Tag Archives: Rainfall

Less rain will fall during Mediterranean winters

Mediterranean winters could bring 40% less rain, hurting farmers in what’s called the cradle of agriculture – and not only farmers.

LONDON, 2 July, 2020 – A warmer world should also be a wetter one, but not for the cockpit of much of human history: Mediterranean winters will become increasingly parched. Winter rainfall – and winter is the rainy season – could see a 40% fall in precipitation.

Agriculture and human civilisation began in the Fertile Crescent that runs from eastern Turkey to Iraq: cattle, sheep and goats were domesticated there; the first figs, almonds, grapes and pulses were planted there; the progenitors of wheat were sown there.

Cities were built, irrigation schemes devised, empires rose and fell. Greece colonised the Mediterranean, Rome later controlled it and set the pattern of law and civic government for the next 2000 years in Northern Europe.

Islamic forces brought a different civilisation to the Balkans, North Africa and almost all of Spain. The grain fields of the Nile Valley underwrote the expansion of the Roman Empire.

“What’s really different about the Mediterranean is the geography. You have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world”

But the pressure of history is likely to be affected by the high pressure of summers to come. In a world of rapid climate change, the already dry and sunny enclosed sea will become sunnier and drier, according to two scientists from the Massachusetts Institute of Technology.

They report in the American Meteorological Society’s Journal of Climate that the winter rains that are normally expected to fill the reservoirs and nourish the rich annual harvest from the orchards, vineyards and wheat fields can be expected to diminish significantly, as atmospheric pressures rise, to reduce rainfall by somewhere between 10% and 60%.

Ordinarily, a warmer world should be a wetter one. More water evaporates, and with each degree-rise in temperature the capacity of the air to hold water vapour increases by 7%, to fall inevitably as rain, somewhere.

But episodes of low pressure associated with rain clouds over the Mediterranean become less likely, according to climate simulations. The topography of the landscape and sea determines the probable pattern of the winds.

High pressure grows

“It just happened that the geography of where the Mediterranean is, and where the mountains are, impacts the pattern of air flow high in the atmosphere in a way that creates a high-pressure area over the Mediterranean,” said Alexandre Tuel, one of the authors.

“What’s really different about the Mediterranean compared to other regions is the geography. Basically, you have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world.”

Another factor is the rate of warming: land warms faster than sea. The North African seaboard and the southern fringe of Europe will become 3 to 4°C hotter over the next hundred years. The sea will warm by only 2°C. The difference between land and sea will become smaller, to add to the pattern of high pressure circulation.

“Basically, the difference between the water and the land becomes smaller with time,” Tuel says.

Frequent warnings

Once again, the finding is no surprise: Europe has a long history of drought and flood, but drought tends to leave the more permanent mark. The eastern Mediterranean has already experienced its harshest drought for 900 years and this has been linked to the bitter conflict in Syria.

Researchers have repeatedly warned that the pattern of drought on the continent is likely to intensify, and at considerable economic and human cost.

What is different is that the latest research offers detailed predictions of the nature of change, and identifies the regions likeliest to be worst hit. These include Morocco in north-west Africa, and the eastern Mediterranean of Turkey and the Levant.

“These are areas where we already detect declines in precipitation,” said Elfatih Eltahir, the senior author. “We document from the observed record of precipitation that this eastern part has already experienced a significant decline of precipitation.” – Climate News Network

Mediterranean winters could bring 40% less rain, hurting farmers in what’s called the cradle of agriculture – and not only farmers.

LONDON, 2 July, 2020 – A warmer world should also be a wetter one, but not for the cockpit of much of human history: Mediterranean winters will become increasingly parched. Winter rainfall – and winter is the rainy season – could see a 40% fall in precipitation.

Agriculture and human civilisation began in the Fertile Crescent that runs from eastern Turkey to Iraq: cattle, sheep and goats were domesticated there; the first figs, almonds, grapes and pulses were planted there; the progenitors of wheat were sown there.

Cities were built, irrigation schemes devised, empires rose and fell. Greece colonised the Mediterranean, Rome later controlled it and set the pattern of law and civic government for the next 2000 years in Northern Europe.

Islamic forces brought a different civilisation to the Balkans, North Africa and almost all of Spain. The grain fields of the Nile Valley underwrote the expansion of the Roman Empire.

“What’s really different about the Mediterranean is the geography. You have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world”

But the pressure of history is likely to be affected by the high pressure of summers to come. In a world of rapid climate change, the already dry and sunny enclosed sea will become sunnier and drier, according to two scientists from the Massachusetts Institute of Technology.

They report in the American Meteorological Society’s Journal of Climate that the winter rains that are normally expected to fill the reservoirs and nourish the rich annual harvest from the orchards, vineyards and wheat fields can be expected to diminish significantly, as atmospheric pressures rise, to reduce rainfall by somewhere between 10% and 60%.

Ordinarily, a warmer world should be a wetter one. More water evaporates, and with each degree-rise in temperature the capacity of the air to hold water vapour increases by 7%, to fall inevitably as rain, somewhere.

But episodes of low pressure associated with rain clouds over the Mediterranean become less likely, according to climate simulations. The topography of the landscape and sea determines the probable pattern of the winds.

High pressure grows

“It just happened that the geography of where the Mediterranean is, and where the mountains are, impacts the pattern of air flow high in the atmosphere in a way that creates a high-pressure area over the Mediterranean,” said Alexandre Tuel, one of the authors.

“What’s really different about the Mediterranean compared to other regions is the geography. Basically, you have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world.”

Another factor is the rate of warming: land warms faster than sea. The North African seaboard and the southern fringe of Europe will become 3 to 4°C hotter over the next hundred years. The sea will warm by only 2°C. The difference between land and sea will become smaller, to add to the pattern of high pressure circulation.

“Basically, the difference between the water and the land becomes smaller with time,” Tuel says.

Frequent warnings

Once again, the finding is no surprise: Europe has a long history of drought and flood, but drought tends to leave the more permanent mark. The eastern Mediterranean has already experienced its harshest drought for 900 years and this has been linked to the bitter conflict in Syria.

Researchers have repeatedly warned that the pattern of drought on the continent is likely to intensify, and at considerable economic and human cost.

What is different is that the latest research offers detailed predictions of the nature of change, and identifies the regions likeliest to be worst hit. These include Morocco in north-west Africa, and the eastern Mediterranean of Turkey and the Levant.

“These are areas where we already detect declines in precipitation,” said Elfatih Eltahir, the senior author. “We document from the observed record of precipitation that this eastern part has already experienced a significant decline of precipitation.” – Climate News Network

Climate change caused havoc 2000 years ago

An Alaskan volcano once spurred climate change, darkening Mediterranean skies, launching a famine and possibly changing history.

LONDON, 1 July, 2020 – Once again, geologists have shown that climate change can be linked to some of the most dramatic moments in human history: civil strife in the Roman Republic that ended with the fall of a Greek dynasty in Egypt and the rise of the Roman Empire.

The summers just after the assassination of Julius Caesar in 44 BCE (Before the Christian Era) were among the coldest in the northern hemisphere for thousands of years, and this sudden prolonged chill can be linked to lost harvests, famine, the failure of the all-important Nile flood and the death of the Roman Mark Antony and the last of Egypt’s Ptolemaic rulers, Cleopatra.

The trigger for that cold shadow over the Mediterranean theatre of history? Summer and autumn temperatures fell to as much as 7°C below normal because on the far side of the hemisphere an Alaskan volcano erupted in 43 BCE to hurl colossal quantities of soot and sulphates into the stratosphere and dim the sun’s radiation for much of the next decade.

And the evidence? Deposits of volcanic ash in the Arctic ice cores that can be linked directly to one once-smoking crater in the Aleutian islands now known as Okmok, according to new research in the Proceedings of the National Academy of Sciences.

Average temperatures fell dramatically. Summer rainfall in southern Europe rose by 50% to 120% above normal. Autumn rainfall rose fourfold.

“To find a volcano on the other side of the Earth contributed to the demise of the Egyptians and the rise of the Roman Empire is fascinating”

The rest is history: literally. Roman and Chinese chronicles surviving from that time record what scientists call “unusual atmospheric phenomena” as well as “widespread famine.”

Less directly, records of lead pollution preserved in the annual layers of ice in Greenland tell a story of economic decline, reflected in what might be the reduction of mining and smelting of lead and silver during the last years of the Roman Republic.

And the effect on the hemisphere’s climate was also recorded in the annual flow and flood of the River Nile, a regular inundation that enriched the grain harvest of the Nile Valley, and supplied bread for Rome and its sister cities.

The research was led by Joe McConnell of the US Desert Research Institute in Nevada. “To find a volcano on the other side of the Earth erupted and effectively contributed to the demise of the Romans and the Egyptians and the rise of the Roman Empire is fascinating,” he said. “It certainly shows how interconnected the world was even 2000 years ago.”

And one of his co-authors, Joseph Manning of Yale University, said: “We know that the Nile River did not flood in 43 BCE and 42 BCE – and now we know why. The volcanic eruption greatly affected the Nile watershed.”

Climate’s role

That mass migration, conflict and the collapse of once-stable regimes can be linked to climate change is not news: researchers have repeatedly found that drought, cold and harvest failure can be matched with the collapse of ancient empires in the Middle East and in the Bronze Age Mediterranean.

Just 1500 years ago volcanic eruptions have been timed to the famine, the Plague of Justinian, and other turmoil in the Byzantine empire. Professor Manning had already linked a failure of the Nile flood to the collapse of the Ptolemaic dynasty in Egypt.

Neither the volcanic eruption nor the consequent climate disruption can be said to have “caused” ancient power struggles. But a backdrop of instability,  hunger and famine can be linked to conflict, and climate is now seen as an inseparable factor. Cold, heavy rain at the wrong season can ruin any harvest.

“In the Mediterranean region, these wet and extremely cold conditions during the agriculturally important spring through autumn seasons probably reduced crop yields and compounded supply problems during the ongoing political upheavals of the period,” said Andrew Wilson of the University of Oxford, another author.

“These findings lend credibility to reports of cold, famine, food shortage and disease described by ancient sources.” – Climate News Network

An Alaskan volcano once spurred climate change, darkening Mediterranean skies, launching a famine and possibly changing history.

LONDON, 1 July, 2020 – Once again, geologists have shown that climate change can be linked to some of the most dramatic moments in human history: civil strife in the Roman Republic that ended with the fall of a Greek dynasty in Egypt and the rise of the Roman Empire.

The summers just after the assassination of Julius Caesar in 44 BCE (Before the Christian Era) were among the coldest in the northern hemisphere for thousands of years, and this sudden prolonged chill can be linked to lost harvests, famine, the failure of the all-important Nile flood and the death of the Roman Mark Antony and the last of Egypt’s Ptolemaic rulers, Cleopatra.

The trigger for that cold shadow over the Mediterranean theatre of history? Summer and autumn temperatures fell to as much as 7°C below normal because on the far side of the hemisphere an Alaskan volcano erupted in 43 BCE to hurl colossal quantities of soot and sulphates into the stratosphere and dim the sun’s radiation for much of the next decade.

And the evidence? Deposits of volcanic ash in the Arctic ice cores that can be linked directly to one once-smoking crater in the Aleutian islands now known as Okmok, according to new research in the Proceedings of the National Academy of Sciences.

Average temperatures fell dramatically. Summer rainfall in southern Europe rose by 50% to 120% above normal. Autumn rainfall rose fourfold.

“To find a volcano on the other side of the Earth contributed to the demise of the Egyptians and the rise of the Roman Empire is fascinating”

The rest is history: literally. Roman and Chinese chronicles surviving from that time record what scientists call “unusual atmospheric phenomena” as well as “widespread famine.”

Less directly, records of lead pollution preserved in the annual layers of ice in Greenland tell a story of economic decline, reflected in what might be the reduction of mining and smelting of lead and silver during the last years of the Roman Republic.

And the effect on the hemisphere’s climate was also recorded in the annual flow and flood of the River Nile, a regular inundation that enriched the grain harvest of the Nile Valley, and supplied bread for Rome and its sister cities.

The research was led by Joe McConnell of the US Desert Research Institute in Nevada. “To find a volcano on the other side of the Earth erupted and effectively contributed to the demise of the Romans and the Egyptians and the rise of the Roman Empire is fascinating,” he said. “It certainly shows how interconnected the world was even 2000 years ago.”

And one of his co-authors, Joseph Manning of Yale University, said: “We know that the Nile River did not flood in 43 BCE and 42 BCE – and now we know why. The volcanic eruption greatly affected the Nile watershed.”

Climate’s role

That mass migration, conflict and the collapse of once-stable regimes can be linked to climate change is not news: researchers have repeatedly found that drought, cold and harvest failure can be matched with the collapse of ancient empires in the Middle East and in the Bronze Age Mediterranean.

Just 1500 years ago volcanic eruptions have been timed to the famine, the Plague of Justinian, and other turmoil in the Byzantine empire. Professor Manning had already linked a failure of the Nile flood to the collapse of the Ptolemaic dynasty in Egypt.

Neither the volcanic eruption nor the consequent climate disruption can be said to have “caused” ancient power struggles. But a backdrop of instability,  hunger and famine can be linked to conflict, and climate is now seen as an inseparable factor. Cold, heavy rain at the wrong season can ruin any harvest.

“In the Mediterranean region, these wet and extremely cold conditions during the agriculturally important spring through autumn seasons probably reduced crop yields and compounded supply problems during the ongoing political upheavals of the period,” said Andrew Wilson of the University of Oxford, another author.

“These findings lend credibility to reports of cold, famine, food shortage and disease described by ancient sources.” – Climate News Network

The wetter world ahead will suffer worse droughts

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

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

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

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

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

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

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

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

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

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

Search for precision

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Search for precision

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

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

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

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

Oxford basks in 140-year-old sunshine record

The ancient UK city of Oxford has registered a month-long sunshine record, the sunniest in nearly 150 years.

OXFORD, 4 June, 2020 – So far this year many parts of the world have seen weather records broken, and not always happily, as floods, storms, heat, cold, drought and more reach new extremes – but, in the temperate United Kingdom, swept frequently by Atlantic storms and Arctic gales, a sunshine record is something to marvel at.

That’s what has just been the experience of the city of Oxford, home not only to an ancient university but to a collection of the longest single-site weather records in the UK, with worldwide relevance.

The university’s Radcliffe Meteorological Station has measured a new record for sunshine. The total for the month just gone was 331.7 hours, making May 2020 the sunniest calendar month in the city since sunshine records began in February 1880, and far beyond the previous holder of the title, July 1911, with its total of 310.4 hours.

Oxford’s record May sunshine was 173% higher than the city’s long-term average total sunshine for the month, 192 hours. It was also higher than the long-term average May sunshine hours for Seville and Malaga (approximately 300hrs each ) in southern Spain.

“You can smell the burning card and sometimes see a small smoke trail. It’s a beautiful and wonderfully simple yet very clever device”

Oxford’s statistics for the months from March to May show as well that spring 2020 has been far sunnier than anything measured in previous years, with 59.3 more hours of sunshine than the previous record, set in 1990.

This sequence of long sunny days has meant something else as well: an almost total absence of rain in Oxford, where rainfall records go back as far as 1767 (though in a different part of the city for the first five years). This month was the driest May since 1795 – only 3.5mm accumulated in the rain gauge.

The Radcliffe station measures sunshine with a robust device invented in 1853, called a Campbell–Stokes recorder, or a Stokes sphere. The original design consisted of a glass sphere set into a wooden bowl, on which the sun burnt a trace.

A modification replaced the bowl with a metal housing and a card holder set behind the sphere. The device, still in use almost unchanged after nearly 170 years, records the hours of sunshine bright enough to burn a hole through the card.

International worth

Thomas Caton Harrison, a doctoral student at the University of Oxford, collected the final figures on 1 June to establish the previous day’s sunshine reading. He said: “You can smell the burning card and sometimes see a small smoke trail. It’s a beautiful and wonderfully simple yet very clever device.”

The Radcliffe station has a unique place in both UK and international weather observation. Record-keeping began here in 1772, and an unbroken daily air temperature record has existed since November 1813. The daily rainfall record runs from January 1827, and sunshine from February 1880. These are the longest single-site weather records in the UK, and amongst the longest in the world.

They are especially valuable because the instruments in use and their exposure have been fully documented throughout the record. The station, based at Green Templeton College, has been managed by the university’s School of Geography and the Environment since 1935.

For more details see Oxford Weather and Climate since 1767, published by Oxford University Press in 2019. The book provides an analysis of the weather records from the Radcliffe Meteorological Station, one of the most detailed accounts for any city in the world. – Climate News Network

* * * * * * *

Ian Curtis is Development Officer of the School of Geography and the Environment, University of Oxford.

The ancient UK city of Oxford has registered a month-long sunshine record, the sunniest in nearly 150 years.

OXFORD, 4 June, 2020 – So far this year many parts of the world have seen weather records broken, and not always happily, as floods, storms, heat, cold, drought and more reach new extremes – but, in the temperate United Kingdom, swept frequently by Atlantic storms and Arctic gales, a sunshine record is something to marvel at.

That’s what has just been the experience of the city of Oxford, home not only to an ancient university but to a collection of the longest single-site weather records in the UK, with worldwide relevance.

The university’s Radcliffe Meteorological Station has measured a new record for sunshine. The total for the month just gone was 331.7 hours, making May 2020 the sunniest calendar month in the city since sunshine records began in February 1880, and far beyond the previous holder of the title, July 1911, with its total of 310.4 hours.

Oxford’s record May sunshine was 173% higher than the city’s long-term average total sunshine for the month, 192 hours. It was also higher than the long-term average May sunshine hours for Seville and Malaga (approximately 300hrs each ) in southern Spain.

“You can smell the burning card and sometimes see a small smoke trail. It’s a beautiful and wonderfully simple yet very clever device”

Oxford’s statistics for the months from March to May show as well that spring 2020 has been far sunnier than anything measured in previous years, with 59.3 more hours of sunshine than the previous record, set in 1990.

This sequence of long sunny days has meant something else as well: an almost total absence of rain in Oxford, where rainfall records go back as far as 1767 (though in a different part of the city for the first five years). This month was the driest May since 1795 – only 3.5mm accumulated in the rain gauge.

The Radcliffe station measures sunshine with a robust device invented in 1853, called a Campbell–Stokes recorder, or a Stokes sphere. The original design consisted of a glass sphere set into a wooden bowl, on which the sun burnt a trace.

A modification replaced the bowl with a metal housing and a card holder set behind the sphere. The device, still in use almost unchanged after nearly 170 years, records the hours of sunshine bright enough to burn a hole through the card.

International worth

Thomas Caton Harrison, a doctoral student at the University of Oxford, collected the final figures on 1 June to establish the previous day’s sunshine reading. He said: “You can smell the burning card and sometimes see a small smoke trail. It’s a beautiful and wonderfully simple yet very clever device.”

The Radcliffe station has a unique place in both UK and international weather observation. Record-keeping began here in 1772, and an unbroken daily air temperature record has existed since November 1813. The daily rainfall record runs from January 1827, and sunshine from February 1880. These are the longest single-site weather records in the UK, and amongst the longest in the world.

They are especially valuable because the instruments in use and their exposure have been fully documented throughout the record. The station, based at Green Templeton College, has been managed by the university’s School of Geography and the Environment since 1935.

For more details see Oxford Weather and Climate since 1767, published by Oxford University Press in 2019. The book provides an analysis of the weather records from the Radcliffe Meteorological Station, one of the most detailed accounts for any city in the world. – Climate News Network

* * * * * * *

Ian Curtis is Development Officer of the School of Geography and the Environment, University of Oxford.

Pandemic and climate extremes hit India together

A fearsome cyclone, other climate extremes, Covid-19 and now locust swarms – Indians may think life could hardly get worse.

DELHI, 2 June, 2020 – India is no stranger to coping with climate extremes and natural emergencies, but this year is likely to lodge in the national memory as one of the most challenging in recent history.

The Covid-19 pandemic is a global scourge, but India also has many regional and national afflictions to make 2020 a year to forget – a massive heatwave, its strongest recorded cyclone, thunderstorms bringing huge hailstones, and floods. Now it is being assailed by all-devouring locust swarms, the worst in 25 years, leaving the land scarred.

Government figures showed more than 5,000 Covid-19 deaths by the end of May. The pandemic is causing a humanitarian crisis as well, with a huge reverse migration of penniless unskilled labourers who have lost their jobs in the cities and are now returning to their rural homes.

Five states – Rajasthan, Gujarat, Punjab, Madhya Pradesh and parts of Maharashtra – have been invaded by the locusts. The swarms normally arrive to breed in June or July but this year the first flew in in mid-April, helped to spread by a strong west wind. Climate scientists say warmer waters in the western Indian Ocean also worsened the problem.

The only saving grace is that there are not many standing crops in many of the affected districts, as the monsoon sowing is yet to begin. “It is only the vegetables, orchards and trees that are the victims of this attack,” an official said.

“This is an emergency situation. These desert locusts will not only leave a severe impact on India’s food production but also deal a double whammy to the farmers, who are already reeling from the economic lockdown”

As the locust threat developed, a range of devastating climate events hit the country in May, starting with heavy rain and hail which killed 29 people in Uttar Pradesh, India’s most populous state. Next came Cyclone Amphan, bringing sustained windspeeds of 270 kms per hour.

It was the strongest storm ever recorded in the Bay of Bengal. When it hit the coast on 20 May more than 80 people died. West Bengal, on the eastern coast bordering Bangladesh, suffered a trail of destruction. The winds even damaged the tiger stronghold of the Sundarbans, the islands  whose mangrove forests in the delta of three major rivers normally give Bengal some protection from the storms.

Amphan’s rampage caused the evacuation of 300,000 people to shelter. Many acres of agricultural land near the coast were flooded by salty water and are now unusable. The government estimated the initial losses caused by the cyclone at one trillion rupees (US$13.2 billion).

Amphan’s storm surge was among its most dangerous threats. Global sea levels have already increased by about 23 cm as a result of human carbon emissions – dramatically increasing the distance that the surges can reach. Sea levels in the North Indian Ocean have risen more quickly than in many oceans elsewhere in recent years.

Assam struck

Amphan’s tail also left its mark on the northeastern state of Assam, which experienced heavy rainfall and flooding in low-lying areas, and then several days later a massive thunderstorm. On 27 May, as the Brahmaputra and its tributaries rose above danger point at several places, over 300 villages experienced heavy flooding.

Nor was that all. The same week maximum temperatures reached 40-45C° in much of northern and central India. While Delhi sizzled at 45-46°, Churu in Rajasthan touched 50°C. Fortunately, there have been no deaths reported this year of farm workers and street vendors, as many people remain locked in their homes because of the virus.

As India braces for the annual monsoon, the government is claiming that it has contained much of the locust threat. But Devinder Sharma, an agriculture and trade policy expert, said: “The government’s preparedness has been too slow to keep pace with this rapid increase in locust swarms.

“This is an emergency situation and requires emergency measures. These desert locusts will not only leave a severe impact on India’s food production but also deal a double whammy to the farmers, who are already reeling from the economic lockdown caused by Covid-19.” – Climate News Network

* * * * * * *

Nivedita Khandekar is an independent journalist based in Delhi. She writes on environmental and developmental issues. She can be reached at nivedita_him@rediffmail.com or @nivedita_Him

A fearsome cyclone, other climate extremes, Covid-19 and now locust swarms – Indians may think life could hardly get worse.

DELHI, 2 June, 2020 – India is no stranger to coping with climate extremes and natural emergencies, but this year is likely to lodge in the national memory as one of the most challenging in recent history.

The Covid-19 pandemic is a global scourge, but India also has many regional and national afflictions to make 2020 a year to forget – a massive heatwave, its strongest recorded cyclone, thunderstorms bringing huge hailstones, and floods. Now it is being assailed by all-devouring locust swarms, the worst in 25 years, leaving the land scarred.

Government figures showed more than 5,000 Covid-19 deaths by the end of May. The pandemic is causing a humanitarian crisis as well, with a huge reverse migration of penniless unskilled labourers who have lost their jobs in the cities and are now returning to their rural homes.

Five states – Rajasthan, Gujarat, Punjab, Madhya Pradesh and parts of Maharashtra – have been invaded by the locusts. The swarms normally arrive to breed in June or July but this year the first flew in in mid-April, helped to spread by a strong west wind. Climate scientists say warmer waters in the western Indian Ocean also worsened the problem.

The only saving grace is that there are not many standing crops in many of the affected districts, as the monsoon sowing is yet to begin. “It is only the vegetables, orchards and trees that are the victims of this attack,” an official said.

“This is an emergency situation. These desert locusts will not only leave a severe impact on India’s food production but also deal a double whammy to the farmers, who are already reeling from the economic lockdown”

As the locust threat developed, a range of devastating climate events hit the country in May, starting with heavy rain and hail which killed 29 people in Uttar Pradesh, India’s most populous state. Next came Cyclone Amphan, bringing sustained windspeeds of 270 kms per hour.

It was the strongest storm ever recorded in the Bay of Bengal. When it hit the coast on 20 May more than 80 people died. West Bengal, on the eastern coast bordering Bangladesh, suffered a trail of destruction. The winds even damaged the tiger stronghold of the Sundarbans, the islands  whose mangrove forests in the delta of three major rivers normally give Bengal some protection from the storms.

Amphan’s rampage caused the evacuation of 300,000 people to shelter. Many acres of agricultural land near the coast were flooded by salty water and are now unusable. The government estimated the initial losses caused by the cyclone at one trillion rupees (US$13.2 billion).

Amphan’s storm surge was among its most dangerous threats. Global sea levels have already increased by about 23 cm as a result of human carbon emissions – dramatically increasing the distance that the surges can reach. Sea levels in the North Indian Ocean have risen more quickly than in many oceans elsewhere in recent years.

Assam struck

Amphan’s tail also left its mark on the northeastern state of Assam, which experienced heavy rainfall and flooding in low-lying areas, and then several days later a massive thunderstorm. On 27 May, as the Brahmaputra and its tributaries rose above danger point at several places, over 300 villages experienced heavy flooding.

Nor was that all. The same week maximum temperatures reached 40-45C° in much of northern and central India. While Delhi sizzled at 45-46°, Churu in Rajasthan touched 50°C. Fortunately, there have been no deaths reported this year of farm workers and street vendors, as many people remain locked in their homes because of the virus.

As India braces for the annual monsoon, the government is claiming that it has contained much of the locust threat. But Devinder Sharma, an agriculture and trade policy expert, said: “The government’s preparedness has been too slow to keep pace with this rapid increase in locust swarms.

“This is an emergency situation and requires emergency measures. These desert locusts will not only leave a severe impact on India’s food production but also deal a double whammy to the farmers, who are already reeling from the economic lockdown caused by Covid-19.” – Climate News Network

* * * * * * *

Nivedita Khandekar is an independent journalist based in Delhi. She writes on environmental and developmental issues. She can be reached at nivedita_him@rediffmail.com or @nivedita_Him

Nuclear tests affected the weather 60 years ago

Cold War nuclear tests did change the weather in the 1960s. The Earth did not catch fire, but a hard rain did begin to fall.

LONDON, 19 May, 2020 – Sixty years on, British scientists have confirmed a once-popular belief: that atmospheric nuclear tests of early weapons under development affected the daily weather. A new study of  weather records from 1962 to 1964 reveals the signature of experimental atomic and thermonuclear explosions during the early days of the Cold War.

The scientists measured atmospheric electric charge and cloud data to find that on those days when radioactively-generated electric charge was higher, clouds were thicker and there was up to a quarter more rain than on those days when charge was low.

The climate impact of nuclear detonations may not have been as devastating as many older lay people appeared to think at the time, and some good came of the tests: researchers who studied radiation distribution as it spread around the planet from weapons test sites built up a body of data that delivered a new way to follow atmospheric circulation patterns.

“We have now re-used this data to examine the effect on rainfall,” said Giles Harrison of the University of Reading in the UK. “The politically charged atmosphere of the Cold War led to a nuclear arms race and worldwide anxiety. Decades later, that global cloud has yielded a silver lining, in giving us a unique way to study how electric charge affects rain.”

Between 1945 and 1980 US, Soviet, British and French governments exploded 510 megatons of nuclear weaponry underground, under water and in the lower and upper atmosphere. Of this, 428 megatons – the equivalent of 29,000 bombs of the size dropped onto Hiroshima in Japan at the end of the Second World War – was in the open air, and the greatest concentration of tests was in the late 1950s and early 1960s.

Weather grumbles

Scientists began to collect strontium-90 isotopes and other radioactive fission products in the rain that fell after such tests. By 1960, people in Europe and the US could be heard grumbling about the supposed impact on the weather of tests carried out 10,000 kilometres away.

British cinemagoers were treated to an improbable vision of climate catastrophe triggered by nuclear tests in the 1961 film The Day the Earth Caught Fire. The US government commissioned the Rand Corporation to deliver an inconclusive report in 1966 on the effect upon weather, but by then an international treaty had banned tests in the atmosphere, in the water and in space.

Very slowly, public concern about radioactive fallout and its consequences for the weather began to fade.

Scientists continued to contemplate the climate effects of nuclear confrontation in other ways: in 1983 US researchers proposed a possible nuclear winter, triggered by radioactive mushroom clouds from burning cities that would reach the stratosphere and dim the sun’s light for a decade.

But long before then, peace and prosperity had created another climatic danger: the accelerating combustion of fossil fuels had begun to raise atmospheric greenhouse gas levels to trigger global warming, and climate scientists began to adopt nuclear yardsticks to measure the effect.

“The atmospheric conditions of 1962-64 were exceptional and it is unlikely they will be repeated, for many reasons”

One calculation is that by flying in jet planes or driving cars or generating electric power, humankind is now adding the equivalent in heat energy of five Hiroshima explosions every second to the world’s atmosphere, thus inexorably altering the global climate.

That has not stopped other scientists from worrying about the chilling effects upon climate and human civilisation of even a limited nuclear  exchange. But the supposed impact of bursts of nuclear radiation upon the weather has been more or less forgotten.

Now Professor Harrison and colleagues have returned to the puzzle in the journal Physical Review Letters, to find that the answer could be disentangled from weather records collected in Kew, near London, and 1000 kms away in Lerwick in the Shetland Islands north-east of Scotland, a site selected because it would be least affected by soot, sulphur particles and other kinds of industrial pollution.

Nuclear radiation ionises the matter in its path to create electrically-charged atoms and molecules. Electric charge changes the way water droplets in clouds collide and combine – think of dramatic thunderstorms, lightning and torrential rain – and this affects the size of the droplets and the volume of rain: that is, the rain doesn’t fall at all until the droplets get big enough.

Usually, the sun does most of the work, but in comparing the weather records from two stations, the researchers were for the first time able to factor in the contribution from Cold War test explosions in the Nevada desert, or the Siberian Arctic, or the faraway south Pacific, on Scottish rainfall between 1962 and 1964.

Difference disappeared

They found 150 days in which atmospheric electricity was high or low, while cloudy in Lerwick: they also found a difference in precipitation which, they say, disappeared once the build-up of nuclear radioactive fallout had vanished.

Their statistical analyses suggest no serious or lasting change, but the connection was there: where radioactivity was high, rainfall increased from 2.1mm per day to 2.6mm – a 24% increase in daily rain. Clouds, too, were thicker.

The study remains as one more piece of the climate jigsaw, as a test of measuring technique, and one more reminder of the lessons still to be learned from the Cold War.

It confirms a deepening understanding of the intricate machinery that delivers the first drops of rain, and ideally scientists won’t get many chances to test their understanding in the same way again.

The authors conclude, in the clipped tones favoured by research publications: “The atmospheric conditions of 1962-64 were exceptional and it is unlikely they will be repeated, for many reasons.” – Climate News Network

Cold War nuclear tests did change the weather in the 1960s. The Earth did not catch fire, but a hard rain did begin to fall.

LONDON, 19 May, 2020 – Sixty years on, British scientists have confirmed a once-popular belief: that atmospheric nuclear tests of early weapons under development affected the daily weather. A new study of  weather records from 1962 to 1964 reveals the signature of experimental atomic and thermonuclear explosions during the early days of the Cold War.

The scientists measured atmospheric electric charge and cloud data to find that on those days when radioactively-generated electric charge was higher, clouds were thicker and there was up to a quarter more rain than on those days when charge was low.

The climate impact of nuclear detonations may not have been as devastating as many older lay people appeared to think at the time, and some good came of the tests: researchers who studied radiation distribution as it spread around the planet from weapons test sites built up a body of data that delivered a new way to follow atmospheric circulation patterns.

“We have now re-used this data to examine the effect on rainfall,” said Giles Harrison of the University of Reading in the UK. “The politically charged atmosphere of the Cold War led to a nuclear arms race and worldwide anxiety. Decades later, that global cloud has yielded a silver lining, in giving us a unique way to study how electric charge affects rain.”

Between 1945 and 1980 US, Soviet, British and French governments exploded 510 megatons of nuclear weaponry underground, under water and in the lower and upper atmosphere. Of this, 428 megatons – the equivalent of 29,000 bombs of the size dropped onto Hiroshima in Japan at the end of the Second World War – was in the open air, and the greatest concentration of tests was in the late 1950s and early 1960s.

Weather grumbles

Scientists began to collect strontium-90 isotopes and other radioactive fission products in the rain that fell after such tests. By 1960, people in Europe and the US could be heard grumbling about the supposed impact on the weather of tests carried out 10,000 kilometres away.

British cinemagoers were treated to an improbable vision of climate catastrophe triggered by nuclear tests in the 1961 film The Day the Earth Caught Fire. The US government commissioned the Rand Corporation to deliver an inconclusive report in 1966 on the effect upon weather, but by then an international treaty had banned tests in the atmosphere, in the water and in space.

Very slowly, public concern about radioactive fallout and its consequences for the weather began to fade.

Scientists continued to contemplate the climate effects of nuclear confrontation in other ways: in 1983 US researchers proposed a possible nuclear winter, triggered by radioactive mushroom clouds from burning cities that would reach the stratosphere and dim the sun’s light for a decade.

But long before then, peace and prosperity had created another climatic danger: the accelerating combustion of fossil fuels had begun to raise atmospheric greenhouse gas levels to trigger global warming, and climate scientists began to adopt nuclear yardsticks to measure the effect.

“The atmospheric conditions of 1962-64 were exceptional and it is unlikely they will be repeated, for many reasons”

One calculation is that by flying in jet planes or driving cars or generating electric power, humankind is now adding the equivalent in heat energy of five Hiroshima explosions every second to the world’s atmosphere, thus inexorably altering the global climate.

That has not stopped other scientists from worrying about the chilling effects upon climate and human civilisation of even a limited nuclear  exchange. But the supposed impact of bursts of nuclear radiation upon the weather has been more or less forgotten.

Now Professor Harrison and colleagues have returned to the puzzle in the journal Physical Review Letters, to find that the answer could be disentangled from weather records collected in Kew, near London, and 1000 kms away in Lerwick in the Shetland Islands north-east of Scotland, a site selected because it would be least affected by soot, sulphur particles and other kinds of industrial pollution.

Nuclear radiation ionises the matter in its path to create electrically-charged atoms and molecules. Electric charge changes the way water droplets in clouds collide and combine – think of dramatic thunderstorms, lightning and torrential rain – and this affects the size of the droplets and the volume of rain: that is, the rain doesn’t fall at all until the droplets get big enough.

Usually, the sun does most of the work, but in comparing the weather records from two stations, the researchers were for the first time able to factor in the contribution from Cold War test explosions in the Nevada desert, or the Siberian Arctic, or the faraway south Pacific, on Scottish rainfall between 1962 and 1964.

Difference disappeared

They found 150 days in which atmospheric electricity was high or low, while cloudy in Lerwick: they also found a difference in precipitation which, they say, disappeared once the build-up of nuclear radioactive fallout had vanished.

Their statistical analyses suggest no serious or lasting change, but the connection was there: where radioactivity was high, rainfall increased from 2.1mm per day to 2.6mm – a 24% increase in daily rain. Clouds, too, were thicker.

The study remains as one more piece of the climate jigsaw, as a test of measuring technique, and one more reminder of the lessons still to be learned from the Cold War.

It confirms a deepening understanding of the intricate machinery that delivers the first drops of rain, and ideally scientists won’t get many chances to test their understanding in the same way again.

The authors conclude, in the clipped tones favoured by research publications: “The atmospheric conditions of 1962-64 were exceptional and it is unlikely they will be repeated, for many reasons.” – Climate News Network

Tree rings and weather data warn of megadrought

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

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

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

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

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

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

Repeating the past

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

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

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

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

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

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

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

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

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

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

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

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

Worsened by heating

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

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

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

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

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

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

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

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

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

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

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

Repeating the past

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

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

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

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

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

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

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

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

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

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

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

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

Worsened by heating

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

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

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

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

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

Violent weather rises spur more political conflict

Violent weather – seasonal storms, floods, fires and droughts – is growing more extreme, more often. And bloodshed may follow oftener too.

LONDON, 16 April, 2020 – Violent weather is on the rise. Days of exceptionally heavy rain in São Paulo, Brazil, have multiplied fourfold in one lifetime. In California, autumns have become hotter, and drier, and the risk of devastating wildfires is on the increase.

And climate extremes bring with them the risk of ever-greater political conflict. In those countries already politically unstable, one third of all episodes of conflict have started within seven days of a heat wave, landslide, storm or drought.

Climate scientists began warning almost 40 years ago that even a small rise in the average annual temperature of planet Earth would be accompanied by a greater frequency of ever more extreme weather events. And now, repeatedly, rainfall, wind speed and thermometer records have begun to provide supporting evidence.

Seventy years ago, any heavy rain – more than 50 mm in a day – in São Paulo was almost unknown. In February 2020, the floods arrived again when the skies opened and delivered 114 millimetres in 24 hours. This was the second highest measured rainfall in any day since 1943. In the last decade, São Paulo citizens have seen such days between two and five times a year.

“Intense rainstorms lasting a few hours with intense amounts of water, such as 80mm or 100mm, are no longer sporadic events,” said José Antonio Marengo, of Brazil’s Natural Disaster Surveillance and Early Warning Centre. “They’re happening more and more frequently.”

Rainfall increase

He and colleagues report in the Annals of the New York Academy of Sciences that the city’s dry season from April to September is now extended to October. The number of consecutive days without any rain has also increased.

But total rainfall has increased over the city, and the state of São Paulo has now recorded a third of all Brazil’s floods. The researchers do not rule out the possibility of natural climate variation, but it may also be related to global warming and to the growth of the city.

Californian scientists however are in no doubt that the risk of longer and more dangerous fire seasons can be linked to climate change driven by global heating, fuelled in turn by greenhouse gas emissions from profligate use of fossil fuels.

They report in the journal Environmental Research Letters that since the early 1980s the frequency of autumn days with extreme fire weather conditions has more than doubled in California, and rainfall during autumn has dropped by 30%, while average temperatures have increased by more than 1°C.

“Climate change makes tense social and political situations even worse, so climate-related disasters may act like a threat multiplier for violent conflicts”

The region’s single deadliest wildfire, the two largest wildfires and the two most destructive wildfires all happened during 2017 and 2018. More than 150 people died. Damage costs reached $50bn.

“Many factors influence wildfire risk, but this study shows that long-term warming, coupled with decreasing autumn precipitation, is already increasing the odds of the kinds of extreme fire weather conditions that have proved so destructive in northern and southern California in recent years,” said Noah Diffenbaugh of Stanford University, one of the researchers.

The bushfires that have devastated eastern Australia since last September are unlikely to spark any civil war, says Tobias Ide of the University of Melbourne. “But when it comes to droughts in Nigeria or storms in Pakistan, where you have large marginalised populations and little state presence, the picture may well change.”

He and colleagues in Germany report in the journal Global Environmental Change that they used a new statistical approach to confirm what other researchers have repeatedly proposed: that climate catastrophe can seemingly heighten the chance of political violence or civil war.

Violence more likely

They counted 176 conflicts in which at least 25 people had died in battle,
and more than 10,000 records of floods, storms, drought, heat wave, landslide and other weather-related phenomena, and found that almost one third of all conflict had been preceded by a climate-related disaster within seven days.

They don’t say the disaster caused the conflict: just that it made violence in already uneasy political conditions more likely.

“Climate change makes tense social and political situations even worse, so climate-related disasters may act like a threat multiplier for violent conflicts,” Dr Ide said.

“Only countries with large populations, the political exclusion of ethnic groups and relatively low levels of economic development, are susceptible to disaster-conflict links.

“Measures to make societies more inclusive and wealthier are, therefore, no-regrets options to increase security in a warming world.” – Climate News Network

Violent weather – seasonal storms, floods, fires and droughts – is growing more extreme, more often. And bloodshed may follow oftener too.

LONDON, 16 April, 2020 – Violent weather is on the rise. Days of exceptionally heavy rain in São Paulo, Brazil, have multiplied fourfold in one lifetime. In California, autumns have become hotter, and drier, and the risk of devastating wildfires is on the increase.

And climate extremes bring with them the risk of ever-greater political conflict. In those countries already politically unstable, one third of all episodes of conflict have started within seven days of a heat wave, landslide, storm or drought.

Climate scientists began warning almost 40 years ago that even a small rise in the average annual temperature of planet Earth would be accompanied by a greater frequency of ever more extreme weather events. And now, repeatedly, rainfall, wind speed and thermometer records have begun to provide supporting evidence.

Seventy years ago, any heavy rain – more than 50 mm in a day – in São Paulo was almost unknown. In February 2020, the floods arrived again when the skies opened and delivered 114 millimetres in 24 hours. This was the second highest measured rainfall in any day since 1943. In the last decade, São Paulo citizens have seen such days between two and five times a year.

“Intense rainstorms lasting a few hours with intense amounts of water, such as 80mm or 100mm, are no longer sporadic events,” said José Antonio Marengo, of Brazil’s Natural Disaster Surveillance and Early Warning Centre. “They’re happening more and more frequently.”

Rainfall increase

He and colleagues report in the Annals of the New York Academy of Sciences that the city’s dry season from April to September is now extended to October. The number of consecutive days without any rain has also increased.

But total rainfall has increased over the city, and the state of São Paulo has now recorded a third of all Brazil’s floods. The researchers do not rule out the possibility of natural climate variation, but it may also be related to global warming and to the growth of the city.

Californian scientists however are in no doubt that the risk of longer and more dangerous fire seasons can be linked to climate change driven by global heating, fuelled in turn by greenhouse gas emissions from profligate use of fossil fuels.

They report in the journal Environmental Research Letters that since the early 1980s the frequency of autumn days with extreme fire weather conditions has more than doubled in California, and rainfall during autumn has dropped by 30%, while average temperatures have increased by more than 1°C.

“Climate change makes tense social and political situations even worse, so climate-related disasters may act like a threat multiplier for violent conflicts”

The region’s single deadliest wildfire, the two largest wildfires and the two most destructive wildfires all happened during 2017 and 2018. More than 150 people died. Damage costs reached $50bn.

“Many factors influence wildfire risk, but this study shows that long-term warming, coupled with decreasing autumn precipitation, is already increasing the odds of the kinds of extreme fire weather conditions that have proved so destructive in northern and southern California in recent years,” said Noah Diffenbaugh of Stanford University, one of the researchers.

The bushfires that have devastated eastern Australia since last September are unlikely to spark any civil war, says Tobias Ide of the University of Melbourne. “But when it comes to droughts in Nigeria or storms in Pakistan, where you have large marginalised populations and little state presence, the picture may well change.”

He and colleagues in Germany report in the journal Global Environmental Change that they used a new statistical approach to confirm what other researchers have repeatedly proposed: that climate catastrophe can seemingly heighten the chance of political violence or civil war.

Violence more likely

They counted 176 conflicts in which at least 25 people had died in battle,
and more than 10,000 records of floods, storms, drought, heat wave, landslide and other weather-related phenomena, and found that almost one third of all conflict had been preceded by a climate-related disaster within seven days.

They don’t say the disaster caused the conflict: just that it made violence in already uneasy political conditions more likely.

“Climate change makes tense social and political situations even worse, so climate-related disasters may act like a threat multiplier for violent conflicts,” Dr Ide said.

“Only countries with large populations, the political exclusion of ethnic groups and relatively low levels of economic development, are susceptible to disaster-conflict links.

“Measures to make societies more inclusive and wealthier are, therefore, no-regrets options to increase security in a warming world.” – 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