Tag Archives: Drought

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

Australia’s sunshine could spare its blazing forests

The hellish sight of Australia’s blazing forests threatens to become all too familiar. But the future doesn’t have to be like this.



LONDON, 16 January, 2020 − Australia burns, and recent studies show that the severity of the heat waves there has been exacerbated by climate change, fuelling this year’s extensive bush fires and torching the blazing forests. And yet Scott Morrison, Australia’s Prime Minister, has not faltered in his support for the fossil fuel industry.

To be fair, he is in a difficult situation. A significant part of the Australian economy is dependent on coal, and the economy would take a real hit if coal mining was shut down. On the other hand, it is clear that the coal industry is a major driver of climate change, the consequences of which his voters are suffering from. There is no easy way out. Morrison’s approval ratings have fallen from +2 to -12 during the past month.

So what can Mr Morrison do if he wants to reduce the impact that climate change will have on Australia’s forests? In my opinion, the answer is obvious. He should make good use of the other natural resource that his country has in abundance: sunshine. Sunshine means energy. For a big country like Australia, it means lots of energy.

Exporting solar-powered electricity directly to neighbouring countries is impractical and not very cost-effective − not least because, for Australia, there are very few such neighbouring countries. However, solar energy could be used to produce synthetic hydrocarbons and be stored and transported that way.

“Mr Morrison, are you prepared to take the initiative in making use of your vast reserves of solar energy to help make the aviation industry significantly greener?”

To take a practical example, there is no prospect in the foreseeable future of airliners being able to run directly on electric batteries charged by renewable sources – to cross the Atlantic, say, the batteries would simply be too heavy. In this respect, kerosene is a remarkable chemical, storing so much energy per gram of fuel. We cannot simply stop aircraft flying – the world’s economy depends on aviation.

Kerosene, as burnt by today’s aircraft, derives from fossil carbon, and it is our emissions of fossil carbon that are causing the climate to change and the Australian bush to burn. But it doesn’t have to be made from fossil carbon.

It can be made by sucking carbon dioxide out of the air and combining it with hydrogen, which has been made by separating it out from oxygen in common-or-garden water (a process known as hydrolysis).

Of course, this process requires energy, and it makes no sense to create synthetic kerosene using energy from fossil carbon. But it makes sense if the kerosene is made using solar energy.

Cost problem

Research has shown that producing synthetic kerosene in this way is possible. The problem of producing it at scale is one of cost. According to recent estimates, the cost of oil would have to exceed US$100 a barrel for synthetic kerosene to become viable.

This is the time for the countries of the world, especially those who have signed up to the 2015 Paris Agreement, to make commitments. A concrete proposal would be that past 2030, aircraft that land and take off at airports in these countries will, if the planes run on fossil kerosene, be taxed by an amount that would make it economically much more attractive for them to run on synthetic kerosene.

Of course, this won’t make sense unless synthetic kerosene is available in sufficient amounts. Herein lies Australia’s unique economic opportunity. As a politically stable country, we would not have to worry about supplies getting shut off by political instability, a concern for some other sunny parts of the world. Australia could easily become the go-to country for synthetic kerosene.

The developed countries of the world should take the lead in announcing a date when planes landing or taking off at their airports will be taxed extra if they burn fossil kerosene. Mr Morrison, if they do so, are you prepared to take the initiative in making use of your vast reserves of solar energy to help make the aviation industry significantly greener? Even if it is only to safeguard your own forests. − Climate News Network

* * * * * * *

Tim Palmer is a Royal Society Research Professor in Climate Physics at the University of Oxford, UK.

The hellish sight of Australia’s blazing forests threatens to become all too familiar. But the future doesn’t have to be like this.



LONDON, 16 January, 2020 − Australia burns, and recent studies show that the severity of the heat waves there has been exacerbated by climate change, fuelling this year’s extensive bush fires and torching the blazing forests. And yet Scott Morrison, Australia’s Prime Minister, has not faltered in his support for the fossil fuel industry.

To be fair, he is in a difficult situation. A significant part of the Australian economy is dependent on coal, and the economy would take a real hit if coal mining was shut down. On the other hand, it is clear that the coal industry is a major driver of climate change, the consequences of which his voters are suffering from. There is no easy way out. Morrison’s approval ratings have fallen from +2 to -12 during the past month.

So what can Mr Morrison do if he wants to reduce the impact that climate change will have on Australia’s forests? In my opinion, the answer is obvious. He should make good use of the other natural resource that his country has in abundance: sunshine. Sunshine means energy. For a big country like Australia, it means lots of energy.

Exporting solar-powered electricity directly to neighbouring countries is impractical and not very cost-effective − not least because, for Australia, there are very few such neighbouring countries. However, solar energy could be used to produce synthetic hydrocarbons and be stored and transported that way.

“Mr Morrison, are you prepared to take the initiative in making use of your vast reserves of solar energy to help make the aviation industry significantly greener?”

To take a practical example, there is no prospect in the foreseeable future of airliners being able to run directly on electric batteries charged by renewable sources – to cross the Atlantic, say, the batteries would simply be too heavy. In this respect, kerosene is a remarkable chemical, storing so much energy per gram of fuel. We cannot simply stop aircraft flying – the world’s economy depends on aviation.

Kerosene, as burnt by today’s aircraft, derives from fossil carbon, and it is our emissions of fossil carbon that are causing the climate to change and the Australian bush to burn. But it doesn’t have to be made from fossil carbon.

It can be made by sucking carbon dioxide out of the air and combining it with hydrogen, which has been made by separating it out from oxygen in common-or-garden water (a process known as hydrolysis).

Of course, this process requires energy, and it makes no sense to create synthetic kerosene using energy from fossil carbon. But it makes sense if the kerosene is made using solar energy.

Cost problem

Research has shown that producing synthetic kerosene in this way is possible. The problem of producing it at scale is one of cost. According to recent estimates, the cost of oil would have to exceed US$100 a barrel for synthetic kerosene to become viable.

This is the time for the countries of the world, especially those who have signed up to the 2015 Paris Agreement, to make commitments. A concrete proposal would be that past 2030, aircraft that land and take off at airports in these countries will, if the planes run on fossil kerosene, be taxed by an amount that would make it economically much more attractive for them to run on synthetic kerosene.

Of course, this won’t make sense unless synthetic kerosene is available in sufficient amounts. Herein lies Australia’s unique economic opportunity. As a politically stable country, we would not have to worry about supplies getting shut off by political instability, a concern for some other sunny parts of the world. Australia could easily become the go-to country for synthetic kerosene.

The developed countries of the world should take the lead in announcing a date when planes landing or taking off at their airports will be taxed extra if they burn fossil kerosene. Mr Morrison, if they do so, are you prepared to take the initiative in making use of your vast reserves of solar energy to help make the aviation industry significantly greener? Even if it is only to safeguard your own forests. − Climate News Network

* * * * * * *

Tim Palmer is a Royal Society Research Professor in Climate Physics at the University of Oxford, UK.

Can batteries help to limit bushfire horrors?

The Australian inferno has yet to reach its worst, but already minds are seeking ways to reduce the bushfire horrors. Could batteries help next time?

LONDON, 9 January, 2020 − With at least 27 human fatalities and a scarcely credible estimate by scientists that more than one billion animals have been killed nationwide by the unprecedented blazes  since September 2019, Australia’s bushfire horrors have stunned the world.

The climate crisis is contributing to the catastrophe, at least to its scale and intensity, whether or not it is its primary cause. And scientists revealed only this month that global heating is causing daily weather change.

But something else happened in Australia in 2019 which could point the way towards a fast route, not for Australia alone but globally, to renewable energy and a safer future.

In the state of South Australia the world’s biggest lithium-ion battery – 129MWh, able to power 30,000 homes for an hour during a blackout – was switched on just 60 days after the contract to build it was signed.

So ways of cutting the use of fossil fuels and reducing their contribution to climate heating, now clearly implicated in Australia’s catastrophe, are within reach.

The battery was commissioned in order to bring greater reliability and stability to the state’s electricity grid, preventing blackouts, improving reliability across the network and helping to even out price spikes.

The state’s efforts to increase its proportion of renewable energy had previously been hampered by freak weather which caused outages, which in turn sparked a political brawl over energy policy. The federal government blamed the supply failures on the use of renewable technologies.

40 days to spare

The state premier challenged the technology entrepreneur Elon Musk,  who replied by saying he would build a massive battery within 100 days of signing the deal. He managed it with 40 days to spare.

His approach − a familiar one in the renewable energy world − was to charge the battery packs when excess power was available and the cost of production very low, and then discharge them when the cost of power production rose.

The world is becoming increasingly reliant on battery power, largely because of the need to reduce carbon in the transport sector; almost 60% of new cars sold in Norway during March 2019 were entirely electric-powered. A recent World Economic Forum (WEF) report expects global battery demand to increase by more than 19 times its current levels in the next decade.

Batteries have historically been a dirty but convenient product, requiring the mining of metals such as nickel and zinc, yet considered disposable; landfills are strewn with these hazardous toxins, with more arriving every day. According to the US Environmental Protection Agency (EPA), each year Americans throw away more than three billion batteries – 180,000 tons of waste.

Yet the WEF report projects that new generation batteries could not only enable 30% of the required reductions in carbon emissions in the transport and power sectors, providing access to electricity to 600 million people who currently have no access; they will also create 10 million safe and sustainable jobs around the world.

Batteries will probably play a large part in future energy supply systems; in 2018, South Australia invested $100 million in a scheme to encourage householders to fit batteries to their solar systems, enabling them to use their own power on site rather than exporting it to the grid. This helps to reduce demand at peak times.

“The federal government blamed the supply failures on the use of renewable technologies”

Electric cars are not the only part of the transportation sector that will be in need of batteries. A number of companies are currently working on electric-powered commercial aircraft designs, and Norway is working on battery technology for shipping, with an all-electric passenger vessel already operating.

The Rapid Transition Alliance (RTA) is a UK-based organisation which argues that humankind must undertake “widespread behaviour change to sustainable lifestyles . . . to live within planetary ecological boundaries and to limit global warming to below 1.5°C”, with the slogan “Evidence-based hope for a warming world”.

It believes there is evidence that batteries can offer hope for Australia  and other countries facing similar lethal threats − provided they absorb several crucial lessons.

First, it says, technological leaps need both the flair of individual effort and the clout of institutional backing if they are to work at scale.

Then behavioural change must be practical and economically viable, because only a small minority of people will ever change for green reasons alone. Simply switching to electricity as a fuel source is not enough: to hit climate targets and maintain a habitable world, there needs to be an absolute reduction in energy consumption.

And finally, as batteries increasingly form part of the energy infrastructure, safeguards must be put in place around the mining involved in obtaining the minerals needed to make them, to ensure that poorer communities in the global South do not pay the price for cutting carbon emissions in richer countries. − Climate News Network

* * * * *

The Rapid Transition Alliance is coordinated by the New Weather Institute, the STEPS Centre at the Institute of  Development Studies, and the School of Global Studies at the University of Sussex, UK. The Climate News Network is partnering with and supported by the Rapid Transition Alliance, and will be reporting regularly on its work. If you would like to see more stories of evidence-based hope for rapid transition, please sign up here.

Do you know a story of rapid transition? If so, we’d like to hear from you. Please send us a brief outline on info@climatenewsnetwork.net. Thank you.

The Australian inferno has yet to reach its worst, but already minds are seeking ways to reduce the bushfire horrors. Could batteries help next time?

LONDON, 9 January, 2020 − With at least 27 human fatalities and a scarcely credible estimate by scientists that more than one billion animals have been killed nationwide by the unprecedented blazes  since September 2019, Australia’s bushfire horrors have stunned the world.

The climate crisis is contributing to the catastrophe, at least to its scale and intensity, whether or not it is its primary cause. And scientists revealed only this month that global heating is causing daily weather change.

But something else happened in Australia in 2019 which could point the way towards a fast route, not for Australia alone but globally, to renewable energy and a safer future.

In the state of South Australia the world’s biggest lithium-ion battery – 129MWh, able to power 30,000 homes for an hour during a blackout – was switched on just 60 days after the contract to build it was signed.

So ways of cutting the use of fossil fuels and reducing their contribution to climate heating, now clearly implicated in Australia’s catastrophe, are within reach.

The battery was commissioned in order to bring greater reliability and stability to the state’s electricity grid, preventing blackouts, improving reliability across the network and helping to even out price spikes.

The state’s efforts to increase its proportion of renewable energy had previously been hampered by freak weather which caused outages, which in turn sparked a political brawl over energy policy. The federal government blamed the supply failures on the use of renewable technologies.

40 days to spare

The state premier challenged the technology entrepreneur Elon Musk,  who replied by saying he would build a massive battery within 100 days of signing the deal. He managed it with 40 days to spare.

His approach − a familiar one in the renewable energy world − was to charge the battery packs when excess power was available and the cost of production very low, and then discharge them when the cost of power production rose.

The world is becoming increasingly reliant on battery power, largely because of the need to reduce carbon in the transport sector; almost 60% of new cars sold in Norway during March 2019 were entirely electric-powered. A recent World Economic Forum (WEF) report expects global battery demand to increase by more than 19 times its current levels in the next decade.

Batteries have historically been a dirty but convenient product, requiring the mining of metals such as nickel and zinc, yet considered disposable; landfills are strewn with these hazardous toxins, with more arriving every day. According to the US Environmental Protection Agency (EPA), each year Americans throw away more than three billion batteries – 180,000 tons of waste.

Yet the WEF report projects that new generation batteries could not only enable 30% of the required reductions in carbon emissions in the transport and power sectors, providing access to electricity to 600 million people who currently have no access; they will also create 10 million safe and sustainable jobs around the world.

Batteries will probably play a large part in future energy supply systems; in 2018, South Australia invested $100 million in a scheme to encourage householders to fit batteries to their solar systems, enabling them to use their own power on site rather than exporting it to the grid. This helps to reduce demand at peak times.

“The federal government blamed the supply failures on the use of renewable technologies”

Electric cars are not the only part of the transportation sector that will be in need of batteries. A number of companies are currently working on electric-powered commercial aircraft designs, and Norway is working on battery technology for shipping, with an all-electric passenger vessel already operating.

The Rapid Transition Alliance (RTA) is a UK-based organisation which argues that humankind must undertake “widespread behaviour change to sustainable lifestyles . . . to live within planetary ecological boundaries and to limit global warming to below 1.5°C”, with the slogan “Evidence-based hope for a warming world”.

It believes there is evidence that batteries can offer hope for Australia  and other countries facing similar lethal threats − provided they absorb several crucial lessons.

First, it says, technological leaps need both the flair of individual effort and the clout of institutional backing if they are to work at scale.

Then behavioural change must be practical and economically viable, because only a small minority of people will ever change for green reasons alone. Simply switching to electricity as a fuel source is not enough: to hit climate targets and maintain a habitable world, there needs to be an absolute reduction in energy consumption.

And finally, as batteries increasingly form part of the energy infrastructure, safeguards must be put in place around the mining involved in obtaining the minerals needed to make them, to ensure that poorer communities in the global South do not pay the price for cutting carbon emissions in richer countries. − Climate News Network

* * * * *

The Rapid Transition Alliance is coordinated by the New Weather Institute, the STEPS Centre at the Institute of  Development Studies, and the School of Global Studies at the University of Sussex, UK. The Climate News Network is partnering with and supported by the Rapid Transition Alliance, and will be reporting regularly on its work. If you would like to see more stories of evidence-based hope for rapid transition, please sign up here.

Do you know a story of rapid transition? If so, we’d like to hear from you. Please send us a brief outline on info@climatenewsnetwork.net. Thank you.

Global heating drives daily weather change

Expect the climate, but prepare for the weather? Not any more. The statistics spell it out: global heating is causing daily weather change.

LONDON, 6 January, 2020 – Swiss scientists have done something many of their colleagues had claimed was impossible: they have linked the random events of the daily weather change we all experience directly to the climate crisis.

It has been an axiom of climate science for decades that – although global heating would inevitably increase the likelihood of more intense or more damaging windstorms, floods, droughts or heat waves – it would not be possible to say that this or that event could not have happened the way it did without the ominous rise in global average temperature, driven by profligate use of fossil fuels.

But that no longer holds, according to a new study in the journal Nature Climate Change.

“Weather when considered globally is now in uncharted territory,” researchers write. “On the basis of a single day of globally observed temperature and moisture, we detect the fingerprint of externally driven climate change, and conclude that the earth as a whole is warming.”

Climate scientists and statisticians from the Swiss Federal Institute of Technology, known simply as ETH Zurich, and from a partner institute in Lausanne known as EPFL, say that the seemingly normal variations in daily weather around the world are telling a clear story – just as long as the observers look at the global picture as well as the local measurements.

Clear pattern

For instance, on the same day as the Swiss study the UK Met Office announced a set of new temperature records for Britain in the last decade. The coldest March day ever recorded was in Gwent, Wales, in March 2018, when the thermometer fell to minus 4.7°C. But during the same decade the rest of Britain experienced four new and unprecedented monthly high temperatures, including an as yet unverified high of 18.7°C late in December.

In January 2020, a village in Norway registered a high of 19°C, a whole 25 degrees above the average for the winter month. But whereas local temperatures can fluctuate wildly, the variation in global average data is very small.

The Swiss scientists combed through the daily mean temperature and rainfall and snowfall data for the years 1951 to 1980, and for 2009 to 2018. They drew bell-shaped curves for each sequence of the years and then tried to match them. Without any overall rise in average global temperatures, the two curves would cover much the same space on the graph paper. They barely overlapped.

They then used a range of sophisticated statistical techniques to make detailed sense of the information in the two patterns of decadal weather. Beyond the jargon of the statistician’s trade – the paper talks of regression coefficients and regularised linear regression models, mean squared errors and Pearson correlations – a clear pattern emerged.

“Weather when considered globally is now in uncharted territory”

The often-wild swings of natural variation could be disentangled from the intensification powered by global heating. Climate change could be detected from global weather in any single year, month or even day. No longer can climate researchers use the old escape clause, “Climate is what you expect, weather is what you get,” to explain away seeming seasonal inconsistencies.

Global heating driven by greenhouse gases released by human economic growth is now shaping the world’s daily weather, from the catastrophic heat extremes and wildfires in Australia to the uncharacteristic winter weather in Moscow.

“The fingerprint of climate change is detected from any single day in the observed global record since early 2012”, the scientists write, “and since 1999 on the basis of a year of data. Detection is robust even when ignoring the long-term global warming trend.” – Climate News Network

Expect the climate, but prepare for the weather? Not any more. The statistics spell it out: global heating is causing daily weather change.

LONDON, 6 January, 2020 – Swiss scientists have done something many of their colleagues had claimed was impossible: they have linked the random events of the daily weather change we all experience directly to the climate crisis.

It has been an axiom of climate science for decades that – although global heating would inevitably increase the likelihood of more intense or more damaging windstorms, floods, droughts or heat waves – it would not be possible to say that this or that event could not have happened the way it did without the ominous rise in global average temperature, driven by profligate use of fossil fuels.

But that no longer holds, according to a new study in the journal Nature Climate Change.

“Weather when considered globally is now in uncharted territory,” researchers write. “On the basis of a single day of globally observed temperature and moisture, we detect the fingerprint of externally driven climate change, and conclude that the earth as a whole is warming.”

Climate scientists and statisticians from the Swiss Federal Institute of Technology, known simply as ETH Zurich, and from a partner institute in Lausanne known as EPFL, say that the seemingly normal variations in daily weather around the world are telling a clear story – just as long as the observers look at the global picture as well as the local measurements.

Clear pattern

For instance, on the same day as the Swiss study the UK Met Office announced a set of new temperature records for Britain in the last decade. The coldest March day ever recorded was in Gwent, Wales, in March 2018, when the thermometer fell to minus 4.7°C. But during the same decade the rest of Britain experienced four new and unprecedented monthly high temperatures, including an as yet unverified high of 18.7°C late in December.

In January 2020, a village in Norway registered a high of 19°C, a whole 25 degrees above the average for the winter month. But whereas local temperatures can fluctuate wildly, the variation in global average data is very small.

The Swiss scientists combed through the daily mean temperature and rainfall and snowfall data for the years 1951 to 1980, and for 2009 to 2018. They drew bell-shaped curves for each sequence of the years and then tried to match them. Without any overall rise in average global temperatures, the two curves would cover much the same space on the graph paper. They barely overlapped.

They then used a range of sophisticated statistical techniques to make detailed sense of the information in the two patterns of decadal weather. Beyond the jargon of the statistician’s trade – the paper talks of regression coefficients and regularised linear regression models, mean squared errors and Pearson correlations – a clear pattern emerged.

“Weather when considered globally is now in uncharted territory”

The often-wild swings of natural variation could be disentangled from the intensification powered by global heating. Climate change could be detected from global weather in any single year, month or even day. No longer can climate researchers use the old escape clause, “Climate is what you expect, weather is what you get,” to explain away seeming seasonal inconsistencies.

Global heating driven by greenhouse gases released by human economic growth is now shaping the world’s daily weather, from the catastrophic heat extremes and wildfires in Australia to the uncharacteristic winter weather in Moscow.

“The fingerprint of climate change is detected from any single day in the observed global record since early 2012”, the scientists write, “and since 1999 on the basis of a year of data. Detection is robust even when ignoring the long-term global warming trend.” – Climate News Network

Jet stream changes may hit global breadbaskets

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

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

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

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

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

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

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

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

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

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

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

Twentyfold increase

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

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

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

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

Remote effects

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Twentyfold increase

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

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

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

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

Remote effects

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

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

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

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

New water for old as glaciers vanish

Voids left as glaciers vanish could be used to store spring snowmelt and rainfall to save the valleys below from summer droughts.

LONDON, 4 December, 2019 – Building dams in high mountains to store water as glaciers vanish could produce much-needed hydropower as well as saving people in the valleys below from summer droughts.

Following an earlier study of their own crisis of retreating glaciers in the Alps, Swiss glaciologists have carried out a worldwide study of 185,000 retreating rivers of ice to assess whether the empty valleys they leave behind could usefully be turned into holding dams.

The issue is urgent, because even with an average climate change scenario about three-quarters of the storage potential of these valleys could become ice-free by 2050 – and all of them by the end of the century.

The retreating ice – apart from spelling the end for some magnificent natural monuments – will dramatically affect the water cycle, leaving large river systems with seriously low flows, and some perhaps drying up altogether in the summer. This would have serious consequences for hydro-electricity production, agriculture and even drinking water for cities downstream.

Although water shortage is a potential problem in many high mountain regions, it is already affecting cities like Peru’s capital, Lima, which lies below the Andes. It also has the potential to cause serious problems in India, Pakistan and China, all of them reliant on summer run-off from the Himalayas.

“This theoretical total potential corresponds to about one third of current hydropower production worldwide. But, in reality, only part of it would be realisable”

The idea of the dams would be to capture the water from winter rainfall and spring snowmelt and retain it for gradual release during the summer – so, at least partly, replicating the current summer glacier melt.

ETH Zurich (the Swiss Federal Institute of Technology) and the Swiss Federal Institute for Forest, Snow and Landscape Research report, in a study published in the journal Nature, that the scheme could be viable in many countries.

The team calculated that theoretically the storage potential of these glacier valleys was 875 cubic kilometres of water, providing enormous hydropower potential.

Daniel Farinotti, professor of glaciology at ETH Zurich, who led the team, said: “This theoretical total potential corresponds to about one third of current hydropower production worldwide. But in reality, only part of it would be realisable.”

Since it was neither realistic nor desirable to build a dam in each of the thousands of the valleys vacated by glaciers, the researchers carried out a suitability assessment for all sites.

Significant addition

They identified around 40% of the theoretical total as “potentially” suitable, equalling a storage volume of 355 cubic km and a hydropower potential of 533 TWh per year. The latter corresponds to around 13% of current global hydropower production, or nine times Switzerland’s annual electricity demand.

“Even this potentially suitable storage volume would be sufficient to store about half of the annual runoff from the studied glacierised basins,” Professor Farinotti said.

The results show that basins which have lost their glaciers could contribute significantly to energy supply and water storage in a number of countries, particularly in the high mountain countries of Asia.

Among those with the largest potentials are Tajikistan, where the calculated hydropower potential could account for up to 80% of current electricity consumption, Chile (40%) and Pakistan (35%).

In Canada, Iceland, Bolivia and Norway, the potential equals 10–25% of their current electricity consumption. For Switzerland, the study shows a potential of 10%. – Climate News Network

Voids left as glaciers vanish could be used to store spring snowmelt and rainfall to save the valleys below from summer droughts.

LONDON, 4 December, 2019 – Building dams in high mountains to store water as glaciers vanish could produce much-needed hydropower as well as saving people in the valleys below from summer droughts.

Following an earlier study of their own crisis of retreating glaciers in the Alps, Swiss glaciologists have carried out a worldwide study of 185,000 retreating rivers of ice to assess whether the empty valleys they leave behind could usefully be turned into holding dams.

The issue is urgent, because even with an average climate change scenario about three-quarters of the storage potential of these valleys could become ice-free by 2050 – and all of them by the end of the century.

The retreating ice – apart from spelling the end for some magnificent natural monuments – will dramatically affect the water cycle, leaving large river systems with seriously low flows, and some perhaps drying up altogether in the summer. This would have serious consequences for hydro-electricity production, agriculture and even drinking water for cities downstream.

Although water shortage is a potential problem in many high mountain regions, it is already affecting cities like Peru’s capital, Lima, which lies below the Andes. It also has the potential to cause serious problems in India, Pakistan and China, all of them reliant on summer run-off from the Himalayas.

“This theoretical total potential corresponds to about one third of current hydropower production worldwide. But, in reality, only part of it would be realisable”

The idea of the dams would be to capture the water from winter rainfall and spring snowmelt and retain it for gradual release during the summer – so, at least partly, replicating the current summer glacier melt.

ETH Zurich (the Swiss Federal Institute of Technology) and the Swiss Federal Institute for Forest, Snow and Landscape Research report, in a study published in the journal Nature, that the scheme could be viable in many countries.

The team calculated that theoretically the storage potential of these glacier valleys was 875 cubic kilometres of water, providing enormous hydropower potential.

Daniel Farinotti, professor of glaciology at ETH Zurich, who led the team, said: “This theoretical total potential corresponds to about one third of current hydropower production worldwide. But in reality, only part of it would be realisable.”

Since it was neither realistic nor desirable to build a dam in each of the thousands of the valleys vacated by glaciers, the researchers carried out a suitability assessment for all sites.

Significant addition

They identified around 40% of the theoretical total as “potentially” suitable, equalling a storage volume of 355 cubic km and a hydropower potential of 533 TWh per year. The latter corresponds to around 13% of current global hydropower production, or nine times Switzerland’s annual electricity demand.

“Even this potentially suitable storage volume would be sufficient to store about half of the annual runoff from the studied glacierised basins,” Professor Farinotti said.

The results show that basins which have lost their glaciers could contribute significantly to energy supply and water storage in a number of countries, particularly in the high mountain countries of Asia.

Among those with the largest potentials are Tajikistan, where the calculated hydropower potential could account for up to 80% of current electricity consumption, Chile (40%) and Pakistan (35%).

In Canada, Iceland, Bolivia and Norway, the potential equals 10–25% of their current electricity consumption. For Switzerland, the study shows a potential of 10%. – Climate News Network

60-year drought ended ancient Assyrian empire

It took only a 60-year drought to lay low one of the first superpowers. It crumbled when harvests withered over two millennia ago.

LONDON, 25 November, 2019 − One of the great ancient empires, the neo-Assyrian world of what is now northern Iraq, flourished in years of plentiful rain, but buckled and collapsed when beset by a 60-year drought.

The biblical city of Nineveh fell in 612 BC, weakened by climate change, never to be occupied again. Chroniclers blamed political instability, the might of Babylon, and the invasions of Medes and Persians.

But climate scientists who have reconstructed the evidence of annual weather records have set the record straight: like the rings of a tree or the sediments in a lake, the isotope records in stalagmites in the floor of the Kuna Ba cave tell a story of a mega-drought that underlay the collapse of one of ancient history’s earliest superpowers.

Stalagmites or speleothems are built up by the steady drip of water through rock and onto the floor of a cave. The scientists report in the journal Science Advances that they used carbon and oxygen isotopes in the layers of stone to reconstruct the climate throughout a 3800-year sequence of rainfall patterns.

The measures of uranium and thorium trapped in the same speleothems provided precise dates for the entire sequence, and these could then be checked against surviving records from an empire that at its height, under King Sennacherib, extended into parts of what are now Turkey, Iran, Syria, Jordan, Lebanon, Israel and Egypt.

“These societies experienced climatic changes that were of such magnitude they could not simply adapt to them”

“We now know that the Assyrian droughts started decades earlier than we had previously thought, and also that the period prior to the onset of drought was one of the wettest in the entire roughly 3800-year sequence.

“It changes some of the other hypotheses we have made”, said Adam Schneider, of the University of Colorado at Boulder, who first proposed a climate link to imperial collapse in 2014.

“For example: King Sennacherib, who ruled from 705 to 681 BC, was well-known for building massive canals and other structures. In our earlier work on the question of drought in ancient Assyria, I and my colleague Dr. Selim Adali had initially viewed him as a short-sighted ruler who had pursued short-term political goals at the expense of long-term drought resilience, and set in motion a catastrophic chain of events as a result.

“But with this new data, we now think that Sennacherib probably was already experiencing drought when he was king, and in fact he may well have been trying to do something about the environmental calamity during that time.”

And a co-author, Harvey Weiss of Yale University, said : “Now we have a historical and environmental dynamic between north and south and between rain-fed agriculture and irrigation-fed agriculture through which we can understand the historical process of how the Babylonians were able to defeat the Assyrians.”

New theory

“This fits into a historical pattern that is not only structured through time and place, but a space and time that is filled with environmental change,” said Professor Weiss. “These societies experienced climatic changes that were of such magnitude they could not simply adapt to them.”

The climate change theory of history is relatively new, but has already been used to provide new explanations for the collapse of the Bronze Age empire in the Mediterranean 3,000 years ago, the downfall of the Ptolemaic dynasty in Egypt, the rise of Genghis Khan’s nomadic hordes  and the fall of the Mayan civilisation in the Americas.

There have been arguments that contemporary conflict can be matched to climate stress in many parts of the modern world.

“The French Revolution is one example. In the two years prior to the French Revolution poor weather led to a series of bad harvests, which alongside other factors helped cause the price of bread to skyrocket, especially in Paris,” said Professor Schneider.

“The question is not ‘Did climate have an impact?’ It’s ‘How, why and how important was climate alongside the other factors?’” − Climate News Network

It took only a 60-year drought to lay low one of the first superpowers. It crumbled when harvests withered over two millennia ago.

LONDON, 25 November, 2019 − One of the great ancient empires, the neo-Assyrian world of what is now northern Iraq, flourished in years of plentiful rain, but buckled and collapsed when beset by a 60-year drought.

The biblical city of Nineveh fell in 612 BC, weakened by climate change, never to be occupied again. Chroniclers blamed political instability, the might of Babylon, and the invasions of Medes and Persians.

But climate scientists who have reconstructed the evidence of annual weather records have set the record straight: like the rings of a tree or the sediments in a lake, the isotope records in stalagmites in the floor of the Kuna Ba cave tell a story of a mega-drought that underlay the collapse of one of ancient history’s earliest superpowers.

Stalagmites or speleothems are built up by the steady drip of water through rock and onto the floor of a cave. The scientists report in the journal Science Advances that they used carbon and oxygen isotopes in the layers of stone to reconstruct the climate throughout a 3800-year sequence of rainfall patterns.

The measures of uranium and thorium trapped in the same speleothems provided precise dates for the entire sequence, and these could then be checked against surviving records from an empire that at its height, under King Sennacherib, extended into parts of what are now Turkey, Iran, Syria, Jordan, Lebanon, Israel and Egypt.

“These societies experienced climatic changes that were of such magnitude they could not simply adapt to them”

“We now know that the Assyrian droughts started decades earlier than we had previously thought, and also that the period prior to the onset of drought was one of the wettest in the entire roughly 3800-year sequence.

“It changes some of the other hypotheses we have made”, said Adam Schneider, of the University of Colorado at Boulder, who first proposed a climate link to imperial collapse in 2014.

“For example: King Sennacherib, who ruled from 705 to 681 BC, was well-known for building massive canals and other structures. In our earlier work on the question of drought in ancient Assyria, I and my colleague Dr. Selim Adali had initially viewed him as a short-sighted ruler who had pursued short-term political goals at the expense of long-term drought resilience, and set in motion a catastrophic chain of events as a result.

“But with this new data, we now think that Sennacherib probably was already experiencing drought when he was king, and in fact he may well have been trying to do something about the environmental calamity during that time.”

And a co-author, Harvey Weiss of Yale University, said : “Now we have a historical and environmental dynamic between north and south and between rain-fed agriculture and irrigation-fed agriculture through which we can understand the historical process of how the Babylonians were able to defeat the Assyrians.”

New theory

“This fits into a historical pattern that is not only structured through time and place, but a space and time that is filled with environmental change,” said Professor Weiss. “These societies experienced climatic changes that were of such magnitude they could not simply adapt to them.”

The climate change theory of history is relatively new, but has already been used to provide new explanations for the collapse of the Bronze Age empire in the Mediterranean 3,000 years ago, the downfall of the Ptolemaic dynasty in Egypt, the rise of Genghis Khan’s nomadic hordes  and the fall of the Mayan civilisation in the Americas.

There have been arguments that contemporary conflict can be matched to climate stress in many parts of the modern world.

“The French Revolution is one example. In the two years prior to the French Revolution poor weather led to a series of bad harvests, which alongside other factors helped cause the price of bread to skyrocket, especially in Paris,” said Professor Schneider.

“The question is not ‘Did climate have an impact?’ It’s ‘How, why and how important was climate alongside the other factors?’” − Climate News Network