Tag Archives: Drought

Water stress rises as more wells run dry

Soon, communities and even nations could be drawing water faster than the skies can replenish it. As the wells run dry, so will the rivers.

LONDON, 9 October, 2019 − Within three decades, almost 80% of the lands that depend on groundwater will start to reach their natural irrigation limits as the wells run dry.

In a world of increasing extremes of drought and rainfall, driven by rising global temperatures and potentially catastrophic climate change, the water will start to run out.

It is happening already: in 20% of those water catchments in which farmers and cities rely on pumped groundwater, the flow of streams and rivers has fallen and the surface flow has dwindled, changed direction or stopped altogether.

“The effects can be seen already in the Midwest of the United States and in the Indus Valley project between Afghanistan and Pakistan,” said Inge de Graaf, a hydrologist at the University of Freiburg.

Groundwater – the billions of tonnes locked in the soils and bedrock, held in vast chalk and limestone aquifers and silently flowing through cracks in other sediments – is the terrestrial planet’s biggest single store of the liquid that sustains all life.

“If we continue to pump as much groundwater in the coming decades as we have done so far, a critical point will be reached for regions in southern and central Europe as well as in North African countries”

Groundwater supplies the inland streams and rivers, and the flow from tributaries is an indicator of the levels of water already in the ground.

For thousands of years, communities have drawn water from wells in the dry season and relied on wet season rainfall to replenish it. But as human numbers have grown, as agriculture has commandeered more and more of the land, and as cities have burgeoned, demand has in some places begun to outstrip supply. The fear is that rising average temperatures will intensify the problem.

Dr de Graaf and colleagues from the Netherlands and Canada report in the journal Nature that they used computer simulations to establish the likely pattern of withdrawal and flow. The news is not good.

“We estimate that, by 2050, environmental flow limits will be reached for approximately 42% to 79% of the watershed in which there is groundwater pumping worldwide, and this will generally occur before substantial losses in groundwater storage are experienced,” they write.

That drylands – home to billions of people – will experience water stress with rising temperatures is not news. Climate scientists have been issuing warnings for years.

Ground level drops

And demand for groundwater has increased with the growth of the population and the worldwide growth of the cities: some US cities are at risk of coastal flooding just because so much groundwater has been extracted that the ground itself has been lowered.

The important thing about the latest research is that it sets – albeit broadly – a timetable and a map of where the water stress is likely to be experienced first.

In a hotter world, plants and animals will demand more water. But in a hotter world, the probability of extremes of drought increases.

“If we continue to pump as much groundwater in the coming decades as we have done so far, a critical point will be reached also for regions in southern and central Europe – such as Portugal, Spain and Italy – as well as in North African countries,” Dr de Graaf warned.

“Climate change may even accelerate this process, as we expect less precipitation, which will further increase the extraction of groundwater and cause dry areas to dry out completely.” − Climate News Network

Soon, communities and even nations could be drawing water faster than the skies can replenish it. As the wells run dry, so will the rivers.

LONDON, 9 October, 2019 − Within three decades, almost 80% of the lands that depend on groundwater will start to reach their natural irrigation limits as the wells run dry.

In a world of increasing extremes of drought and rainfall, driven by rising global temperatures and potentially catastrophic climate change, the water will start to run out.

It is happening already: in 20% of those water catchments in which farmers and cities rely on pumped groundwater, the flow of streams and rivers has fallen and the surface flow has dwindled, changed direction or stopped altogether.

“The effects can be seen already in the Midwest of the United States and in the Indus Valley project between Afghanistan and Pakistan,” said Inge de Graaf, a hydrologist at the University of Freiburg.

Groundwater – the billions of tonnes locked in the soils and bedrock, held in vast chalk and limestone aquifers and silently flowing through cracks in other sediments – is the terrestrial planet’s biggest single store of the liquid that sustains all life.

“If we continue to pump as much groundwater in the coming decades as we have done so far, a critical point will be reached for regions in southern and central Europe as well as in North African countries”

Groundwater supplies the inland streams and rivers, and the flow from tributaries is an indicator of the levels of water already in the ground.

For thousands of years, communities have drawn water from wells in the dry season and relied on wet season rainfall to replenish it. But as human numbers have grown, as agriculture has commandeered more and more of the land, and as cities have burgeoned, demand has in some places begun to outstrip supply. The fear is that rising average temperatures will intensify the problem.

Dr de Graaf and colleagues from the Netherlands and Canada report in the journal Nature that they used computer simulations to establish the likely pattern of withdrawal and flow. The news is not good.

“We estimate that, by 2050, environmental flow limits will be reached for approximately 42% to 79% of the watershed in which there is groundwater pumping worldwide, and this will generally occur before substantial losses in groundwater storage are experienced,” they write.

That drylands – home to billions of people – will experience water stress with rising temperatures is not news. Climate scientists have been issuing warnings for years.

Ground level drops

And demand for groundwater has increased with the growth of the population and the worldwide growth of the cities: some US cities are at risk of coastal flooding just because so much groundwater has been extracted that the ground itself has been lowered.

The important thing about the latest research is that it sets – albeit broadly – a timetable and a map of where the water stress is likely to be experienced first.

In a hotter world, plants and animals will demand more water. But in a hotter world, the probability of extremes of drought increases.

“If we continue to pump as much groundwater in the coming decades as we have done so far, a critical point will be reached also for regions in southern and central Europe – such as Portugal, Spain and Italy – as well as in North African countries,” Dr de Graaf warned.

“Climate change may even accelerate this process, as we expect less precipitation, which will further increase the extraction of groundwater and cause dry areas to dry out completely.” − Climate News Network

Drought may hit half world’s wheat at once

Wheat yields could be hit by severe drought across half the world at once, driving up prices and making problems for global markets.

LONDON, 2 October, 2019 − The planet’s daily bread could be at risk as the global thermometer creeps up and climates begin to change. New research has warned that almost two thirds of the world’s wheat-growing areas could face “severe, prolonged, and near-simultaneous droughts” by the century’s end.

Right now, 15% of the world’s wheat producing regions are at risk of severe water scarcity at the same time. Even if the 195 nations that agreed in Paris to stop global average temperatures from rising beyond 1.5°C by 2100 keep that promise, the chance of simultaneous water stress across continents would still double between 2030 and 2070.

But if nations fail to mitigate the climate change and extremes of heat and rainfall that would inevitably follow runaway global heating, then the chances of devastating failure of wheat harvests in both Europe and North America, or both Europe and Australia, or Russia, Ukraine and Kazakhstan, begin to soar.

Wheat provides one-fifth of all the calories for humankind. It is the world’s largest rain-fed crop and the global wheat trade matches the traffic in rice and in maize combined. Ten regions account for 54% of the planet’s wheat fields, and 57% of the world’s wheat.

“The results indicate a severely heightened risk of high-impact extreme events under the future climate”

Scientists from Europe, the US and China report in the journal Science Advances that they worked with computer simulations to model the future global weather for water scarcity with changes in temperature for the next eight decades.

Wheat is a successful crop partly because its water needs are relatively low, but it can’t flourish without reliable rainfall before and during growth. And the new simulations confirm earlier fears: that extremes of heat and devastating drought could happen in more than one continent at the same time.

When this happened in the 19th century, global famine followed. Forecasts already warn that with each 1°C rise in temperature, global wheat yield will fall by between 4% and 6.5%. Researchers have repeatedly warned that extremes of heat can slash yields and limit the vital nutrients in cereal harvests. Other teams have found that climate change may already be making this happen.

Worse could follow as one heat wave is pursued promptly by another. And all this could happen in a world in which, as population grows, demand for wheat could increase by at least 43%.

Continued checking

Scientists tend not to take the research of others for granted: they keep on checking. The latest simulation analysed 27 different climate models, each with three different scenarios.

The scientists looked at evidence from the near-past to find that between 1985 and 2007, the impact of drought on world wheat production was twice that between 1964 and 1984.

They included developing countries and low-income nations in eastern and southern Asia in their survey, because these are where half of the already hungry and under-nourished live, and where bread is an important part of people’s diet.

“The results indicate a severely heightened risk of high-impact extreme events under the future climate, which would likely affect all market players, ranging from direct influences on subsistence farmers to price-mediated changes in international markets”, they write. − Climate News Network

Wheat yields could be hit by severe drought across half the world at once, driving up prices and making problems for global markets.

LONDON, 2 October, 2019 − The planet’s daily bread could be at risk as the global thermometer creeps up and climates begin to change. New research has warned that almost two thirds of the world’s wheat-growing areas could face “severe, prolonged, and near-simultaneous droughts” by the century’s end.

Right now, 15% of the world’s wheat producing regions are at risk of severe water scarcity at the same time. Even if the 195 nations that agreed in Paris to stop global average temperatures from rising beyond 1.5°C by 2100 keep that promise, the chance of simultaneous water stress across continents would still double between 2030 and 2070.

But if nations fail to mitigate the climate change and extremes of heat and rainfall that would inevitably follow runaway global heating, then the chances of devastating failure of wheat harvests in both Europe and North America, or both Europe and Australia, or Russia, Ukraine and Kazakhstan, begin to soar.

Wheat provides one-fifth of all the calories for humankind. It is the world’s largest rain-fed crop and the global wheat trade matches the traffic in rice and in maize combined. Ten regions account for 54% of the planet’s wheat fields, and 57% of the world’s wheat.

“The results indicate a severely heightened risk of high-impact extreme events under the future climate”

Scientists from Europe, the US and China report in the journal Science Advances that they worked with computer simulations to model the future global weather for water scarcity with changes in temperature for the next eight decades.

Wheat is a successful crop partly because its water needs are relatively low, but it can’t flourish without reliable rainfall before and during growth. And the new simulations confirm earlier fears: that extremes of heat and devastating drought could happen in more than one continent at the same time.

When this happened in the 19th century, global famine followed. Forecasts already warn that with each 1°C rise in temperature, global wheat yield will fall by between 4% and 6.5%. Researchers have repeatedly warned that extremes of heat can slash yields and limit the vital nutrients in cereal harvests. Other teams have found that climate change may already be making this happen.

Worse could follow as one heat wave is pursued promptly by another. And all this could happen in a world in which, as population grows, demand for wheat could increase by at least 43%.

Continued checking

Scientists tend not to take the research of others for granted: they keep on checking. The latest simulation analysed 27 different climate models, each with three different scenarios.

The scientists looked at evidence from the near-past to find that between 1985 and 2007, the impact of drought on world wheat production was twice that between 1964 and 1984.

They included developing countries and low-income nations in eastern and southern Asia in their survey, because these are where half of the already hungry and under-nourished live, and where bread is an important part of people’s diet.

“The results indicate a severely heightened risk of high-impact extreme events under the future climate, which would likely affect all market players, ranging from direct influences on subsistence farmers to price-mediated changes in international markets”, they write. − Climate News Network

Starvation may force nations to war

Unless nations act now to halt the spread of deserts, they may face wars over food shortages and starvation by mid-century, the UN says.

DELHI, 26 September, 2019 − A stark warning that the exposure of more and more people to water scarcity, hunger and outright starvation may lead to the “failure of fragile states and regional conflicts” has been given by the United Nations as it attempts to galvanise governments into halting the spread of deserts before more cropland is lost.

The climate summit in New York was presented with a plan to try to halt the annual loss of 12 million hectares (30mn acres) of productive land caused by the nations which are parties to the UN’s Convention to Combat Desertification (UNCCD), which recently ended a high-level meeting here.

The plan was the list of actions nations agreed at the meeting of more than 190 countries to attempt to reverse the spread of land degradation that the UN estimates will displace 135 million people by 2045. The battle to halt the spread of deserts is seen by the UN as an integral part of the international effort to halt climate change.

How successful the new plans will be remains to be seen, as although  the Convention, like the Climate Change Convention, has been in existence since the last century, the problems continue to get worse. However, all the countries involved now have national plans to halt land degradation and restore croplands and forests.

One of the key new promises made at the Delhi meeting, which ended on 13 September, was to grant land tenure to groups to give them an incentive to protect soils and the ability of the land to grow crops.

“Land restoration is the cheapest solution to climate change and biodiversity loss”

Delegates also agreed to improve the rights of women, promote land restoration and reduce land-related carbon emissions, both from poor soil management and the destruction of trees. New ways of financing these schemes from government and private sources were proposed.

The scale of the problem is enormous. Close to a quarter of global land is almost unusable, and by the middle of the century humans will need to produce twice as much grain as they do today to keep up with global population growth, the UNCCD says.

At the closing session Ibrahim Thiaw, executive secretary of the UNCCD, said: “Land restoration is the cheapest solution to climate change and biodiversity loss; land restoration makes business sense if we have regulations and incentives to reward investment.”

In addition, he said, preparing for the increasing number of droughts and coping with them are critical in the face of climate change. He emphasised the need to involve young people and women and to secure land rights.

However, despite the adoption of the New Delhi Declaration, in which ministers and delegates expressed support for new initiatives or coalitions aiming to improve human health and well-being and the health of ecosystems, and to advance peace and security, there were dissenting voices at the conference.

Dilution and omissions

The Centre for Science and Environment (CSE) said in a statement: “The New Delhi Declaration has diluted the role of international funding bodies in combating desertification. It has also sidestepped the contentious issue of tenure rights to land.”

The CSE said the statement had removed any mention of the Green Climate Fund, the Global Environment Facility and the Adaptation Fund  from the Declaration and there were no mentions of specific measures that could be used for adaptation nor, in fact, the word “adaptation” itself. Countries were left to develop their own plans.

Local politics also plays an important part in creating the problem. For example, across South Asia severe drought areas are used for water-guzzling crops such as sugarcane, or for very large monoculture plantations for palm oil or rubber.

Some speakers felt it was going to be an uphill struggle for poorer countries to get funding for restoring degraded land.

Early warning systems, climate-resilient infrastructure, improved dry land agriculture, mangrove protection and investments in making water resources more resilient were all vital. Adapting to land degradation and climate change was in everyone’s strong economic self-interest, Thiaw said. − Climate News Network

Unless nations act now to halt the spread of deserts, they may face wars over food shortages and starvation by mid-century, the UN says.

DELHI, 26 September, 2019 − A stark warning that the exposure of more and more people to water scarcity, hunger and outright starvation may lead to the “failure of fragile states and regional conflicts” has been given by the United Nations as it attempts to galvanise governments into halting the spread of deserts before more cropland is lost.

The climate summit in New York was presented with a plan to try to halt the annual loss of 12 million hectares (30mn acres) of productive land caused by the nations which are parties to the UN’s Convention to Combat Desertification (UNCCD), which recently ended a high-level meeting here.

The plan was the list of actions nations agreed at the meeting of more than 190 countries to attempt to reverse the spread of land degradation that the UN estimates will displace 135 million people by 2045. The battle to halt the spread of deserts is seen by the UN as an integral part of the international effort to halt climate change.

How successful the new plans will be remains to be seen, as although  the Convention, like the Climate Change Convention, has been in existence since the last century, the problems continue to get worse. However, all the countries involved now have national plans to halt land degradation and restore croplands and forests.

One of the key new promises made at the Delhi meeting, which ended on 13 September, was to grant land tenure to groups to give them an incentive to protect soils and the ability of the land to grow crops.

“Land restoration is the cheapest solution to climate change and biodiversity loss”

Delegates also agreed to improve the rights of women, promote land restoration and reduce land-related carbon emissions, both from poor soil management and the destruction of trees. New ways of financing these schemes from government and private sources were proposed.

The scale of the problem is enormous. Close to a quarter of global land is almost unusable, and by the middle of the century humans will need to produce twice as much grain as they do today to keep up with global population growth, the UNCCD says.

At the closing session Ibrahim Thiaw, executive secretary of the UNCCD, said: “Land restoration is the cheapest solution to climate change and biodiversity loss; land restoration makes business sense if we have regulations and incentives to reward investment.”

In addition, he said, preparing for the increasing number of droughts and coping with them are critical in the face of climate change. He emphasised the need to involve young people and women and to secure land rights.

However, despite the adoption of the New Delhi Declaration, in which ministers and delegates expressed support for new initiatives or coalitions aiming to improve human health and well-being and the health of ecosystems, and to advance peace and security, there were dissenting voices at the conference.

Dilution and omissions

The Centre for Science and Environment (CSE) said in a statement: “The New Delhi Declaration has diluted the role of international funding bodies in combating desertification. It has also sidestepped the contentious issue of tenure rights to land.”

The CSE said the statement had removed any mention of the Green Climate Fund, the Global Environment Facility and the Adaptation Fund  from the Declaration and there were no mentions of specific measures that could be used for adaptation nor, in fact, the word “adaptation” itself. Countries were left to develop their own plans.

Local politics also plays an important part in creating the problem. For example, across South Asia severe drought areas are used for water-guzzling crops such as sugarcane, or for very large monoculture plantations for palm oil or rubber.

Some speakers felt it was going to be an uphill struggle for poorer countries to get funding for restoring degraded land.

Early warning systems, climate-resilient infrastructure, improved dry land agriculture, mangrove protection and investments in making water resources more resilient were all vital. Adapting to land degradation and climate change was in everyone’s strong economic self-interest, Thiaw said. − Climate News Network

Moderate forest damage raises local temperature

Trees cool the world. They also cool themselves. Even moderate forest damage makes local temperatures soar.

LONDON, 13 September, 2019 − Destruction of the Amazon rainforest is bad news for the planet. It isn’t good news for the people, plants and animals of the region either. And even moderate forest damage raises local temperatures faster than it can affect the average global temperature.

British researchers used comprehensive and systematic sets of satellite data to test the local temperatures of both surviving tropical rainforest in the Amazon basin, and of the surfaces cleared of canopy by fire, axe, drought and grazing.

They report that even if two-thirds of the tree cover survived, the local ground temperature increased. The more canopy that was lost, the more pronounced the effect.

Local thermometer readings went up by almost half a degree in the first 13 years of this century, compared with the original undisturbed forest. And in the dry season, over the areas most affected by severe deforestation, the average temperatures soared by 1.5°C compared with intact forest.

This figure of 1.5°C has almost iconic status. It represents what 195 nations in Paris in 2015 agreed should be the limit of global average warming by the end of the century.

“The Amazon wildfires have reminded us all of the important role that forests play in our global systems. But intact Amazon forests are also crucially important for Brazil’s local climate”

Forests – and in particular the tropical rainforests – are part of the global strategy to constrain global heating driven by ever-increasing levels of greenhouse gases in the atmosphere, themselves the product of fossil fuel use and the destruction of grasslands and forests.

In a process called evapotranspiration, great tracts of canopy draw cascades of water from the soil and release it into the atmosphere, to lower local temperatures and at the same time absorb atmospheric carbon dioxide.

But rainforests such as the Amazon are also at risk, directly from human assault and less directly from global heating as higher temperatures increase the hazard of longer droughts, which in turn intensifies the loss of canopy.

And political change in Brazil now means that the planet’s “green lungs” are more at risk than ever, as fires blaze over the region.

Jessica Baker from the University of Leeds and her co-author report in the journal Frontiers in Forests and Global Change that almost one million square kilometres – an area the size of Egypt – of the Amazon has already been cleared: this is nearly a fifth of the original forest.

Damage increases heat

The researchers combed through local studies, satellite observations made by day and night, and other research to grade the forest as intact or no longer intact, and then as moderately or severely affected, and then started comparing averaged data from the three years 2001-2003 with that of 2011-2013.

They found that even if 70% of the canopy survived, the damaged forest was significantly warmer than the nearest intact forest. Towards the end of the dry season of August and September, heavily disturbed forest regions warmed by as much as 1.5°C compared to intact canopy.

“The Amazon wildfires have reminded us all of the important role that forests play in our global systems,” Dr Baker said. “But it cannot be overlooked that intact Amazon forests are also crucially important for Brazil’s local climate.”

And her co-author Dominick Spracklen said: “Evapotranspiration can be thought of as the forest ‘sweating’; when the moisture emitted by the forests evaporates it cools the local climate. Deforestation reduces evapotranspiration, taking away this cooling function and causing local temperatures to rise.

“As temperatures rise this increases drought stress and makes forests more susceptible to burning.” − Climate News Network

Trees cool the world. They also cool themselves. Even moderate forest damage makes local temperatures soar.

LONDON, 13 September, 2019 − Destruction of the Amazon rainforest is bad news for the planet. It isn’t good news for the people, plants and animals of the region either. And even moderate forest damage raises local temperatures faster than it can affect the average global temperature.

British researchers used comprehensive and systematic sets of satellite data to test the local temperatures of both surviving tropical rainforest in the Amazon basin, and of the surfaces cleared of canopy by fire, axe, drought and grazing.

They report that even if two-thirds of the tree cover survived, the local ground temperature increased. The more canopy that was lost, the more pronounced the effect.

Local thermometer readings went up by almost half a degree in the first 13 years of this century, compared with the original undisturbed forest. And in the dry season, over the areas most affected by severe deforestation, the average temperatures soared by 1.5°C compared with intact forest.

This figure of 1.5°C has almost iconic status. It represents what 195 nations in Paris in 2015 agreed should be the limit of global average warming by the end of the century.

“The Amazon wildfires have reminded us all of the important role that forests play in our global systems. But intact Amazon forests are also crucially important for Brazil’s local climate”

Forests – and in particular the tropical rainforests – are part of the global strategy to constrain global heating driven by ever-increasing levels of greenhouse gases in the atmosphere, themselves the product of fossil fuel use and the destruction of grasslands and forests.

In a process called evapotranspiration, great tracts of canopy draw cascades of water from the soil and release it into the atmosphere, to lower local temperatures and at the same time absorb atmospheric carbon dioxide.

But rainforests such as the Amazon are also at risk, directly from human assault and less directly from global heating as higher temperatures increase the hazard of longer droughts, which in turn intensifies the loss of canopy.

And political change in Brazil now means that the planet’s “green lungs” are more at risk than ever, as fires blaze over the region.

Jessica Baker from the University of Leeds and her co-author report in the journal Frontiers in Forests and Global Change that almost one million square kilometres – an area the size of Egypt – of the Amazon has already been cleared: this is nearly a fifth of the original forest.

Damage increases heat

The researchers combed through local studies, satellite observations made by day and night, and other research to grade the forest as intact or no longer intact, and then as moderately or severely affected, and then started comparing averaged data from the three years 2001-2003 with that of 2011-2013.

They found that even if 70% of the canopy survived, the damaged forest was significantly warmer than the nearest intact forest. Towards the end of the dry season of August and September, heavily disturbed forest regions warmed by as much as 1.5°C compared to intact canopy.

“The Amazon wildfires have reminded us all of the important role that forests play in our global systems,” Dr Baker said. “But it cannot be overlooked that intact Amazon forests are also crucially important for Brazil’s local climate.”

And her co-author Dominick Spracklen said: “Evapotranspiration can be thought of as the forest ‘sweating’; when the moisture emitted by the forests evaporates it cools the local climate. Deforestation reduces evapotranspiration, taking away this cooling function and causing local temperatures to rise.

“As temperatures rise this increases drought stress and makes forests more susceptible to burning.” − Climate News Network

Sand and dust storms pose global threat

The United Nations plans to tame lethal sand and dust storms with a mixture of modern technology and traditional knowledge.

DELHI, 12 September, 2019 − The standard bearer of the United Nations’ effort to combat desert spread and the threat from sand and dust storms, meeting here, is determined to be remembered as not just a global talking shop, but a launchpad for action.

The UN Convention to Combat Desertification (UNCCD) has launched a coalition to energise the UN’s response to the problem.  One focus for the new body will be to develop the sand and dust storms (SDS) source base map to improve the monitoring of the storms.

Iran told the meeting that both traditional and modern knowledge on SDS hot spots could help to create a stronger knowledge base for regional initiatives. The coalition’s members include  the International Civil Aviation Organization and the World Meteorological Organization (WMO).

The WMO already has an established SDS warning advisory system (SDS-WAS) to research the problem and try to provide forecasts of dangerous storms. Countries are now being asked to explore ways of reducing man-made contributions to dust storms, for example by not denuding land of vegetation.

Climate change and extreme weather have made SDS a threat to more than 150 countries, causing economic damage and threatening health. The storms, once thought of as a local problem in desert or arid regions, are now recognised as a global hazard.

“There is a need for more accurate real-time observations of dust properties and for understanding dust triggering mechanisms, seasonal variabilities, and transport dynamics”

Huge quantities of sand and dust can be lifted into the air by high winds and distributed over hundreds of miles. The problem is worsening as droughts increase and land is degraded by deforestation and poor agricultural practices.

Dust is also intensifying climate change, for example by discolouring ice so that it melts faster, and human health is affected by increased asthma and the spread of diseases such as valley fever and meningitis.

Aviation suffers when storms close airports or cause damage when dust is sucked into engines. Roads are lost under sand and electricity supplies disrupted. Even fisheries are damaged by sand settling in the oceans and affecting plankton growth.

The storms can be severe. In 2018 more than 125 people died and 200 were injured by a high-velocity dust storm in northern India. Even in Europe large areas can be covered in orange sand and dust from the Sahara.

Hesham El-Askary, professor of earth systems science and remote sensing at Chapman University in California, said: “There is a need for more accurate real-time observations of dust properties and for understanding dust triggering mechanisms, seasonal variabilities, and transport dynamics to assist mitigation of windblown dust consequences in many applications. These include human health, weather, solar and wind energy systems, aviation, highway safety and urban development.”

Higher cyclone intensity

The Asia Pacific Disaster Report 2019, released in August, suggests that the impacts of climate change differ by sub-region: “Temperature increase is likely to cause a rise in the number and duration of heat waves and droughts . . . Climate change is also expected to increase cyclone intensity, with serious threats along the coastal areas of countries in south-east Asia.”

A complex sequence of climate and weather disasters such as drought, SDS, desertification and floods is on the rise in arid and semi-arid sub-regions of south-west and central Asia, the report said. And, as indicated clearly in the recent IPCC report on global warming of 1.5°C, the decrease in soil moisture will increase the frequency and intensity of sand and dust storms in south, south-west and central Asia.

A recent example was the powerful dust storm that swept over parts of Iran, Afghanistan and Pakistan in May 2018. There was also a toxic salt storm from the Aral Sea that hit northern Turkmenistan and western Uzbekistan.

The storms then moved through Iran, Afghanistan, Pakistan and north-west India and collided with the pre-monsoon weather, including thunderstorms and rain, affecting a wide area and causing the loss of hundreds of lives. − Climate News Network

* * * * *

Nivedita Khandekar is an independent journalist based in Delhi. She writes on environmental and developmental issues. Email: nivedita_him@rediffmail.com; Twitter: @nivedita_Him

The United Nations plans to tame lethal sand and dust storms with a mixture of modern technology and traditional knowledge.

DELHI, 12 September, 2019 − The standard bearer of the United Nations’ effort to combat desert spread and the threat from sand and dust storms, meeting here, is determined to be remembered as not just a global talking shop, but a launchpad for action.

The UN Convention to Combat Desertification (UNCCD) has launched a coalition to energise the UN’s response to the problem.  One focus for the new body will be to develop the sand and dust storms (SDS) source base map to improve the monitoring of the storms.

Iran told the meeting that both traditional and modern knowledge on SDS hot spots could help to create a stronger knowledge base for regional initiatives. The coalition’s members include  the International Civil Aviation Organization and the World Meteorological Organization (WMO).

The WMO already has an established SDS warning advisory system (SDS-WAS) to research the problem and try to provide forecasts of dangerous storms. Countries are now being asked to explore ways of reducing man-made contributions to dust storms, for example by not denuding land of vegetation.

Climate change and extreme weather have made SDS a threat to more than 150 countries, causing economic damage and threatening health. The storms, once thought of as a local problem in desert or arid regions, are now recognised as a global hazard.

“There is a need for more accurate real-time observations of dust properties and for understanding dust triggering mechanisms, seasonal variabilities, and transport dynamics”

Huge quantities of sand and dust can be lifted into the air by high winds and distributed over hundreds of miles. The problem is worsening as droughts increase and land is degraded by deforestation and poor agricultural practices.

Dust is also intensifying climate change, for example by discolouring ice so that it melts faster, and human health is affected by increased asthma and the spread of diseases such as valley fever and meningitis.

Aviation suffers when storms close airports or cause damage when dust is sucked into engines. Roads are lost under sand and electricity supplies disrupted. Even fisheries are damaged by sand settling in the oceans and affecting plankton growth.

The storms can be severe. In 2018 more than 125 people died and 200 were injured by a high-velocity dust storm in northern India. Even in Europe large areas can be covered in orange sand and dust from the Sahara.

Hesham El-Askary, professor of earth systems science and remote sensing at Chapman University in California, said: “There is a need for more accurate real-time observations of dust properties and for understanding dust triggering mechanisms, seasonal variabilities, and transport dynamics to assist mitigation of windblown dust consequences in many applications. These include human health, weather, solar and wind energy systems, aviation, highway safety and urban development.”

Higher cyclone intensity

The Asia Pacific Disaster Report 2019, released in August, suggests that the impacts of climate change differ by sub-region: “Temperature increase is likely to cause a rise in the number and duration of heat waves and droughts . . . Climate change is also expected to increase cyclone intensity, with serious threats along the coastal areas of countries in south-east Asia.”

A complex sequence of climate and weather disasters such as drought, SDS, desertification and floods is on the rise in arid and semi-arid sub-regions of south-west and central Asia, the report said. And, as indicated clearly in the recent IPCC report on global warming of 1.5°C, the decrease in soil moisture will increase the frequency and intensity of sand and dust storms in south, south-west and central Asia.

A recent example was the powerful dust storm that swept over parts of Iran, Afghanistan and Pakistan in May 2018. There was also a toxic salt storm from the Aral Sea that hit northern Turkmenistan and western Uzbekistan.

The storms then moved through Iran, Afghanistan, Pakistan and north-west India and collided with the pre-monsoon weather, including thunderstorms and rain, affecting a wide area and causing the loss of hundreds of lives. − Climate News Network

* * * * *

Nivedita Khandekar is an independent journalist based in Delhi. She writes on environmental and developmental issues. Email: nivedita_him@rediffmail.com; Twitter: @nivedita_Him

Tree loss brings more warming as world heats

Blazing forests cannot dampen climate change, tree loss will worsen it, and poorly nourished trees will make the next century more challenging.

LONDON, 27 August, 2019 − As global temperatures soar, tree loss will mean the world’s forests may no longer be able to function fully as safe stores for atmospheric carbon dioxide.

Forests play a key role in the effort to contain climate change driven by human combustion of fossil fuels. But as the Arctic burns and fires race through the Amazon forest four new studies cast doubt on whether the planetary canopy can keep up.

The boreal forests of the north-west territories of Canada are home to vast tracts of spruce and other conifers: they cover soils so rich in carbon that a square metre could hold 75 kilograms of life’s most vital element.

But in 2014 wildfires made more probable by rising temperatures spread across more than 2.8 million hectares of Canada, turning at least 340,000 ha of the territories from a carbon sink into a source for more planet-heating greenhouse gas.

Limit to benefits

More carbon dioxide should fertilise more abundant growth in those forests not destroyed by fire and drought. But a new study from California and Spain warns that by 2100, the woodland world may reach breaking point. It isn’t clear that forests can go on benefiting from higher levels of carbon dioxide.

And new measurements from the Amazon, which in theory absorbs around a quarter of all human fossil fuel emissions each year, demonstrate why: the region’s soils are deficient in phosphorus. Without this vital element, the trees cannot take full advantage of the extra carbon fertilizer.

A fourth study presents an overall picture of change driven in some way by climate change. Fires, windstorms, insect outbreaks and other large disturbances account for more than a tenth of all tree death worldwide.

That the world’s forests are part of the campaign to mitigate climate change is not in doubt: one study even presents a picture of all waste land covered by new canopy as possibly the solution. There are an estimated three trillion trees on the planet, being destroyed at the rate of 15 billion a year. Losses are happening worldwide but nowhere with more devastating consequences than in the rainy tropics.

“We have already witnessed indiscriminate logging in pristine tropical forests, the largest reservoirs of biomass on the planet. We stand to lose a tremendously important tool to limit global warming”

But fire and drought are now more frequent even in the temperate and northern zones. Researchers from the US and Canada visited 200 different stands of scorched and incinerated spruce forest to sample the levels of carbon in the soils. They report in the journal Nature that as fires become more frequent, ever more of the rich legacy of carbon stored over hundreds of thousands of years of green canopy is being returned to the atmosphere.

“In older stands that burn, this carbon is protected by thick organic soils,” said Xanthe Walker, graduate of the University of Saskatchewan and now at Northern Arizona University. “But in younger stands that burn, the soil does not have time to re-accumulate. after the previous fire, making legacy carbon vulnerable to burning. This pattern could shift boreal forests to a new domain of carbon cycling, where they become a carbon source instead of a sink.”

Researchers wonder in the journal Nature Climate Change about the capacity of forests to go on indefinitely absorbing ever more carbon dioxide, given that to do so they will also need ever more nitrogen and phosphorus.

Losses already happening

Scientists from Stanford University in California and the Autonomous University of Barcelona took data from 138 experiments with heightened atmospheric carbon dioxide over cropland, grasslands, shrubs and forests and used computer models to peer into the future.

By the end of the century, this extra greenhouse gas could boost the biomass of foliage by 12% the equivalent of about six years of fossil fuel emissions. But the forests of the Amazon, the Congo and Indonesia will be crucial.

“We have already witnessed indiscriminate logging in pristine tropical forests, which are the largest reservoirs of biomass on the planet,” said César Terrer of Stanford University. “We stand to lose a tremendously important tool to limit global warming.”

Now a study from an international team suggests that some forest capacity is already being lost. They report in Nature Geoscience that they used computer models to check the increasing uptake of carbon in the Amazon, given the finite levels of soil phosphorus, a condition current estimates have not properly taken into account. The news is not encouraging.

Multiple stresses

“In reality the ecosystem is millions of years old, highly weathered and therefore depleted on phosphorus in many parts of the Amazon,” said Jennifer Holm of Lawrence Berkeley National Laboratory, one of the authors.

And even if there was a healthy supply of nutrients, the stresses linked to rising temperatures – greater extremes of flood, heat, drought and wind – will take their toll. Scientists from Europe and the US studied the satellite data to build up a picture of profit and loss in the wooded world and found that, along with harvesting, such upsets account for 12% of forest loss. And with the loss, the surrender of carbon continues, they suggest in the journal Nature Geoscience.

“This year’s large fires across the Arctic may be just an anomaly, they may be a sign that disturbances in the region are becoming more frequent relative to the historical norm,” said Thomas Pugh of the University of Birmingham in the UK, who led the research.

“If that’s the case, we can expect large amounts of carbon to be released from these forests over the coming century and perhaps wholesale changes in the mix of vegetation that make up the forests.” − Climate News Network

Blazing forests cannot dampen climate change, tree loss will worsen it, and poorly nourished trees will make the next century more challenging.

LONDON, 27 August, 2019 − As global temperatures soar, tree loss will mean the world’s forests may no longer be able to function fully as safe stores for atmospheric carbon dioxide.

Forests play a key role in the effort to contain climate change driven by human combustion of fossil fuels. But as the Arctic burns and fires race through the Amazon forest four new studies cast doubt on whether the planetary canopy can keep up.

The boreal forests of the north-west territories of Canada are home to vast tracts of spruce and other conifers: they cover soils so rich in carbon that a square metre could hold 75 kilograms of life’s most vital element.

But in 2014 wildfires made more probable by rising temperatures spread across more than 2.8 million hectares of Canada, turning at least 340,000 ha of the territories from a carbon sink into a source for more planet-heating greenhouse gas.

Limit to benefits

More carbon dioxide should fertilise more abundant growth in those forests not destroyed by fire and drought. But a new study from California and Spain warns that by 2100, the woodland world may reach breaking point. It isn’t clear that forests can go on benefiting from higher levels of carbon dioxide.

And new measurements from the Amazon, which in theory absorbs around a quarter of all human fossil fuel emissions each year, demonstrate why: the region’s soils are deficient in phosphorus. Without this vital element, the trees cannot take full advantage of the extra carbon fertilizer.

A fourth study presents an overall picture of change driven in some way by climate change. Fires, windstorms, insect outbreaks and other large disturbances account for more than a tenth of all tree death worldwide.

That the world’s forests are part of the campaign to mitigate climate change is not in doubt: one study even presents a picture of all waste land covered by new canopy as possibly the solution. There are an estimated three trillion trees on the planet, being destroyed at the rate of 15 billion a year. Losses are happening worldwide but nowhere with more devastating consequences than in the rainy tropics.

“We have already witnessed indiscriminate logging in pristine tropical forests, the largest reservoirs of biomass on the planet. We stand to lose a tremendously important tool to limit global warming”

But fire and drought are now more frequent even in the temperate and northern zones. Researchers from the US and Canada visited 200 different stands of scorched and incinerated spruce forest to sample the levels of carbon in the soils. They report in the journal Nature that as fires become more frequent, ever more of the rich legacy of carbon stored over hundreds of thousands of years of green canopy is being returned to the atmosphere.

“In older stands that burn, this carbon is protected by thick organic soils,” said Xanthe Walker, graduate of the University of Saskatchewan and now at Northern Arizona University. “But in younger stands that burn, the soil does not have time to re-accumulate. after the previous fire, making legacy carbon vulnerable to burning. This pattern could shift boreal forests to a new domain of carbon cycling, where they become a carbon source instead of a sink.”

Researchers wonder in the journal Nature Climate Change about the capacity of forests to go on indefinitely absorbing ever more carbon dioxide, given that to do so they will also need ever more nitrogen and phosphorus.

Losses already happening

Scientists from Stanford University in California and the Autonomous University of Barcelona took data from 138 experiments with heightened atmospheric carbon dioxide over cropland, grasslands, shrubs and forests and used computer models to peer into the future.

By the end of the century, this extra greenhouse gas could boost the biomass of foliage by 12% the equivalent of about six years of fossil fuel emissions. But the forests of the Amazon, the Congo and Indonesia will be crucial.

“We have already witnessed indiscriminate logging in pristine tropical forests, which are the largest reservoirs of biomass on the planet,” said César Terrer of Stanford University. “We stand to lose a tremendously important tool to limit global warming.”

Now a study from an international team suggests that some forest capacity is already being lost. They report in Nature Geoscience that they used computer models to check the increasing uptake of carbon in the Amazon, given the finite levels of soil phosphorus, a condition current estimates have not properly taken into account. The news is not encouraging.

Multiple stresses

“In reality the ecosystem is millions of years old, highly weathered and therefore depleted on phosphorus in many parts of the Amazon,” said Jennifer Holm of Lawrence Berkeley National Laboratory, one of the authors.

And even if there was a healthy supply of nutrients, the stresses linked to rising temperatures – greater extremes of flood, heat, drought and wind – will take their toll. Scientists from Europe and the US studied the satellite data to build up a picture of profit and loss in the wooded world and found that, along with harvesting, such upsets account for 12% of forest loss. And with the loss, the surrender of carbon continues, they suggest in the journal Nature Geoscience.

“This year’s large fires across the Arctic may be just an anomaly, they may be a sign that disturbances in the region are becoming more frequent relative to the historical norm,” said Thomas Pugh of the University of Birmingham in the UK, who led the research.

“If that’s the case, we can expect large amounts of carbon to be released from these forests over the coming century and perhaps wholesale changes in the mix of vegetation that make up the forests.” − Climate News Network

European Union helped to cool 2003 heatwave

Small local changes make a big difference as the temperature soars. And the European Union’s existence once cooled a vicious heatwave.

LONDON, 9 August, 2019 − Of all the political plaudits or economic brickbats hurled at the European Union, this might be the least expected: simply because it existed, it somehow ameliorated or damped down the worst of the 2003 heatwave.

This moment of extreme summer heat is believed to have caused an estimated 40,000 excess deaths and cost the European economy more than €13 billion in economic losses and infrastructure damage.

And yet it could have been worse. Had what is now a 28-nation political and economic behemoth not been formed in 1993, the way the member nations used their land would not have changed, and the heatwave might have been more intense, more severe and more destructive still.

The formation of the EU with its single market and customs union wasn’t the only political shift. The end of the Cold War and the collapse of the Soviet Union in 1991 also played a role in determining how farmers, graziers, foresters, conservationists and ministerial managers used the terrain of the European continent.

And – without thinking much about future climate shifts – farmers and foresters collectively began a series of changes that meant that what had once been farmland was abandoned, in Portugal and Spain, in eastern Europe and in Italy, as intensive production shifted to other economic zones.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe”

As more than 8% of what had been ploughed land reverted to grassland and scrub, the shallow groundwater in the abandoned soil began to act in unexpected ways. There was more evapotranspiration, which meant more cloud, which meant more reflectivity, which meant that lower levels of radiation actually scorched the landscape.

And, in turn, temperatures, as torrid as they were in the unprecedented heat that August, were damped down.

Samuel Zipper, then of the University of Victoria in Canada, now at the University of Kansas, and colleagues from Belgium and Germany report in the journal Environmental Research Letters that they used what they call “bedrock to atmosphere” computer models to simulate the way water and energy cycles shifted over western Europe between 1990 and 2010. They then made an estimate of what might have happened had there been no changes in the way the land was used.

“What we think is happening is that the agricultural abandonment led to an increase in the amount of water that plants transpired into the atmosphere, which caused increased cloud formation,” Dr Zipper said.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe.”

France spared

They found in addition that the changes in land use overall had some effect on local climate even in those places where land had not been abandoned.

They found that even France – the nation most harshly hit by the extremes of heat that summer – experienced less heat than it would have without shifts in land use further south and east.

And they confirmed that soil moisture, especially in the first metre or so of ground, played a powerful role in moderating atmospheric temperatures that in that region in that year, and in other places exposed to heat extremes since, put the very young, the elderly, the already ill and the poorly housed at ever greater risk of death in dangerous temperatures.

The scientists completed their research long before the unprecedented temperatures recorded in Western Europe this 2019 summer. Such what-if studies based on alternative histories arrive with inherent uncertainties. There is no way to conduct any convincing real life experiment that replicates the same heat wave under different landscape changes.

But the research confirms what climate scientists have been arguing for decades, and that is that the way land is used inevitably contributes to local shifts in temperature, and therefore to overall annual average warming, and inevitably to long-term, lethal and potentially catastrophic extremes. − Climate News Network

Small local changes make a big difference as the temperature soars. And the European Union’s existence once cooled a vicious heatwave.

LONDON, 9 August, 2019 − Of all the political plaudits or economic brickbats hurled at the European Union, this might be the least expected: simply because it existed, it somehow ameliorated or damped down the worst of the 2003 heatwave.

This moment of extreme summer heat is believed to have caused an estimated 40,000 excess deaths and cost the European economy more than €13 billion in economic losses and infrastructure damage.

And yet it could have been worse. Had what is now a 28-nation political and economic behemoth not been formed in 1993, the way the member nations used their land would not have changed, and the heatwave might have been more intense, more severe and more destructive still.

The formation of the EU with its single market and customs union wasn’t the only political shift. The end of the Cold War and the collapse of the Soviet Union in 1991 also played a role in determining how farmers, graziers, foresters, conservationists and ministerial managers used the terrain of the European continent.

And – without thinking much about future climate shifts – farmers and foresters collectively began a series of changes that meant that what had once been farmland was abandoned, in Portugal and Spain, in eastern Europe and in Italy, as intensive production shifted to other economic zones.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe”

As more than 8% of what had been ploughed land reverted to grassland and scrub, the shallow groundwater in the abandoned soil began to act in unexpected ways. There was more evapotranspiration, which meant more cloud, which meant more reflectivity, which meant that lower levels of radiation actually scorched the landscape.

And, in turn, temperatures, as torrid as they were in the unprecedented heat that August, were damped down.

Samuel Zipper, then of the University of Victoria in Canada, now at the University of Kansas, and colleagues from Belgium and Germany report in the journal Environmental Research Letters that they used what they call “bedrock to atmosphere” computer models to simulate the way water and energy cycles shifted over western Europe between 1990 and 2010. They then made an estimate of what might have happened had there been no changes in the way the land was used.

“What we think is happening is that the agricultural abandonment led to an increase in the amount of water that plants transpired into the atmosphere, which caused increased cloud formation,” Dr Zipper said.

“Our results suggest that if this land use change had not occurred, the 2003 heatwave may have been more severe.”

France spared

They found in addition that the changes in land use overall had some effect on local climate even in those places where land had not been abandoned.

They found that even France – the nation most harshly hit by the extremes of heat that summer – experienced less heat than it would have without shifts in land use further south and east.

And they confirmed that soil moisture, especially in the first metre or so of ground, played a powerful role in moderating atmospheric temperatures that in that region in that year, and in other places exposed to heat extremes since, put the very young, the elderly, the already ill and the poorly housed at ever greater risk of death in dangerous temperatures.

The scientists completed their research long before the unprecedented temperatures recorded in Western Europe this 2019 summer. Such what-if studies based on alternative histories arrive with inherent uncertainties. There is no way to conduct any convincing real life experiment that replicates the same heat wave under different landscape changes.

But the research confirms what climate scientists have been arguing for decades, and that is that the way land is used inevitably contributes to local shifts in temperature, and therefore to overall annual average warming, and inevitably to long-term, lethal and potentially catastrophic extremes. − Climate News Network

Ancient water-saving can help modern Peru

Ancient water-saving methods may help Lima, Peru’s capital, through its water crisis, caused by climate change and population growth.

LONDON, 2 July, 2019 − There’s plenty to learn in modern Peru from the designers of ancient water-saving methods, scientists are finding. Our forebears could even keep the capital’s taps running through the summer heat.

Lima, Peru’s desert capital, a city of 12 million people, expects to run out of water by 2025. It already faces a crisis each summer as the supply from the mountains dwindles to a trickle. Yet the quantity of rain in the wet season can be overwhelming.

Between the Andes and the Pacific ocean, Lima sits on a coastal plain where the average rainfall is a tiny 9 mm a year, and it has to rely on the snow melt from the mountains and glaciers to provide summer drinking water and the needs of industry and farming.

But with the glaciers disappearing because of climate change, and the population increasing, the city will soon become untenable for many of the poor in summer, unless water supplies can be improved.

A group of scientists has found that reviving systems developed 1,400 years ago by local people before the Inca empire existed could harvest water from the winter rainy season in the mountains to ensure Lima’s summer supplies.

“You’d be forgiven for wondering how ancient methods could apply to modern-day problems. However we have lots to learn from our ancestors’ creative problem-solving skills”

Researchers from Imperial College London and their colleagues at the Regional Initiative for Hydrological Monitoring of Andean Ecosystems studied a water system in Huamantanga, in the central Andes, one of the last of its kind.

The local people still use a method developed in 600 AD by Peruvian civilisations that created systems in the mountains to divert excess rainwater from source streams through ponds and canals onto mountain slopes and down through fissures in the rocks.

The water would take weeks or even months to trickle through the system and resurface downstream – just in time for the dry season.

The researchers used dye tracers and hydrological monitoring to study the system from the wet to dry seasons of 2014–2015 and 2015–2016. Social scientists involved also worked with Huamantanga’s local people to understand the practice and help map the landscape.

Big increase

They found the water took between two weeks and eight months to re-emerge, with an average time of 45 days. From these timescales, they calculated that, if governments upscale the systems to cater for today’s population size, they could reroute and delay 35% of wet season water, equivalent to 99 million cubic metres per year of water flowing through Lima’s natural terrain.

This could increase the water available in the dry season by up to 33% in the early months, and an average of 7.5% for the rest of the summer.

The method could essentially extend the wet season, providing more drinking water and longer crop-growing periods for local farmers.

The study, published in the journal Nature Sustainability, is the first to examine the pre-Inca system in this much detail to find answers to modern problems. The authors say their research shows how indigenous systems could complement modern engineering solutions for water security in coastal Peru.

Lead author Dr Boris Ochoa-Tocachi, from Imperial’s Department of Civil and Environmental Engineering, said: “With the advent of modern science, you’d be forgiven for wondering how ancient methods could apply to modern-day problems. However, it turns out that we have lots to learn from our ancestors’ creative problem-solving skills.”

Growing too fast

Senior author Dr Wouter Buytaert, from the same department, said: “Like many tropical cities, Lima’s population is growing fast – too fast for water reserves to keep up during dry seasons. Upscaling existing pre-Inca systems could help relieve Peru’s wet months of water and quench its dry ones.”

The seasonal variability typical of coastal Peru is worsened by human impacts. Apart from glacier melting caused by global warming, humans also contribute to erosion, which renders soil too weak to support dams big enough to hold all the water needed in the summer.

Climate change also makes wet seasons wetter, and dry seasons drier − making the need for effective water storage in Peru even more urgent.

The authors say combining pre-Inca systems with classic structures, such as smaller dams, could also help to improve adaptability and water supply in an unpredictable climate. − Climate News Network

Ancient water-saving methods may help Lima, Peru’s capital, through its water crisis, caused by climate change and population growth.

LONDON, 2 July, 2019 − There’s plenty to learn in modern Peru from the designers of ancient water-saving methods, scientists are finding. Our forebears could even keep the capital’s taps running through the summer heat.

Lima, Peru’s desert capital, a city of 12 million people, expects to run out of water by 2025. It already faces a crisis each summer as the supply from the mountains dwindles to a trickle. Yet the quantity of rain in the wet season can be overwhelming.

Between the Andes and the Pacific ocean, Lima sits on a coastal plain where the average rainfall is a tiny 9 mm a year, and it has to rely on the snow melt from the mountains and glaciers to provide summer drinking water and the needs of industry and farming.

But with the glaciers disappearing because of climate change, and the population increasing, the city will soon become untenable for many of the poor in summer, unless water supplies can be improved.

A group of scientists has found that reviving systems developed 1,400 years ago by local people before the Inca empire existed could harvest water from the winter rainy season in the mountains to ensure Lima’s summer supplies.

“You’d be forgiven for wondering how ancient methods could apply to modern-day problems. However we have lots to learn from our ancestors’ creative problem-solving skills”

Researchers from Imperial College London and their colleagues at the Regional Initiative for Hydrological Monitoring of Andean Ecosystems studied a water system in Huamantanga, in the central Andes, one of the last of its kind.

The local people still use a method developed in 600 AD by Peruvian civilisations that created systems in the mountains to divert excess rainwater from source streams through ponds and canals onto mountain slopes and down through fissures in the rocks.

The water would take weeks or even months to trickle through the system and resurface downstream – just in time for the dry season.

The researchers used dye tracers and hydrological monitoring to study the system from the wet to dry seasons of 2014–2015 and 2015–2016. Social scientists involved also worked with Huamantanga’s local people to understand the practice and help map the landscape.

Big increase

They found the water took between two weeks and eight months to re-emerge, with an average time of 45 days. From these timescales, they calculated that, if governments upscale the systems to cater for today’s population size, they could reroute and delay 35% of wet season water, equivalent to 99 million cubic metres per year of water flowing through Lima’s natural terrain.

This could increase the water available in the dry season by up to 33% in the early months, and an average of 7.5% for the rest of the summer.

The method could essentially extend the wet season, providing more drinking water and longer crop-growing periods for local farmers.

The study, published in the journal Nature Sustainability, is the first to examine the pre-Inca system in this much detail to find answers to modern problems. The authors say their research shows how indigenous systems could complement modern engineering solutions for water security in coastal Peru.

Lead author Dr Boris Ochoa-Tocachi, from Imperial’s Department of Civil and Environmental Engineering, said: “With the advent of modern science, you’d be forgiven for wondering how ancient methods could apply to modern-day problems. However, it turns out that we have lots to learn from our ancestors’ creative problem-solving skills.”

Growing too fast

Senior author Dr Wouter Buytaert, from the same department, said: “Like many tropical cities, Lima’s population is growing fast – too fast for water reserves to keep up during dry seasons. Upscaling existing pre-Inca systems could help relieve Peru’s wet months of water and quench its dry ones.”

The seasonal variability typical of coastal Peru is worsened by human impacts. Apart from glacier melting caused by global warming, humans also contribute to erosion, which renders soil too weak to support dams big enough to hold all the water needed in the summer.

Climate change also makes wet seasons wetter, and dry seasons drier − making the need for effective water storage in Peru even more urgent.

The authors say combining pre-Inca systems with classic structures, such as smaller dams, could also help to improve adaptability and water supply in an unpredictable climate. − Climate News Network

Climate change blamed as Chennai runs dry

The monsoon’s failure and government mismanagement in the Indian state of Tamil Nadu are being blamed as Chennai runs dry.

CHENNAI, 1 July, 2019 − Some of the poorest people of India’s sixth largest city are having to spend half their weekly income on water as Chennai runs dry: its four reservoirs lie empty and the government’s relief tankers cannot keep up with demand from citizens.

Despite government claims that there is no water crisis, the taps are empty and many of Chennai’s nine million people are queuing from early morning, awaiting what water the tankers can deliver.

Monsoon rains have failed for the last two years, leaving the city enduring a heat wave with no water. The government is delivering 10 million litres daily by train from 200 kilometres away in a bid to provide enough water for the poor to survive. In the richer areas private water tankers are maintaining supplies, charging double the normal rate to fill a roof tank.

Businesses, particularly restaurants, have been forced to close, and children are not attending school because they are spending all day queuing for water for their families.

Although it is clear that climate change is affecting the monsoon’s pattern and it may be October before Chennai gets enough water to restore supplies to normal, government mismanagement is also being blamed.

Contrasting views

The city’s plight has been highlighted by Leonardo DiCaprio, the American actor and environmentalist, who is a UN climate change ambassador.

His message is in stark contrast to that from Tamil Nadu chief minister Edappadi K Palaniswami. He told the media he uses only two pots of water every day, and that his government is taking good care of its citizens. This was after local media reported that his house in Chennai was receiving two truckloads of water a day.

A senior official in the Chennai metro water board said that efforts had been made since early June to ensure residents’ minimum water needs were met: “The government has initiated plans to bring water from nearby districts. Since the monsoon rains failed consecutively for the third year, we couldn’t store any water.”

He said sources in use now included water from stone quarries, two desalination plants in the city, a local lake and some borewells in the suburbs.

The government is trying to suppress demonstrations. When a voluntary organisation, Arappor Iyakkam, sought permission from the Chennai police commissioner for a protest about the water crisis, he refused, citing what he said was the need to protect law and order and the effect on peace and tranquillity at a time when the government was already striving to provide water. So the protestors approached the Madras high court for permission to go ahead.

“The government does not stop supplying water for multi-national companies when its own people are struggling to quench their thirst’’

According to Arappor Iyakkam’s co-ordinator, Jayaraman, the court said public awareness about the crisis was important, and granted permission. Iyakkam said: “Chennai and many parts of Tamil Nadu are facing an acute water crisis, and this has arisen due to continuous neglect of water bodies, and maladministration and corruption by the ruling governments.

“The present government has been in a denial mode, acknowledging the level of water shortage and its failure to work on solutions. Our campaign would emphasise the need for action on a war footing.”

Social activist Arul Doss argues that the government is losing its focus on seeking long-term solutions and is instead spending money on desalination plants. “The rich can afford to buy water for double the price. But the poor workers are now forced to spend half of their salary for water. What kind of development are we heading to?

“The government does not stop supplying water for multi-national companies when its own people are struggling to quench their thirst,’’ he said.

“Instead of spending money on recycling water and de-silting all the water bodies before the monsoon season, the government is working hard on opening new desalination plants in Chennai. It is hard to believe this is the same city that suffered flash floods in 2015.

Getting worse

“At least by now the government should have cleaned up water bodies and ensured grey water usage in high-rise apartments in the city,’’ Arul Doss told Climate News Network.

The plight of ordinary people is growing more extreme. A Chennai resident, K Meena, a student, has to fetch water. “We have to depend on the tanker supply, because the taps in our streets have dried up. Ours is a family of five. My parents and siblings take turns to collect water for bathing and cooking. I skipped classes and went late to college because I had to wait for the lorry,” said Meena.

Cab driver A Logeswaran uses the toilet facilities at petrol stations and sleeps in his car every other night to avoid using precious water supplies at home, which are kept for his wife and three-year-old child.

“Some of my neighbours sent their children and wives back to their native villages due to the water crisis. This is a very sad state for our city. Water is a basic need and I feel the government has failed completely,’’ he said in despair. − Climate News Network

The monsoon’s failure and government mismanagement in the Indian state of Tamil Nadu are being blamed as Chennai runs dry.

CHENNAI, 1 July, 2019 − Some of the poorest people of India’s sixth largest city are having to spend half their weekly income on water as Chennai runs dry: its four reservoirs lie empty and the government’s relief tankers cannot keep up with demand from citizens.

Despite government claims that there is no water crisis, the taps are empty and many of Chennai’s nine million people are queuing from early morning, awaiting what water the tankers can deliver.

Monsoon rains have failed for the last two years, leaving the city enduring a heat wave with no water. The government is delivering 10 million litres daily by train from 200 kilometres away in a bid to provide enough water for the poor to survive. In the richer areas private water tankers are maintaining supplies, charging double the normal rate to fill a roof tank.

Businesses, particularly restaurants, have been forced to close, and children are not attending school because they are spending all day queuing for water for their families.

Although it is clear that climate change is affecting the monsoon’s pattern and it may be October before Chennai gets enough water to restore supplies to normal, government mismanagement is also being blamed.

Contrasting views

The city’s plight has been highlighted by Leonardo DiCaprio, the American actor and environmentalist, who is a UN climate change ambassador.

His message is in stark contrast to that from Tamil Nadu chief minister Edappadi K Palaniswami. He told the media he uses only two pots of water every day, and that his government is taking good care of its citizens. This was after local media reported that his house in Chennai was receiving two truckloads of water a day.

A senior official in the Chennai metro water board said that efforts had been made since early June to ensure residents’ minimum water needs were met: “The government has initiated plans to bring water from nearby districts. Since the monsoon rains failed consecutively for the third year, we couldn’t store any water.”

He said sources in use now included water from stone quarries, two desalination plants in the city, a local lake and some borewells in the suburbs.

The government is trying to suppress demonstrations. When a voluntary organisation, Arappor Iyakkam, sought permission from the Chennai police commissioner for a protest about the water crisis, he refused, citing what he said was the need to protect law and order and the effect on peace and tranquillity at a time when the government was already striving to provide water. So the protestors approached the Madras high court for permission to go ahead.

“The government does not stop supplying water for multi-national companies when its own people are struggling to quench their thirst’’

According to Arappor Iyakkam’s co-ordinator, Jayaraman, the court said public awareness about the crisis was important, and granted permission. Iyakkam said: “Chennai and many parts of Tamil Nadu are facing an acute water crisis, and this has arisen due to continuous neglect of water bodies, and maladministration and corruption by the ruling governments.

“The present government has been in a denial mode, acknowledging the level of water shortage and its failure to work on solutions. Our campaign would emphasise the need for action on a war footing.”

Social activist Arul Doss argues that the government is losing its focus on seeking long-term solutions and is instead spending money on desalination plants. “The rich can afford to buy water for double the price. But the poor workers are now forced to spend half of their salary for water. What kind of development are we heading to?

“The government does not stop supplying water for multi-national companies when its own people are struggling to quench their thirst,’’ he said.

“Instead of spending money on recycling water and de-silting all the water bodies before the monsoon season, the government is working hard on opening new desalination plants in Chennai. It is hard to believe this is the same city that suffered flash floods in 2015.

Getting worse

“At least by now the government should have cleaned up water bodies and ensured grey water usage in high-rise apartments in the city,’’ Arul Doss told Climate News Network.

The plight of ordinary people is growing more extreme. A Chennai resident, K Meena, a student, has to fetch water. “We have to depend on the tanker supply, because the taps in our streets have dried up. Ours is a family of five. My parents and siblings take turns to collect water for bathing and cooking. I skipped classes and went late to college because I had to wait for the lorry,” said Meena.

Cab driver A Logeswaran uses the toilet facilities at petrol stations and sleeps in his car every other night to avoid using precious water supplies at home, which are kept for his wife and three-year-old child.

“Some of my neighbours sent their children and wives back to their native villages due to the water crisis. This is a very sad state for our city. Water is a basic need and I feel the government has failed completely,’’ he said in despair. − Climate News Network

Climate crisis raises risk of conflict

A warmer world will be more dangerous. As the thermometer rises, so does the risk of conflict and bloodshed in more vulnerable regions.

LONDON, 14 June, 2019 − If the world warms by 4°C this century, the climate factor becomes more dangerous – five times more dangerous, according to new research, which predicts a 26% increase in the risk of conflict, just because of climate change.

Even if the world sticks to a promise made in Paris in 2015, when 195 nations vowed to contain global warming to “well below” 2°C above pre-industrial levels by the end of the century, the impact of climate on the risk of armed conflict will double. The risk will rise to 13%.

US researchers report in the journal Nature that they quizzed a pool of 11 experts on climate and conflict from a range of disciplines. There is no consensus on the mechanism that links a shift in average temperatures and ethnic bitterness, migration, violence and outright civil war within any single nation. But there is a simple conclusion: whatever the process, climate change raises the risk of conflict.

And the study comes just as the latest publication of the  Global Peace Index warns that 971 million people now live in areas with what is termed high or “very high climate change exposure”, and 400 million of these people already live in countries with “low levels of peacefulness.”

Making conflict likelier

The Global Peace Index issues the same warning: that climate change can indirectly increase the likelihood of violent conflict by affecting the resources available to citizens, to jobs and careers, and by undermining security and forcing migration.

And, the same study says, this comes at a colossal economic cost. In 2018, the impact of violence on the global economy totalled $14.1 trillion in purchasing power. This is more than 11% of the world’s economic activity and adds up to $1,853 per person.

Both studies reinforce earlier research. Social scientists, geographers and statisticians have repeatedly found links between climate change and conflict, between climate change and migration, and have warned of more to come, specifically in South Asia, and worldwide.

“Over this century, unprecedented climate change is going to have significant impacts … but it is extremely hard to anticipate whether the political changes related to climate change will have big effects on armed conflict in turn”

There is a debate about the role of drought in the bloodshed in Syria, but there is less argument about the proposition that climate change unsettles what may already be nations or communities vulnerable to conflict.

There have also been bleak warnings from prehistory: archaeologists think that climate change may have been behind the collapse of the Bronze Age Mediterranean culture and the fall of an ancient Assyrian society.

The point of the latest study was simply to find some consensus on the risks of conflict in a world in climate crisis. The theorists think that climate stresses over the last century have already influenced in some way between 3% and 20% of armed conflict risk.

They think the risks could increase dramatically, as normally productive agricultural regions face catastrophic crop failure, as extremes of temperature make crowded cities more dangerous, as people are driven off their land by sustained drought, and as climate impacts impoverish the already vulnerable, to increase global levels of injustice and inequality.

Planning protection

Armed with a sense of the scale of the future hazard, governments and international agencies could equip themselves with strategies that might help to increase global food security and provide other economic opportunities. Peacekeeping forces and aid agencies need to understand, too, that climate factors are, increasingly, part of the risk.

“Historically, levels of armed conflict over time have been heavily influenced by shocks to, and changes in, international relations among states and in their domestic political systems,” said James Fearon, a political scientist at Stanford University and one of the authors.

“It is quite likely that, over this century, unprecedented climate change is going to have significant impacts on both, but it is extremely hard to anticipate whether the political changes related to climate change will have big effects on armed conflict in turn. So I think putting non-trivial weight on significant climate effects on conflict is reasonable.” − Climate News Network

A warmer world will be more dangerous. As the thermometer rises, so does the risk of conflict and bloodshed in more vulnerable regions.

LONDON, 14 June, 2019 − If the world warms by 4°C this century, the climate factor becomes more dangerous – five times more dangerous, according to new research, which predicts a 26% increase in the risk of conflict, just because of climate change.

Even if the world sticks to a promise made in Paris in 2015, when 195 nations vowed to contain global warming to “well below” 2°C above pre-industrial levels by the end of the century, the impact of climate on the risk of armed conflict will double. The risk will rise to 13%.

US researchers report in the journal Nature that they quizzed a pool of 11 experts on climate and conflict from a range of disciplines. There is no consensus on the mechanism that links a shift in average temperatures and ethnic bitterness, migration, violence and outright civil war within any single nation. But there is a simple conclusion: whatever the process, climate change raises the risk of conflict.

And the study comes just as the latest publication of the  Global Peace Index warns that 971 million people now live in areas with what is termed high or “very high climate change exposure”, and 400 million of these people already live in countries with “low levels of peacefulness.”

Making conflict likelier

The Global Peace Index issues the same warning: that climate change can indirectly increase the likelihood of violent conflict by affecting the resources available to citizens, to jobs and careers, and by undermining security and forcing migration.

And, the same study says, this comes at a colossal economic cost. In 2018, the impact of violence on the global economy totalled $14.1 trillion in purchasing power. This is more than 11% of the world’s economic activity and adds up to $1,853 per person.

Both studies reinforce earlier research. Social scientists, geographers and statisticians have repeatedly found links between climate change and conflict, between climate change and migration, and have warned of more to come, specifically in South Asia, and worldwide.

“Over this century, unprecedented climate change is going to have significant impacts … but it is extremely hard to anticipate whether the political changes related to climate change will have big effects on armed conflict in turn”

There is a debate about the role of drought in the bloodshed in Syria, but there is less argument about the proposition that climate change unsettles what may already be nations or communities vulnerable to conflict.

There have also been bleak warnings from prehistory: archaeologists think that climate change may have been behind the collapse of the Bronze Age Mediterranean culture and the fall of an ancient Assyrian society.

The point of the latest study was simply to find some consensus on the risks of conflict in a world in climate crisis. The theorists think that climate stresses over the last century have already influenced in some way between 3% and 20% of armed conflict risk.

They think the risks could increase dramatically, as normally productive agricultural regions face catastrophic crop failure, as extremes of temperature make crowded cities more dangerous, as people are driven off their land by sustained drought, and as climate impacts impoverish the already vulnerable, to increase global levels of injustice and inequality.

Planning protection

Armed with a sense of the scale of the future hazard, governments and international agencies could equip themselves with strategies that might help to increase global food security and provide other economic opportunities. Peacekeeping forces and aid agencies need to understand, too, that climate factors are, increasingly, part of the risk.

“Historically, levels of armed conflict over time have been heavily influenced by shocks to, and changes in, international relations among states and in their domestic political systems,” said James Fearon, a political scientist at Stanford University and one of the authors.

“It is quite likely that, over this century, unprecedented climate change is going to have significant impacts on both, but it is extremely hard to anticipate whether the political changes related to climate change will have big effects on armed conflict in turn. So I think putting non-trivial weight on significant climate effects on conflict is reasonable.” − Climate News Network