so far away from us.” − Climate News Network

Roof of the world is home to microplastic fibres

Microplastic fibres have been found in the snows of Everest. Pollution levels have literally reached new heights.

LONDON, 26 November, 2020 − Scientists have set a new record for the identification of microplastic fibres − an altitude record. They have found them at 8,440 metres high in the Himalayas, almost at the summit of Mt Everest.

It should be no surprise. Microplastic fibres and polymer fragments − derived from plastic products and especially from plastic waste − have been found in the sediments at the bottom of the sea, on the beaches around barren Antarctic islands, in the Arctic ice, on the surfaces of the ocean, and in the tissues of living things, from sea snails to whales.

And as the issue of plastic pollution made its way up the political agenda, it has now also climbed Mt Everest. Researchers report, in the journal One Earth, that they identified 12 fibrous plastic particles in every litre of snow from the highest measuring point, the so-called Balcony of Everest; particles were also identified in stream water at high altitudes and in even greater numbers − 79 per litre of snow − at the famous Everest Base Camp.

Their arrival on the world’s highest and most famous peak would have been inevitable. Seventy years ago manufacturers made plastic products at the rate of 5 million tonnes a year. In 2020, the world purchased 330 million tonnes, much of it used once and discarded.

“It really surprised me to find microplastics in every single snow sample. To know we are polluting near the top of the tallest mountain is a real eye-opener”

Somewhere between 93,000 tonnes and 236,000 tonnes is estimated to be floating on the sea surfaces. The cascade of polyester, acrylic, nylon, polypropylene and other polymer waste could increase threefold in the next two decades.

And just as there is more plastic on the planet, so there are more and more visitors to Sagamartha National Park in Nepal, and to the slopes of Mt Everest. In 1979, the region was host to 3,600 trekkers and climbers. By 2016, that number had climbed to 45,000. By 2019, climbers were forming an orderly queue and taking turns to reach the summit.

And each of these would have been wearing high-performance outdoor clothing, while carrying − and sometimes leaving behind − ropes, tents and lunch boxes fashioned from polymer materials.

The snow samples were collected by a National Geographic research team
formed to investigate the impact of climate change on the world’s highest peak, and studied by Imogen Napper of the University of Plymouth in the UK.

No longer pristine

“Mt Everest has been described as the world’s highest junkyard. Microplastics haven’t been studied on the mountain before, but they are generally just as persistent and typically more difficult to remove than larger items of debris,” Dr Napper said.

“I didn’t know what to expect in terms of results, but it really surprised me to find microplastics in every single snow sample I analysed. Mt Everest is somewhere I had always considered remote and pristine. To know we are polluting near the top of the tallest mountain is a real eye-opener.”

She added: “These are the highest microplastics discovered so far. While it sounds exciting, it means that microplastics have been discovered from the depths of the ocean all the way to the highest mountain on Earth.

“With microplastics so ubiquitous in our environment, it’s time to focus on informing appropriate environmental solutions. We need to protect and care for our planet.” − Climate News Network

Microplastic fibres have been found in the snows of Everest. Pollution levels have literally reached new heights.

LONDON, 26 November, 2020 − Scientists have set a new record for the identification of microplastic fibres − an altitude record. They have found them at 8,440 metres high in the Himalayas, almost at the summit of Mt Everest.

It should be no surprise. Microplastic fibres and polymer fragments − derived from plastic products and especially from plastic waste − have been found in the sediments at the bottom of the sea, on the beaches around barren Antarctic islands, in the Arctic ice, on the surfaces of the ocean, and in the tissues of living things, from sea snails to whales.

And as the issue of plastic pollution made its way up the political agenda, it has now also climbed Mt Everest. Researchers report, in the journal One Earth, that they identified 12 fibrous plastic particles in every litre of snow from the highest measuring point, the so-called Balcony of Everest; particles were also identified in stream water at high altitudes and in even greater numbers − 79 per litre of snow − at the famous Everest Base Camp.

Their arrival on the world’s highest and most famous peak would have been inevitable. Seventy years ago manufacturers made plastic products at the rate of 5 million tonnes a year. In 2020, the world purchased 330 million tonnes, much of it used once and discarded.

“It really surprised me to find microplastics in every single snow sample. To know we are polluting near the top of the tallest mountain is a real eye-opener”

Somewhere between 93,000 tonnes and 236,000 tonnes is estimated to be floating on the sea surfaces. The cascade of polyester, acrylic, nylon, polypropylene and other polymer waste could increase threefold in the next two decades.

And just as there is more plastic on the planet, so there are more and more visitors to Sagamartha National Park in Nepal, and to the slopes of Mt Everest. In 1979, the region was host to 3,600 trekkers and climbers. By 2016, that number had climbed to 45,000. By 2019, climbers were forming an orderly queue and taking turns to reach the summit.

And each of these would have been wearing high-performance outdoor clothing, while carrying − and sometimes leaving behind − ropes, tents and lunch boxes fashioned from polymer materials.

The snow samples were collected by a National Geographic research team
formed to investigate the impact of climate change on the world’s highest peak, and studied by Imogen Napper of the University of Plymouth in the UK.

No longer pristine

“Mt Everest has been described as the world’s highest junkyard. Microplastics haven’t been studied on the mountain before, but they are generally just as persistent and typically more difficult to remove than larger items of debris,” Dr Napper said.

“I didn’t know what to expect in terms of results, but it really surprised me to find microplastics in every single snow sample I analysed. Mt Everest is somewhere I had always considered remote and pristine. To know we are polluting near the top of the tallest mountain is a real eye-opener.”

She added: “These are the highest microplastics discovered so far. While it sounds exciting, it means that microplastics have been discovered from the depths of the ocean all the way to the highest mountain on Earth.

“With microplastics so ubiquitous in our environment, it’s time to focus on informing appropriate environmental solutions. We need to protect and care for our planet.” − Climate News Network

Big builders’ plans threaten to wreck forest survival

Plans by corporate power and government investors risk corporate good intentions and national vows for forest survival.

LONDON, 24 November, 2020 − Forest survival in the world’s great conservation targets − the Amazon, the Congo and South-east Asia, for example − is at risk from not just ranchers, loggers and illegal foresters: it’s also under assault from some of the planet’s biggest spenders: governments and the big banks, giant mining corporations and road builders.

A new report warns that in the Amazon region alone − across Bolivia, Brazil, Colombia, Peru and Ecuador − governments have promised $27bn worth of investment on 12,000 kms (7,456 miles) of roads over the next five years. If all the promised infrastructure goes ahead, that could mean the loss of 24,000 square kilometres of forest in the next 20 years.

The Indonesian government is planning to drive a 4,000 km network of highway through a national park in Papua, western New Guinea, for access to 500 sq kms of mining concessions. A new planned railway in Kalimantan, Indonesia, will open up new opportunities for palm oil plantations and coal mining concessions.

And in sub-Saharan Africa nations plan dozens of “international development corridors” to provide access to minerals and to energy. The plans threaten to cut through 400 protected areas and degrade another 1800.

Threat intensified

“Big new projects under way or planned in the Amazon, Indonesia, Meso-America, the Congo basin and beyond, reveal that our insatiable appetite for coal, minerals, metals, energy and agricultural commodities like soy has opened up a new front in the battle to protect the world’s forests,” said Franziska Haupt, executive director of Climate Focus, Berlin, and the lead author of a new report on efforts so far to limit the destruction of the world’s forests.

“Some governments are compounding this threat and rolling back forest protections, as countries struggle to cope with the economic fallout of Covid-19.”

Forests are key to limiting climate change. It is not enough simply to switch from fossil fuels to renewable energy to halt global heating: the climate emergency also requires nations to halt the destruction of, and restore, the world’s great forests.

But much of the promised investment will be devoted to destroying forest and then compounding the damage by producing new reserves of fossil fuels to increase levels of greenhouse gas emissions.

“We are living in a dreamworld of pledges, but a reality of very little progress, lack of transparency, vested interests and short-termism … Alas, reality will always catch us up”

“Many of these projects would never get the green light if the true value of forests was factored in − their role in reducing climate change, protecting animal habitats and reducing the spread of zoonotic diseases [infections caught from other creatures], keeping water sources clean, providing economic opportunity and a long list of other benefits without a price tag,” said Erin Matson, a consultant at Climate Focus, and a co-author.

“Forests are at a dangerous tipping point, and these new large-scale infrastructure projects could push us over the edge and undermine global efforts to stop deforestation.

“There’s a very small − and closing − window of opportunity now to rethink and re-orient these projects in a more sustainable direction. Governments, companies and investors all need to step up, commit to more transparency and act quickly to avoid further harm to people, wildlife and nature.”

The report points out that mining is the world’s “most violent” economic sector, with the largest share of environmental conflicts. In 2019, 50 environmental defenders were murdered.

“Local peoples tend to have little say in economic development approaches and the allocation and use of forest lands,” the report says. “Instead, powerful corporations and national elites influence decision-making to facilitate resource exploitation, while grassroots actors who express their preferences are often shunted aside or ignored.”

Doubtful promise

Forest survival is tough going. Roads, too, are part of the problem: roads and road networks make it easier for farmers and loggers to clear land. They could account for as much as 16% of the destruction of tropical and subtropical forests.

Six years ago, in what became known as the New York Declaration on Forests, endorsed by the world’s governments, multinationals and non-governmental organisations, there were international pledges to halve deforestation by 2020, and end it by 2030.

The 2020 target will not be met. The 2030 pledge looks increasingly improbable. In 2019, a World Bank analysis of 29 case studies of sites of large-scale mining in forests could not find a single example of a mining operation that properly addressed and limited the risks to the forest and its biodiversity.

“This is a salutary reminder that we are living in a dreamworld of pledges, but a reality of very little progress, lack of transparency, vested interests and short-termism,” said Robert Nasi, director general of the International Centre for Forest Research. “Alas, reality will always catch us up.” − Climate News Network

Plans by corporate power and government investors risk corporate good intentions and national vows for forest survival.

LONDON, 24 November, 2020 − Forest survival in the world’s great conservation targets − the Amazon, the Congo and South-east Asia, for example − is at risk from not just ranchers, loggers and illegal foresters: it’s also under assault from some of the planet’s biggest spenders: governments and the big banks, giant mining corporations and road builders.

A new report warns that in the Amazon region alone − across Bolivia, Brazil, Colombia, Peru and Ecuador − governments have promised $27bn worth of investment on 12,000 kms (7,456 miles) of roads over the next five years. If all the promised infrastructure goes ahead, that could mean the loss of 24,000 square kilometres of forest in the next 20 years.

The Indonesian government is planning to drive a 4,000 km network of highway through a national park in Papua, western New Guinea, for access to 500 sq kms of mining concessions. A new planned railway in Kalimantan, Indonesia, will open up new opportunities for palm oil plantations and coal mining concessions.

And in sub-Saharan Africa nations plan dozens of “international development corridors” to provide access to minerals and to energy. The plans threaten to cut through 400 protected areas and degrade another 1800.

Threat intensified

“Big new projects under way or planned in the Amazon, Indonesia, Meso-America, the Congo basin and beyond, reveal that our insatiable appetite for coal, minerals, metals, energy and agricultural commodities like soy has opened up a new front in the battle to protect the world’s forests,” said Franziska Haupt, executive director of Climate Focus, Berlin, and the lead author of a new report on efforts so far to limit the destruction of the world’s forests.

“Some governments are compounding this threat and rolling back forest protections, as countries struggle to cope with the economic fallout of Covid-19.”

Forests are key to limiting climate change. It is not enough simply to switch from fossil fuels to renewable energy to halt global heating: the climate emergency also requires nations to halt the destruction of, and restore, the world’s great forests.

But much of the promised investment will be devoted to destroying forest and then compounding the damage by producing new reserves of fossil fuels to increase levels of greenhouse gas emissions.

“We are living in a dreamworld of pledges, but a reality of very little progress, lack of transparency, vested interests and short-termism … Alas, reality will always catch us up”

“Many of these projects would never get the green light if the true value of forests was factored in − their role in reducing climate change, protecting animal habitats and reducing the spread of zoonotic diseases [infections caught from other creatures], keeping water sources clean, providing economic opportunity and a long list of other benefits without a price tag,” said Erin Matson, a consultant at Climate Focus, and a co-author.

“Forests are at a dangerous tipping point, and these new large-scale infrastructure projects could push us over the edge and undermine global efforts to stop deforestation.

“There’s a very small − and closing − window of opportunity now to rethink and re-orient these projects in a more sustainable direction. Governments, companies and investors all need to step up, commit to more transparency and act quickly to avoid further harm to people, wildlife and nature.”

The report points out that mining is the world’s “most violent” economic sector, with the largest share of environmental conflicts. In 2019, 50 environmental defenders were murdered.

“Local peoples tend to have little say in economic development approaches and the allocation and use of forest lands,” the report says. “Instead, powerful corporations and national elites influence decision-making to facilitate resource exploitation, while grassroots actors who express their preferences are often shunted aside or ignored.”

Doubtful promise

Forest survival is tough going. Roads, too, are part of the problem: roads and road networks make it easier for farmers and loggers to clear land. They could account for as much as 16% of the destruction of tropical and subtropical forests.

Six years ago, in what became known as the New York Declaration on Forests, endorsed by the world’s governments, multinationals and non-governmental organisations, there were international pledges to halve deforestation by 2020, and end it by 2030.

The 2020 target will not be met. The 2030 pledge looks increasingly improbable. In 2019, a World Bank analysis of 29 case studies of sites of large-scale mining in forests could not find a single example of a mining operation that properly addressed and limited the risks to the forest and its biodiversity.

“This is a salutary reminder that we are living in a dreamworld of pledges, but a reality of very little progress, lack of transparency, vested interests and short-termism,” said Robert Nasi, director general of the International Centre for Forest Research. “Alas, reality will always catch us up.” − Climate News Network

Mixed farming beats intensive agriculture methods

It sounds like the conservationist’s dream. But a return to traditional mixed farming ways could pay off for farmers too.

LONDON, 23 November, 2020 − Once again, researchers have shown that it should be possible to feed the human race and leave enough space for the rest of creation, simply by going back to centuries-old mixed farming practices.

That would mean an end to highly intensively-farmed landscapes composed of vast fields that were home to just one crop, and a return to a number of once-traditional husbandry methods. It sounds counter-intuitive, but European researchers are convinced that it could be good value.

They report in the journal Science Advances that they looked at more than 5,000 studies that made more than 40,000 comparisons between what they term diversified and simplified agriculture.

And they found that crop yield in general either kept to the same level or even increased when farmers adopted what they called diversified practices of the kind that sustained subsistence farmers for many centuries.

These include intercropping − different crops side by side − and multiple crops in rotation, strips of flowers to encourage pollinating insects, lower levels of disturbance of the soil and hedges, and forested shelter belts to encourage wildlife alongside farmland.

“Most often, diversification practices resulted in win-win support of services and crop yields”

The payoff? Better ecosystem services such as pollination, the regulation of crop pests by natural enemies, a more efficient turnover of nutrients, higher water quality, and in many cases better storage of carbon in ways that could mitigate climate change.

This, of course, is not how big agribusiness delivers much of the world’s food.

“The trend is that we are simplifying major cropping systems worldwide,” said Giovanni Tamburini, an ecologist at the Swedish University of Agricultural Sciences in Uppsala, who led the study.

“We grow monoculture on enlarged fields in homogenised landscapes. According to our study, diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself.”

It’s an old argument. Is it better for a farmer to invest all in one vast crop of maize or wheat or soy, regularly nourished by commercial fertilisers, routinely sprayed to suppress pests, moulds and mildews, with the land ploughed and harrowed after harvest for the next crop, and always at risk of frost or flood, locust swarms, drought or blight?

All-round winners

Or would it be better in the long run for the farmer to spread the risk by changing and multiplying the crops, and to rely more on undisturbed soils and local habitats for birds and insects that would demolish some of the pests (and of course take some of the crop)?

Researchers have repeatedly argued that both to contain climate change and to preserve the natural world from which all human nourishment and almost all human wealth ultimately derive, farming practices must change, and so must human appetite. The argument remains: what is the best way to set about change down on the farm itself?

There have already been a large number of studies of this question. There have also been meta-analyses, or studies of collected studies. Dr Tamburini and his colleagues identified 41,946 comparisons embedded in 5,160 original studies. They also found 98 meta-analyses. And they took a fresh look at the whole lot to identify what could be win-win, trade-off and lose-lose outcomes.

They found that diversification is better for biodiversity, pollination, pest control, nutrient cycling, soil fertility and water regulation at least 63% of the time. “Most often, diversification practices resulted in win-win support of services and crop yields,” they report.

“Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.” − Climate News Network

It sounds like the conservationist’s dream. But a return to traditional mixed farming ways could pay off for farmers too.

LONDON, 23 November, 2020 − Once again, researchers have shown that it should be possible to feed the human race and leave enough space for the rest of creation, simply by going back to centuries-old mixed farming practices.

That would mean an end to highly intensively-farmed landscapes composed of vast fields that were home to just one crop, and a return to a number of once-traditional husbandry methods. It sounds counter-intuitive, but European researchers are convinced that it could be good value.

They report in the journal Science Advances that they looked at more than 5,000 studies that made more than 40,000 comparisons between what they term diversified and simplified agriculture.

And they found that crop yield in general either kept to the same level or even increased when farmers adopted what they called diversified practices of the kind that sustained subsistence farmers for many centuries.

These include intercropping − different crops side by side − and multiple crops in rotation, strips of flowers to encourage pollinating insects, lower levels of disturbance of the soil and hedges, and forested shelter belts to encourage wildlife alongside farmland.

“Most often, diversification practices resulted in win-win support of services and crop yields”

The payoff? Better ecosystem services such as pollination, the regulation of crop pests by natural enemies, a more efficient turnover of nutrients, higher water quality, and in many cases better storage of carbon in ways that could mitigate climate change.

This, of course, is not how big agribusiness delivers much of the world’s food.

“The trend is that we are simplifying major cropping systems worldwide,” said Giovanni Tamburini, an ecologist at the Swedish University of Agricultural Sciences in Uppsala, who led the study.

“We grow monoculture on enlarged fields in homogenised landscapes. According to our study, diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself.”

It’s an old argument. Is it better for a farmer to invest all in one vast crop of maize or wheat or soy, regularly nourished by commercial fertilisers, routinely sprayed to suppress pests, moulds and mildews, with the land ploughed and harrowed after harvest for the next crop, and always at risk of frost or flood, locust swarms, drought or blight?

All-round winners

Or would it be better in the long run for the farmer to spread the risk by changing and multiplying the crops, and to rely more on undisturbed soils and local habitats for birds and insects that would demolish some of the pests (and of course take some of the crop)?

Researchers have repeatedly argued that both to contain climate change and to preserve the natural world from which all human nourishment and almost all human wealth ultimately derive, farming practices must change, and so must human appetite. The argument remains: what is the best way to set about change down on the farm itself?

There have already been a large number of studies of this question. There have also been meta-analyses, or studies of collected studies. Dr Tamburini and his colleagues identified 41,946 comparisons embedded in 5,160 original studies. They also found 98 meta-analyses. And they took a fresh look at the whole lot to identify what could be win-win, trade-off and lose-lose outcomes.

They found that diversification is better for biodiversity, pollination, pest control, nutrient cycling, soil fertility and water regulation at least 63% of the time. “Most often, diversification practices resulted in win-win support of services and crop yields,” they report.

“Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.” − Climate News Network

Global heating may go on for five more centuries

Global heating now means more warming for 500 years ahead, even if all greenhouse emissions stop. Or is that too simple?

LONDON, 20 November, 2020 − Norwegian scientists have mapped the future of the Earth in a regime of climate change and have come to an uncomfortable conclusion: it’s likely that global heating will persist until around the year 2500.

Even if human beings immediately ceased all use of fossil fuels that spill greenhouse gases into the planetary atmosphere, the world would be committed to warming for the next five centuries, they suggest.

By then global temperatures would be at least 3°C higher, and sea levels three metres higher, than they would have been in 1850. Even with a dramatic halt to the emissions that fuel global heating, they warn in the journal Scientific Reports, the Arctic ice would go on melting, water vapour would continue to build up in the atmosphere, the permafrost would continue to thaw and vast reservoirs of ancient carbon that had been trapped in the once-frozen ground would escape into the atmosphere.

The message − one that comes hedged with caution − is that to keep continental temperatures and sea levels as they were for most of human history, nations should have started to reduce greenhouse gas emissions six decades ago.

And to slow the warming that might now be inexorable, nations must unite to somehow remove 33 billion tonnes of carbon dioxide (CO2) − an almost unimaginable volume − from the atmosphere every year from now on.

Challenged by colleagues

Caution is necessary because, as the researchers themselves point out, the finding presents an extremely simple model of cause and effect on a simulated planet not unlike Earth, but without the untidy mosaic of natural and human processes that directly influence the rate at which CO2 builds up in the atmosphere.

And the two scientists who wrote the study directly urge other climate researchers to check their findings with more sophisticated simulations. They have made a stab at predicting the future, and they know it could be wrong.

But if it isn’t wrong, then the message is that profligate human use of fossil fuels, combined with heedless destruction of many of the planet’s natural ecosystems, and then topped with the massive construction of human cities, industries and travel networks, may have already pushed the planet past a tipping point, beyond which the slide into potentially catastrophic climate change has become inexorable.

And they are not the first to make such a suggestion. Nor are they the first to warn that what had once been trailed as a notional “worst case” scenario has of late increasingly begun to look like modern reality.

The finding has been comprehensively challenged by British scientists, not because it could be wrong, but because the simulation is too simple, and doesn’t incorporate many of the processes that happen in the real world. One distinguished researcher called it “a toy model”.

“To keep global warming to just 1.5°C this century we already know we will have to have negative carbon emissions from 2050 to 2100”

But almost all who commented also conceded that to steer the planet away from permanent and devastating climate change, nations may have left concerted and sustained action a bit late.

Reduction of carbon emissions to zero in the next three decades would be just a start. And the world would go on warming for some time, just as a reaction to the extra carbon dioxide already spilled into the atmosphere in the last three decades.

“To keep global warming to just 1.5°C this century we already know we will have to have negative carbon emissions from 2050 to 2100,” said Mark Maslin, a climatologist at University College, London.

“If this study is confirmed, then we may have to continue drawing down carbon dioxide from the atmosphere way beyond the end of this century. And I would suggest that if we have been able to successfully deal with climate change in this century, we really will not have to worry about dealing with a much smaller warming over the next 400 years.”

But even as both the authors and their critics warn that the outcome should be treated with caution, other research has almost coincidentally begun to suggest that the world may be nearing a tipping point.

Positive feedback?

Last month German scientists contemplated the increasing loss of ice in the Arctic − all the sea ice could have vanished in summer before mid-century − and in the mountain regions worldwide, and reasoned that, instead of reflecting radiation back into space, the darker ocean or rock revealed beneath the ice would absorb it, to increase rates of warming.

They warn in Nature Communications that this process alone could increase long-term global warming by 0.43°C, to accelerate yet more thawing of the permafrost: an example of the vicious circle that could go on delivering climate change by exactly the kind of positive feedback the Norwegian scientists fear.

And in one respect, their fellow scientists agree with them: further warming is already “baked in” to the future climate. Even if the world turns off greenhouse gas emissions right now, global heating will continue for decades. For how long, and how swiftly, is difficult to calculate.

“Even if the paper is right in every respect and we are already committed to at least 3°C warming if we stop emissions tomorrow, this warming will take 500 years,” said Andrew Watson, of the University of Exeter.

“This is preferable to 3°C warming over 100 years, which would be far more disruptive and might happen if we don’t cut emissions.” − Climate News Network

Global heating now means more warming for 500 years ahead, even if all greenhouse emissions stop. Or is that too simple?

LONDON, 20 November, 2020 − Norwegian scientists have mapped the future of the Earth in a regime of climate change and have come to an uncomfortable conclusion: it’s likely that global heating will persist until around the year 2500.

Even if human beings immediately ceased all use of fossil fuels that spill greenhouse gases into the planetary atmosphere, the world would be committed to warming for the next five centuries, they suggest.

By then global temperatures would be at least 3°C higher, and sea levels three metres higher, than they would have been in 1850. Even with a dramatic halt to the emissions that fuel global heating, they warn in the journal Scientific Reports, the Arctic ice would go on melting, water vapour would continue to build up in the atmosphere, the permafrost would continue to thaw and vast reservoirs of ancient carbon that had been trapped in the once-frozen ground would escape into the atmosphere.

The message − one that comes hedged with caution − is that to keep continental temperatures and sea levels as they were for most of human history, nations should have started to reduce greenhouse gas emissions six decades ago.

And to slow the warming that might now be inexorable, nations must unite to somehow remove 33 billion tonnes of carbon dioxide (CO2) − an almost unimaginable volume − from the atmosphere every year from now on.

Challenged by colleagues

Caution is necessary because, as the researchers themselves point out, the finding presents an extremely simple model of cause and effect on a simulated planet not unlike Earth, but without the untidy mosaic of natural and human processes that directly influence the rate at which CO2 builds up in the atmosphere.

And the two scientists who wrote the study directly urge other climate researchers to check their findings with more sophisticated simulations. They have made a stab at predicting the future, and they know it could be wrong.

But if it isn’t wrong, then the message is that profligate human use of fossil fuels, combined with heedless destruction of many of the planet’s natural ecosystems, and then topped with the massive construction of human cities, industries and travel networks, may have already pushed the planet past a tipping point, beyond which the slide into potentially catastrophic climate change has become inexorable.

And they are not the first to make such a suggestion. Nor are they the first to warn that what had once been trailed as a notional “worst case” scenario has of late increasingly begun to look like modern reality.

The finding has been comprehensively challenged by British scientists, not because it could be wrong, but because the simulation is too simple, and doesn’t incorporate many of the processes that happen in the real world. One distinguished researcher called it “a toy model”.

“To keep global warming to just 1.5°C this century we already know we will have to have negative carbon emissions from 2050 to 2100”

But almost all who commented also conceded that to steer the planet away from permanent and devastating climate change, nations may have left concerted and sustained action a bit late.

Reduction of carbon emissions to zero in the next three decades would be just a start. And the world would go on warming for some time, just as a reaction to the extra carbon dioxide already spilled into the atmosphere in the last three decades.

“To keep global warming to just 1.5°C this century we already know we will have to have negative carbon emissions from 2050 to 2100,” said Mark Maslin, a climatologist at University College, London.

“If this study is confirmed, then we may have to continue drawing down carbon dioxide from the atmosphere way beyond the end of this century. And I would suggest that if we have been able to successfully deal with climate change in this century, we really will not have to worry about dealing with a much smaller warming over the next 400 years.”

But even as both the authors and their critics warn that the outcome should be treated with caution, other research has almost coincidentally begun to suggest that the world may be nearing a tipping point.

Positive feedback?

Last month German scientists contemplated the increasing loss of ice in the Arctic − all the sea ice could have vanished in summer before mid-century − and in the mountain regions worldwide, and reasoned that, instead of reflecting radiation back into space, the darker ocean or rock revealed beneath the ice would absorb it, to increase rates of warming.

They warn in Nature Communications that this process alone could increase long-term global warming by 0.43°C, to accelerate yet more thawing of the permafrost: an example of the vicious circle that could go on delivering climate change by exactly the kind of positive feedback the Norwegian scientists fear.

And in one respect, their fellow scientists agree with them: further warming is already “baked in” to the future climate. Even if the world turns off greenhouse gas emissions right now, global heating will continue for decades. For how long, and how swiftly, is difficult to calculate.

“Even if the paper is right in every respect and we are already committed to at least 3°C warming if we stop emissions tomorrow, this warming will take 500 years,” said Andrew Watson, of the University of Exeter.

“This is preferable to 3°C warming over 100 years, which would be far more disruptive and might happen if we don’t cut emissions.” − Climate News Network

Shrinking world leaves less room for wild creatures

Wild creatures are losing their range. One day jaguars and rhinos, pandas and tigers, may have nowhere left to go.

LONDON, 18 November, 2020 − Thanks to climate change and to the human colonisation of the natural landscape, the world’s wild creatures have vanishing space in which to roam. In the last two centuries birds, mammals and amphibians have lost − this is an average figure − almost a fifth of their natural range.

By the close of the century, this freedom will have been limited even more, by almost a fourth of their living space. That is a conclusion based on close observation by generations of naturalists since 1700, of almost 17,000 species on all the main continents. And those figures, remember, are simply averages.

Individual species may have lost much, much more of the habitat and climate regime on which they depend to survive. According to the International Union for Conservation of Nature’s species Red List the jaguar has lost 21% of its living space; the cheetah 28%; the black rhinoceros 53%.

Even those charismatic creatures slow in movement and static of habit have felt the confinement. The panda has 11% less freedom. The koala’s range has been reduced by 22%.

Tropics hit hardest

And despite decades of conservation effort, the Bengal tiger’s hunting grounds have been diminished by a fifth.

“The habitat size of almost all known birds, mammals and amphibians is shrinking, primarily because of land conversion by humans as we continue to expand our agricultural and urban areas,” said Robert Beyer, a zoologist at the University of Cambridge in the UK, first author of the study, in the journal Nature Communications, of the habitat of 16,919 animals.

One in six of these has already lost half its estimated natural range. By 2100, it could be more than one in four, depending on a range of climate scenarios.

The swiftest and most dramatic changes have been in the tropical zones, as wilderness has given way to palm oil plantation or cattle range. In many cases, the tropical species’ ranges were smaller to begin with.

“The habitat size of almost all known birds, mammals and amphibians is shrinking, primarily because of land conversion by humans as we continue to expand our agricultural and urban areas”

“The tropics are biodiversity hotspots with lots of small-range species. If one hectare of forest is converted to agricultural land, a lot more species lose larger proportions of their home than in places like Europe,” Dr Beyer said.

“Species in the Amazon have adapted to living in tropical rainforest. If climate change causes this ecosystem to change, many of those species won’t be able to survive − or they will be pushed into smaller areas of remaining rainforest. We found that the higher the carbon emissions, the worse it gets for most species in terms of habitat loss.”

Researchers have calculated that perhaps a million species could be threatened with extinction as a consequence of the human conversion of wilderness and human-fuelled climate change. Cambridge co-author Andrea Manica warned that what happens to the creatures of the tropical wilderness will depend on just how much more fossil fuels humans burn, and how rapaciously human intruders scorch and clear the forests and grasslands.

“While our study quantifies the drastic consequences for species’ ranges, if global land use and climate change are left unchecked, it also demonstrates the tremendous potential of timely and concerted policy action for halting − and indeed reversing − previous trends in global range contractions,” he said.

“It all depends on what we do next.” Remembering the needs of the wild creatures who share the planet would be a start. − Climate News Network

Wild creatures are losing their range. One day jaguars and rhinos, pandas and tigers, may have nowhere left to go.

LONDON, 18 November, 2020 − Thanks to climate change and to the human colonisation of the natural landscape, the world’s wild creatures have vanishing space in which to roam. In the last two centuries birds, mammals and amphibians have lost − this is an average figure − almost a fifth of their natural range.

By the close of the century, this freedom will have been limited even more, by almost a fourth of their living space. That is a conclusion based on close observation by generations of naturalists since 1700, of almost 17,000 species on all the main continents. And those figures, remember, are simply averages.

Individual species may have lost much, much more of the habitat and climate regime on which they depend to survive. According to the International Union for Conservation of Nature’s species Red List the jaguar has lost 21% of its living space; the cheetah 28%; the black rhinoceros 53%.

Even those charismatic creatures slow in movement and static of habit have felt the confinement. The panda has 11% less freedom. The koala’s range has been reduced by 22%.

Tropics hit hardest

And despite decades of conservation effort, the Bengal tiger’s hunting grounds have been diminished by a fifth.

“The habitat size of almost all known birds, mammals and amphibians is shrinking, primarily because of land conversion by humans as we continue to expand our agricultural and urban areas,” said Robert Beyer, a zoologist at the University of Cambridge in the UK, first author of the study, in the journal Nature Communications, of the habitat of 16,919 animals.

One in six of these has already lost half its estimated natural range. By 2100, it could be more than one in four, depending on a range of climate scenarios.

The swiftest and most dramatic changes have been in the tropical zones, as wilderness has given way to palm oil plantation or cattle range. In many cases, the tropical species’ ranges were smaller to begin with.

“The habitat size of almost all known birds, mammals and amphibians is shrinking, primarily because of land conversion by humans as we continue to expand our agricultural and urban areas”

“The tropics are biodiversity hotspots with lots of small-range species. If one hectare of forest is converted to agricultural land, a lot more species lose larger proportions of their home than in places like Europe,” Dr Beyer said.

“Species in the Amazon have adapted to living in tropical rainforest. If climate change causes this ecosystem to change, many of those species won’t be able to survive − or they will be pushed into smaller areas of remaining rainforest. We found that the higher the carbon emissions, the worse it gets for most species in terms of habitat loss.”

Researchers have calculated that perhaps a million species could be threatened with extinction as a consequence of the human conversion of wilderness and human-fuelled climate change. Cambridge co-author Andrea Manica warned that what happens to the creatures of the tropical wilderness will depend on just how much more fossil fuels humans burn, and how rapaciously human intruders scorch and clear the forests and grasslands.

“While our study quantifies the drastic consequences for species’ ranges, if global land use and climate change are left unchecked, it also demonstrates the tremendous potential of timely and concerted policy action for halting − and indeed reversing − previous trends in global range contractions,” he said.

“It all depends on what we do next.” Remembering the needs of the wild creatures who share the planet would be a start. − Climate News Network

Climate crisis finds ample answers in world’s trees

The world’s trees can build cities, devour carbon and feed developing countries’ small farmers. It’s time to branch out.

LONDON, 17 November, 2020 − The great climate change challenge should consider the world’s trees. New wooden cities and suburbs − that is, new homes fashioned from wood rather than bricks and mortar − could consume 55 million tonnes of carbon dioxide (CO2) a year: that adds up to almost half of the annual greenhouse gas emissions from Europe’s cement industry.

And the bigger and more substantial the tree, the more value in the arboreal effort to limit global warming and contain climate change. A US study has found that large trees − those with trunks of 53 cms at breast height − might make up only 3% of a measured plot, but contain 42% of all the above-ground carbon.

And trees could enhance human health as well as capture carbon: an international team believes that tree-sourced food − think mangoes, avocados, Brazil nuts and so on − could deliver much more nourishment for tomorrow’s supper tables.

The planet is home to at least 7,000 edible plants. Half the world’s calories come from just four crops, all high in calories but low in nutrients − wheat, rice, sugar cane and maize − that simultaneously fuel both malnutrition and obesity. There are 50,000 tree species in the tropics alone, a number of them potentially new sources of high quality food.

The conclusions of all three studies are tentative. But they are also familiar: that is, other research teams have for years been investigating trees as fabric, trees as absorbers of atmospheric carbon, and trees as enhanced forms of farming.

“This is the first time that the carbon storage potential of wooden building construction has been evaluated on the European level”

But all three offer a new and more detailed look, and confirm the big picture: when it comes to climate, the world’s trees are among the most important things on the planet.

Finnish scientists report in the journal Environmental Research Letters that they looked again at 50 case studies of timber as a way of growing cities: Europe builds about 190 million square metres of housing each year, largely in cities, and this demand for new homes is growing at 1% a year. Buildings worldwide − concrete, steel, glass, bricks, tiles, paving and so on − account for one third of global greenhouse gas emissions.

If however 80% of new residential buildings in Europe were built of, clad with and furnished from timber from sustainable forests, then this could represent a carbon sink of 55 million tonnes of CO2 a year, represent a 47% cut in greenhouse gas emissions from Europe’s cement-makers, and deliver energy-efficient homes.

“This is the first time that the carbon storage potential of wooden building construction has been evaluated on the European level, in different scenarios,” said Ali Amiri, of Aalto University, who led the study. “We hope that our model could be used as a roadmap to increase wooden construction in Europe.”

US scientists report in the journal Frontiers in Forests and Global Change that they took a close look at large diameter trees on National Forest lands in the states of Oregon and Washington.

Size matters

Trees with diameters greater than 21 inches, or 53.3 cms, accounted for only 3% of the total number of trees in the plots they chose to study. But when it came to absorbing atmospheric carbon, these were the real heavyweights. They contained 42% of all the above-ground carbon in the entire measured ecosystem.

Trees bigger than 30 inches, or 76 cms in diameter, made up only 0.6% of the total number, but accounted for 16% of the total above-ground carbon. The message was, the bigger the better.

The forest giants are themselves natural habitat: they support birds, mammals, insects, microbes and other plants; they serve as soaring water towers, tapping groundwater and cooling the environment through evotranspiration. And their value as a store of atmospheric carbon has been confirmed again and again.

“If you think of adding a ring of new growth to the circumference of a large tree and its branches every year, that ring adds up to a lot more carbon than the ring of a small tree,” said David Mildrexler, of Eastern Oregon Legacy Lands, who led the research. “This is why specifically letting large trees grow larger is important for climate change.”

And trees, researchers from five nations argue in the journal People and Nature, could be the healthy solution both to the climate crisis and to poor diet.

Better fed

Of the world’s 100 most nourishing foods, 14 come from trees. The planet is home to 60,000 species of tree, and many − especially in the tropics − provide nutritious fruits, nuts, leaves and seeds. Many are exploited only by small rural communities.

In the Amazon basin, for instance, a shrub called Myrciaria dubia was found to have a vitamin C content 54 times that of an orange. The scientists looked at seven tropical nations to identify foods from 90 tree species: these provided local families with 11% of diet by mass but 31% of the daily intake of vitamins A and C.

Never mind the giant commercial palm oil plantations and cacao harvests: the researchers see tree crops as something that could sustainably help hundreds of millions of the world’s smallholder farmers, by diversifying income and providing more and healthier food with a very low investment.

“The right type of trees in the right place can provide nutritious foods to improve diets sustainably while providing other valuable ecosystem services such as carbon sequestration,” said Merel Jansen, of the Swiss Federal Institute of Technology known as ETH Zurich, who led the investigation.

“It can also contribute to development issues related to poverty reduction, biodiversity conservation, and food security.” − Climate News Network

The world’s trees can build cities, devour carbon and feed developing countries’ small farmers. It’s time to branch out.

LONDON, 17 November, 2020 − The great climate change challenge should consider the world’s trees. New wooden cities and suburbs − that is, new homes fashioned from wood rather than bricks and mortar − could consume 55 million tonnes of carbon dioxide (CO2) a year: that adds up to almost half of the annual greenhouse gas emissions from Europe’s cement industry.

And the bigger and more substantial the tree, the more value in the arboreal effort to limit global warming and contain climate change. A US study has found that large trees − those with trunks of 53 cms at breast height − might make up only 3% of a measured plot, but contain 42% of all the above-ground carbon.

And trees could enhance human health as well as capture carbon: an international team believes that tree-sourced food − think mangoes, avocados, Brazil nuts and so on − could deliver much more nourishment for tomorrow’s supper tables.

The planet is home to at least 7,000 edible plants. Half the world’s calories come from just four crops, all high in calories but low in nutrients − wheat, rice, sugar cane and maize − that simultaneously fuel both malnutrition and obesity. There are 50,000 tree species in the tropics alone, a number of them potentially new sources of high quality food.

The conclusions of all three studies are tentative. But they are also familiar: that is, other research teams have for years been investigating trees as fabric, trees as absorbers of atmospheric carbon, and trees as enhanced forms of farming.

“This is the first time that the carbon storage potential of wooden building construction has been evaluated on the European level”

But all three offer a new and more detailed look, and confirm the big picture: when it comes to climate, the world’s trees are among the most important things on the planet.

Finnish scientists report in the journal Environmental Research Letters that they looked again at 50 case studies of timber as a way of growing cities: Europe builds about 190 million square metres of housing each year, largely in cities, and this demand for new homes is growing at 1% a year. Buildings worldwide − concrete, steel, glass, bricks, tiles, paving and so on − account for one third of global greenhouse gas emissions.

If however 80% of new residential buildings in Europe were built of, clad with and furnished from timber from sustainable forests, then this could represent a carbon sink of 55 million tonnes of CO2 a year, represent a 47% cut in greenhouse gas emissions from Europe’s cement-makers, and deliver energy-efficient homes.

“This is the first time that the carbon storage potential of wooden building construction has been evaluated on the European level, in different scenarios,” said Ali Amiri, of Aalto University, who led the study. “We hope that our model could be used as a roadmap to increase wooden construction in Europe.”

US scientists report in the journal Frontiers in Forests and Global Change that they took a close look at large diameter trees on National Forest lands in the states of Oregon and Washington.

Size matters

Trees with diameters greater than 21 inches, or 53.3 cms, accounted for only 3% of the total number of trees in the plots they chose to study. But when it came to absorbing atmospheric carbon, these were the real heavyweights. They contained 42% of all the above-ground carbon in the entire measured ecosystem.

Trees bigger than 30 inches, or 76 cms in diameter, made up only 0.6% of the total number, but accounted for 16% of the total above-ground carbon. The message was, the bigger the better.

The forest giants are themselves natural habitat: they support birds, mammals, insects, microbes and other plants; they serve as soaring water towers, tapping groundwater and cooling the environment through evotranspiration. And their value as a store of atmospheric carbon has been confirmed again and again.

“If you think of adding a ring of new growth to the circumference of a large tree and its branches every year, that ring adds up to a lot more carbon than the ring of a small tree,” said David Mildrexler, of Eastern Oregon Legacy Lands, who led the research. “This is why specifically letting large trees grow larger is important for climate change.”

And trees, researchers from five nations argue in the journal People and Nature, could be the healthy solution both to the climate crisis and to poor diet.

Better fed

Of the world’s 100 most nourishing foods, 14 come from trees. The planet is home to 60,000 species of tree, and many − especially in the tropics − provide nutritious fruits, nuts, leaves and seeds. Many are exploited only by small rural communities.

In the Amazon basin, for instance, a shrub called Myrciaria dubia was found to have a vitamin C content 54 times that of an orange. The scientists looked at seven tropical nations to identify foods from 90 tree species: these provided local families with 11% of diet by mass but 31% of the daily intake of vitamins A and C.

Never mind the giant commercial palm oil plantations and cacao harvests: the researchers see tree crops as something that could sustainably help hundreds of millions of the world’s smallholder farmers, by diversifying income and providing more and healthier food with a very low investment.

“The right type of trees in the right place can provide nutritious foods to improve diets sustainably while providing other valuable ecosystem services such as carbon sequestration,” said Merel Jansen, of the Swiss Federal Institute of Technology known as ETH Zurich, who led the investigation.

“It can also contribute to development issues related to poverty reduction, biodiversity conservation, and food security.” − Climate News Network

Food system causes one third of greenhouse gases

How we eat causes dangerous climate heating. It’s time to change not only our diet, but the entire global food system.

LONDON, 13 November, 2020 − If the nations of the world really want to limit climate change to the level agreed five years ago, it will not be enough to immediately abandon fossil fuels as the principal source of energy: the global food system demands radical overhaul.

Humans will have to make dramatic changes to every aspect of agriculture worldwide, to planetary diet and to much else besides.

That is because the global food system − everything from clearing land and felling forests for cattle ranches to the arrival of meat and two vegetables on a suburban family dinner plate − accounts for 30% of the world’s greenhouse gas emissions. And to contain global heating later this century to no more than 1.5°C above the levels that existed before the Industrial Revolution, urgent action is needed.

In Paris in 2015, 195 nations undertook to limit the planetary thermometer rise to “well below” 2°C. The undeclared target was 1.5°C. In the last century, the global temperature has already risen by 1°C, and at the present rate it’s heading for a potentially catastrophic 3°C or more rise by around 2100.

“Food is a much greater contributor to climate change than is widely known”

British and US scientists report in the journal Science that they looked at the challenge of feeding a global population that has almost trebled in one human lifetime, and could reach 9bn or even 10bn later this century.

They found that the greenhouse gas emissions from food production alone would by 2050 take the world to the 1.5°C target, and to 2°C by the end of the century.

In just the five years that separated 2010 from 2017, the global food system accounted for an average of 16 billion tonnes of carbon dioxide equivalent in emissions each year. If humans go on pursuing business as usual, then the cumulative emissions from the food system could add up to 1,365 billion tonnes.

Emissions on that scale from the food system alone would take the planet past the preferred 1.5°C limit some time between 2051 and 2063, and reach the 2°C limit by 2100.

Remedies at hand

“Food is a much greater contributor to climate change than is widely known,” said Jason Hill, of the University of Minnesota, and one of the authors. “Fortunately, we can fix this problem by using fertiliser more efficiently, by eating less meat and more fruits, vegetables, whole grains and nuts, and by making other important changes to our food system.”

The finding should come as no great surprise: global heating is driven by more than simply the return of carbon dioxide fossilised 300 million years ago as coal, oil and natural gas to the atmosphere with every touch of the accelerator, with every jet plane take-off, with every ignition of the electric light, the air conditioning system and the heating, and every turn of industrial machinery around the planet.

It is also fuelled by the devastating clearance of natural forest, grassland and marsh for grazing land or plantation, and the conversion of natural canopy to fodder crops to nourish the world’s domestic cattle and sheep.

Researchers have repeatedly pointed out that even a relatively simple shift to greater reliance on a plant diet could save on carbon emissions, protect the million or so species threatened with imminent extinction, and improve global health, all at the same time.

Multiple benefits

So the latest study offers a new way of spelling out the scale of the problem − a global challenge that could be resolved by concerted and coherent international action.

The researchers identified five strategies that, they believe, could both help limit climate change and improve human health, enhance air quality, reduce water pollution, slow extinction rates and make farms more profitable.

The challenge is to increase crop yields per hectare, reduce food waste, improve farm efficiency and switch to healthy calorie supplies based increasingly on plant crops.

“Even partially adopting several of these five changes would solve this problem as long as we start right now,” said David Tilman, another author, and an ecologist at the university’s College of Biological Sciences. − Climate News Network

How we eat causes dangerous climate heating. It’s time to change not only our diet, but the entire global food system.

LONDON, 13 November, 2020 − If the nations of the world really want to limit climate change to the level agreed five years ago, it will not be enough to immediately abandon fossil fuels as the principal source of energy: the global food system demands radical overhaul.

Humans will have to make dramatic changes to every aspect of agriculture worldwide, to planetary diet and to much else besides.

That is because the global food system − everything from clearing land and felling forests for cattle ranches to the arrival of meat and two vegetables on a suburban family dinner plate − accounts for 30% of the world’s greenhouse gas emissions. And to contain global heating later this century to no more than 1.5°C above the levels that existed before the Industrial Revolution, urgent action is needed.

In Paris in 2015, 195 nations undertook to limit the planetary thermometer rise to “well below” 2°C. The undeclared target was 1.5°C. In the last century, the global temperature has already risen by 1°C, and at the present rate it’s heading for a potentially catastrophic 3°C or more rise by around 2100.

“Food is a much greater contributor to climate change than is widely known”

British and US scientists report in the journal Science that they looked at the challenge of feeding a global population that has almost trebled in one human lifetime, and could reach 9bn or even 10bn later this century.

They found that the greenhouse gas emissions from food production alone would by 2050 take the world to the 1.5°C target, and to 2°C by the end of the century.

In just the five years that separated 2010 from 2017, the global food system accounted for an average of 16 billion tonnes of carbon dioxide equivalent in emissions each year. If humans go on pursuing business as usual, then the cumulative emissions from the food system could add up to 1,365 billion tonnes.

Emissions on that scale from the food system alone would take the planet past the preferred 1.5°C limit some time between 2051 and 2063, and reach the 2°C limit by 2100.

Remedies at hand

“Food is a much greater contributor to climate change than is widely known,” said Jason Hill, of the University of Minnesota, and one of the authors. “Fortunately, we can fix this problem by using fertiliser more efficiently, by eating less meat and more fruits, vegetables, whole grains and nuts, and by making other important changes to our food system.”

The finding should come as no great surprise: global heating is driven by more than simply the return of carbon dioxide fossilised 300 million years ago as coal, oil and natural gas to the atmosphere with every touch of the accelerator, with every jet plane take-off, with every ignition of the electric light, the air conditioning system and the heating, and every turn of industrial machinery around the planet.

It is also fuelled by the devastating clearance of natural forest, grassland and marsh for grazing land or plantation, and the conversion of natural canopy to fodder crops to nourish the world’s domestic cattle and sheep.

Researchers have repeatedly pointed out that even a relatively simple shift to greater reliance on a plant diet could save on carbon emissions, protect the million or so species threatened with imminent extinction, and improve global health, all at the same time.

Multiple benefits

So the latest study offers a new way of spelling out the scale of the problem − a global challenge that could be resolved by concerted and coherent international action.

The researchers identified five strategies that, they believe, could both help limit climate change and improve human health, enhance air quality, reduce water pollution, slow extinction rates and make farms more profitable.

The challenge is to increase crop yields per hectare, reduce food waste, improve farm efficiency and switch to healthy calorie supplies based increasingly on plant crops.

“Even partially adopting several of these five changes would solve this problem as long as we start right now,” said David Tilman, another author, and an ecologist at the university’s College of Biological Sciences. − Climate News Network

More avoidable pandemics await a heedless world

There will be more avoidable pandemics, more devastating and lethal, as humans intrude further upon the planet’s forests.

LONDON, 11 November, 2020 − Once again, naturalists have warned that the invasion of wilderness can seriously damage human health: avoidable pandemics − Covid-19 is an instance of a disease transferred from wild mammals to humans − threaten to arrive more often, spread more rapidly, do more damage to the global economy, and kill more people.

That’s because the odds on even more fearful infections remain very high: the world’s wild mammals could between them be hosts to 1.7 million viruses that have yet to be identified and named. If only a third of them them could infect humans, that’s 540,000 new diseases waiting to happen.

The number could be higher: perhaps 850,000 potential infections lie so far undisturbed, waiting to happen.

A new report by a team of 22 global experts warns that Covid-19 is at least the sixth global health pandemic since the Great Influenza Epidemic of 1918: all had their origins in microbes carried by animals, and all were awakened and spread by human interaction with the wilderness.

By July 2020, the coronavirus linked to a market in wild animals in Wuhan in China had spread around the planet at a cost of between US$8 trillion and $16tn. The world has already seen the Ebola virus devastating West African communities, the HIV/Aids epidemic, Zika, and many others claiming lives in the last century.

Wilderness no more

The arrival of new zoonotic diseases − infections caught from other creatures − has been counted at roughly two a year since 1918. The number could increase to as many as five a year. And most of them will be linked to increasing human impact upon what had once been largely undisturbed wilderness.

“There is no great mystery about the cause of the Covid-19 pandemic − or of any modern pandemic”, said Peter Daszak, president of EcoHealth Alliance and chair of a workshop of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES for short) that assembled the research.

“The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on our environment. Changes in the way we use land; the expansion and intensification of agriculture; and unsustainable trade, production and consumption disrupt nature and increase contact between wildlife, livestock, pathogens and people. This is the path to pandemics.”

All living things are host to viruses and other microbes: in most cases host and parasite adapt to live peaceably with each other. The danger comes when a microbe transfers to a new host that is entirely unprepared for the invader.

“We still rely on attempts to contain and control diseases after they emerge. We can escape the era of pandemics, but this requires a greater focus on prevention”

What became known as the human immuno-deficiency virus HIV-1 is believed to have emerged first in West or Central Africa from the remains of chimpanzees hunted and sold for bushmeat. It spread around the planet within a decade, to claim millions of lives as the disease AIDS. Ebola infects both primates and humans: in an outbreak among humans, it has been known to kill 90% of all infected people.

Researchers have consistently linked epidemic and pandemic outbreaks to climate change, to the destruction and degradation of the wilderness, and to the traffic in wild creatures as objects of value or commerce.

And all are consequences ultimately of exponential growth in human numbers in the last century, a growth that puts ever greater pressure on what had once been largely undisturbed tropical forest, grassland and wetland.

Around a quarter of all wild terrestrial vertebrate species are traded globally. International, legal wildlife trade has increased fivefold in revenue in the last 14 years. It is now worth an estimated $107bn.

The illegal traffic in wildlife could be worth anywhere between $7bn and $23bn annually. The US imports around 10 to 20 million wild animals a year. In China in 2016, what is now called wildlife farming employed 14 million people and generated $77bn in revenue.

Negligible cost

Researchers have already argued that intrusion into what should be protected ecosystems that are home to the shrinking pool of wild birds, mammals, reptiles and amphibians − a million species could be nearing global extinction − not only threatens the wellbeing of the planet; it also generates an increasing health hazard.

The latest study lists a range of policy options to reduce the risk of assault by new plagues. These rest upon greater awareness of, and respect for, the natural capital of the wilderness. Conservation of this kind costs money, but at least 100 times less than the toll of successive pandemics likely without a change in human attitudes.

“We have increasing ability to prevent pandemics, but the way we are tackling them right now largely ignores that ability,” Dr Daszak said. “Our approach has effectively stagnated − we still rely on attempts to contain and control diseases after they emerge, through vaccines and therapeutics.

“We can escape the era of pandemics, but this requires a greater focus on prevention in addition to reaction.” − Climate News Network

There will be more avoidable pandemics, more devastating and lethal, as humans intrude further upon the planet’s forests.

LONDON, 11 November, 2020 − Once again, naturalists have warned that the invasion of wilderness can seriously damage human health: avoidable pandemics − Covid-19 is an instance of a disease transferred from wild mammals to humans − threaten to arrive more often, spread more rapidly, do more damage to the global economy, and kill more people.

That’s because the odds on even more fearful infections remain very high: the world’s wild mammals could between them be hosts to 1.7 million viruses that have yet to be identified and named. If only a third of them them could infect humans, that’s 540,000 new diseases waiting to happen.

The number could be higher: perhaps 850,000 potential infections lie so far undisturbed, waiting to happen.

A new report by a team of 22 global experts warns that Covid-19 is at least the sixth global health pandemic since the Great Influenza Epidemic of 1918: all had their origins in microbes carried by animals, and all were awakened and spread by human interaction with the wilderness.

By July 2020, the coronavirus linked to a market in wild animals in Wuhan in China had spread around the planet at a cost of between US$8 trillion and $16tn. The world has already seen the Ebola virus devastating West African communities, the HIV/Aids epidemic, Zika, and many others claiming lives in the last century.

Wilderness no more

The arrival of new zoonotic diseases − infections caught from other creatures − has been counted at roughly two a year since 1918. The number could increase to as many as five a year. And most of them will be linked to increasing human impact upon what had once been largely undisturbed wilderness.

“There is no great mystery about the cause of the Covid-19 pandemic − or of any modern pandemic”, said Peter Daszak, president of EcoHealth Alliance and chair of a workshop of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES for short) that assembled the research.

“The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on our environment. Changes in the way we use land; the expansion and intensification of agriculture; and unsustainable trade, production and consumption disrupt nature and increase contact between wildlife, livestock, pathogens and people. This is the path to pandemics.”

All living things are host to viruses and other microbes: in most cases host and parasite adapt to live peaceably with each other. The danger comes when a microbe transfers to a new host that is entirely unprepared for the invader.

“We still rely on attempts to contain and control diseases after they emerge. We can escape the era of pandemics, but this requires a greater focus on prevention”

What became known as the human immuno-deficiency virus HIV-1 is believed to have emerged first in West or Central Africa from the remains of chimpanzees hunted and sold for bushmeat. It spread around the planet within a decade, to claim millions of lives as the disease AIDS. Ebola infects both primates and humans: in an outbreak among humans, it has been known to kill 90% of all infected people.

Researchers have consistently linked epidemic and pandemic outbreaks to climate change, to the destruction and degradation of the wilderness, and to the traffic in wild creatures as objects of value or commerce.

And all are consequences ultimately of exponential growth in human numbers in the last century, a growth that puts ever greater pressure on what had once been largely undisturbed tropical forest, grassland and wetland.

Around a quarter of all wild terrestrial vertebrate species are traded globally. International, legal wildlife trade has increased fivefold in revenue in the last 14 years. It is now worth an estimated $107bn.

The illegal traffic in wildlife could be worth anywhere between $7bn and $23bn annually. The US imports around 10 to 20 million wild animals a year. In China in 2016, what is now called wildlife farming employed 14 million people and generated $77bn in revenue.

Negligible cost

Researchers have already argued that intrusion into what should be protected ecosystems that are home to the shrinking pool of wild birds, mammals, reptiles and amphibians − a million species could be nearing global extinction − not only threatens the wellbeing of the planet; it also generates an increasing health hazard.

The latest study lists a range of policy options to reduce the risk of assault by new plagues. These rest upon greater awareness of, and respect for, the natural capital of the wilderness. Conservation of this kind costs money, but at least 100 times less than the toll of successive pandemics likely without a change in human attitudes.

“We have increasing ability to prevent pandemics, but the way we are tackling them right now largely ignores that ability,” Dr Daszak said. “Our approach has effectively stagnated − we still rely on attempts to contain and control diseases after they emerge, through vaccines and therapeutics.

“We can escape the era of pandemics, but this requires a greater focus on prevention in addition to reaction.” − Climate News Network

Natural hotspots lose ground to farms and cities

Nature concentrates its riches in selected spots. Save those natural hotspots, and you could save biodiversity. Really?

LONDON, 6 November, 2020 − Nations that signed up to preserve biodiversity − the richness of living things in the world’s forests, grasslands and wetlands − are not doing so very well: in one generation they have altered, degraded or cleared at least 1.48 million square kilometres of natural hotspots unusually rich in wildlife.

This is an area in total larger than South Africa, or Peru. It is almost as large as Mongolia. And importantly, this lost landscape adds up to 6% of the scattered ecosystems that make up the world’s biodiversity hotspots.

The biodiversity hotspot was defined, in 2000, as an area of land home to at least 0.5% of the world’s endemic species of plant. That means that a tract of marsh, savannah, upland or forest that may have already lost 70% of its cover is host to at least 1500 species native to that landscape and nowhere else.

Researchers at the time calculated that 44% of all vascular plants and 35% of all amphibians, reptiles, birds and mammals could be concentrated in just 25 such hotspots on the world’s continents and islands.

The hotspot count has since been increased to 34. But the message has remained. Focus on preserving and protecting these areas and you have a “silver bullet” strategy for conserving wildlife worldwide.

First such inventory

But, say scientists in the journal Frontiers in Ecology and the Environment, between 1992 and 2015 much of this precious wilderness has been consumed by agriculture, or paved by sprawling cities.

Their analysis of high resolution land-cover maps made by the European Space Agency is the first to try to look at the global inventory of hotspots, over a time frame of almost a quarter century.

“We see that not even focusing protection on a small range of areas worked well,” said Francesco Cherubini of the Norwegian University of Science and Technology, who with colleagues carried out the research. “There was major deforestation even in areas that were supposed to be protected.”

Two fifths of the lost landscapes were in forests, and agriculture accounted for most of this loss, particularly in the tropical forests of Indonesia, the Indo-Burma region and Mesoamerica. Five per cent of the lost hotspots were in areas formally declared as under state protection.

“The soils in these areas are very fertile, and agricultural yields can be very high. So it’s very productive land from an agricultural point of view, and attractive to farmers and local authorities that have to think about rising local incomes by feeding a growing population,” Professor Cherubini said.

“Not even focusing protection on a small range of areas worked well … There was major deforestation even in areas that were supposed to be protected.”

But most of the lost land went not to feeding people: it went instead to producing palm oil or soybeans for cattle feed. And local people may not have benefited: the change was driven by commercial agribusiness.

“You have these big companies that are making these investments, with high risks of land overexploitation and environmental degradation. The local population might get some benefits from revenues, but not much.”

The tension between hungry humans and vulnerable wilderness continues. Once again, such research supports a call for the people of the planet to consider a switch to plant-based diets, a switch that could contain climate change and preserve the natural capital on which all life depends. But many of those rich habitats are in some of the poorest countries.

“We need to be able somehow to link protection to poverty alleviation, because most of the biodiversity hotspots are in underdeveloped countries and it’s difficult to go there and say to a farmer, ‘Well, you need to keep this forest − don’t have a rice paddy or a field to feed your family’”, Professor Cherubini said.

“We need to also make it possible for the local communities to benefit from protection measures. They need income, too.” − Climate News Network

Nature concentrates its riches in selected spots. Save those natural hotspots, and you could save biodiversity. Really?

LONDON, 6 November, 2020 − Nations that signed up to preserve biodiversity − the richness of living things in the world’s forests, grasslands and wetlands − are not doing so very well: in one generation they have altered, degraded or cleared at least 1.48 million square kilometres of natural hotspots unusually rich in wildlife.

This is an area in total larger than South Africa, or Peru. It is almost as large as Mongolia. And importantly, this lost landscape adds up to 6% of the scattered ecosystems that make up the world’s biodiversity hotspots.

The biodiversity hotspot was defined, in 2000, as an area of land home to at least 0.5% of the world’s endemic species of plant. That means that a tract of marsh, savannah, upland or forest that may have already lost 70% of its cover is host to at least 1500 species native to that landscape and nowhere else.

Researchers at the time calculated that 44% of all vascular plants and 35% of all amphibians, reptiles, birds and mammals could be concentrated in just 25 such hotspots on the world’s continents and islands.

The hotspot count has since been increased to 34. But the message has remained. Focus on preserving and protecting these areas and you have a “silver bullet” strategy for conserving wildlife worldwide.

First such inventory

But, say scientists in the journal Frontiers in Ecology and the Environment, between 1992 and 2015 much of this precious wilderness has been consumed by agriculture, or paved by sprawling cities.

Their analysis of high resolution land-cover maps made by the European Space Agency is the first to try to look at the global inventory of hotspots, over a time frame of almost a quarter century.

“We see that not even focusing protection on a small range of areas worked well,” said Francesco Cherubini of the Norwegian University of Science and Technology, who with colleagues carried out the research. “There was major deforestation even in areas that were supposed to be protected.”

Two fifths of the lost landscapes were in forests, and agriculture accounted for most of this loss, particularly in the tropical forests of Indonesia, the Indo-Burma region and Mesoamerica. Five per cent of the lost hotspots were in areas formally declared as under state protection.

“The soils in these areas are very fertile, and agricultural yields can be very high. So it’s very productive land from an agricultural point of view, and attractive to farmers and local authorities that have to think about rising local incomes by feeding a growing population,” Professor Cherubini said.

“Not even focusing protection on a small range of areas worked well … There was major deforestation even in areas that were supposed to be protected.”

But most of the lost land went not to feeding people: it went instead to producing palm oil or soybeans for cattle feed. And local people may not have benefited: the change was driven by commercial agribusiness.

“You have these big companies that are making these investments, with high risks of land overexploitation and environmental degradation. The local population might get some benefits from revenues, but not much.”

The tension between hungry humans and vulnerable wilderness continues. Once again, such research supports a call for the people of the planet to consider a switch to plant-based diets, a switch that could contain climate change and preserve the natural capital on which all life depends. But many of those rich habitats are in some of the poorest countries.

“We need to be able somehow to link protection to poverty alleviation, because most of the biodiversity hotspots are in underdeveloped countries and it’s difficult to go there and say to a farmer, ‘Well, you need to keep this forest − don’t have a rice paddy or a field to feed your family’”, Professor Cherubini said.

“We need to also make it possible for the local communities to benefit from protection measures. They need income, too.” − Climate News Network