Tag Archives: Flooding

Flood risk will rise as climate heat intensifies

A warmer world will be a wetter one. Ever more people will face a higher flood risk as rivers rise and city streets fill up.

LONDON, 5 August, 2021 − In a world of climate change, the flood risk will be more intense and more frequent, presenting higher danger to ever more people in a greater number of countries.

In this century alone, the global population has increased by 18%. But the number of people exposed to damage and death by rising waters has increased by more than 34%.

This finding is not based on mathematical simulations powered by weather data. It is based on direct and detailed observation. Researchers report in the journal Nature that they looked at more than 12,700 satellite images, at a resolution of 250 metres, of 913 large flood events between the years 2000 and 2015.

During those years, and those floods, water spilled from the rivers to inundate a total of 2.23 million square kilometres. This, considered as one event, would cover a total area larger than Saudi Arabia. And during those first 15 years of the century, the number of people directly affected by the floods was at least 255m, and possibly 290m.

“Governments across the world have been too slow in reducing greenhouse gas emissions . . . This, alongside the current floods in Europe, is the wake-up call we need”

In those 15 years, the numbers of people in the way of the ever more devastating floods rose by at least 58m, and possibly as many as 86m. That’s a rise of as much as 24%.

It will get worse. According to the researchers, climate change and the multiplication of human numbers will extend the reach of flood risk: 32 nations already experience ever more flooding. By 2030, another 25 countries will have joined them.

The humans caught up in the sickening flow of mud, sewage and silt spilling from the rising rivers will mostly be in south and south-east Asia − think of the Indus, Ganges-Brahmaputra and Mekong Rivers − and many of them will have migrated to the danger zones: poverty and population pressure will leave them no choice.

None of this should come as a surprise. In the past 50 years, according to a new compilation by the World Meteorological Organisation, weather, climate and water were implicated in 50% of all disasters of any kind; in 45% of all reported deaths and 74% of all economic losses. Floods have claimed 58,700 lives in the last five decades. Between them, floods and storms − the two are often linked − cost Europe at least US$377bn in economic losses.

Higher flooding frequency

And things will certainly get much worse for Europe as global average temperatures continue to rise in response to ever higher greenhouse gas emissions from ever greater use of fossil fuels. That is because what had once been relatively rare events will grow in force and frequency.

More heat means more evaporation, and a warmer atmosphere has a greater capacity to absorb water vapour. So it will rain harder. And the arrival, say researchers in the journal Geophysical Research Letters, of intense, slow-moving storms that precipitate devastating flash floods of the kind that swept Belgium and Germany this summer will by the close of the century become 14 times more frequent.

“Governments across the world have been too slow in reducing greenhouse gas emissions and global warming continues apace,” said Hayley Fowler, a climate scientist at Newcastle University in the UK, and one of the researchers.

“This study suggests that changes to extreme storms will be significant and cause an increase in the frequency of devastating flooding across Europe. This, alongside the current floods in Europe, is the wake-up call we need.” − Climate News Network

A warmer world will be a wetter one. Ever more people will face a higher flood risk as rivers rise and city streets fill up.

LONDON, 5 August, 2021 − In a world of climate change, the flood risk will be more intense and more frequent, presenting higher danger to ever more people in a greater number of countries.

In this century alone, the global population has increased by 18%. But the number of people exposed to damage and death by rising waters has increased by more than 34%.

This finding is not based on mathematical simulations powered by weather data. It is based on direct and detailed observation. Researchers report in the journal Nature that they looked at more than 12,700 satellite images, at a resolution of 250 metres, of 913 large flood events between the years 2000 and 2015.

During those years, and those floods, water spilled from the rivers to inundate a total of 2.23 million square kilometres. This, considered as one event, would cover a total area larger than Saudi Arabia. And during those first 15 years of the century, the number of people directly affected by the floods was at least 255m, and possibly 290m.

“Governments across the world have been too slow in reducing greenhouse gas emissions . . . This, alongside the current floods in Europe, is the wake-up call we need”

In those 15 years, the numbers of people in the way of the ever more devastating floods rose by at least 58m, and possibly as many as 86m. That’s a rise of as much as 24%.

It will get worse. According to the researchers, climate change and the multiplication of human numbers will extend the reach of flood risk: 32 nations already experience ever more flooding. By 2030, another 25 countries will have joined them.

The humans caught up in the sickening flow of mud, sewage and silt spilling from the rising rivers will mostly be in south and south-east Asia − think of the Indus, Ganges-Brahmaputra and Mekong Rivers − and many of them will have migrated to the danger zones: poverty and population pressure will leave them no choice.

None of this should come as a surprise. In the past 50 years, according to a new compilation by the World Meteorological Organisation, weather, climate and water were implicated in 50% of all disasters of any kind; in 45% of all reported deaths and 74% of all economic losses. Floods have claimed 58,700 lives in the last five decades. Between them, floods and storms − the two are often linked − cost Europe at least US$377bn in economic losses.

Higher flooding frequency

And things will certainly get much worse for Europe as global average temperatures continue to rise in response to ever higher greenhouse gas emissions from ever greater use of fossil fuels. That is because what had once been relatively rare events will grow in force and frequency.

More heat means more evaporation, and a warmer atmosphere has a greater capacity to absorb water vapour. So it will rain harder. And the arrival, say researchers in the journal Geophysical Research Letters, of intense, slow-moving storms that precipitate devastating flash floods of the kind that swept Belgium and Germany this summer will by the close of the century become 14 times more frequent.

“Governments across the world have been too slow in reducing greenhouse gas emissions and global warming continues apace,” said Hayley Fowler, a climate scientist at Newcastle University in the UK, and one of the researchers.

“This study suggests that changes to extreme storms will be significant and cause an increase in the frequency of devastating flooding across Europe. This, alongside the current floods in Europe, is the wake-up call we need.” − Climate News Network

Climate heat’s tides may rise above safety levels

Millions will either have to flee from climate heat’s tides, or find new ways to stay above water.

LONDON, 21 June, 2021 − If global heating is not to be stopped − which seems the case − then governments, civil authorities and communities must start thinking of ways to live with it, including how to survive climate heat’s tides.

That could mean building floating cities that will bob up and down with the tides, or existing cities in which the streets have become canals and the parks have become lakes. It will also mean, as land is surrendered to the sea, that cities will have to become more compact, and more crowded, on higher ground.

It could also mean urban forests and vertical forests: skyscrapers with balcony gardens, orchards and micro-wildernesses all the way up. It could mean that farms convert to aquaculture: where saltmarsh lamb once grazed, farmers might raise shrimps and shellfish.

This is called managed retreat. As the polar icecaps melt, temperature extremes rise, droughts multiply and floods and superstorms become ever more intense, humans will have to adapt.

“Climate change is affecting people all over the world. One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked”

By 2100, at the most conservative estimate, around 88 million people could be forced to relocate, as the high tides get ever higher, and the seas begin to erode or invade the world’s coasts. At the most alarming estimate, the numbers of displaced persons could rise to 1.4 billion.

“Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it. One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked,” said A R Siders, of the Disaster Research Center at the University of Delaware in the US.

“We are looking at the different ways society can dream bigger when planning for climate change and how community values and priorities play a role in that.”

She and a colleague argue in the journal Science that in a small way managed retreat has already begun: in the US some 45,000 families have been helped to move out of flood-prone housing in the last 30 years, and “this represents a tiny fraction of the millions at risk and is fewer than the number of homes experiencing repeated damage and the number of new homes built in floodplains.”

The point is that much climate thinking is still short-term. “It’s hard to make decisions about climate change if we are thinking 5-10 years out. We are building infrastructure that lasts 50-100 years; our planning should be equally long,” Dr Siders said.

Living with risk

The researchers list the challenges ahead: communities that live near the wild lands must learn to live with the increasing threat of forest fires; city dwellers in the warmer climates could have to face potentially lethal extremes of heat; low-lying island nations in the Pacific may have to transfer whole populations to other countries.

Some low-lying coastal cities have already begun to adapt: Rotterdam in the Netherlands already has floating homes in Nassau Harbour that rise and fall with the tides. New York City, hard hit by Superstorm Sandy in 2012, is contemplating a floodwall in its East River.

Flooding on the US Atlantic coasts is expected to get worse: millions of Americans will probably have to migrate inland or become climate refugees. Dr Siders and colleagues began urging strategies of what she calls planned retreat two years ago.

At least one US Atlantic settlement could be be swept away or inundated by mid-century. For the people of Delaware, the problems are immediate.
“Communities, towns and cities are making decisions now that affect the future,” Dr Siders said.

“Locally, Delaware is building faster inside the floodplain than out of it. We are making plans for beach nourishment and where to build sea walls. We’re making these decisions now, so we should be considering all the options on the table, not just the ones that keep people in place.” − Climate News Network.

Millions will either have to flee from climate heat’s tides, or find new ways to stay above water.

LONDON, 21 June, 2021 − If global heating is not to be stopped − which seems the case − then governments, civil authorities and communities must start thinking of ways to live with it, including how to survive climate heat’s tides.

That could mean building floating cities that will bob up and down with the tides, or existing cities in which the streets have become canals and the parks have become lakes. It will also mean, as land is surrendered to the sea, that cities will have to become more compact, and more crowded, on higher ground.

It could also mean urban forests and vertical forests: skyscrapers with balcony gardens, orchards and micro-wildernesses all the way up. It could mean that farms convert to aquaculture: where saltmarsh lamb once grazed, farmers might raise shrimps and shellfish.

This is called managed retreat. As the polar icecaps melt, temperature extremes rise, droughts multiply and floods and superstorms become ever more intense, humans will have to adapt.

“Climate change is affecting people all over the world. One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked”

By 2100, at the most conservative estimate, around 88 million people could be forced to relocate, as the high tides get ever higher, and the seas begin to erode or invade the world’s coasts. At the most alarming estimate, the numbers of displaced persons could rise to 1.4 billion.

“Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it. One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked,” said A R Siders, of the Disaster Research Center at the University of Delaware in the US.

“We are looking at the different ways society can dream bigger when planning for climate change and how community values and priorities play a role in that.”

She and a colleague argue in the journal Science that in a small way managed retreat has already begun: in the US some 45,000 families have been helped to move out of flood-prone housing in the last 30 years, and “this represents a tiny fraction of the millions at risk and is fewer than the number of homes experiencing repeated damage and the number of new homes built in floodplains.”

The point is that much climate thinking is still short-term. “It’s hard to make decisions about climate change if we are thinking 5-10 years out. We are building infrastructure that lasts 50-100 years; our planning should be equally long,” Dr Siders said.

Living with risk

The researchers list the challenges ahead: communities that live near the wild lands must learn to live with the increasing threat of forest fires; city dwellers in the warmer climates could have to face potentially lethal extremes of heat; low-lying island nations in the Pacific may have to transfer whole populations to other countries.

Some low-lying coastal cities have already begun to adapt: Rotterdam in the Netherlands already has floating homes in Nassau Harbour that rise and fall with the tides. New York City, hard hit by Superstorm Sandy in 2012, is contemplating a floodwall in its East River.

Flooding on the US Atlantic coasts is expected to get worse: millions of Americans will probably have to migrate inland or become climate refugees. Dr Siders and colleagues began urging strategies of what she calls planned retreat two years ago.

At least one US Atlantic settlement could be be swept away or inundated by mid-century. For the people of Delaware, the problems are immediate.
“Communities, towns and cities are making decisions now that affect the future,” Dr Siders said.

“Locally, Delaware is building faster inside the floodplain than out of it. We are making plans for beach nourishment and where to build sea walls. We’re making these decisions now, so we should be considering all the options on the table, not just the ones that keep people in place.” − Climate News Network.

Rising floods threaten Danish financial system

Stormier seas and more frequent floods can cause havoc anywhere. The Danish financial system is now growing apprehensive.

LONDON, 16 June, 2021 − Flooding caused by storm surges and general changes in climate give rise to misery around the world, destroying homes and livelihoods and forcing the migration of hundreds of thousands of people. The financial impact of floods can also impose severe economic strains, and not just in the developing world: the Danish financial system now fears growing losses to come.

Denmark is a relatively small country but has a long coastline, stretching for more than 8,000 kilometres.

As part of a series of reports on the impacts of climate change, Danmarks NationalBank, the country’s central bank, warns that billions of dollars have been loaned to householders and businesses located in coastal and other flood-prone areas.

Flood damage could make recouping many of these loans extremely difficult; credit institutions with substantial exposure to such loans could go out of business. The integrity of the financial system might be threatened.

“Climate change is leading to increased recurrence and severity of flooding from storm surges”

“Exposures of 41 billion krone (US$7billion) are currently located in areas already at risk of flooding”, says the central bank.

“This amount will increase to DKK198 billion (US$32 billion) over the next 50-80 years in the most extreme climate scenario…this implies that the risk could constitute a risk for individual credit institutions as well as the financial system.”

The central bank’s report says the occurrence of floods round the country is increasing, with more than 40 flooding events caused by storm surges happening in the 1991 to 2017 period.

“Climate change is leading to increased recurrence and severity of flooding from storm surges, and the effect from storm surges is further exacerbated by sea level rises,” says the report.

Losses passed on

Areas of the country most exposed to flooding include the area round Copenhagen, the capital, the west coast, and Jutland in the north.

Initially, says the bank, homeowners and businesses with premises located in flood-prone areas will bear the financial costs of flood damage.

“However, the loss can ultimately affect credit institutions…value depreciation has a direct effect on homeowners and can be transmitted to credit institutions if the real estate has been pledged as collateral for the loan.”

Central banks around the world are issuing increasingly strident warnings to banks and other credit institutions about the challenges posed by climate change.

Warned off

In many instances insurance companies and other financial institutions are being told to put aside a portion of their earnings in order to cope with the increased costs climate change will bring.

Investors are being warned that putting money into fossil fuel companies and related enterprises is an increasingly risky business.

Fossil fuel companies are also being told to revise their accounts to take into consideration so-called “stranded assets” – corporate fossil fuel holdings made essentially worthless due to the looming climate catastrophe and the growth of regulation forbidding their exploitation.

As a result, many billions of dollars have been written off the value of what were, till a few years ago, some of the world’s biggest and most financially powerful companies. Climate News Network

Stormier seas and more frequent floods can cause havoc anywhere. The Danish financial system is now growing apprehensive.

LONDON, 16 June, 2021 − Flooding caused by storm surges and general changes in climate give rise to misery around the world, destroying homes and livelihoods and forcing the migration of hundreds of thousands of people. The financial impact of floods can also impose severe economic strains, and not just in the developing world: the Danish financial system now fears growing losses to come.

Denmark is a relatively small country but has a long coastline, stretching for more than 8,000 kilometres.

As part of a series of reports on the impacts of climate change, Danmarks NationalBank, the country’s central bank, warns that billions of dollars have been loaned to householders and businesses located in coastal and other flood-prone areas.

Flood damage could make recouping many of these loans extremely difficult; credit institutions with substantial exposure to such loans could go out of business. The integrity of the financial system might be threatened.

“Climate change is leading to increased recurrence and severity of flooding from storm surges”

“Exposures of 41 billion krone (US$7billion) are currently located in areas already at risk of flooding”, says the central bank.

“This amount will increase to DKK198 billion (US$32 billion) over the next 50-80 years in the most extreme climate scenario…this implies that the risk could constitute a risk for individual credit institutions as well as the financial system.”

The central bank’s report says the occurrence of floods round the country is increasing, with more than 40 flooding events caused by storm surges happening in the 1991 to 2017 period.

“Climate change is leading to increased recurrence and severity of flooding from storm surges, and the effect from storm surges is further exacerbated by sea level rises,” says the report.

Losses passed on

Areas of the country most exposed to flooding include the area round Copenhagen, the capital, the west coast, and Jutland in the north.

Initially, says the bank, homeowners and businesses with premises located in flood-prone areas will bear the financial costs of flood damage.

“However, the loss can ultimately affect credit institutions…value depreciation has a direct effect on homeowners and can be transmitted to credit institutions if the real estate has been pledged as collateral for the loan.”

Central banks around the world are issuing increasingly strident warnings to banks and other credit institutions about the challenges posed by climate change.

Warned off

In many instances insurance companies and other financial institutions are being told to put aside a portion of their earnings in order to cope with the increased costs climate change will bring.

Investors are being warned that putting money into fossil fuel companies and related enterprises is an increasingly risky business.

Fossil fuel companies are also being told to revise their accounts to take into consideration so-called “stranded assets” – corporate fossil fuel holdings made essentially worthless due to the looming climate catastrophe and the growth of regulation forbidding their exploitation.

As a result, many billions of dollars have been written off the value of what were, till a few years ago, some of the world’s biggest and most financially powerful companies. Climate News Network

The very expensive human cost of climate change

Storms devastate. Climate change makes them more devastating. Now we know how much the human cost of climate change really is.

LONDON, 25 May, 2021 − We know already that the human cost of climate change is immense. Now we can put a figure on it. Nine years on, New Yorkers have a clearer idea of the direct cost of human-driven climate change to them during just one stormy weekend in October 2012.

They became poorer by $8.1 billion, say researchers from Princeton, New Brunswick and Hoboken in New Jersey, and Boston in Massachusetts, just because of sea level rise powered first by global heating fuelled by profligate combustion worldwide of coal, oil and gas, and then by a superstorm called Hurricane Sandy.

Researchers can also number the additional people who suffered damages inflicted precisely because of human-driven climate change on that one long, painful weekend: 71,000.

“This study is the first to isolate the human-contributed sea level effects during a coastal storm and put a dollar sign to the additional flooding damage,” said Philip Orton, of Stevens Institute of Technology in Hoboken, one of the authors.

“With coastal flooding increasingly impacting communities and causing widespread destruction, pinpointing the financial toll and lives affected by climate change will hopefully add urgency to our efforts to reduce it.”

“If we were to calculate the cost of climate change across all flooding events that figure would provide clarity on the severe damage we are inflicting on our planet”

There would have been damage anyway: Sandy was a powerful hurricane that slammed into the northeast US coast so hard it set the earthquake alarms ringing. The destruction attributed to Sandy is more than $62 billion, as one of the worst storms in history at the New York bight arrived with the evening high tide to cause devastation and disruption in New York City, New Jersey and Connecticut.

It also killed 43 people in New York City and destroyed thousands of homes and around a quarter of a million cars, vans, buses and trucks.

And now a study in the journal Nature Communications reasons that anthropogenic or human-powered sea level rise must have accounted for at least 13% of the total bill. That is because global heating from greenhouse gas emissions seems to have raised mean sea levels in the New York region by around 10 cms over the last century or so. In fact, Sandy arrived with the highest water level in at least 300 years in the New York metropolitan area.

The researchers set themselves the target of identifying precisely the impact of climate change on sea level rise in that region. To do that, they had to subtract the change that could be explained by coastal subsidence: as a consequence of heavy construction and groundwater abstraction, coastal settlements everywhere are likely to subside.

Knowing the threat

Then they combed maps of the damage, contour data and insurance data to arrive at a specific contribution by sea level rise linked to climate change: at the very least, they judged, $4.7bn, at the most $14bn, and so they compromised on $8bn.

They then numbered the humans who might not have been hit by flooding had there been no climate change: they calculated at least 40,000, and no more than 131,000, before settling on 70,000 additional victims.

Such exercises matter: city planners, coastal defence agencies, insurers and seaside property-holders need to know the scale of extra risk conferred by climate change. There will be more storm damage and flooding, and the new methodology could be adapted to other vulnerable cities.

US coasts already face more frequent floods, rising seas promise more such superstorms and − once again because of global heating − the north-eastern US seaboard can expect to be in the track of fiercer hurricanes.

“If we were to calculate the cost of climate change across all flooding events − both nuisance floods and those caused by extreme storm events − that figure would be enormous,” Dr Orton said. ”It would provide clarity on the severe damage we are inflicting on ourselves and on our planet.” − Climate News Network

Storms devastate. Climate change makes them more devastating. Now we know how much the human cost of climate change really is.

LONDON, 25 May, 2021 − We know already that the human cost of climate change is immense. Now we can put a figure on it. Nine years on, New Yorkers have a clearer idea of the direct cost of human-driven climate change to them during just one stormy weekend in October 2012.

They became poorer by $8.1 billion, say researchers from Princeton, New Brunswick and Hoboken in New Jersey, and Boston in Massachusetts, just because of sea level rise powered first by global heating fuelled by profligate combustion worldwide of coal, oil and gas, and then by a superstorm called Hurricane Sandy.

Researchers can also number the additional people who suffered damages inflicted precisely because of human-driven climate change on that one long, painful weekend: 71,000.

“This study is the first to isolate the human-contributed sea level effects during a coastal storm and put a dollar sign to the additional flooding damage,” said Philip Orton, of Stevens Institute of Technology in Hoboken, one of the authors.

“With coastal flooding increasingly impacting communities and causing widespread destruction, pinpointing the financial toll and lives affected by climate change will hopefully add urgency to our efforts to reduce it.”

“If we were to calculate the cost of climate change across all flooding events that figure would provide clarity on the severe damage we are inflicting on our planet”

There would have been damage anyway: Sandy was a powerful hurricane that slammed into the northeast US coast so hard it set the earthquake alarms ringing. The destruction attributed to Sandy is more than $62 billion, as one of the worst storms in history at the New York bight arrived with the evening high tide to cause devastation and disruption in New York City, New Jersey and Connecticut.

It also killed 43 people in New York City and destroyed thousands of homes and around a quarter of a million cars, vans, buses and trucks.

And now a study in the journal Nature Communications reasons that anthropogenic or human-powered sea level rise must have accounted for at least 13% of the total bill. That is because global heating from greenhouse gas emissions seems to have raised mean sea levels in the New York region by around 10 cms over the last century or so. In fact, Sandy arrived with the highest water level in at least 300 years in the New York metropolitan area.

The researchers set themselves the target of identifying precisely the impact of climate change on sea level rise in that region. To do that, they had to subtract the change that could be explained by coastal subsidence: as a consequence of heavy construction and groundwater abstraction, coastal settlements everywhere are likely to subside.

Knowing the threat

Then they combed maps of the damage, contour data and insurance data to arrive at a specific contribution by sea level rise linked to climate change: at the very least, they judged, $4.7bn, at the most $14bn, and so they compromised on $8bn.

They then numbered the humans who might not have been hit by flooding had there been no climate change: they calculated at least 40,000, and no more than 131,000, before settling on 70,000 additional victims.

Such exercises matter: city planners, coastal defence agencies, insurers and seaside property-holders need to know the scale of extra risk conferred by climate change. There will be more storm damage and flooding, and the new methodology could be adapted to other vulnerable cities.

US coasts already face more frequent floods, rising seas promise more such superstorms and − once again because of global heating − the north-eastern US seaboard can expect to be in the track of fiercer hurricanes.

“If we were to calculate the cost of climate change across all flooding events − both nuisance floods and those caused by extreme storm events − that figure would be enormous,” Dr Orton said. ”It would provide clarity on the severe damage we are inflicting on ourselves and on our planet.” − Climate News Network

Tide of climate refugees swells as Earth heats up

Prepare for the arrival of more displaced persons, climate refugees driven from their homes by global heating.

LONDON, 11 May, 2021 − Natural hazards − most of them driven by climate change − have forced an estimated 288 million people from their homes since 2008. That is three times the numbers displaced by war and conflict. These people have become, however briefly, climate refugees.

And the number will grow. A new study has found that for every 1°C rise in global average temperatures, the chance of displacement from river flooding alone will rise by 50%. And that calculation is based on population numbers right now. As human numbers rise, so will the risk − by 110%.

Another study makes an even more precise prediction: thanks to rising sea levels and more intense cyclonic storms, an estimated 1.3 million people in Bangladesh will be forced into migration by 2050. Many will move further inland − but many are likely to be forced across national borders, to trigger more displacement.

Drought and famine are climate-related natural disasters. So are forest fires, extreme heat waves, catastrophic windstorms and devastating floods, driven either by torrential rainfall or rising sea levels, or both.

Climate scientists, environmentalists and geographers have been warning for years that the numbers of people driven from their homes by climate change is on the increase: even in the US, as many as 13 million people could be forced from their coastal settlements by sea level rise.

“It is imperative that we have a better understanding of how the risks are changing”

Swiss scientists report in the journal Environmental Research Letters that even if the world keeps to an agreement to limit global warming to no more than 2°C, because the global population is rising, the average risk of displacement by river flooding is likely to rise by 110% by the end of the century.

If however nations take no drastic action, and go on burning ever more fossil fuels, the global average risk of being forced from home by swirling waters could rise by up to 350%.

“Because floods are a major driver of displacement, and due to the fact that they are influenced by climate change, it is imperative that we have a better understanding of how the risks are changing,” said Pui Man Kam of the Swiss Federal Institute of Technology, known as ETH Zurich, who led the study.

An estimated 680 million people worldwide live in low-lying coastal zones. Spanish, Italian and US scientists report in the journal Earth’s Future that they had developed a data model to predict the numbers likely to be displaced by any natural hazard to become climate refugees.

They tested it in the context of sea level rise, storms and floods in one low-lying country laced with rivers: Bangladesh. It is home to 163 million people, of whom 41% live at elevations lower than 10 metres above sea level.

Countrywide unrest likely

Their research found that although people in the coastal districts along the Bay of Bengal would be flooded, a surge of migration would ripple across the landscape and impact all 64 districts, including the capital, Dhaka.

Thanks to climate migration, numbers in the city should grow and eventually decline, as people moved to get away from the new arrivals. That is, flood events at the coast could ultimately trigger human unrest in the entire country.
“Droughts, desertification, floods, earthquakes, and wildfire threaten livelihoods worldwide; from wealthy to developing economies, every country is vulnerable to environmental change,” said Maurizio Porfiri of New York University’s Tandon School of Engineering.

“Mathematical models can assist in providing reliable predictions of environmental migration, which are critical for devising effective policy initiatives and improving our preparedness for future migration patterns.” − Climate News Network

Prepare for the arrival of more displaced persons, climate refugees driven from their homes by global heating.

LONDON, 11 May, 2021 − Natural hazards − most of them driven by climate change − have forced an estimated 288 million people from their homes since 2008. That is three times the numbers displaced by war and conflict. These people have become, however briefly, climate refugees.

And the number will grow. A new study has found that for every 1°C rise in global average temperatures, the chance of displacement from river flooding alone will rise by 50%. And that calculation is based on population numbers right now. As human numbers rise, so will the risk − by 110%.

Another study makes an even more precise prediction: thanks to rising sea levels and more intense cyclonic storms, an estimated 1.3 million people in Bangladesh will be forced into migration by 2050. Many will move further inland − but many are likely to be forced across national borders, to trigger more displacement.

Drought and famine are climate-related natural disasters. So are forest fires, extreme heat waves, catastrophic windstorms and devastating floods, driven either by torrential rainfall or rising sea levels, or both.

Climate scientists, environmentalists and geographers have been warning for years that the numbers of people driven from their homes by climate change is on the increase: even in the US, as many as 13 million people could be forced from their coastal settlements by sea level rise.

“It is imperative that we have a better understanding of how the risks are changing”

Swiss scientists report in the journal Environmental Research Letters that even if the world keeps to an agreement to limit global warming to no more than 2°C, because the global population is rising, the average risk of displacement by river flooding is likely to rise by 110% by the end of the century.

If however nations take no drastic action, and go on burning ever more fossil fuels, the global average risk of being forced from home by swirling waters could rise by up to 350%.

“Because floods are a major driver of displacement, and due to the fact that they are influenced by climate change, it is imperative that we have a better understanding of how the risks are changing,” said Pui Man Kam of the Swiss Federal Institute of Technology, known as ETH Zurich, who led the study.

An estimated 680 million people worldwide live in low-lying coastal zones. Spanish, Italian and US scientists report in the journal Earth’s Future that they had developed a data model to predict the numbers likely to be displaced by any natural hazard to become climate refugees.

They tested it in the context of sea level rise, storms and floods in one low-lying country laced with rivers: Bangladesh. It is home to 163 million people, of whom 41% live at elevations lower than 10 metres above sea level.

Countrywide unrest likely

Their research found that although people in the coastal districts along the Bay of Bengal would be flooded, a surge of migration would ripple across the landscape and impact all 64 districts, including the capital, Dhaka.

Thanks to climate migration, numbers in the city should grow and eventually decline, as people moved to get away from the new arrivals. That is, flood events at the coast could ultimately trigger human unrest in the entire country.
“Droughts, desertification, floods, earthquakes, and wildfire threaten livelihoods worldwide; from wealthy to developing economies, every country is vulnerable to environmental change,” said Maurizio Porfiri of New York University’s Tandon School of Engineering.

“Mathematical models can assist in providing reliable predictions of environmental migration, which are critical for devising effective policy initiatives and improving our preparedness for future migration patterns.” − Climate News Network

Big carbon users top global sports sponsors’ league

Big Tobacco used to be one of the principal sports sponsors. Now some major climate polluters have replaced it: Big Carbon.

LONDON, 22 March, 2021 − Who backs the world of sport with hard cash? The prosperous tobacco industry was till 2005 among the main sports sponsors, but that year the European Union banned the backing by tobacco of sporting events, although in other parts of the world the cash continues to pour from hand to hand unchecked.

Now though there’s an even more formidable funder than smoking which is opening its wallet to the world’s athletes: Big Carbon.

Three UK-based groups say their research has found that over 250 sports advertising deals with the biggest contributors to climate change have been revealed by a new analysis. Andrew Simms, co-director of the New Weather Institute and one of the research team, said: “Sport is in the front line of the climate emergency but floats on a sea of sponsorship deals with the major polluters.

“It makes the crisis worse by normalising high-carbon, polluting lifestyles, and reducing the pressure for climate action. Major polluters have replaced once common tobacco companies as big sports sponsors. They should be stopped for the same reason tobacco sponsorship ended − for the health of people, sports and the planet.”

A report published by the three groups as part of the Badvertising campaign says football was found to be the biggest beneficiary of the traffic, receiving 57 sponsorships from high-carbon industries, from oil and gas to airlines and cars.

“It’s wrong for these companies, who are fully aware of the deadly impact of their products, to use the power and beauty of sport to normalise and hide their behaviour”

The report, Sweat not oil: why sports should drop advertising and sponsorship from high-carbon polluters, is the work of the think tank New Weather Institute; a climate charity, Possible; and the Rapid Transition Alliance.

It identifies advertising and sponsorship deals with major polluters across 13 different sports, from football, cricket and tennis to major events such as the Olympics.

The deals have been concluded despite moves in the last year by the sports industry to cut its carbon emissions and to play a bigger role in tackling the climate crisis. The report comes days ahead of the Football World Cup Qualifiers on 24 March − sponsored by Qatar Airways.

Football is the most targeted sport. The automotive industry is the most active high-carbon industry courting sports sponsorship, with 199 deals across different sports. Airlines come second with 63, followed by oil and gas companies such as the Russian energy company Gazprom and the British chemicals multinational Ineos, whose deals have already been criticised by climate campaigns.

Health risks

The report reveals the Japanese carmaker Toyota as the largest sponsor by number after 31 sports deals were identified, closely followed by the airline Emirates with 29 partnerships. These findings follow warnings from experts about the risk that climate change poses to sporting events, from the flooding of football grounds to the melting of winter sports venues.

The researchers argue that the direct association with high-carbon products contradicts recent pledges made by clubs and sports bodies to take action on the climate crisis. With climate heating increasingly seen as a health crisis, and concerns over linked issues like air pollution on the rise, the report warns that sports bodies and also individuals risk their credibility as promoters of public health.

The authors say there are parallels between these deals with high-carbon companies and the now disgraced deals which sports bodies used to have with the tobacco industry.

The team behind the report is calling for sports bodies around the world to drop all advertising and sponsorship deals with companies which promote high-carbon lifestyles, products and services.

Power to inspire

The report includes more recommendations to sports bodies, for instance cutting their reliance on air travel and signing up to the UN Sports for Climate Action movement.

The British canoeist Etienne Stott, a gold medallist at the London 2012 Olympics, said: “It’s wrong for these companies, who are fully aware of the deadly impact of their products, to use the power and beauty of sport to normalise and hide their behaviour.

“Sport has a unique power to connect and inspire people. I would like to see it use its voice to promote the idea of care and stewardship of our planetary resources, not insane exploitation and destruction.”

Melissa Wilson, a leading British rower and a qualifier for the Tokyo Olympics, says: “As athletes, we focus a lot on keeping sport ‘clean’ through prioritising anti-doping.

“Yet continuing to pollute in the face of the climate emergency is the Earth-equivalent of doping, or scoring own goals. By keeping polluting sponsors on board, sports detract from their opportunity to play a productive part in the race to zero carbon.” − Climate News Network

Big Tobacco used to be one of the principal sports sponsors. Now some major climate polluters have replaced it: Big Carbon.

LONDON, 22 March, 2021 − Who backs the world of sport with hard cash? The prosperous tobacco industry was till 2005 among the main sports sponsors, but that year the European Union banned the backing by tobacco of sporting events, although in other parts of the world the cash continues to pour from hand to hand unchecked.

Now though there’s an even more formidable funder than smoking which is opening its wallet to the world’s athletes: Big Carbon.

Three UK-based groups say their research has found that over 250 sports advertising deals with the biggest contributors to climate change have been revealed by a new analysis. Andrew Simms, co-director of the New Weather Institute and one of the research team, said: “Sport is in the front line of the climate emergency but floats on a sea of sponsorship deals with the major polluters.

“It makes the crisis worse by normalising high-carbon, polluting lifestyles, and reducing the pressure for climate action. Major polluters have replaced once common tobacco companies as big sports sponsors. They should be stopped for the same reason tobacco sponsorship ended − for the health of people, sports and the planet.”

A report published by the three groups as part of the Badvertising campaign says football was found to be the biggest beneficiary of the traffic, receiving 57 sponsorships from high-carbon industries, from oil and gas to airlines and cars.

“It’s wrong for these companies, who are fully aware of the deadly impact of their products, to use the power and beauty of sport to normalise and hide their behaviour”

The report, Sweat not oil: why sports should drop advertising and sponsorship from high-carbon polluters, is the work of the think tank New Weather Institute; a climate charity, Possible; and the Rapid Transition Alliance.

It identifies advertising and sponsorship deals with major polluters across 13 different sports, from football, cricket and tennis to major events such as the Olympics.

The deals have been concluded despite moves in the last year by the sports industry to cut its carbon emissions and to play a bigger role in tackling the climate crisis. The report comes days ahead of the Football World Cup Qualifiers on 24 March − sponsored by Qatar Airways.

Football is the most targeted sport. The automotive industry is the most active high-carbon industry courting sports sponsorship, with 199 deals across different sports. Airlines come second with 63, followed by oil and gas companies such as the Russian energy company Gazprom and the British chemicals multinational Ineos, whose deals have already been criticised by climate campaigns.

Health risks

The report reveals the Japanese carmaker Toyota as the largest sponsor by number after 31 sports deals were identified, closely followed by the airline Emirates with 29 partnerships. These findings follow warnings from experts about the risk that climate change poses to sporting events, from the flooding of football grounds to the melting of winter sports venues.

The researchers argue that the direct association with high-carbon products contradicts recent pledges made by clubs and sports bodies to take action on the climate crisis. With climate heating increasingly seen as a health crisis, and concerns over linked issues like air pollution on the rise, the report warns that sports bodies and also individuals risk their credibility as promoters of public health.

The authors say there are parallels between these deals with high-carbon companies and the now disgraced deals which sports bodies used to have with the tobacco industry.

The team behind the report is calling for sports bodies around the world to drop all advertising and sponsorship deals with companies which promote high-carbon lifestyles, products and services.

Power to inspire

The report includes more recommendations to sports bodies, for instance cutting their reliance on air travel and signing up to the UN Sports for Climate Action movement.

The British canoeist Etienne Stott, a gold medallist at the London 2012 Olympics, said: “It’s wrong for these companies, who are fully aware of the deadly impact of their products, to use the power and beauty of sport to normalise and hide their behaviour.

“Sport has a unique power to connect and inspire people. I would like to see it use its voice to promote the idea of care and stewardship of our planetary resources, not insane exploitation and destruction.”

Melissa Wilson, a leading British rower and a qualifier for the Tokyo Olympics, says: “As athletes, we focus a lot on keeping sport ‘clean’ through prioritising anti-doping.

“Yet continuing to pollute in the face of the climate emergency is the Earth-equivalent of doping, or scoring own goals. By keeping polluting sponsors on board, sports detract from their opportunity to play a productive part in the race to zero carbon.” − Climate News Network

Alpine plants face risk from growing climate heat

Like many mountainous regions, the European Alps are warming fast. Alpine plants will suffer – and life below ground as well.

LONDON, 1 March, 2021 – The early melting of snow in the Alps is not just bad news for ardent skiers and for those who are dependent on the money they earn during the winter sports season: Alpine plants are in danger too.

Rising temperatures due to climate change are also having a negative impact deep below the surface of the ground.

New research by scientists at the University of Manchester in the UK demonstrates that warming in the area is threatening microbes which live in the Alpine soils.

The microbes play a critical role in supporting life forms above ground, recycling key nutrients upon which animals, plants – and humans – depend.

“More extreme advances in snowmelt timing are forecast for the end of the century”

The microbes also control the amount of carbon stored in the soil: if the cycle of microbial activity is disrupted, then more carbon is released into the atmosphere, resulting in further global warming.

Arthur Broadbent, lead author of a research paper in the ISME Journal,  says climate change is having an alarming impact on microbial communities in Alpine soils.

“Using a high-alpine experiment in the Austrian Alps, we discovered that spring snowmelt triggers an abrupt seasonal transition in soil microbial communities, which is closely linked to rapid shifts in carbon and nitrogen cycling”, he said.

During the winter, microbes in the Alpine soils depend on snow to act as an insulating blanket, allowing them to continue to work throughout the cold months.

Himalayan disaster

The researchers say that climate change in the Alps is taking place at double the rate of the global average. Separate research indicates that profound changes are happening in the Alps and in many other mountainous regions around the world.

In February a flash flood in Uttarakhand in northern India killed nearly 70 people, with 136 more missing and now presumed dead. Most scientists believe the warming climate was the cause of the glacier melt which triggered the disaster.

There are predictions that over the next 80 years more than 90% of glacier ice in the Alpine region will be lost due to ever-rising temperatures.

“Snowmelt is predicted to occur 50 to 130 days earlier in alpine regions due to climate change by the end of the century”, says Dr Broadbent.

Increased warming

“Using experimental manipulations, we demonstrated that earlier snowmelt, of even just 10 days, leads to an earlier seasonal transition in microbial communities and biogeochemical cycling.”

The research paper says that changes in the microbial cycle caused by snow melt will result in less carbon being retained in the soil and so have a negative impact on the growth and productivity of plants.

“This would negatively affect agricultural production and disrupt natural ecosystems. It will also alter annual carbon fluxes in these ecosystems with the potential to cause further climate warming.”

The authors conclude with a clear warning: “More extreme advances in snowmelt timing are forecast for the end of the century.” – Climate News Network

Like many mountainous regions, the European Alps are warming fast. Alpine plants will suffer – and life below ground as well.

LONDON, 1 March, 2021 – The early melting of snow in the Alps is not just bad news for ardent skiers and for those who are dependent on the money they earn during the winter sports season: Alpine plants are in danger too.

Rising temperatures due to climate change are also having a negative impact deep below the surface of the ground.

New research by scientists at the University of Manchester in the UK demonstrates that warming in the area is threatening microbes which live in the Alpine soils.

The microbes play a critical role in supporting life forms above ground, recycling key nutrients upon which animals, plants – and humans – depend.

“More extreme advances in snowmelt timing are forecast for the end of the century”

The microbes also control the amount of carbon stored in the soil: if the cycle of microbial activity is disrupted, then more carbon is released into the atmosphere, resulting in further global warming.

Arthur Broadbent, lead author of a research paper in the ISME Journal,  says climate change is having an alarming impact on microbial communities in Alpine soils.

“Using a high-alpine experiment in the Austrian Alps, we discovered that spring snowmelt triggers an abrupt seasonal transition in soil microbial communities, which is closely linked to rapid shifts in carbon and nitrogen cycling”, he said.

During the winter, microbes in the Alpine soils depend on snow to act as an insulating blanket, allowing them to continue to work throughout the cold months.

Himalayan disaster

The researchers say that climate change in the Alps is taking place at double the rate of the global average. Separate research indicates that profound changes are happening in the Alps and in many other mountainous regions around the world.

In February a flash flood in Uttarakhand in northern India killed nearly 70 people, with 136 more missing and now presumed dead. Most scientists believe the warming climate was the cause of the glacier melt which triggered the disaster.

There are predictions that over the next 80 years more than 90% of glacier ice in the Alpine region will be lost due to ever-rising temperatures.

“Snowmelt is predicted to occur 50 to 130 days earlier in alpine regions due to climate change by the end of the century”, says Dr Broadbent.

Increased warming

“Using experimental manipulations, we demonstrated that earlier snowmelt, of even just 10 days, leads to an earlier seasonal transition in microbial communities and biogeochemical cycling.”

The research paper says that changes in the microbial cycle caused by snow melt will result in less carbon being retained in the soil and so have a negative impact on the growth and productivity of plants.

“This would negatively affect agricultural production and disrupt natural ecosystems. It will also alter annual carbon fluxes in these ecosystems with the potential to cause further climate warming.”

The authors conclude with a clear warning: “More extreme advances in snowmelt timing are forecast for the end of the century.” – Climate News Network

Rising sea levels may make some airports unusable

High flyers could soon have a problem with high water. Rising sea levels could one day shut down airports.

LONDON, 3 February, 2021 − Passengers, prepare for splashdown. Take-off may have to wait for low tide. By 2100, thanks to rising sea levels, around 100 of the world’s airports could be below mean sea level and at least 364 will be vulnerable to flooding.

And that’s assuming the world’s nations keep a promise made in 2015 and confine global heating to no more than 2°C above the average maintained for most of human history. If humans go on burning fossil fuels and clearing forests at the present rate, then at least 572 of the world’s airports could be at risk of flooding from extreme tides, according to a new study in the journal Climate Risk Management.

These things have already happened: in 2018 a typhoon storm surge inundated Kansai International Airport in Osaka Bay, Japan. Superstorm Sandy in 2012 closed New York City’s La Guardia Airport for three days. One-tenth of the planet’s population lives on coastlines less than 10 metres above sea level.

Airports grow up around the great cities: they require flat land and a clear flight path. Coastal flood plains, wetlands and reclaimed land provide exactly that.

Serious risk

“These coastal airports are disproportionately important to the global airline network, and by 2100 between 10% and 20% of all routes will be at risk of disruption,” said Richard Dawson, an engineer at Newcastle University in the United Kingdom. “Sea level rise therefore poses a serious risk to global passenger and freight movements, with considerable cost of damage and disruption.”

He and a colleague looked at the world’s 14,000 airports and helicopter pads to identify 1,238 airports in what geographers call low elevation coastal zones: that is, down by the seaside. Of these, 199, serving 3,436 routes, were in the US; China had 30 airports serving 2,333 routes.

They found that just 20 airports at risk handled more than 800 million passengers in 2018 − approaching a fifth of the world’s passenger traffic that year − and nearly 16 million tonnes of cargo: one-fourth of all the world’s air freight that year. They then started looking at what climate change could do to all that business.

Even before the shutdown of traffic because of the global pandemic, the world’s airlines had been feeling the heat. Research teams have confirmed that ever higher global temperatures mean more atmospheric turbulence at altitude; that wind speed changes will slow flights and raise costs; that extremes of heat could even close airport runways and delay flights for extended periods.

“These coastal airports are disproportionately important to the global airline network, and by 2100 between 10% and 20% of all routes will be at risk of disruption”

Now Professor Dawson and his colleague have compiled a table of hazard rankings for flooded airstrips under a range of climate change scenarios.

Right now, 269 of the world’s airports are at some risk of coastal flooding. This number must rise: by how much, and at what cost, depends on what actions the world takes. But the researchers calculate that by 2100 the risk of disruption could increase 17-fold, or even 69-fold. And because so many important airports are already at or near sea level, up to a fifth of all the world’s routes will be at risk.

And that means higher costs for flood protection, or action to raise airport sites, or relocation. The choice is to adapt or, quite literally, to go under.

“The cost of adaptation will be modest in the context of global infrastructure expenditure,” Professor Dawson said. “However, in some locations the rate of sea level rise, limited economic resources or space for alternative locations will make some airports unviable.” − Climate News Network

High flyers could soon have a problem with high water. Rising sea levels could one day shut down airports.

LONDON, 3 February, 2021 − Passengers, prepare for splashdown. Take-off may have to wait for low tide. By 2100, thanks to rising sea levels, around 100 of the world’s airports could be below mean sea level and at least 364 will be vulnerable to flooding.

And that’s assuming the world’s nations keep a promise made in 2015 and confine global heating to no more than 2°C above the average maintained for most of human history. If humans go on burning fossil fuels and clearing forests at the present rate, then at least 572 of the world’s airports could be at risk of flooding from extreme tides, according to a new study in the journal Climate Risk Management.

These things have already happened: in 2018 a typhoon storm surge inundated Kansai International Airport in Osaka Bay, Japan. Superstorm Sandy in 2012 closed New York City’s La Guardia Airport for three days. One-tenth of the planet’s population lives on coastlines less than 10 metres above sea level.

Airports grow up around the great cities: they require flat land and a clear flight path. Coastal flood plains, wetlands and reclaimed land provide exactly that.

Serious risk

“These coastal airports are disproportionately important to the global airline network, and by 2100 between 10% and 20% of all routes will be at risk of disruption,” said Richard Dawson, an engineer at Newcastle University in the United Kingdom. “Sea level rise therefore poses a serious risk to global passenger and freight movements, with considerable cost of damage and disruption.”

He and a colleague looked at the world’s 14,000 airports and helicopter pads to identify 1,238 airports in what geographers call low elevation coastal zones: that is, down by the seaside. Of these, 199, serving 3,436 routes, were in the US; China had 30 airports serving 2,333 routes.

They found that just 20 airports at risk handled more than 800 million passengers in 2018 − approaching a fifth of the world’s passenger traffic that year − and nearly 16 million tonnes of cargo: one-fourth of all the world’s air freight that year. They then started looking at what climate change could do to all that business.

Even before the shutdown of traffic because of the global pandemic, the world’s airlines had been feeling the heat. Research teams have confirmed that ever higher global temperatures mean more atmospheric turbulence at altitude; that wind speed changes will slow flights and raise costs; that extremes of heat could even close airport runways and delay flights for extended periods.

“These coastal airports are disproportionately important to the global airline network, and by 2100 between 10% and 20% of all routes will be at risk of disruption”

Now Professor Dawson and his colleague have compiled a table of hazard rankings for flooded airstrips under a range of climate change scenarios.

Right now, 269 of the world’s airports are at some risk of coastal flooding. This number must rise: by how much, and at what cost, depends on what actions the world takes. But the researchers calculate that by 2100 the risk of disruption could increase 17-fold, or even 69-fold. And because so many important airports are already at or near sea level, up to a fifth of all the world’s routes will be at risk.

And that means higher costs for flood protection, or action to raise airport sites, or relocation. The choice is to adapt or, quite literally, to go under.

“The cost of adaptation will be modest in the context of global infrastructure expenditure,” Professor Dawson said. “However, in some locations the rate of sea level rise, limited economic resources or space for alternative locations will make some airports unviable.” − Climate News Network

US pays rising costs for climate’s flood damage

America’s rainfall patterns are changing with the global climate − and making catastrophic flood damage even more costly.

LONDON, 21 January, 2021 − Climate change alone has cost the United States a total of $73 billion in flood damage in the last 30 years.

The figure is significant: floods are an expensive fact of life. But Californian scientists are now sure that more than one-third of the costs of US floods must be attributed to the global heating driven by human use of fossil fuels.

The news comes hard on the heels of a second finding: that over the last century, the count of what hydrologists call “extreme streamflow” events in Canada and the US has increased significantly. This confirms that droughts are on the increase − and so are floods.

Such findings matter to engineers and city planners, and to insurers, and each resolves some long-standing uncertainties.

Because floods and droughts are part of the challenge of living close to a constant flow of water, researchers have never been too sure whether costly floods are on the increase or are just more obvious because population growth and urban spread mean that more people with more expensive property are increasingly at risk.

“The shifts towards more extreme events are especially important given the age of our dams, bridges and roads”

A new study in the Proceedings of the National Academy of Sciences settles the matter of rising costs: researchers looked at 6,600 reports of flood damage and rainfall data between 1988 and 2017 and then applied sophisticated mathematical techniques to tease out the contribution from higher precipitation driven by higher average temperatures, driven in turn by ever-higher ratios of carbon dioxide in the atmosphere.

They decided that of the $199bn flood damage costs during those years, human-triggered climate change could account for 36%.

“The fact that extreme precipitation has been increasing and will likely increase is well-known, but what effect that has had on financial damages has been uncertain,” said Frances Davenport, of Stanford University.

“What we find is that, even in states where long-term mean precipitation hasn’t changed, in most cases the wettest events have intensified, increasing the financial damages relative to what would have occurred without the changes in precipitation.”

Higher temperatures mean more evaporation. Higher temperatures mean a bigger burden of water vapour in the atmosphere. So higher rainfall is inevitable.

Variable impacts

But repeated studies have found this will happen unevenly: those places already rainy will see more rain. Other regions can expect longer, more intense dry spells.

A second team of US researchers reports in the journal Science Advances that they looked at streamflow data from 541 North American stations since 1910.

They found that in the US west and south-east, the frequency of “extreme low-flow events” has been on the increase, particularly during summer and autumn. In zones where rivers were likely to be fed by melting snow, there was a discernible rise in flood events. Once again, this is a finding with practical consequences.

“The shifts towards more extreme events are especially important given the age of our dams, bridges and roads,” said Evan Dethier, of Dartmouth College in New Hampshire. “The changes to river flows that we found are important for those who manage or depend on this type of infrastructure.” − Climate News Network

America’s rainfall patterns are changing with the global climate − and making catastrophic flood damage even more costly.

LONDON, 21 January, 2021 − Climate change alone has cost the United States a total of $73 billion in flood damage in the last 30 years.

The figure is significant: floods are an expensive fact of life. But Californian scientists are now sure that more than one-third of the costs of US floods must be attributed to the global heating driven by human use of fossil fuels.

The news comes hard on the heels of a second finding: that over the last century, the count of what hydrologists call “extreme streamflow” events in Canada and the US has increased significantly. This confirms that droughts are on the increase − and so are floods.

Such findings matter to engineers and city planners, and to insurers, and each resolves some long-standing uncertainties.

Because floods and droughts are part of the challenge of living close to a constant flow of water, researchers have never been too sure whether costly floods are on the increase or are just more obvious because population growth and urban spread mean that more people with more expensive property are increasingly at risk.

“The shifts towards more extreme events are especially important given the age of our dams, bridges and roads”

A new study in the Proceedings of the National Academy of Sciences settles the matter of rising costs: researchers looked at 6,600 reports of flood damage and rainfall data between 1988 and 2017 and then applied sophisticated mathematical techniques to tease out the contribution from higher precipitation driven by higher average temperatures, driven in turn by ever-higher ratios of carbon dioxide in the atmosphere.

They decided that of the $199bn flood damage costs during those years, human-triggered climate change could account for 36%.

“The fact that extreme precipitation has been increasing and will likely increase is well-known, but what effect that has had on financial damages has been uncertain,” said Frances Davenport, of Stanford University.

“What we find is that, even in states where long-term mean precipitation hasn’t changed, in most cases the wettest events have intensified, increasing the financial damages relative to what would have occurred without the changes in precipitation.”

Higher temperatures mean more evaporation. Higher temperatures mean a bigger burden of water vapour in the atmosphere. So higher rainfall is inevitable.

Variable impacts

But repeated studies have found this will happen unevenly: those places already rainy will see more rain. Other regions can expect longer, more intense dry spells.

A second team of US researchers reports in the journal Science Advances that they looked at streamflow data from 541 North American stations since 1910.

They found that in the US west and south-east, the frequency of “extreme low-flow events” has been on the increase, particularly during summer and autumn. In zones where rivers were likely to be fed by melting snow, there was a discernible rise in flood events. Once again, this is a finding with practical consequences.

“The shifts towards more extreme events are especially important given the age of our dams, bridges and roads,” said Evan Dethier, of Dartmouth College in New Hampshire. “The changes to river flows that we found are important for those who manage or depend on this type of infrastructure.” − Climate News Network

Fire and flood menace parts of US and Bangladesh

Fire and flood are on the rise. Bangladesh and New York face more flooding: the American West may see more forests burn.

LONDON, 14 December, 2020 − More extreme weather is on the way for the hapless residents of Bangladesh, New York and the western US,  facing the prospect of worsening fire and flood.

There is a new future for New York. By the close of the century, thanks to sea level rise and global heating, parts of it could be swept by hurricane-driven catastrophic floods almost every year.

Things don’t look much brighter for much of Bangladesh. Scientists have recalculated the risk of flooding by the Brahmaputra river system to find that, even without the climate emergency, they had under-estimated the likelihood of devastating floods across the crowded, low-lying landscape.

And far away in the American west, US citizens face yet more and more devastating seasons of fire. The area incinerated by severe fires has increased eight-fold in the last 40 years, thanks to intensifying heat and drought. And thanks to climate change, drought will become more extended and more frequent. The temperatures, too, will go on rising.

All this emerged in just another week of routine climate science, as researchers try to gauge the difficulties to come, for national and civic authorities, for foresters and for farmers.

“The increase in these once-in-a-generation floods is so dramatic because the impact of sea-level rise will create greater flooding, even if the storms today stay the same”

In 2012, Hurricane Sandy hit the US to cause $70bn in damages, and even slammed unexpectedly into New York, to devastate parts of the city. It counted as a once-in-500 years event.

Researchers report in the journal Climatic Change that they looked at the probabilities of more flooding in Jamaica Bay, on Long Island, New York as sea levels rose, along with the sea surface temperatures that drive fiercer storm weather, through the century.

Floods that tend to happen every century could, by 2050, occur every nine years. By 2080 to 2100, they could become annual events. And 500-year events like the 2012 superstorm could by the end of the century happen perhaps once every four years.

“Future projections of the hurricane climatology suggest that climate change would lead to storms that move more slowly and are more intense than we have ever seen before hitting Jamaica Bay,” said Reza Marsooli, an environmental engineer at the Stevens Institute of Technology in Hoboken, New Jersey, a co-author.

“But the increase in these once-in-a-generation or even less frequent floods is so dramatic because the impact of sea-level rise will create greater flooding, even if the storms we are seeing today stayed the same.”

Prepare for worse

The hazard that faces Bangladesh − much of which is at sea level, on fertile floodplain created by the Ganges-Brahmaputra river system − is more insidious.

One of the great waterways of the world, it rises in the Himalayan snows and swells in the monsoon season to flood the rice paddies and replenish farmlands with nourishing sediments. Occasionally the floods become devastating: in 1998, some 70% of the nation was submerged. Floods have recurred, in 2007, 2010 and 2020.

Engineers have been monitoring the flow since the 1950s, and thought they knew the flood probabilities. But US, Australian and Chinese scientists report in the journal Nature Communications that they studied the growth rings in ancient trees to find that Bangladeshis have been living in unusual times: for much of the past 70 years, on the evidence told by old trees along the watershed, the river flow has been unusually dry − the driest in the last 700 years.

“The tree rings suggest that the long-term baseline conditions are much wetter than thought,” said Mukund Palat Rao, of the Lamont-Doherty Earth Observatory at Columbia University in New York, who led the research.

“Whether you consider climate models or natural variability, the message is the same. We should prepare for a higher frequency of flooding than we are currently predicting.”

Forests’ future threatened

In the past 40 years, thanks to global heating driven by ever-higher emissions of greenhouse gases from the combustion of fossil fuels, the state of California has experienced a series of droughts that lasted for years. The fire season too has begun earlier and lasted much longer.

Ecologists report in the journal Geophysical Research Letters that they defined high-severity fires as those that killed 95% of all trees. They then counted the most severe episodes of burning in four great regions of the western US from 1985 to 2017.

They found that by 2017, the area wiped out by severe fires had risen eight times, to more than 2,000 sq kms or 800 sq miles. Much of the tree cover of the US west is adapted to episodes of fire. But the frequency and intensity of recent blazes threatens the future of the forests altogether.

“As more area burns at high severity, the likelihood of conversion to different forest types or even to non-forest increases,” said Sean Parks of the US Forest Service Rocky Mountain Research Station, and the lead author.

“At the same time, the post-fire climate is making it increasingly difficult for seedlings to establish and survive, further reducing the potential for forests to return to their pre-fire condition.” − Climate News Network

Fire and flood are on the rise. Bangladesh and New York face more flooding: the American West may see more forests burn.

LONDON, 14 December, 2020 − More extreme weather is on the way for the hapless residents of Bangladesh, New York and the western US,  facing the prospect of worsening fire and flood.

There is a new future for New York. By the close of the century, thanks to sea level rise and global heating, parts of it could be swept by hurricane-driven catastrophic floods almost every year.

Things don’t look much brighter for much of Bangladesh. Scientists have recalculated the risk of flooding by the Brahmaputra river system to find that, even without the climate emergency, they had under-estimated the likelihood of devastating floods across the crowded, low-lying landscape.

And far away in the American west, US citizens face yet more and more devastating seasons of fire. The area incinerated by severe fires has increased eight-fold in the last 40 years, thanks to intensifying heat and drought. And thanks to climate change, drought will become more extended and more frequent. The temperatures, too, will go on rising.

All this emerged in just another week of routine climate science, as researchers try to gauge the difficulties to come, for national and civic authorities, for foresters and for farmers.

“The increase in these once-in-a-generation floods is so dramatic because the impact of sea-level rise will create greater flooding, even if the storms today stay the same”

In 2012, Hurricane Sandy hit the US to cause $70bn in damages, and even slammed unexpectedly into New York, to devastate parts of the city. It counted as a once-in-500 years event.

Researchers report in the journal Climatic Change that they looked at the probabilities of more flooding in Jamaica Bay, on Long Island, New York as sea levels rose, along with the sea surface temperatures that drive fiercer storm weather, through the century.

Floods that tend to happen every century could, by 2050, occur every nine years. By 2080 to 2100, they could become annual events. And 500-year events like the 2012 superstorm could by the end of the century happen perhaps once every four years.

“Future projections of the hurricane climatology suggest that climate change would lead to storms that move more slowly and are more intense than we have ever seen before hitting Jamaica Bay,” said Reza Marsooli, an environmental engineer at the Stevens Institute of Technology in Hoboken, New Jersey, a co-author.

“But the increase in these once-in-a-generation or even less frequent floods is so dramatic because the impact of sea-level rise will create greater flooding, even if the storms we are seeing today stayed the same.”

Prepare for worse

The hazard that faces Bangladesh − much of which is at sea level, on fertile floodplain created by the Ganges-Brahmaputra river system − is more insidious.

One of the great waterways of the world, it rises in the Himalayan snows and swells in the monsoon season to flood the rice paddies and replenish farmlands with nourishing sediments. Occasionally the floods become devastating: in 1998, some 70% of the nation was submerged. Floods have recurred, in 2007, 2010 and 2020.

Engineers have been monitoring the flow since the 1950s, and thought they knew the flood probabilities. But US, Australian and Chinese scientists report in the journal Nature Communications that they studied the growth rings in ancient trees to find that Bangladeshis have been living in unusual times: for much of the past 70 years, on the evidence told by old trees along the watershed, the river flow has been unusually dry − the driest in the last 700 years.

“The tree rings suggest that the long-term baseline conditions are much wetter than thought,” said Mukund Palat Rao, of the Lamont-Doherty Earth Observatory at Columbia University in New York, who led the research.

“Whether you consider climate models or natural variability, the message is the same. We should prepare for a higher frequency of flooding than we are currently predicting.”

Forests’ future threatened

In the past 40 years, thanks to global heating driven by ever-higher emissions of greenhouse gases from the combustion of fossil fuels, the state of California has experienced a series of droughts that lasted for years. The fire season too has begun earlier and lasted much longer.

Ecologists report in the journal Geophysical Research Letters that they defined high-severity fires as those that killed 95% of all trees. They then counted the most severe episodes of burning in four great regions of the western US from 1985 to 2017.

They found that by 2017, the area wiped out by severe fires had risen eight times, to more than 2,000 sq kms or 800 sq miles. Much of the tree cover of the US west is adapted to episodes of fire. But the frequency and intensity of recent blazes threatens the future of the forests altogether.

“As more area burns at high severity, the likelihood of conversion to different forest types or even to non-forest increases,” said Sean Parks of the US Forest Service Rocky Mountain Research Station, and the lead author.

“At the same time, the post-fire climate is making it increasingly difficult for seedlings to establish and survive, further reducing the potential for forests to return to their pre-fire condition.” − Climate News Network