Tag Archives: Drought

Drought-hit forests may worsen climate change

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

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

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

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

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

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

Flying blind

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

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

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

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

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

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

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

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

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

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

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

No guarantee

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

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

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

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

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

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

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

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

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

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

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

Flying blind

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

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

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

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

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

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

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

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

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

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

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

No guarantee

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

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

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

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

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

The wetter world ahead will suffer worse droughts

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

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

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

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

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

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

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

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

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

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

Search for precision

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Search for precision

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

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

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

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

3 bn people may face Saharan heat levels by 2070

For three billion people or more, heat levels could prove almost impossible for human civilisation – in half a century.

LONDON, 3 June, 2020 – If humans go on burning ever more fossil fuels to put ever higher concentrations of greenhouse gases into the atmosphere, then one third of the world’s population may face – within 50 years – heat levels that could be all but intolerable.

By 2070, 19% of the land area of the planet, home to 3.5 billion people, could be faced with a mean annual temperature of 29°C. That is, although there would be seasons in which temperatures fell well below this average, these would be followed by summers in which the thermometer went much higher.

Right now, only 0.8% of the land surface of the planet experiences such a mean annual temperature, and most of this space is located in the Saharan desert region of North Africa. But population growth – already highest in the poorest and hottest parts of the globe – and the projected increases in planetary average temperatures will expand this danger zone to almost one fifth of the planet’s land area, to embrace a third of the world’s people.

The conclusion – published in the Proceedings of the National Academy of Sciences – sounds like a dramatic advance on repeated warnings that planetary average temperatures could be 3°C above the long-term average for almost all of human history. But it may not be.

One important difference is that climate science forecasts tend to describe the entire planet. But almost three fourths of the planet is ocean, which is warming much more slowly than the land surfaces. Another is that climate forecasts predict average change for a sphere with a circumference of 40,000 kms. And the third factor is that such predictions do not specifically address where humans choose to live.

“Our computations show that each degree of warming above present levels corresponds to roughly one billion people falling outside of the climate niche”

Xu Chi of Nanjing University in China and his European co-authors started from the premise that humans – like all animal species – have a preferred climate niche. They looked back through 6000 years of the history of civilisation and concluded that most of humankind flourished within a climate space between annual averages of 11°C and 15°C. A much smaller number of people lived in places where the average temperature was between 20°C and 25°C.

And they found that – although civilisations rose and fell, whole peoples disappeared, wars, plagues and famines struck, and entire populations migrated to or invaded other homes – nearly all of humankind continued to prefer to live in land zones at between 11°C and 15°C.

“This strikingly constant climate niche likely represents fundamental constraints on what humans need to survive and thrive,” said Marten Scheffer of Wageningen University in the Netherlands.

But in the next 50 years, the average temperature experienced by an average human is expected to rise by 7.5°C. And because population growth is highest in the already hottest regions, these temperature rises will affect more and more people.

Warnings mount

By 2070 this total could reach 3.5bn people, across 19% of the planet’s land surface, many of them exposed to temperatures and climate conditions that right now would be considered difficult to survive.

In just the last six or seven weeks, climate scientists have warned that rising temperatures present a direct threat to the natural ecosystems on which human civilisation depends; that the number of days that US farmworkers will find dangerously hot will almost double; that potentially lethal combinations of heat and humidity trailed as a future hazard may already have arrived, in limited locations for brief periods; that some will find more heat brings more extremes of rainfall, while other regions will become increasingly arid; and that South Asia, in particular, is at increasing hazard from ever more extreme temperatures and choking pollution, thanks to global climate change.

But the latest attempt to look at the big picture trumps all of these already bleak findings. As usual, other climate researchers will question their assumptions and challenge their conclusions, but the authors are fairly sure of their ground.

“We were frankly blown away by our initial results,” said Dr Xu. “As our findings were striking, we took an extra year to carefully check all assumptions and computations. We also decided to publish all data and computer codes for transparency and to facilitate follow-up work by others.

“The results are as important to China as they are to any other nation. Clearly we will need a global approach to safeguard our children against the potentially enormous social tensions the projected change could invoke.”

Range of pressures

This also raises issues already repeatedly raised by climate forecasters: the people most threatened by climate change are already among the world’s poorest. So there will be pressure to migrate. And there will be potential for conflict.

What will happen in the next 50 years under circumstances in which governments go on authorising fossil fuel consumption is difficult to predict with any certainty. Communities will to a certain extent adapt. Economic development could help contain some of the challenges. And governments could decide to act.

“The good news is that these impacts can be greatly reduced if humanity succeeds in curbing global warming,” said Tim Lenton, of Exeter University in the UK.

“Our computations show that each degree of warming above present levels corresponds to roughly one billion people falling outside of the climate niche.” – Climate News Network

For three billion people or more, heat levels could prove almost impossible for human civilisation – in half a century.

LONDON, 3 June, 2020 – If humans go on burning ever more fossil fuels to put ever higher concentrations of greenhouse gases into the atmosphere, then one third of the world’s population may face – within 50 years – heat levels that could be all but intolerable.

By 2070, 19% of the land area of the planet, home to 3.5 billion people, could be faced with a mean annual temperature of 29°C. That is, although there would be seasons in which temperatures fell well below this average, these would be followed by summers in which the thermometer went much higher.

Right now, only 0.8% of the land surface of the planet experiences such a mean annual temperature, and most of this space is located in the Saharan desert region of North Africa. But population growth – already highest in the poorest and hottest parts of the globe – and the projected increases in planetary average temperatures will expand this danger zone to almost one fifth of the planet’s land area, to embrace a third of the world’s people.

The conclusion – published in the Proceedings of the National Academy of Sciences – sounds like a dramatic advance on repeated warnings that planetary average temperatures could be 3°C above the long-term average for almost all of human history. But it may not be.

One important difference is that climate science forecasts tend to describe the entire planet. But almost three fourths of the planet is ocean, which is warming much more slowly than the land surfaces. Another is that climate forecasts predict average change for a sphere with a circumference of 40,000 kms. And the third factor is that such predictions do not specifically address where humans choose to live.

“Our computations show that each degree of warming above present levels corresponds to roughly one billion people falling outside of the climate niche”

Xu Chi of Nanjing University in China and his European co-authors started from the premise that humans – like all animal species – have a preferred climate niche. They looked back through 6000 years of the history of civilisation and concluded that most of humankind flourished within a climate space between annual averages of 11°C and 15°C. A much smaller number of people lived in places where the average temperature was between 20°C and 25°C.

And they found that – although civilisations rose and fell, whole peoples disappeared, wars, plagues and famines struck, and entire populations migrated to or invaded other homes – nearly all of humankind continued to prefer to live in land zones at between 11°C and 15°C.

“This strikingly constant climate niche likely represents fundamental constraints on what humans need to survive and thrive,” said Marten Scheffer of Wageningen University in the Netherlands.

But in the next 50 years, the average temperature experienced by an average human is expected to rise by 7.5°C. And because population growth is highest in the already hottest regions, these temperature rises will affect more and more people.

Warnings mount

By 2070 this total could reach 3.5bn people, across 19% of the planet’s land surface, many of them exposed to temperatures and climate conditions that right now would be considered difficult to survive.

In just the last six or seven weeks, climate scientists have warned that rising temperatures present a direct threat to the natural ecosystems on which human civilisation depends; that the number of days that US farmworkers will find dangerously hot will almost double; that potentially lethal combinations of heat and humidity trailed as a future hazard may already have arrived, in limited locations for brief periods; that some will find more heat brings more extremes of rainfall, while other regions will become increasingly arid; and that South Asia, in particular, is at increasing hazard from ever more extreme temperatures and choking pollution, thanks to global climate change.

But the latest attempt to look at the big picture trumps all of these already bleak findings. As usual, other climate researchers will question their assumptions and challenge their conclusions, but the authors are fairly sure of their ground.

“We were frankly blown away by our initial results,” said Dr Xu. “As our findings were striking, we took an extra year to carefully check all assumptions and computations. We also decided to publish all data and computer codes for transparency and to facilitate follow-up work by others.

“The results are as important to China as they are to any other nation. Clearly we will need a global approach to safeguard our children against the potentially enormous social tensions the projected change could invoke.”

Range of pressures

This also raises issues already repeatedly raised by climate forecasters: the people most threatened by climate change are already among the world’s poorest. So there will be pressure to migrate. And there will be potential for conflict.

What will happen in the next 50 years under circumstances in which governments go on authorising fossil fuel consumption is difficult to predict with any certainty. Communities will to a certain extent adapt. Economic development could help contain some of the challenges. And governments could decide to act.

“The good news is that these impacts can be greatly reduced if humanity succeeds in curbing global warming,” said Tim Lenton, of Exeter University in the UK.

“Our computations show that each degree of warming above present levels corresponds to roughly one billion people falling outside of the climate niche.” – Climate News Network

Increasingly arid future faces the American West

Climate change will take its toll of the US. The evidence repeatedly points to an ever more arid future for the American West.

LONDON, May 26, 2020 – The great American West is becoming inexorably more parched, with an inescapably arid future ahead. The winter snows will be lighter, and the spring melt much earlier. The river flows will slow, in some cases to a trickle, trees will die, and catastrophic wildfires will become more frequent. Agricultural harvests will be affected, and droughts will become more protracted.

The trend is clear and – without dramatic action by global governments to reduce greenhouse gas emissions and slow global warming – is likely to be costly for one of the world’s richest nations.

“The impact of warming on the West’s river flows, soils and forests is now unequivocal,” say Jonathan Overpeck, of the University of Michigan, and Bradley Udall of Colorado State University, in the Proceedings of the National Academy of Sciences.

“There is a clear longer-term trend toward greater aridification, a trend that only climate action can stop.”

They make a point other researchers have repeatedly made over the last decade: that droughts will become longer and deeper in the US West, that climate change can only harm the US economy, and that the areas of increasing aridity are slowly shifting eastward: once rich soils could soon no longer sustain the crops of American farmers.

“The sooner emissions of greenhouse gases are halted, the sooner the aridification of North America will stop getting worse”

The comments were triggered by a recent study in the same journal by a US Geological Survey team. Scientists used tree ring records and data for the first decade of this century to measure change in flow in the Upper Missouri River basin.

They concluded that recent regional warming, driven by increasing greenhouse gas emissions worldwide, aligned with “increasing drought severities that rival or exceed any estimated over the last 12 centuries.”

The US West, and the Southwest, is used to drought, sometimes sustained. In the past the snows have returned, the rivers have swollen again. But Dr Overpeck and Dr Udall think this is now a wrong assumption.

“We now know with high confidence that continued emissions of greenhouse gases into the atmosphere guarantee continued warming, and that this continued warming makes more widespread, prolonged and severe droughts almost a sure bet. Greater aridity is redefining the West in many ways, and the costs to human and natural systems will only increase as we let the warming continue.”

The rivers of the US Southwest are the only large, sure water supply for 40 million Americans. But since the late 20th century the flows of the Colorado River and the Rio Grande have fallen, and this is in large part due to ever higher temperatures, driven by ever greater consumption of fossil fuels. Higher temperatures mean that the atmosphere can absorb ever greater levels of water vapour, to dry out the soils.

Faltering action

This extra vapour would normally fall as rain or snow – and it certainly has in some parts of the US – but all the evidence suggests that droughts in the Southwest will increase both in frequency and intensity.

All nations have been slow to act decisively on climate change: President Trump has notoriously denounced climate change as a “hoax” and promised to withdraw the US from the only global agreement that promises concerted action.

“Perhaps most troubling is the growing co-occurrence of hot and dry summer conditions, and the likely expansion, absent climate change action, of these hot dry extremes all the way to the East Coast of North America, north deep into Canada, and south into Mexico,” the two scientists write.

Extreme dry spells, flash floods and droughts will become part of the new normal.

“Unfortunately, climate change and this aridification are likely to be irreversible on human time scales, so the sooner emissions of greenhouse gases are halted, the sooner the aridification of North America will stop getting worse.” – Climate News Network

Climate change will take its toll of the US. The evidence repeatedly points to an ever more arid future for the American West.

LONDON, May 26, 2020 – The great American West is becoming inexorably more parched, with an inescapably arid future ahead. The winter snows will be lighter, and the spring melt much earlier. The river flows will slow, in some cases to a trickle, trees will die, and catastrophic wildfires will become more frequent. Agricultural harvests will be affected, and droughts will become more protracted.

The trend is clear and – without dramatic action by global governments to reduce greenhouse gas emissions and slow global warming – is likely to be costly for one of the world’s richest nations.

“The impact of warming on the West’s river flows, soils and forests is now unequivocal,” say Jonathan Overpeck, of the University of Michigan, and Bradley Udall of Colorado State University, in the Proceedings of the National Academy of Sciences.

“There is a clear longer-term trend toward greater aridification, a trend that only climate action can stop.”

They make a point other researchers have repeatedly made over the last decade: that droughts will become longer and deeper in the US West, that climate change can only harm the US economy, and that the areas of increasing aridity are slowly shifting eastward: once rich soils could soon no longer sustain the crops of American farmers.

“The sooner emissions of greenhouse gases are halted, the sooner the aridification of North America will stop getting worse”

The comments were triggered by a recent study in the same journal by a US Geological Survey team. Scientists used tree ring records and data for the first decade of this century to measure change in flow in the Upper Missouri River basin.

They concluded that recent regional warming, driven by increasing greenhouse gas emissions worldwide, aligned with “increasing drought severities that rival or exceed any estimated over the last 12 centuries.”

The US West, and the Southwest, is used to drought, sometimes sustained. In the past the snows have returned, the rivers have swollen again. But Dr Overpeck and Dr Udall think this is now a wrong assumption.

“We now know with high confidence that continued emissions of greenhouse gases into the atmosphere guarantee continued warming, and that this continued warming makes more widespread, prolonged and severe droughts almost a sure bet. Greater aridity is redefining the West in many ways, and the costs to human and natural systems will only increase as we let the warming continue.”

The rivers of the US Southwest are the only large, sure water supply for 40 million Americans. But since the late 20th century the flows of the Colorado River and the Rio Grande have fallen, and this is in large part due to ever higher temperatures, driven by ever greater consumption of fossil fuels. Higher temperatures mean that the atmosphere can absorb ever greater levels of water vapour, to dry out the soils.

Faltering action

This extra vapour would normally fall as rain or snow – and it certainly has in some parts of the US – but all the evidence suggests that droughts in the Southwest will increase both in frequency and intensity.

All nations have been slow to act decisively on climate change: President Trump has notoriously denounced climate change as a “hoax” and promised to withdraw the US from the only global agreement that promises concerted action.

“Perhaps most troubling is the growing co-occurrence of hot and dry summer conditions, and the likely expansion, absent climate change action, of these hot dry extremes all the way to the East Coast of North America, north deep into Canada, and south into Mexico,” the two scientists write.

Extreme dry spells, flash floods and droughts will become part of the new normal.

“Unfortunately, climate change and this aridification are likely to be irreversible on human time scales, so the sooner emissions of greenhouse gases are halted, the sooner the aridification of North America will stop getting worse.” – Climate News Network

Heatwaves too hot and wet for human life are here

Lethal heatwaves carrying air turned too hot and wet to survive are a threat which has arrived, thanks to climate change.

LONDON, 11 May, 2020 – Scientists who have repeatedly warned of future lethal conditions of temperature and humidity caused by heatwaves in a world of climate change have grim news: that future has already arrived.

They have combed through local records to identify thousands of episodes in which the dangerous combination of high temperatures and high humidity has risen to levels at which humans could not in theory survive for long. These have happened in Asia, Africa, South and North America and Australia.

More than a dozen such episodes have already been recorded around the Persian Gulf, a region that – researchers warned years ago – could one day become deadly for outdoor workers.

These outbreaks of both sweltering heat and stifling humidity have, researchers report in the journal Science Advances, so far been confined to localised areas and have lasted only hours, but they are now increasing in frequency and intensity.

There are many ways in which extreme heat can lead to death – one group has identified as many as 27 – but at its simplest, a species adapted to maintain a stable temperature by shivering when cold and perspiring when too hot can be overwhelmed by very high temperatures, or in conditions in which the body can no longer lose heat because the air is too moist for perspiration to evaporate.

“Previous studies projected that this would happen several decades from now, but this shows it’s happening right now”

Scientists measure such hazards by what they call a “wet bulb” temperature, and even the strongest and best adapted humans cannot work safely outdoors when this hits 32°C.

Potentially fatal readings identified in hourly reports from 7,877 weather stations between 1979 and 2017 confirm that such temperatures have already reached dangerous levels – and even as high as 35°C – in Saudi Arabia, Doha in Qatar, in the United Arab Emirates, in Texas, Louisiana, Mississippi, Alabama and Florida in the US, India and Bangladesh, south China, northwest Australia and Iran.

Researchers began warning years ago of the notional threat of extreme heat and extreme humidity in a world in which humans continue to burn fossil fuels and increase greenhouse gases’ concentrations in the atmosphere, and repeated studies have confirmed the reality of the hazard.

Humans cannot survive outdoor “wet bulb” conditions of 35°C for long. The number of readings beyond 30°C has doubled since 1979. There have been 1,000 readings of 31°C and 80 of 33°C.

“Previous studies projected that this would happen several decades from now, but this shows it’s happening right now,” said Colin Raymond, who completed the research at the Lamont-Doherty Earth Observatory at Columbia University, but who is now at Nasa’s Jet Propulsion Laboratory.

“The times these events last will increase, and the areas they affect will grow, in direct correlation with global warming.” – Climate News Network

Lethal heatwaves carrying air turned too hot and wet to survive are a threat which has arrived, thanks to climate change.

LONDON, 11 May, 2020 – Scientists who have repeatedly warned of future lethal conditions of temperature and humidity caused by heatwaves in a world of climate change have grim news: that future has already arrived.

They have combed through local records to identify thousands of episodes in which the dangerous combination of high temperatures and high humidity has risen to levels at which humans could not in theory survive for long. These have happened in Asia, Africa, South and North America and Australia.

More than a dozen such episodes have already been recorded around the Persian Gulf, a region that – researchers warned years ago – could one day become deadly for outdoor workers.

These outbreaks of both sweltering heat and stifling humidity have, researchers report in the journal Science Advances, so far been confined to localised areas and have lasted only hours, but they are now increasing in frequency and intensity.

There are many ways in which extreme heat can lead to death – one group has identified as many as 27 – but at its simplest, a species adapted to maintain a stable temperature by shivering when cold and perspiring when too hot can be overwhelmed by very high temperatures, or in conditions in which the body can no longer lose heat because the air is too moist for perspiration to evaporate.

“Previous studies projected that this would happen several decades from now, but this shows it’s happening right now”

Scientists measure such hazards by what they call a “wet bulb” temperature, and even the strongest and best adapted humans cannot work safely outdoors when this hits 32°C.

Potentially fatal readings identified in hourly reports from 7,877 weather stations between 1979 and 2017 confirm that such temperatures have already reached dangerous levels – and even as high as 35°C – in Saudi Arabia, Doha in Qatar, in the United Arab Emirates, in Texas, Louisiana, Mississippi, Alabama and Florida in the US, India and Bangladesh, south China, northwest Australia and Iran.

Researchers began warning years ago of the notional threat of extreme heat and extreme humidity in a world in which humans continue to burn fossil fuels and increase greenhouse gases’ concentrations in the atmosphere, and repeated studies have confirmed the reality of the hazard.

Humans cannot survive outdoor “wet bulb” conditions of 35°C for long. The number of readings beyond 30°C has doubled since 1979. There have been 1,000 readings of 31°C and 80 of 33°C.

“Previous studies projected that this would happen several decades from now, but this shows it’s happening right now,” said Colin Raymond, who completed the research at the Lamont-Doherty Earth Observatory at Columbia University, but who is now at Nasa’s Jet Propulsion Laboratory.

“The times these events last will increase, and the areas they affect will grow, in direct correlation with global warming.” – Climate News Network

Tree rings and weather data warn of megadrought

Farmers in the US West know they have a drought, but may not yet realise these arid years could become a megadrought.

LONDON, 17 April, 2020 – Climate change could be pushing the US west and northern Mexico towards the most severe and most extended period of drought observed in a thousand years of US history, a full-blown megadrought.

Natural atmospheric forces have always triggered prolonged spells with little rain. But warming driven by profligate human use of fossil fuels could now be making a bad situation much worse.

The warning of what climate scientists call a megadrought – outlined in the journal Science – is based not on computer simulations but on direct testimony from more than a century of weather records and the much longer story told by 1200 consecutive years of evidence preserved in the annual growth rings of trees that provide a record of changing levels of soil moisture.

“Earlier studies were largely model projections of the future. We are no longer looking at projections, but at where we are now,” said Park Williams, a bioclimatologist at the Lamont Doherty Earth Observatory of Columbia University in the US.

“We now have enough observations of current drought and tree ring records of past drought to say we’re on the same trajectory as the worst prehistoric droughts.”

Repeating the past

Previous research has already linked catastrophic drought to turmoil among pre-Columbian civilisations in the American Southwest.

Studies by other groups have also warned that what happened in the past could happen again, as carbon dioxide emissions from fossil fuel combustion enrich the atmosphere, raise temperatures and parch the soils of the US West.

Global heating has been repeatedly linked to the last devastating drought in California, and to the possible return of Dust Bowl conditions in the Midwestern grain belt.

The latest study delivers a long-term analysis of conditions across nine US states, from Oregon and Montana in the north down to California, New Mexico and part of northern Mexico.

With the evidence preserved in old tree trunks, the scientists identified dozens of droughts in the region from 800 AD. They found four megadroughts – periods in which the conditions became extreme – between 800 and 1600. Since then there have been no droughts that could be matched with these – so far.

And then the researchers matched the megadrought tree ring evidence with soil moisture records collected in the first 19 years of this century, and compared this with any 19-year period in the prehistoric droughts.

“We’ll need more and more good luck to break out of drought, and less and less bad luck to get into drought”

They found that the current prolonged dry spell is already more pronounced than the three earliest records of megadrought. The fourth megadrought – it ran from 1575 to 1603 – may still have been the worst of all, but the match with the present years is so close that nobody can be sure.

But the team behind the Science study is sure of one thing. This drought right now is affecting wider stretches of landscape more consistently than any of the earlier megadroughts, and this, they say, is a signature of global heating. All the ancient megadroughts lasted longer, and sometimes much longer, than 19 years, but all began in a way very similar to the present.

The snowpack in the western high mountains has fallen dramatically, the flow of the rivers has dwindled, lake levels have fallen, farmers have been  hit and the wildfires have become more prolonged and more intense.

Drought and even the chance of megadrought may be a fact of life in the US West. During occasional natural atmospheric cycles, the tropical Pacific cools and storm tracks shift further north, taking rainfall away from the US drylands.

But since 2000, average air temperatures in the western states have risen by more than 1.2°C above the normal over earlier centuries. So soils already starved of rain began to lose their stored moisture at an ever-increasing rate.

Worsened by heating

Without the additional global heating, this drought might have happened anyway, and perhaps even been the 11th worst ever recorded, rather than almost the worst ever in human experience.

“It doesn’t matter if this is exactly the worst drought ever,” said Benjamin Cook, a co-author, from Nasa’s Goddard Institute for Space Studies. “What matters is that it has been made much worse than it could have been because of climate change.”

The researchers also found that the 20th century was the wettest century in the entire 1200 year record, and this relatively plentiful supply of water must have helped enrich the US West and make California, for instance, become the Golden State, the most populous in the US.

“Because the background is getting warmer, the dice are increasingly loaded towards longer and more severe droughts,” Professor Williams said. “We may get lucky, and natural variability will bring more precipitation for a while.

“But going forward, we’ll need more and more good luck to break out of drought, and less and less bad luck to get into drought.” – Climate News Network

Farmers in the US West know they have a drought, but may not yet realise these arid years could become a megadrought.

LONDON, 17 April, 2020 – Climate change could be pushing the US west and northern Mexico towards the most severe and most extended period of drought observed in a thousand years of US history, a full-blown megadrought.

Natural atmospheric forces have always triggered prolonged spells with little rain. But warming driven by profligate human use of fossil fuels could now be making a bad situation much worse.

The warning of what climate scientists call a megadrought – outlined in the journal Science – is based not on computer simulations but on direct testimony from more than a century of weather records and the much longer story told by 1200 consecutive years of evidence preserved in the annual growth rings of trees that provide a record of changing levels of soil moisture.

“Earlier studies were largely model projections of the future. We are no longer looking at projections, but at where we are now,” said Park Williams, a bioclimatologist at the Lamont Doherty Earth Observatory of Columbia University in the US.

“We now have enough observations of current drought and tree ring records of past drought to say we’re on the same trajectory as the worst prehistoric droughts.”

Repeating the past

Previous research has already linked catastrophic drought to turmoil among pre-Columbian civilisations in the American Southwest.

Studies by other groups have also warned that what happened in the past could happen again, as carbon dioxide emissions from fossil fuel combustion enrich the atmosphere, raise temperatures and parch the soils of the US West.

Global heating has been repeatedly linked to the last devastating drought in California, and to the possible return of Dust Bowl conditions in the Midwestern grain belt.

The latest study delivers a long-term analysis of conditions across nine US states, from Oregon and Montana in the north down to California, New Mexico and part of northern Mexico.

With the evidence preserved in old tree trunks, the scientists identified dozens of droughts in the region from 800 AD. They found four megadroughts – periods in which the conditions became extreme – between 800 and 1600. Since then there have been no droughts that could be matched with these – so far.

And then the researchers matched the megadrought tree ring evidence with soil moisture records collected in the first 19 years of this century, and compared this with any 19-year period in the prehistoric droughts.

“We’ll need more and more good luck to break out of drought, and less and less bad luck to get into drought”

They found that the current prolonged dry spell is already more pronounced than the three earliest records of megadrought. The fourth megadrought – it ran from 1575 to 1603 – may still have been the worst of all, but the match with the present years is so close that nobody can be sure.

But the team behind the Science study is sure of one thing. This drought right now is affecting wider stretches of landscape more consistently than any of the earlier megadroughts, and this, they say, is a signature of global heating. All the ancient megadroughts lasted longer, and sometimes much longer, than 19 years, but all began in a way very similar to the present.

The snowpack in the western high mountains has fallen dramatically, the flow of the rivers has dwindled, lake levels have fallen, farmers have been  hit and the wildfires have become more prolonged and more intense.

Drought and even the chance of megadrought may be a fact of life in the US West. During occasional natural atmospheric cycles, the tropical Pacific cools and storm tracks shift further north, taking rainfall away from the US drylands.

But since 2000, average air temperatures in the western states have risen by more than 1.2°C above the normal over earlier centuries. So soils already starved of rain began to lose their stored moisture at an ever-increasing rate.

Worsened by heating

Without the additional global heating, this drought might have happened anyway, and perhaps even been the 11th worst ever recorded, rather than almost the worst ever in human experience.

“It doesn’t matter if this is exactly the worst drought ever,” said Benjamin Cook, a co-author, from Nasa’s Goddard Institute for Space Studies. “What matters is that it has been made much worse than it could have been because of climate change.”

The researchers also found that the 20th century was the wettest century in the entire 1200 year record, and this relatively plentiful supply of water must have helped enrich the US West and make California, for instance, become the Golden State, the most populous in the US.

“Because the background is getting warmer, the dice are increasingly loaded towards longer and more severe droughts,” Professor Williams said. “We may get lucky, and natural variability will bring more precipitation for a while.

“But going forward, we’ll need more and more good luck to break out of drought, and less and less bad luck to get into drought.” – 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

India finally takes climate crisis seriously

India

With financial losses and a heavy death toll from climate-related disasters constantly rising, India is at last focusing on the dangers of global warming.

NEW DELHI, 18 March, 2020 – After decades of concentrating on economic development and insisting that global warming was mainly a problem for the more industrially-developed countries to solve, Indian industry is at last facing up to dangers posed to its own future by climate change.

More than 40 organisations – including major industrial corporations such as Tata, Godrej, Mahindra and Wipro through their various philanthropic organisations, plus academic thinktanks, business schools, aid agencies, and the government’s scientific advisers – have come together to co-operate on climate solutions.

The umbrella organisation, called the India Climate Collaborative (ICC), also includes international institutions such as Bloomberg Philanthropies and the MacArthur Foundation.

Climate disasters

Although there have been many individual initiatives in India on climate change, and there has been government support for renewables, particularly solar power, efforts so far have been fragmented.

State and national governments, individual departments, businesses, non-governmental organisations, and academics have all worked separately, and sometimes in opposition to each other.

The scale of the task facing India is underlined by the fact it has taken two years to get the ICC up and running. However, with India ranked fifth in the Global Climate Risk Index 2019 and facing one climate disaster after another – sometimes simultaneous extreme weather events – these organisations have agreed that the issue can no longer be ignored.

“It is clear that the world cannot continue to pursue a business-as-usual approach, and nobody can solve the problem on their own.”

Commenting on the launch, Anand Mahindra, chairman of the Mahindra Group, said: “It is clear that the world cannot continue to pursue a business-as-usual approach, and nobody can solve the problem on their own. Business, government and philanthropy must collaborate within and among themselves themselves to drive results quickly and at scale. The India Climate Collaborative can make this happen.”

The ICC has identified three critical risk factors for India:

The first is that an astonishing 700 million people are still dependent on agriculture and they are the most vulnerable to an erratic climate.

The second is that around the country’s approximately 7,500 km coastline are several major cities. Many of these important economic hubs, which include all the country’s main ports, are a metre or less above current sea level.

Third, even with the increasingly rigorous focus on renewable energy, there is continued heavy reliance on fossil fuels for producing electricity, which is still in short supply.

According to the India Philanthropy Report 2019, private funds in India, mostly raised through non-government philanthropy, provided about Rs 70,000 crore ($9.5 billion) in 2018 for the social sector, mostly focusing on key aspects such as health, education and agriculture.

However, only a small proportion was spent on climate change, and so the ICC aims to raise the current spending of about 7 % to at least 20 %.

Another hindrance to India’s many plans for adaptation or mitigation is the lack of capacity among government departments. Something as basic as preparing workable proposals for funding action is a tough task for many state governments.

The ICC plans to conduct technical training as “there are gaps to be filled to take care of the talent shortfall, and there is overall lack of capacity.”

One of the first training exercises is planned for state-level bureaucrats from Rajasthan, Madhya Pradesh, Chhattisgarh, Maharashtra, and in the western state of Rajasthan.

Cross-purposes

There is some concern that while the India government is represented on the ICC by Prof K. VijayRaghavan, its Principal Scientific Adviser, there is no representation from the Ministry of Environment, Forests & Climate Change (MoEFCC), which represents the country at the climate talks.

Critics claim that this is particularly worrying because the various government departments are already seen as not working together, or often working at cross-purposes.

There are also fears that there is lack of community involvement, particularly the farmers, who are the largest single group most affected by adverse weather conditions caused by climate change.

However, Shloka Nath, executive director of the ICC and head of Sustainability and Special Projects at the Tata Trust, says the ICC plans to work with the MoEFCC to reach representatives of civil society and bring them into the process.

“It is through them [the ministry] that we plan to reach out to the community,” she says. “The people will be very much involved.”

Despite these shortcomings, Chandra Bhushan, President and CEO of the International Forum for Environment, Sustainability and Technology (iFOREST), welcomes the idea. He says: “It is for the first time that Indian companies are understanding climate change and willing to invest in it.” – Climate News Network

With financial losses and a heavy death toll from climate-related disasters constantly rising, India is at last focusing on the dangers of global warming.

NEW DELHI, 18 March, 2020 – After decades of concentrating on economic development and insisting that global warming was mainly a problem for the more industrially-developed countries to solve, Indian industry is at last facing up to dangers posed to its own future by climate change.

More than 40 organisations – including major industrial corporations such as Tata, Godrej, Mahindra and Wipro through their various philanthropic organisations, plus academic thinktanks, business schools, aid agencies, and the government’s scientific advisers – have come together to co-operate on climate solutions.

The umbrella organisation, called the India Climate Collaborative (ICC), also includes international institutions such as Bloomberg Philanthropies and the MacArthur Foundation.

Climate disasters

Although there have been many individual initiatives in India on climate change, and there has been government support for renewables, particularly solar power, efforts so far have been fragmented.

State and national governments, individual departments, businesses, non-governmental organisations, and academics have all worked separately, and sometimes in opposition to each other.

The scale of the task facing India is underlined by the fact it has taken two years to get the ICC up and running. However, with India ranked fifth in the Global Climate Risk Index 2019 and facing one climate disaster after another – sometimes simultaneous extreme weather events – these organisations have agreed that the issue can no longer be ignored.

“It is clear that the world cannot continue to pursue a business-as-usual approach, and nobody can solve the problem on their own.”

Commenting on the launch, Anand Mahindra, chairman of the Mahindra Group, said: “It is clear that the world cannot continue to pursue a business-as-usual approach, and nobody can solve the problem on their own. Business, government and philanthropy must collaborate within and among themselves themselves to drive results quickly and at scale. The India Climate Collaborative can make this happen.”

The ICC has identified three critical risk factors for India:

The first is that an astonishing 700 million people are still dependent on agriculture and they are the most vulnerable to an erratic climate.

The second is that around the country’s approximately 7,500 km coastline are several major cities. Many of these important economic hubs, which include all the country’s main ports, are a metre or less above current sea level.

Third, even with the increasingly rigorous focus on renewable energy, there is continued heavy reliance on fossil fuels for producing electricity, which is still in short supply.

According to the India Philanthropy Report 2019, private funds in India, mostly raised through non-government philanthropy, provided about Rs 70,000 crore ($9.5 billion) in 2018 for the social sector, mostly focusing on key aspects such as health, education and agriculture.

However, only a small proportion was spent on climate change, and so the ICC aims to raise the current spending of about 7 % to at least 20 %.

Another hindrance to India’s many plans for adaptation or mitigation is the lack of capacity among government departments. Something as basic as preparing workable proposals for funding action is a tough task for many state governments.

The ICC plans to conduct technical training as “there are gaps to be filled to take care of the talent shortfall, and there is overall lack of capacity.”

One of the first training exercises is planned for state-level bureaucrats from Rajasthan, Madhya Pradesh, Chhattisgarh, Maharashtra, and in the western state of Rajasthan.

Cross-purposes

There is some concern that while the India government is represented on the ICC by Prof K. VijayRaghavan, its Principal Scientific Adviser, there is no representation from the Ministry of Environment, Forests & Climate Change (MoEFCC), which represents the country at the climate talks.

Critics claim that this is particularly worrying because the various government departments are already seen as not working together, or often working at cross-purposes.

There are also fears that there is lack of community involvement, particularly the farmers, who are the largest single group most affected by adverse weather conditions caused by climate change.

However, Shloka Nath, executive director of the ICC and head of Sustainability and Special Projects at the Tata Trust, says the ICC plans to work with the MoEFCC to reach representatives of civil society and bring them into the process.

“It is through them [the ministry] that we plan to reach out to the community,” she says. “The people will be very much involved.”

Despite these shortcomings, Chandra Bhushan, President and CEO of the International Forum for Environment, Sustainability and Technology (iFOREST), welcomes the idea. He says: “It is for the first time that Indian companies are understanding climate change and willing to invest in it.” – Climate News Network

Fresh water from sunshine can keep thirst at bay

Seaside communities with plenty of sun can soon have ample fresh water without any need for electricity.

LONDON, 11 February, 2020 − An international team of scientists has developed a cheap way to provide fresh water to thirsty communities by making seawater drinkable without using electricity.

So long as the sun is shining, they say, their device will produce enough high-quality potable water to cover a family’s needs, at a cost of around US$100 (£77).

The scientists, from Massachusetts institute of Technology (MIT), US and Shanghai Jiao Tong University, China, believe their brainwave offers a simple solution to thirsty islands and arid coastal areas which lack a reliable electricity supply but have access to seawater. It could even help to prevent some of the mass migrations expected with climate change.

The researchers report their work in the journal Energy and Environmental Science. Testing their prototype on a roof at the Massachusetts Institute of Technology, they produced more than 1.5 gallons of fresh drinking water every hour for every square metre of solar collecting area.

Their device is cube-shaped, with multiple layers of solar evaporators and condensers piled one on top of another, surmounted with a layer of transparent insulation. Essentially it is a multi-layer solar still, similar to those used for centuries to make strong liquor and used today in many applications.

“This new approach is very significant. One of the challenges in solar still-based desalination has been low efficiency. This increased efficiency will have an overall impact on reducing the cost of produced water”

A solar still uses flat panels to absorb heat which it then transfers to a layer of water, which begins to evaporate. The vapour condenses on the next panel and the water is collected, while the heat from the vapour condensation is passed to the layer above.

Whenever vapour condenses on a surface, it releases heat; in typical condenser systems, that heat is simply lost to the environment. But in this multi-layer version the released heat flows to the next evaporating layer, recycling the solar heat and boosting overall efficiency.

The efficiency comes from using each of the multiple stages to remove salt from the sea water, with the heat released by the previous stage  harnessed instead of wasted. In this way, the team’s demonstration device achieved an overall efficiency of 385% in converting the energy of sunlight into evaporation.

Evelyn Wang, a co-author, said: “When you condense water, you release energy as heat. If you have more than one stage, you can take advantage of that heat.”

Cost trade-off

Although adding more layers increases the conversion efficiency of the system, each layer also adds cost and bulk. The team settled on a 10-stage system for their proof-of-concept device.

It delivered pure water that exceeded city drinking water standards, at a rate of 5.78 litres per square metre (about 1.52 gallons per 11 square feet) of solar collecting area. This is more than twice as much as the record amount previously produced by any such passive solar-powered desalination system, Professor Wang says.

And a big advantage of the system is that it has a self-flushing mechanism which will clean out the accumulation of salt each night and return it to the sea.

One possible way of using the system would be with floating panels on a body of saltwater. The panels could deliver constant fresh water through pipes to the shore so long as the sun was shining. Other systems could be designed to serve a single household, perhaps using a flat panel on a large shallow tank of seawater.

The team estimates that a system with a roughly one-square-meter solar collecting area could meet the daily drinking water needs of one person. In production, they think a system built to serve the needs of a family might be built for around $100.

Cheaper replacements

The most expensive component of the prototype is the layer of transparent aerogel used as an insulator at the top of the stack, but the team suggests other less expensive insulators could be used instead. (The aerogel itself is made from very cheap silica but requires specialised drying equipment during its manufacture.)

“This new approach is very significant,” says Professor Ravi Prasher of Lawrence Berkeley National Laboratory and the University of California at Berkeley, who was not involved in the research.

“One of the challenges in solar still-based desalination has been low efficiency due to the loss of significant energy in condensation.

“By efficiently harvesting the condensation energy, the overall solar to vapour efficiency is dramatically improved … This increased efficiency will have an overall impact on reducing the cost of produced water.” − Climate News Network

Seaside communities with plenty of sun can soon have ample fresh water without any need for electricity.

LONDON, 11 February, 2020 − An international team of scientists has developed a cheap way to provide fresh water to thirsty communities by making seawater drinkable without using electricity.

So long as the sun is shining, they say, their device will produce enough high-quality potable water to cover a family’s needs, at a cost of around US$100 (£77).

The scientists, from Massachusetts institute of Technology (MIT), US and Shanghai Jiao Tong University, China, believe their brainwave offers a simple solution to thirsty islands and arid coastal areas which lack a reliable electricity supply but have access to seawater. It could even help to prevent some of the mass migrations expected with climate change.

The researchers report their work in the journal Energy and Environmental Science. Testing their prototype on a roof at the Massachusetts Institute of Technology, they produced more than 1.5 gallons of fresh drinking water every hour for every square metre of solar collecting area.

Their device is cube-shaped, with multiple layers of solar evaporators and condensers piled one on top of another, surmounted with a layer of transparent insulation. Essentially it is a multi-layer solar still, similar to those used for centuries to make strong liquor and used today in many applications.

“This new approach is very significant. One of the challenges in solar still-based desalination has been low efficiency. This increased efficiency will have an overall impact on reducing the cost of produced water”

A solar still uses flat panels to absorb heat which it then transfers to a layer of water, which begins to evaporate. The vapour condenses on the next panel and the water is collected, while the heat from the vapour condensation is passed to the layer above.

Whenever vapour condenses on a surface, it releases heat; in typical condenser systems, that heat is simply lost to the environment. But in this multi-layer version the released heat flows to the next evaporating layer, recycling the solar heat and boosting overall efficiency.

The efficiency comes from using each of the multiple stages to remove salt from the sea water, with the heat released by the previous stage  harnessed instead of wasted. In this way, the team’s demonstration device achieved an overall efficiency of 385% in converting the energy of sunlight into evaporation.

Evelyn Wang, a co-author, said: “When you condense water, you release energy as heat. If you have more than one stage, you can take advantage of that heat.”

Cost trade-off

Although adding more layers increases the conversion efficiency of the system, each layer also adds cost and bulk. The team settled on a 10-stage system for their proof-of-concept device.

It delivered pure water that exceeded city drinking water standards, at a rate of 5.78 litres per square metre (about 1.52 gallons per 11 square feet) of solar collecting area. This is more than twice as much as the record amount previously produced by any such passive solar-powered desalination system, Professor Wang says.

And a big advantage of the system is that it has a self-flushing mechanism which will clean out the accumulation of salt each night and return it to the sea.

One possible way of using the system would be with floating panels on a body of saltwater. The panels could deliver constant fresh water through pipes to the shore so long as the sun was shining. Other systems could be designed to serve a single household, perhaps using a flat panel on a large shallow tank of seawater.

The team estimates that a system with a roughly one-square-meter solar collecting area could meet the daily drinking water needs of one person. In production, they think a system built to serve the needs of a family might be built for around $100.

Cheaper replacements

The most expensive component of the prototype is the layer of transparent aerogel used as an insulator at the top of the stack, but the team suggests other less expensive insulators could be used instead. (The aerogel itself is made from very cheap silica but requires specialised drying equipment during its manufacture.)

“This new approach is very significant,” says Professor Ravi Prasher of Lawrence Berkeley National Laboratory and the University of California at Berkeley, who was not involved in the research.

“One of the challenges in solar still-based desalination has been low efficiency due to the loss of significant energy in condensation.

“By efficiently harvesting the condensation energy, the overall solar to vapour efficiency is dramatically improved … This increased efficiency will have an overall impact on reducing the cost of produced water.” − Climate News Network

New forests mean permanently lower river flows

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

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

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

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

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

Age effect missed

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Age effect missed

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

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

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

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

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

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

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

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

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