Tag Archives: Weather

Cloud forests risk drying out by 2060

For the world’s cloud forests, the future is overcast. Some face fiercer storm and flood: they could even lose their unique clouds.

LONDON, 23 April, 2019 – Planet Earth may be about to lose a whole ecosystem: the cloud forests – those species-rich, high altitude rainforests found mostly in Central and South America – could be all but gone in 40 years.

Researchers warn that within 25 years, global warming driven by ever increasing use of fossil fuels could dry up 60-80% of the misty mountain forests of Mexico, Puerto Rico, Costa Rica, Ecuador and Peru, simply by dispersing the clouds that keep them ever moist, and rich with plant, insect and bird life.

And as the habitat alters, that could be it for the Monarch butterflies that migrate in their millions to the mountains of Mexico, the elfin woods warbler found only in Puerto Rico, and the other creatures that make their homes in forests so rich and wet that even the trees are home to yet more green habitat: ferns, lichens, mosses and other epiphytes nourished by year-round water and water vapour.

And the reason? The clouds will have dispersed, or moved uphill, or simply been blown away as greenhouse gas ratios in the atmosphere continue to grow and temperatures creep ever higher, according to new research in the Public Library of Science journal PLOS One.

“Maria is more extreme in its precipitation than anything else the island has ever seen. I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years”

And if nations go on burning ever greater quantities of coal, oil and natural gas to power economic growth, then the cloud and frost that keep the equatorial cloud forests unique homes to living things will have gone.

Nine-tenths of the cloud forests in the Western Hemisphere will have been lost by 2060, if the calculations funded by the US Department of Agriculture’s Forest Service are correct.

Researchers mapped cloud forest across the Western Hemisphere with data collected over the last 60 years and then used climate simulations to see how the habitat would change with time.

They found that indeed some regions would become even more immersed in cloud: this however would only add up to perhaps 1%. For the most part the clouds would thin, the steady supply of moisture would thin, and the forests would begin to change inexorably.

Trees head uphill

This is not the first research to suggest that ever higher temperatures would affect cloud patterns. Scientists using a different approach reported earlier this year that tropical cloud formation of the kind that damps down equatorial temperatures could be at risk.

Other researchers have used historic data to record the steady uphill march of characteristic trees in the Andean forests in response to average global temperature increases of 1°C in the past century.

And yet another team has warned that the increasingly violent winds that arrived in Puerto Rico with Hurricane Maria in 2017 would in any case change the make-up of forest species.

Devastating winds that uproot forest giants at all altitudes won’t be the only problem for the climate-hit forests and the region. Hurricane Maria dumped an unprecedented 1.029 mm of rain in a day on Puerto Rico.

Recurrence likely

A second study from the American Geophysical Union has confirmed that the extreme rainfall that accompanied Maria was not only the worst in the last 60 years, but has become much more likely to happen again.

Thanks to global warming, which increased the capacity of the atmosphere to absorb moisture, such floods are now five times more likely, they write in the journal Geophysical Research Letters.

“Maria is more extreme in its precipitation than anything else the island has ever seen,” said David Keellings of the University of Alabama, one of the authors.

“I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years.” – Climate News Network

For the world’s cloud forests, the future is overcast. Some face fiercer storm and flood: they could even lose their unique clouds.

LONDON, 23 April, 2019 – Planet Earth may be about to lose a whole ecosystem: the cloud forests – those species-rich, high altitude rainforests found mostly in Central and South America – could be all but gone in 40 years.

Researchers warn that within 25 years, global warming driven by ever increasing use of fossil fuels could dry up 60-80% of the misty mountain forests of Mexico, Puerto Rico, Costa Rica, Ecuador and Peru, simply by dispersing the clouds that keep them ever moist, and rich with plant, insect and bird life.

And as the habitat alters, that could be it for the Monarch butterflies that migrate in their millions to the mountains of Mexico, the elfin woods warbler found only in Puerto Rico, and the other creatures that make their homes in forests so rich and wet that even the trees are home to yet more green habitat: ferns, lichens, mosses and other epiphytes nourished by year-round water and water vapour.

And the reason? The clouds will have dispersed, or moved uphill, or simply been blown away as greenhouse gas ratios in the atmosphere continue to grow and temperatures creep ever higher, according to new research in the Public Library of Science journal PLOS One.

“Maria is more extreme in its precipitation than anything else the island has ever seen. I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years”

And if nations go on burning ever greater quantities of coal, oil and natural gas to power economic growth, then the cloud and frost that keep the equatorial cloud forests unique homes to living things will have gone.

Nine-tenths of the cloud forests in the Western Hemisphere will have been lost by 2060, if the calculations funded by the US Department of Agriculture’s Forest Service are correct.

Researchers mapped cloud forest across the Western Hemisphere with data collected over the last 60 years and then used climate simulations to see how the habitat would change with time.

They found that indeed some regions would become even more immersed in cloud: this however would only add up to perhaps 1%. For the most part the clouds would thin, the steady supply of moisture would thin, and the forests would begin to change inexorably.

Trees head uphill

This is not the first research to suggest that ever higher temperatures would affect cloud patterns. Scientists using a different approach reported earlier this year that tropical cloud formation of the kind that damps down equatorial temperatures could be at risk.

Other researchers have used historic data to record the steady uphill march of characteristic trees in the Andean forests in response to average global temperature increases of 1°C in the past century.

And yet another team has warned that the increasingly violent winds that arrived in Puerto Rico with Hurricane Maria in 2017 would in any case change the make-up of forest species.

Devastating winds that uproot forest giants at all altitudes won’t be the only problem for the climate-hit forests and the region. Hurricane Maria dumped an unprecedented 1.029 mm of rain in a day on Puerto Rico.

Recurrence likely

A second study from the American Geophysical Union has confirmed that the extreme rainfall that accompanied Maria was not only the worst in the last 60 years, but has become much more likely to happen again.

Thanks to global warming, which increased the capacity of the atmosphere to absorb moisture, such floods are now five times more likely, they write in the journal Geophysical Research Letters.

“Maria is more extreme in its precipitation than anything else the island has ever seen,” said David Keellings of the University of Alabama, one of the authors.

“I just didn’t expect that it was going to be so much more than anything else that has happened in the last 60 years.” – Climate News Network

Ocean heatwaves drive more fish north

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

As sea water warms, sub-tropical fish swim north. They may do so more often as ocean heatwaves add to the sweltering.

LONDON, 22 March, 2019 – With a little help from ocean heatwaves, the world’s seas are changing. Researchers in California can now name 37 species that have shifted their range further north than ever before in response to unusually hot summers in the eastern Pacific.

In the years 2014-2016, the pelagic red crab Pleuroncodes planipes was spotted off Agate Beach, Oregon, a full 595 kilometres further north than ever before. A deepwater invertebrate called the black-tipped spiny dorid Acanthodoris rhodoceras also made it to Oregon, 620 kilometres from what had previously been its most northerly range.

Both were joined by an assortment of snails, sea butterflies, pteropods, nudibranchs, red algae, sea anemones, siphonophores, fish, dolphins, sea turtles and other citizens of the sub-tropical seas in making the great trek north to what had once been cooler waters, the researchers record in the journal Scientific Reports.

They collected their data in the wake of two significant changes in water temperatures. One involved a mysterious “blob” of warm water that made the journey south from the Gulf of Alaska, the other a blister of warm water on the way north associated with a natural phenomenon known as El Niño in 2015.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems”

Altogether they recorded 67 rare, warm water sightings off California and Oregon: of these 37 had never been observed so far north.

“Against a backdrop of climate change, we hope southern species will track northward because that’s necessary for their persistence and survival,” said Eric Sanford, an ecologist at the University of California, Davis, who led the study.

“It’s perhaps a glimpse of what northern California’s coast might look like in the future as ocean temperatures continue to warm.”

And just in case anyone thinks the temperatures in 2014-2016 were a freak – a response to an unprecedented pattern of weather events – a second set of scientists has uncomfortable news.

Extreme heat increases

Not only were the oceans in 2018 hotter than at any time  since records began, but periods of extreme heat on the high seas – that is, marine heatwaves – are on the increase around the globe.

Between 1987 and 2016, the number of heatwave days per year was 54% higher than for the years 1925 to 1954. And this is true not just for the eastern Pacific but for many regions in the Atlantic and Indian Oceans as well.

This is likely to be bad news for individual species, bad news for ecosystems and bad news for the key species – kelps, corals, sea grasses and so on – that provide vital habitats for marine life, they report in the journal Nature Climate Change.

The researchers define marine heatwaves as episodes in which sea surface temperatures exceed the seasonal norm for at least five consecutive days.

Marine threat

Increasing heatwaves over land have already been identified as potentially a threat to human life. They will menace marine life as well, the scientists say.

“Ocean ecosystems currently face a number of threats, including overfishing, acidification and plastic pollution, but periods of extreme temperatures can cause rapid and profound ecological changes, leading to loss of habitat, local extinctions, reduced fisheries catches and altered food webs”, said Dan Smale, of the UK Marine Biological Association, who led the research.

“The major concern is that the oceans have warmed significantly as a consequence of manmade climate change, so that marine heatwaves have become more frequent and will likely intensify over the coming decades.

“Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.” – Climate News Network

The day the Earth’s climate went berserk

The day in 1815 when the world’s climate went berserk was only the start of months and years of global climate disruption and social unrest.

LONDON, 19 March, 2019 − If you had been in what were then called the Dutch East Indies on 10 April 1815, the day would have been etched indelibly on your memory: it was the day the global climate went berserk.

Many parts of the world are already feeling the effects of a changing climate. Island nations in the Pacific are seeing their lands eaten away by rising sea levels.

Whole communities of people in Arctic regions are threatened by rapidly expanding ice melt. The foundations of houses are being swept away. Traditional hunting grounds are being lost.

Wolfgang Behringer is a climate historian who seeks to draw parallels between what is going on now and events long ago. In particular Behringer, a professor of early modern history at Saarland University in Germany, looks at how changes in climate can influence and shape events – political, economic and social.

In a new book he focuses on the 1815 volcanic explosion of Tambora, on the island of Sumbawa in present-day Indonesia. The eruption still rates as the largest in human history; the cloud that burst from the volcano reached a height of 45 kilometres.

“Apparently minor changes in temperature and humidity suffice to shake up entrenched ecosystems, but above all entrenched agricultural systems”

Many thousands of people were killed on Sumbawa and adjoining islands, including Lombok and Bali. Dust clouds from Tambora were swept around the globe; the world’s climate went berserk, says Behringer.

“The dimensions of the Tambora crisis were so extraordinary because its roots lay in nature, in processes of geology, atmospheric physics and meteorology. These forces of nature respect no borders.”

The suspended particles from the volcano reduced solar radiation and led to global cooling. What scientists call a dry fog enveloped much of Asia. A blue sun appeared in Latin America. Snow that fell in Italy was red and yellow.

The winter of 1815/16 in much of the world was one of the coldest of the century. In Europe, 1816 became known as the year without summer. In North America what was described as the “Yankee chill” resulted in the worst harvest ever recorded.

Global upset

Torrential rains caused floods and thousands of deaths in China and India. Famine was widespread.

Behringer says the changes in climate provoked social unrest on a worldwide scale.

“The reactions to the crisis offer an example of how societies and individuals respond to climate change, what risks emerge and what opportunities may be associated with it”, he writes.

Epidemics broke out. In 1817 the cholera pathogen appeared for the first time. In India alone it’s believed 1.25 million died of the disease each year for more than a decade following the Tambora explosion. The suffering led to uprisings against British colonial rule in India and Ceylon, today’s Sri Lanka.

Simmering revolution

In Ireland, Scotland and Wales people rioted as grain prices soared. In England the authorities became concerned at a rise in revolutionary activity. Prisons filled up.

The years following 1815 were a time of mass migration. Hundreds of thousands of people in Europe, in an effort to escape hunger, travelled across the Atlantic to the US and Canada. Within the US there was a movement westwards towards California, which had largely escaped the more severe effects of the eruption.

There were other, less dramatic consequences. Behringer says Tambora inspired a new-found preoccupation with weather and climate phenomena. Not surprisingly, it spurred the emergence of the science of volcanology.

Establishing the cause and effect of changes in climate – whether caused by volcanic eruptions or by the burning of fossil fuels and the increasing amounts of greenhouse gases in the atmosphere in consequence – is an extremely tricky business.

Temporary influence

Behringer makes the point that not all of the events of 1815 and subsequent years can be directly attributed to Tambora. But the explosion did act as a catalyst.

The eruption was a single event and its after-effects were not permanent though, for a limited period, the world’s ecological framework was altered.

“Apparently minor changes in temperature and humidity sufficed (and still suffice today) to shake up entrenched ecosystems, but above all entrenched agricultural systems.

“And without their daily bread, people can very quickly become angry. In such situations it is clear – even in absolutist monarchies or dictatorships – who the sovereign is.” − Climate News Network

* * *

Tambora and the Year without a Summer, Polity Books, £25.00: to be published on 26 April, 2019.

The day in 1815 when the world’s climate went berserk was only the start of months and years of global climate disruption and social unrest.

LONDON, 19 March, 2019 − If you had been in what were then called the Dutch East Indies on 10 April 1815, the day would have been etched indelibly on your memory: it was the day the global climate went berserk.

Many parts of the world are already feeling the effects of a changing climate. Island nations in the Pacific are seeing their lands eaten away by rising sea levels.

Whole communities of people in Arctic regions are threatened by rapidly expanding ice melt. The foundations of houses are being swept away. Traditional hunting grounds are being lost.

Wolfgang Behringer is a climate historian who seeks to draw parallels between what is going on now and events long ago. In particular Behringer, a professor of early modern history at Saarland University in Germany, looks at how changes in climate can influence and shape events – political, economic and social.

In a new book he focuses on the 1815 volcanic explosion of Tambora, on the island of Sumbawa in present-day Indonesia. The eruption still rates as the largest in human history; the cloud that burst from the volcano reached a height of 45 kilometres.

“Apparently minor changes in temperature and humidity suffice to shake up entrenched ecosystems, but above all entrenched agricultural systems”

Many thousands of people were killed on Sumbawa and adjoining islands, including Lombok and Bali. Dust clouds from Tambora were swept around the globe; the world’s climate went berserk, says Behringer.

“The dimensions of the Tambora crisis were so extraordinary because its roots lay in nature, in processes of geology, atmospheric physics and meteorology. These forces of nature respect no borders.”

The suspended particles from the volcano reduced solar radiation and led to global cooling. What scientists call a dry fog enveloped much of Asia. A blue sun appeared in Latin America. Snow that fell in Italy was red and yellow.

The winter of 1815/16 in much of the world was one of the coldest of the century. In Europe, 1816 became known as the year without summer. In North America what was described as the “Yankee chill” resulted in the worst harvest ever recorded.

Global upset

Torrential rains caused floods and thousands of deaths in China and India. Famine was widespread.

Behringer says the changes in climate provoked social unrest on a worldwide scale.

“The reactions to the crisis offer an example of how societies and individuals respond to climate change, what risks emerge and what opportunities may be associated with it”, he writes.

Epidemics broke out. In 1817 the cholera pathogen appeared for the first time. In India alone it’s believed 1.25 million died of the disease each year for more than a decade following the Tambora explosion. The suffering led to uprisings against British colonial rule in India and Ceylon, today’s Sri Lanka.

Simmering revolution

In Ireland, Scotland and Wales people rioted as grain prices soared. In England the authorities became concerned at a rise in revolutionary activity. Prisons filled up.

The years following 1815 were a time of mass migration. Hundreds of thousands of people in Europe, in an effort to escape hunger, travelled across the Atlantic to the US and Canada. Within the US there was a movement westwards towards California, which had largely escaped the more severe effects of the eruption.

There were other, less dramatic consequences. Behringer says Tambora inspired a new-found preoccupation with weather and climate phenomena. Not surprisingly, it spurred the emergence of the science of volcanology.

Establishing the cause and effect of changes in climate – whether caused by volcanic eruptions or by the burning of fossil fuels and the increasing amounts of greenhouse gases in the atmosphere in consequence – is an extremely tricky business.

Temporary influence

Behringer makes the point that not all of the events of 1815 and subsequent years can be directly attributed to Tambora. But the explosion did act as a catalyst.

The eruption was a single event and its after-effects were not permanent though, for a limited period, the world’s ecological framework was altered.

“Apparently minor changes in temperature and humidity sufficed (and still suffice today) to shake up entrenched ecosystems, but above all entrenched agricultural systems.

“And without their daily bread, people can very quickly become angry. In such situations it is clear – even in absolutist monarchies or dictatorships – who the sovereign is.” − Climate News Network

* * *

Tambora and the Year without a Summer, Polity Books, £25.00: to be published on 26 April, 2019.

For offshore wind turbines size matters

As turbines grow in size and costs tumble, offshore wind turbines, both floating and fixed to the seabed, have vast potential.

LONDON, 7 March, 2019 − Offshore wind power is set to become one of the world’s largest electricity producers in the next decade as costs fall and turbines grow in size.

Up till now turbines standing on the seabed near to the coast in Europe have been seen as the most promising technology for offshore wind farms. But the success of floating machines that can be deployed in deeper water has meant many more coastal communities can benefit. Japan and the US are among the countries with the greatest potential.

The speed with which the industry has grown in the last decade has defied all expectations. Large turbines used to have a two to three megawatt output, but now the standard size is 7.5 megawatts and turbines capable of generating up to 10 megawatts are in the pipeline.

As a result the output of one offshore turbine is thirty times greater than with the first ones deployed in 1991 − and the cost has fallen to half that of new nuclear power.

This, coupled with experience showing that the wind blows more steadily out to sea and produces far more consistent power than turbines on land, has led many more countries to see offshore wind as a major potential source of renewable energy. The turbines have shown themselves to be robust even in extreme storm conditions.

“Previous estimates of the growth of renewables, at least wind and solar power, have always been underestimates”

Production has just begun from the world’s largest offshore wind farm in the North Sea, where construction started only in January 2018 and which began feeding power ashore in England 13 months later. The project is enormous, all four phases covering nearly 2,000 square miles, and will produce up to 6 GW of power, the same as five large nuclear power stations.

Apart from the sheer size, the plan is to have the whole development completed by 2025, before the partly-constructed Hinkley Point C nuclear power station in the West of England will start up, and providing return on capital for the investors years before its nuclear rivals.

While the market for turbines fixed to the seabed is expected to continue to grow very fast, it is floating turbines that will be the next big player. These are again huge machines, taking advantage of the steadier
winds out to sea, and not needing expensive seabed foundations.

It took 15 years for the Norwegian state oil company Statoil, now rebranded as Equinor to emphasise its partial move to renewables, to develop the first offshore wind farm 15 miles of the coast of Aberdeen in Scotland.

Outrunning expectations

There are five turbines with blades 175 metres long and a counterweight extending 78 metres below the surface, which is chained to the seabed. The turbines started feeding into the grid in October 2017 and output was soon exceeding expectations.

The fact that it was Statoil that designed and developed the floating turbines is significant. The offshore wind industry uses many of the skills developed by offshore gas and oil ventures and provides an investment opportunity for oil majors under pressure to diversify and show they have green credentials.

A report, Wind Power to Spare, produced last year by a research and campaigning group, Environment America, showed that there was enough potential wind power just off the US east coast to provide more electricity than was currently used in the region’s maritime states – plus enough for powering electric cars and for providing heating for the entire population of the eastern coastal states in the future.

Since the report was published developers, looking at the success of Europe in exploiting this resource, have shown an escalation of interest. The same is true of Japan, where the nuclear industry remains in deep trouble as a result of the Fukushima accident in 2011, with many of its reactors not expected to restart.

Potential ignored

Back in Europe, where offshore wind was first developed, manufacturers are eyeing up potential new markets both in the North Sea and elsewhere. France for example has no offshore wind farms but could deploy hundreds of floating turbines.

Research suggests that water depths in the North Sea are ideal for floating turbines. If half the area available could be covered in turbines they would make enough electricity to power the whole EU four times over.

That prediction is made by Equinor. It also estimates in the same report that by 2030 Japan could have 3.5 gigawatts of floating wind power, France 2.9 GW and the US 2 GW, with a further 1.9 GW in the UK and Ireland.

This would make a significant contribution to reducing the world’s burning of fossil fuels, particularly since previous estimates of the growth of renewables, at least wind and solar power, have always been underestimates. − Climate News Network

As turbines grow in size and costs tumble, offshore wind turbines, both floating and fixed to the seabed, have vast potential.

LONDON, 7 March, 2019 − Offshore wind power is set to become one of the world’s largest electricity producers in the next decade as costs fall and turbines grow in size.

Up till now turbines standing on the seabed near to the coast in Europe have been seen as the most promising technology for offshore wind farms. But the success of floating machines that can be deployed in deeper water has meant many more coastal communities can benefit. Japan and the US are among the countries with the greatest potential.

The speed with which the industry has grown in the last decade has defied all expectations. Large turbines used to have a two to three megawatt output, but now the standard size is 7.5 megawatts and turbines capable of generating up to 10 megawatts are in the pipeline.

As a result the output of one offshore turbine is thirty times greater than with the first ones deployed in 1991 − and the cost has fallen to half that of new nuclear power.

This, coupled with experience showing that the wind blows more steadily out to sea and produces far more consistent power than turbines on land, has led many more countries to see offshore wind as a major potential source of renewable energy. The turbines have shown themselves to be robust even in extreme storm conditions.

“Previous estimates of the growth of renewables, at least wind and solar power, have always been underestimates”

Production has just begun from the world’s largest offshore wind farm in the North Sea, where construction started only in January 2018 and which began feeding power ashore in England 13 months later. The project is enormous, all four phases covering nearly 2,000 square miles, and will produce up to 6 GW of power, the same as five large nuclear power stations.

Apart from the sheer size, the plan is to have the whole development completed by 2025, before the partly-constructed Hinkley Point C nuclear power station in the West of England will start up, and providing return on capital for the investors years before its nuclear rivals.

While the market for turbines fixed to the seabed is expected to continue to grow very fast, it is floating turbines that will be the next big player. These are again huge machines, taking advantage of the steadier
winds out to sea, and not needing expensive seabed foundations.

It took 15 years for the Norwegian state oil company Statoil, now rebranded as Equinor to emphasise its partial move to renewables, to develop the first offshore wind farm 15 miles of the coast of Aberdeen in Scotland.

Outrunning expectations

There are five turbines with blades 175 metres long and a counterweight extending 78 metres below the surface, which is chained to the seabed. The turbines started feeding into the grid in October 2017 and output was soon exceeding expectations.

The fact that it was Statoil that designed and developed the floating turbines is significant. The offshore wind industry uses many of the skills developed by offshore gas and oil ventures and provides an investment opportunity for oil majors under pressure to diversify and show they have green credentials.

A report, Wind Power to Spare, produced last year by a research and campaigning group, Environment America, showed that there was enough potential wind power just off the US east coast to provide more electricity than was currently used in the region’s maritime states – plus enough for powering electric cars and for providing heating for the entire population of the eastern coastal states in the future.

Since the report was published developers, looking at the success of Europe in exploiting this resource, have shown an escalation of interest. The same is true of Japan, where the nuclear industry remains in deep trouble as a result of the Fukushima accident in 2011, with many of its reactors not expected to restart.

Potential ignored

Back in Europe, where offshore wind was first developed, manufacturers are eyeing up potential new markets both in the North Sea and elsewhere. France for example has no offshore wind farms but could deploy hundreds of floating turbines.

Research suggests that water depths in the North Sea are ideal for floating turbines. If half the area available could be covered in turbines they would make enough electricity to power the whole EU four times over.

That prediction is made by Equinor. It also estimates in the same report that by 2030 Japan could have 3.5 gigawatts of floating wind power, France 2.9 GW and the US 2 GW, with a further 1.9 GW in the UK and Ireland.

This would make a significant contribution to reducing the world’s burning of fossil fuels, particularly since previous estimates of the growth of renewables, at least wind and solar power, have always been underestimates. − Climate News Network

Melting polar ice sheets will alter weather

Sea level rise and melting polar ice sheets may not cause a climate catastrophe, but they will certainly change weather patterns unpredictably.

LONDON, 15 February, 2019 – The global weather is about to get worse. The melting polar ice sheets will mean rainfall and windstorms could become more violent, and hot spells and ice storms could become more extreme.

This is because the ice sheets of Greenland and Antarctica are melting, to affect what were once stable ocean currents and airflow patterns around the globe.

Planetary surface temperatures could rise by 3°C or even 4°C by the end of the century. Global sea levels will rise in ways that would “enhance global temperature variability”, but this might not be as high as earlier studies have predicted. That is because the ice cliffs of Antarctica might not be so much at risk of disastrous collapse that would set the glaciers accelerating to the sea.

The latest revision of evidence from the melting ice sheets in two hemispheres – and there is plenty of evidence that melting is happening at ever greater rates – is based on two studies of what could happen to the world’s greatest reservoirs of frozen freshwater if nations pursue current policies, fossil fuel combustion continues to increase, and global average temperatures creep up to unprecedented levels.

“Even if we do include ice-cliff instability … the most likely contribution to sea level rise would be less than half a metre by 2100”

“Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic ice sheets to enter Earth’s oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world,” said Nick Golledge, a south polar researcher at Victoria University, in New Zealand.

He and colleagues from Canada, the US, Germany and the UK report in Nature that they matched satellite observations of what is happening to the ice sheets with detailed simulations of the complex effects of melting over time, and according to the human response so far to warnings of climate change.

In Paris in 2015, leaders from 195 nations vowed to contain global warming to “well below” an average rise of 2°C by 2100. But promises have yet to become concerted and coherent action, and researchers warn that on present policies, a 3°C rise seems inevitable.

Sea levels have already risen by about 14 cms in the last century: the worst scenarios have proposed a devastating rise of 130 cms by 2100. The fastest increase in the rise of sea levels is likely to happen between 2065 and 2075.

Gulf Stream weakens

As warmer melt water gets into the North Atlantic, that major ocean current the Gulf Stream is likely to be weakened. Air temperatures are likely to rise over eastern Canada, central America and the high Arctic. Northwestern Europe – scientists have been warning of this for years – will become cooler.

In the Antarctic, a lens of warm fresh water will form over the surface, allowing uprising warm ocean water to spread and cause what could be further Antarctic melting.

But how bad this could be is re-examined in a second, companion paper in Nature. Tamsin Edwards, now at King’s College London, Dr Golledge and others took a fresh look at an old scare: that the vast cliffs of ice – some of them 100 metres above sea level – around the Antarctic could become unstable and collapse, accelerating the retreat of the ice behind them.

They used geophysical techniques to analyse dramatic episodes of ice loss that must have happened 3 million years ago and 125,000 years ago, and they went back to the present patterns of melt. These losses, in their calculations, did not cause unstoppable ice loss in the past, and may not affect the future much either.

Instability less important

“We’ve shown that ice-cliff instability doesn’t appear to be an essential mechanism in reproducing past sea level changes and so this suggests ‘the jury’s still out’ when it comes to including it in future predictions,” said Dr Edwards.

“Even if we do include ice-cliff instability, our more thorough assessment shows the most likely contribution to sea level rise would be less than half a metre by 2100.”

At worst, there is a one in 20 chance that enough of Antarctica’s glacial burden will melt to raise sea levels by 39 cms. More likely, both studies conclude, under high levels of greenhouse gas concentrations, south polar ice will only melt to raise sea levels worldwide by about 15 cms. – Climate News Network

Sea level rise and melting polar ice sheets may not cause a climate catastrophe, but they will certainly change weather patterns unpredictably.

LONDON, 15 February, 2019 – The global weather is about to get worse. The melting polar ice sheets will mean rainfall and windstorms could become more violent, and hot spells and ice storms could become more extreme.

This is because the ice sheets of Greenland and Antarctica are melting, to affect what were once stable ocean currents and airflow patterns around the globe.

Planetary surface temperatures could rise by 3°C or even 4°C by the end of the century. Global sea levels will rise in ways that would “enhance global temperature variability”, but this might not be as high as earlier studies have predicted. That is because the ice cliffs of Antarctica might not be so much at risk of disastrous collapse that would set the glaciers accelerating to the sea.

The latest revision of evidence from the melting ice sheets in two hemispheres – and there is plenty of evidence that melting is happening at ever greater rates – is based on two studies of what could happen to the world’s greatest reservoirs of frozen freshwater if nations pursue current policies, fossil fuel combustion continues to increase, and global average temperatures creep up to unprecedented levels.

“Even if we do include ice-cliff instability … the most likely contribution to sea level rise would be less than half a metre by 2100”

“Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic ice sheets to enter Earth’s oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world,” said Nick Golledge, a south polar researcher at Victoria University, in New Zealand.

He and colleagues from Canada, the US, Germany and the UK report in Nature that they matched satellite observations of what is happening to the ice sheets with detailed simulations of the complex effects of melting over time, and according to the human response so far to warnings of climate change.

In Paris in 2015, leaders from 195 nations vowed to contain global warming to “well below” an average rise of 2°C by 2100. But promises have yet to become concerted and coherent action, and researchers warn that on present policies, a 3°C rise seems inevitable.

Sea levels have already risen by about 14 cms in the last century: the worst scenarios have proposed a devastating rise of 130 cms by 2100. The fastest increase in the rise of sea levels is likely to happen between 2065 and 2075.

Gulf Stream weakens

As warmer melt water gets into the North Atlantic, that major ocean current the Gulf Stream is likely to be weakened. Air temperatures are likely to rise over eastern Canada, central America and the high Arctic. Northwestern Europe – scientists have been warning of this for years – will become cooler.

In the Antarctic, a lens of warm fresh water will form over the surface, allowing uprising warm ocean water to spread and cause what could be further Antarctic melting.

But how bad this could be is re-examined in a second, companion paper in Nature. Tamsin Edwards, now at King’s College London, Dr Golledge and others took a fresh look at an old scare: that the vast cliffs of ice – some of them 100 metres above sea level – around the Antarctic could become unstable and collapse, accelerating the retreat of the ice behind them.

They used geophysical techniques to analyse dramatic episodes of ice loss that must have happened 3 million years ago and 125,000 years ago, and they went back to the present patterns of melt. These losses, in their calculations, did not cause unstoppable ice loss in the past, and may not affect the future much either.

Instability less important

“We’ve shown that ice-cliff instability doesn’t appear to be an essential mechanism in reproducing past sea level changes and so this suggests ‘the jury’s still out’ when it comes to including it in future predictions,” said Dr Edwards.

“Even if we do include ice-cliff instability, our more thorough assessment shows the most likely contribution to sea level rise would be less than half a metre by 2100.”

At worst, there is a one in 20 chance that enough of Antarctica’s glacial burden will melt to raise sea levels by 39 cms. More likely, both studies conclude, under high levels of greenhouse gas concentrations, south polar ice will only melt to raise sea levels worldwide by about 15 cms. – Climate News Network

Worse storms in prospect as warmth rises

Once again, US government scientists warn that hurricane and flood hazard is amplified by a warming world. But worse storms are caused by big cities too.

LONDON, 19 November, 2018 – Worse storms are on the way, as many Americans know all too well. Hurricane Katrina was the costliest natural disaster ever to hit the US: it blew ashore over New Orleans in August 2005 to claim at least 1,833 lives and wreak economic damage worth, in today’s prices, $160bn.

And however bad it was, climate change made it worse. Because of global warming up to that point, up to 9% more rain fell over the city, some of it to sweep away the river defences and precipitate disastrous flooding.

A second study, also in Nature, warns: big cities make bad storms even worse. Urbanisation – all those roads, pavements, rooftops and so on – multiplies the risk of flooding on average 21-fold. The growth of Houston in Texas left a city at the mercy of Hurricane Harvey in 2017: the scale of flooding was without precedent.

The research is based on computer modelling of the impact of overall planetary warming – around 1°C in the past century – on local sea and coastal conditions.

Rising economic harm

Warmer atmospheres hold more water. With each 1°C rise, the capacity to absorb moisture increases by 7% , so in a warmer world storms will be wetter. With higher temperatures, storms are likely to be more ferocious. Researchers have repeatedly warned that because of these simple principles, as global temperatures rise, the US faces ever bigger economic losses each succeeding hurricane season.

Houston wasn’t prepared for what seemed like a once-in-a-thousand-years storm, but extreme rainstorms will become even more extreme and in Texas more Harvey-scale storms are on the way.

Water that falls on forest or wetland or coastal savannah is at least partly absorbed. Hard rain that hits tarmacadam and concrete could swiftly become a flash flood. So the latest study is a confirmation of much previous research.

“Efforts to build flood mitigation strategies must use an improved understanding of the multiple processes in place”

And although President Trump has condemned climate change science as a hoax devised by the Chinese, and announced a withdrawal from the Paris Agreement signed by 195 nations to limit global warming to if possible less than 2°C by 2100, the confirmation of greater climate change danger once again comes from a US government research base, the Lawrence Berkeley National Laboratory.

Christina Patricola, of the laboratory’s climate division, reports in Nature that she and a colleague chose 15 tropical cyclones that have occurred in the last decade in the Atlantic, the Pacific and the Indian Oceans, and then built computer simulations of those storms while changing factors such as air and ocean temperatures, humidity, and the greenhouse gas concentrations that dictate overall planetary temperatures.

The two scientists looked at the effects of climate change so far, and the shape of storms to come. They found that warming hitherto has made rainfall between 5% and 10% more intense, but may not have so far made much difference to overall hurricane windspeeds.

Strengthening winds

But if the climate continues to warm – and it could warm by 3°C or more this century, as ever greater combustion of fossil fuels puts ever more carbon dioxide into the atmosphere – peak wind speeds could increase by up to 25 knots or very nearly 50 kilometres per hour.

The scientists also found that future rainfall in such storms could increase by between 15% and 35%. And the same computer models that predict windier, wetter storms tomorrow accurately predicted the pattern of the storms that had already happened. “The fact that almost all of the 15 tropical cyclones responded in a similar way gives confidence to the results,” Dr Patricola said.

In a companion study, scientists from US universities looked at the other component of the Hurricane Harvey disaster in 2017: the changes in the city of Houston itself.

Between 25 and 30 August, Harvey dumped 1.3 metres of rain on the metropolis. Between 2000 and 2011, Houston had the largest urban growth and the fifth largest population growth in the entire US. That is, it became a bigger target, with a greater area of paving and sealed surfaces to channel the flowing water.

Slower and wetter

The changing contour of the city helped increase atmospheric drag, slowing the passage of the hurricane and delaying it for long enough to drop even more rain. And then the surface of asphalt and concrete made conditions worse.

So, the researchers concluded, the new building made the risk of catastrophic flooding somewhere between hardly at all and up to 90 times more likely, depending on which part of the city they were looking at. Altogether, the risk of more flooding on the scale of Harvey had increased 21-fold.

The message is that coastal cities must plan for the worst and keep planning. Hurricane winds and rainfall are going to intensify in the future. Cities will keep on growing as human numbers increase.

“Planning must take into account the compounded nature of these risks,” they conclude, “and efforts to build flood mitigation strategies must use an improved understanding of the multiple processes in place.” – Climate News Network

Once again, US government scientists warn that hurricane and flood hazard is amplified by a warming world. But worse storms are caused by big cities too.

LONDON, 19 November, 2018 – Worse storms are on the way, as many Americans know all too well. Hurricane Katrina was the costliest natural disaster ever to hit the US: it blew ashore over New Orleans in August 2005 to claim at least 1,833 lives and wreak economic damage worth, in today’s prices, $160bn.

And however bad it was, climate change made it worse. Because of global warming up to that point, up to 9% more rain fell over the city, some of it to sweep away the river defences and precipitate disastrous flooding.

A second study, also in Nature, warns: big cities make bad storms even worse. Urbanisation – all those roads, pavements, rooftops and so on – multiplies the risk of flooding on average 21-fold. The growth of Houston in Texas left a city at the mercy of Hurricane Harvey in 2017: the scale of flooding was without precedent.

The research is based on computer modelling of the impact of overall planetary warming – around 1°C in the past century – on local sea and coastal conditions.

Rising economic harm

Warmer atmospheres hold more water. With each 1°C rise, the capacity to absorb moisture increases by 7% , so in a warmer world storms will be wetter. With higher temperatures, storms are likely to be more ferocious. Researchers have repeatedly warned that because of these simple principles, as global temperatures rise, the US faces ever bigger economic losses each succeeding hurricane season.

Houston wasn’t prepared for what seemed like a once-in-a-thousand-years storm, but extreme rainstorms will become even more extreme and in Texas more Harvey-scale storms are on the way.

Water that falls on forest or wetland or coastal savannah is at least partly absorbed. Hard rain that hits tarmacadam and concrete could swiftly become a flash flood. So the latest study is a confirmation of much previous research.

“Efforts to build flood mitigation strategies must use an improved understanding of the multiple processes in place”

And although President Trump has condemned climate change science as a hoax devised by the Chinese, and announced a withdrawal from the Paris Agreement signed by 195 nations to limit global warming to if possible less than 2°C by 2100, the confirmation of greater climate change danger once again comes from a US government research base, the Lawrence Berkeley National Laboratory.

Christina Patricola, of the laboratory’s climate division, reports in Nature that she and a colleague chose 15 tropical cyclones that have occurred in the last decade in the Atlantic, the Pacific and the Indian Oceans, and then built computer simulations of those storms while changing factors such as air and ocean temperatures, humidity, and the greenhouse gas concentrations that dictate overall planetary temperatures.

The two scientists looked at the effects of climate change so far, and the shape of storms to come. They found that warming hitherto has made rainfall between 5% and 10% more intense, but may not have so far made much difference to overall hurricane windspeeds.

Strengthening winds

But if the climate continues to warm – and it could warm by 3°C or more this century, as ever greater combustion of fossil fuels puts ever more carbon dioxide into the atmosphere – peak wind speeds could increase by up to 25 knots or very nearly 50 kilometres per hour.

The scientists also found that future rainfall in such storms could increase by between 15% and 35%. And the same computer models that predict windier, wetter storms tomorrow accurately predicted the pattern of the storms that had already happened. “The fact that almost all of the 15 tropical cyclones responded in a similar way gives confidence to the results,” Dr Patricola said.

In a companion study, scientists from US universities looked at the other component of the Hurricane Harvey disaster in 2017: the changes in the city of Houston itself.

Between 25 and 30 August, Harvey dumped 1.3 metres of rain on the metropolis. Between 2000 and 2011, Houston had the largest urban growth and the fifth largest population growth in the entire US. That is, it became a bigger target, with a greater area of paving and sealed surfaces to channel the flowing water.

Slower and wetter

The changing contour of the city helped increase atmospheric drag, slowing the passage of the hurricane and delaying it for long enough to drop even more rain. And then the surface of asphalt and concrete made conditions worse.

So, the researchers concluded, the new building made the risk of catastrophic flooding somewhere between hardly at all and up to 90 times more likely, depending on which part of the city they were looking at. Altogether, the risk of more flooding on the scale of Harvey had increased 21-fold.

The message is that coastal cities must plan for the worst and keep planning. Hurricane winds and rainfall are going to intensify in the future. Cities will keep on growing as human numbers increase.

“Planning must take into account the compounded nature of these risks,” they conclude, “and efforts to build flood mitigation strategies must use an improved understanding of the multiple processes in place.” – Climate News Network

Weakened hurricanes may be wind farm bonus

When high winds meet tall sails in the right place, something’s got to give. Offshore wind farms may lead to weakened hurricanes.

LONDON, 23 October, 2018 − US scientists have identified yet another wonder of that icon of renewable energy, the offshore wind farm: they may result in weakened hurricanes. Turbines in the right place could not just take the heat out of a hurricane, they could reduce the risk of catastrophic flooding as well.

The prediction is based entirely on computer simulation: the US so far has just one 30MW commercial wind farm in operation with just five turbines, off the coast of Rhode Island.

But the reasoning begins from the basic laws of physics, and the answer delivers yet another argument for investment in renewable sources of energy, if only because the ferocity and destructive power of US hurricanes is set to increase with ever-greater emissions of greenhouse gases from fossil fuel combustion, and consequent ever-greater global warming.

Cristina Archer, a scientist at the University of Delaware, has already studied the ideal placing of wind turbines to extract maximum energy from the world’s winds, and more recently confirmed, with other researchers, that any hurricane that blew over a big enough marine wind farm would shed energy and hit the land with less destructive power.

“If you have arrays of wind turbines in the areas where there are hurricanes, you will likely see a reduction in precipitation inland”

It is an axiom of physics that energy is always conserved: if a turbine’s sails generate electrical energy from wind, then some of the kinetic energy of the wind must be surrendered.

Professor Archer and her colleagues report in the journal Environmental Research Letters that they took, among others, the case of Hurricane Harvey, which in 2017 deposited almost two thirds of a metre of rainwater on Houston, Texas, to cause devastating floods. They tested the behaviour of the simulated hurricane as it blew across a hypothetical barrier of from zero to 74,619 turbines.

When strong winds hit the turbines, they slow down. Wind scientists call this convergence. Winds slow, and are more likely to dump the water they hold, and then rise. Then the winds speed up again, a phenomenon known as divergence.

“Divergence is the opposite effect. It causes a downward motion, attracting air coming down, which is drier, and suppresses precipitation. I was wondering what would also happen when there is an offshore farm”, she said.

Multiple simulations

The researchers modelled a range of simulations with hypothetical wind farms staggered along the coasts of Texas and Louisiana. Hypothetical hurricanes caught up in a pattern of convergence would drop their rain before they hit the coast, and then begin divergence, which would mean that even less rain would be carried to landfall.

“By the time the air reaches the land, it’s been squeezed out of a lot of moisture,” Professor Archer said. “We got a 30% reduction of the precipitation with Harvey simulations. That means, potentially, if you have arrays of wind turbines in the areas where there are hurricanes, you will likely see a reduction in precipitation inland if the farm is there.”

This doesn’t mean that wind farms can always take the heat out of a hurricane: important factors include the hurricane’s precise track and the distance offshore of the turbines. There are no wind farms anywhere in the world with the tens of thousands of turbines modelled in the simulation: one of the world’s biggest, off Anholt Island, Denmark, has only 111 turbines.

“The more windfarms you have, the more impact they will have on a hurricane,” Professor Archer said. “By the time a hurricane actually makes a landfall, these arrays of turbines have been operating for days and days, extracting energy and moisture out of the storm. As a result, the storm will be weaker. Literally.” − Climate News Network

When high winds meet tall sails in the right place, something’s got to give. Offshore wind farms may lead to weakened hurricanes.

LONDON, 23 October, 2018 − US scientists have identified yet another wonder of that icon of renewable energy, the offshore wind farm: they may result in weakened hurricanes. Turbines in the right place could not just take the heat out of a hurricane, they could reduce the risk of catastrophic flooding as well.

The prediction is based entirely on computer simulation: the US so far has just one 30MW commercial wind farm in operation with just five turbines, off the coast of Rhode Island.

But the reasoning begins from the basic laws of physics, and the answer delivers yet another argument for investment in renewable sources of energy, if only because the ferocity and destructive power of US hurricanes is set to increase with ever-greater emissions of greenhouse gases from fossil fuel combustion, and consequent ever-greater global warming.

Cristina Archer, a scientist at the University of Delaware, has already studied the ideal placing of wind turbines to extract maximum energy from the world’s winds, and more recently confirmed, with other researchers, that any hurricane that blew over a big enough marine wind farm would shed energy and hit the land with less destructive power.

“If you have arrays of wind turbines in the areas where there are hurricanes, you will likely see a reduction in precipitation inland”

It is an axiom of physics that energy is always conserved: if a turbine’s sails generate electrical energy from wind, then some of the kinetic energy of the wind must be surrendered.

Professor Archer and her colleagues report in the journal Environmental Research Letters that they took, among others, the case of Hurricane Harvey, which in 2017 deposited almost two thirds of a metre of rainwater on Houston, Texas, to cause devastating floods. They tested the behaviour of the simulated hurricane as it blew across a hypothetical barrier of from zero to 74,619 turbines.

When strong winds hit the turbines, they slow down. Wind scientists call this convergence. Winds slow, and are more likely to dump the water they hold, and then rise. Then the winds speed up again, a phenomenon known as divergence.

“Divergence is the opposite effect. It causes a downward motion, attracting air coming down, which is drier, and suppresses precipitation. I was wondering what would also happen when there is an offshore farm”, she said.

Multiple simulations

The researchers modelled a range of simulations with hypothetical wind farms staggered along the coasts of Texas and Louisiana. Hypothetical hurricanes caught up in a pattern of convergence would drop their rain before they hit the coast, and then begin divergence, which would mean that even less rain would be carried to landfall.

“By the time the air reaches the land, it’s been squeezed out of a lot of moisture,” Professor Archer said. “We got a 30% reduction of the precipitation with Harvey simulations. That means, potentially, if you have arrays of wind turbines in the areas where there are hurricanes, you will likely see a reduction in precipitation inland if the farm is there.”

This doesn’t mean that wind farms can always take the heat out of a hurricane: important factors include the hurricane’s precise track and the distance offshore of the turbines. There are no wind farms anywhere in the world with the tens of thousands of turbines modelled in the simulation: one of the world’s biggest, off Anholt Island, Denmark, has only 111 turbines.

“The more windfarms you have, the more impact they will have on a hurricane,” Professor Archer said. “By the time a hurricane actually makes a landfall, these arrays of turbines have been operating for days and days, extracting energy and moisture out of the storm. As a result, the storm will be weaker. Literally.” − Climate News Network

Australian rain proves fiercer than expected

As the world warms, the storm clouds gather. And Australian rain is now often of a ferocity and intensity without precedent.

LONDON, 8 August, 2018 – Australian rain across much of the country is reaching an unexpected ferocity, and scientists who predicted a greater number of ever more intense rainstorms as the planet warms may have to think again – and think big.

A new study says the rate of rainfall in Australia during thunderstorms is in fact increasing twice or even three times beyond expectation, and much faster than would be expected with global warming. The largest downpours arrive with the most extreme events.

And although climate change predictions long ago foresaw the danger of ever more intense storms, researchers have looked back over the last 50 years to show that this is already happening.

What they did not expect to find was that such rainstorms are much more intense than anything they had expected under a regime of global warming and climate change, driven by profligate human use of fossil fuels.

“The important thing now is to understand why rainfall is becoming so much more intense in Australia and to look at changes in other places around the world”

“It was thought there was a limit on how much more rain could fall during these extreme events as a result of rising temperatures,” said Selma Guerreiro, an engineer at the University of Newcastle in the UK, who led the study.

“Now that upper limit has been broken, and instead we are seeing increases in rainfall, two to three times higher than expected during these short, intense rainstorms. This does not mean that we will see this rate of increase everywhere. But the important thing now is to understand why rainfall is becoming so much more intense in Australia and to look at changes in other places around the world.

“How these rainfall events will change in the future will vary from place to place and depend on local conditions besides temperature increases.”

She and her colleagues report in Nature Climate Change that they looked at what could be expected, under predictable conditions. One expectation is that as the air warms by 1°C, its capacity to absorb moisture increases by almost 7%, which means with more warmth there will be more evaporation, and more rainfall.

They looked over the records for the years 1966-1989 and 1990-2013 at data for daily and hourly rainfall – which should record the most intense downpours – from more than 100 weather stations. Between the two periods, global average temperatures increased by 0.48°C. They observed hourly extremes that were double, and even three times, the expected scale for any particular temperature rise.

Consistent predictions

That Australia is a continent of extremes, and a landscape that continues to deliver the unexpected, is no surprise. All climate models predict more extreme rainfall.  Climate change has already been implicated in Australia’s catastrophic 2010 floods. Researchers have consistently predicted a stormier future for Australia, with ever greater temperatures.

One of the researchers, Seth Westra of the University of Adelaide, explicitly predicted rising rainfall five years ago. In the same year researchers confirmed that so much rain had fallen on Australia in 2010 that global sea level actually dropped.

But the latest study does more than confirm recent certainties: it highlights the peculiar hazard that can be linked to storm intensity. The heavier and more focused the downpour, the greater the risk of urban flooding, landslips and potentially lethal flash floods. And although engineers and city planners expected to have to deal with more stormwater, what could happen is far worse than anything they are now prepared for.

“If we keep seeing this rate of change,” Professor Westra said, “we risk committing future generations to levels of flood risk that are unacceptable by today’s standards.” – Climate News Network

As the world warms, the storm clouds gather. And Australian rain is now often of a ferocity and intensity without precedent.

LONDON, 8 August, 2018 – Australian rain across much of the country is reaching an unexpected ferocity, and scientists who predicted a greater number of ever more intense rainstorms as the planet warms may have to think again – and think big.

A new study says the rate of rainfall in Australia during thunderstorms is in fact increasing twice or even three times beyond expectation, and much faster than would be expected with global warming. The largest downpours arrive with the most extreme events.

And although climate change predictions long ago foresaw the danger of ever more intense storms, researchers have looked back over the last 50 years to show that this is already happening.

What they did not expect to find was that such rainstorms are much more intense than anything they had expected under a regime of global warming and climate change, driven by profligate human use of fossil fuels.

“The important thing now is to understand why rainfall is becoming so much more intense in Australia and to look at changes in other places around the world”

“It was thought there was a limit on how much more rain could fall during these extreme events as a result of rising temperatures,” said Selma Guerreiro, an engineer at the University of Newcastle in the UK, who led the study.

“Now that upper limit has been broken, and instead we are seeing increases in rainfall, two to three times higher than expected during these short, intense rainstorms. This does not mean that we will see this rate of increase everywhere. But the important thing now is to understand why rainfall is becoming so much more intense in Australia and to look at changes in other places around the world.

“How these rainfall events will change in the future will vary from place to place and depend on local conditions besides temperature increases.”

She and her colleagues report in Nature Climate Change that they looked at what could be expected, under predictable conditions. One expectation is that as the air warms by 1°C, its capacity to absorb moisture increases by almost 7%, which means with more warmth there will be more evaporation, and more rainfall.

They looked over the records for the years 1966-1989 and 1990-2013 at data for daily and hourly rainfall – which should record the most intense downpours – from more than 100 weather stations. Between the two periods, global average temperatures increased by 0.48°C. They observed hourly extremes that were double, and even three times, the expected scale for any particular temperature rise.

Consistent predictions

That Australia is a continent of extremes, and a landscape that continues to deliver the unexpected, is no surprise. All climate models predict more extreme rainfall.  Climate change has already been implicated in Australia’s catastrophic 2010 floods. Researchers have consistently predicted a stormier future for Australia, with ever greater temperatures.

One of the researchers, Seth Westra of the University of Adelaide, explicitly predicted rising rainfall five years ago. In the same year researchers confirmed that so much rain had fallen on Australia in 2010 that global sea level actually dropped.

But the latest study does more than confirm recent certainties: it highlights the peculiar hazard that can be linked to storm intensity. The heavier and more focused the downpour, the greater the risk of urban flooding, landslips and potentially lethal flash floods. And although engineers and city planners expected to have to deal with more stormwater, what could happen is far worse than anything they are now prepared for.

“If we keep seeing this rate of change,” Professor Westra said, “we risk committing future generations to levels of flood risk that are unacceptable by today’s standards.” – Climate News Network

Stormier weather ahead raises fishing risks

A warmer world means stormier weather ahead, and ever-greater dangers for those who work in the world’s commercial fishing fleets.

LONDON, 2 July, 2018 – Here is the shipping forecast for the next two centuries: there’s stormier weather ahead. Typhoons will be on the increase in the east China Sea. There will be a greater frequency of post-monsoon storms in the Arabian Sea.

The forecast for the Mediterranean is somewhat milder: storms could be reduced over the next 200 years. But the outlook for the northeast Atlantic is not good: autumn and winter storms are likely to increase, both in number and in intensity, off the coasts of the UK, Ireland and France.

And the impact on the fishing industry could, say the authors of a new study, be catastrophic.

Around 38 million people worldwide already engage in capture fishing, according to a study in Nature Climate Change. They regularly, the scientists say, “risk their lives in one of the most dangerous jobs on Earth.”

And as a consequence of climate change driven by global warming, fuelled by profligate combustion of fossil fuels that increase the levels of greenhouse gases in the atmosphere, fishing is about to become even more dangerous.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people”

Global warming has already begun to affect commercial fishing. As waters warm, fish begin to shift their grounds, both in the warmer seas and in the colder waters that have supported fishing industries for centuries, with troubling consequences both for international tensions  and for future diets.

The researchers report that although warming could certainly alter the potential fish catch over the next 50 to 100 years, “changing storminess has the potential to cause more immediate and catastrophic impacts.”

And they argue that once researchers understand better how the fisheries industry and community cope with stormy weather, there might be ways to adjust practices and safeguard both lives and livelihoods.

Between them, capture fisheries – with trawls, seine nets and long lines – and aquaculture, or fish farming, support the livelihoods of 12% of the global population. Fish provide more than 3 billion people with around one-fifth of their animal protein: there is a lot at stake.

Fish at risk

And storms are a threat not just to fishing crews but to the fish as well. Warming waters change the composition of submarine populations and in effect gradually alter the local ecosystems. But severe storms can displace whole fish populations, interfere with the dispersal of the larvae that will become fish, and even destroy the habitat that fish depend upon.

The scientists want to see a co-ordinated examination of the hazards ahead, drawing upon expertise from psychologists, anthropologists and economists as well as marine scientists and climatologists.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people around the world who rely on fish for their daily nutrition,” said Nigel Sainsbury, a social scientist at the University of Exeter, UK, who led the study.

“Changing storminess could have serious consequences for vulnerable coastal communities around the world. Conducting research in this area is critical to support the adaptation of fisheries to climate change.” – Climate News Network

A warmer world means stormier weather ahead, and ever-greater dangers for those who work in the world’s commercial fishing fleets.

LONDON, 2 July, 2018 – Here is the shipping forecast for the next two centuries: there’s stormier weather ahead. Typhoons will be on the increase in the east China Sea. There will be a greater frequency of post-monsoon storms in the Arabian Sea.

The forecast for the Mediterranean is somewhat milder: storms could be reduced over the next 200 years. But the outlook for the northeast Atlantic is not good: autumn and winter storms are likely to increase, both in number and in intensity, off the coasts of the UK, Ireland and France.

And the impact on the fishing industry could, say the authors of a new study, be catastrophic.

Around 38 million people worldwide already engage in capture fishing, according to a study in Nature Climate Change. They regularly, the scientists say, “risk their lives in one of the most dangerous jobs on Earth.”

And as a consequence of climate change driven by global warming, fuelled by profligate combustion of fossil fuels that increase the levels of greenhouse gases in the atmosphere, fishing is about to become even more dangerous.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people”

Global warming has already begun to affect commercial fishing. As waters warm, fish begin to shift their grounds, both in the warmer seas and in the colder waters that have supported fishing industries for centuries, with troubling consequences both for international tensions  and for future diets.

The researchers report that although warming could certainly alter the potential fish catch over the next 50 to 100 years, “changing storminess has the potential to cause more immediate and catastrophic impacts.”

And they argue that once researchers understand better how the fisheries industry and community cope with stormy weather, there might be ways to adjust practices and safeguard both lives and livelihoods.

Between them, capture fisheries – with trawls, seine nets and long lines – and aquaculture, or fish farming, support the livelihoods of 12% of the global population. Fish provide more than 3 billion people with around one-fifth of their animal protein: there is a lot at stake.

Fish at risk

And storms are a threat not just to fishing crews but to the fish as well. Warming waters change the composition of submarine populations and in effect gradually alter the local ecosystems. But severe storms can displace whole fish populations, interfere with the dispersal of the larvae that will become fish, and even destroy the habitat that fish depend upon.

The scientists want to see a co-ordinated examination of the hazards ahead, drawing upon expertise from psychologists, anthropologists and economists as well as marine scientists and climatologists.

“Storms are a threat to fishermen’s safety, productivity, assets and jobs and to the health of billions of people around the world who rely on fish for their daily nutrition,” said Nigel Sainsbury, a social scientist at the University of Exeter, UK, who led the study.

“Changing storminess could have serious consequences for vulnerable coastal communities around the world. Conducting research in this area is critical to support the adaptation of fisheries to climate change.” – Climate News Network

Turbulent California weather in prospect

Turbulent California faces a future of parched croplands and then flooded townships. Climate scientists call such things whiplash events.

LONDON, 3 May, 2018 – Life is about to become uncomfortable for 40 million people in turbulent California. The  citizens of the golden state face a future of extremes, according to new research.  The number and severity of floods will grow. But so will the number of extended and severe droughts.

The backcloth to California’s climate – the overall annual precipitation – may not change greatly as the world, and the US with it, warms as a consequence of greenhouse gas emissions from fossil fuel combustion on a global scale.

What instead will happen is that droughts will last longer, and when the rain arrives it will fall much more heavily.

“These are actually huge changes occurring: they are just on opposite ends of the spectrum,” said Daniel Swain, a climate scientist at the University of California, Los Angeles. “If you only look for shifts in average precipitation, you’re missing all of the important changes in the character of precipitation.”

More probable

Dr Swain and colleagues report in the journal Nature Climate Change that they made mathematical simulations of the future pattern of the state’s climate as ever greater ratios of carbon dioxide drive global warming and potentially catastrophic climate change.

Even with small changes in overall precipitation, the probability of what they call “whiplash events” – shifts from extreme drought to devastating flood – grows measurably.

The state experienced a four-year drought between 2012 and 2016, and then what they call “an extraordinarily high number of atmospheric river storms” in the winter of 2016-2017. Roads and bridges were washed away by floods and mudslides, and after a dam failed almost 250,000 people were evacuated from their homes. And, the researchers promise, the pattern will continue into the future.

Once again, such studies deliver cumulative confidence: in the last few years scientists have repeatedly, and using separate approaches, confirmed the dangers of climate extremes in California.

They have linked devastating drought to human-induced climate change; they have warned that such droughts could be “the new normal” for citizens; and that when the rains fall, they will bring ever more flooding.

”These are actually huge changes occurring: they are just on opposite ends of the spectrum”

The double impact of warming atmosphere and warming oceans means that more water will be deposited when the rains do arrive. And, say the researchers, the chance of a catastrophic flood to match the 1862 calamity that destroyed one-third of the state’s taxable land will grow three or fourfold.

If it happened again – after 150 years of population growth – it could be a trillion dollar disaster, and millions would have to abandon their homes.

“We may be going from a situation where an event as big as 1862 was unlikely to occur by the end of the century to a situation where it may happen more than once,” said Dr Swain.

“People tend not to die in droughts in places with a developed economy. People do still die in floods. It happened this year and last year in California. During an event of a magnitude similar to the 1862 flood, a lot of lives would be at risk.” – Climate News Network

Turbulent California faces a future of parched croplands and then flooded townships. Climate scientists call such things whiplash events.

LONDON, 3 May, 2018 – Life is about to become uncomfortable for 40 million people in turbulent California. The  citizens of the golden state face a future of extremes, according to new research.  The number and severity of floods will grow. But so will the number of extended and severe droughts.

The backcloth to California’s climate – the overall annual precipitation – may not change greatly as the world, and the US with it, warms as a consequence of greenhouse gas emissions from fossil fuel combustion on a global scale.

What instead will happen is that droughts will last longer, and when the rain arrives it will fall much more heavily.

“These are actually huge changes occurring: they are just on opposite ends of the spectrum,” said Daniel Swain, a climate scientist at the University of California, Los Angeles. “If you only look for shifts in average precipitation, you’re missing all of the important changes in the character of precipitation.”

More probable

Dr Swain and colleagues report in the journal Nature Climate Change that they made mathematical simulations of the future pattern of the state’s climate as ever greater ratios of carbon dioxide drive global warming and potentially catastrophic climate change.

Even with small changes in overall precipitation, the probability of what they call “whiplash events” – shifts from extreme drought to devastating flood – grows measurably.

The state experienced a four-year drought between 2012 and 2016, and then what they call “an extraordinarily high number of atmospheric river storms” in the winter of 2016-2017. Roads and bridges were washed away by floods and mudslides, and after a dam failed almost 250,000 people were evacuated from their homes. And, the researchers promise, the pattern will continue into the future.

Once again, such studies deliver cumulative confidence: in the last few years scientists have repeatedly, and using separate approaches, confirmed the dangers of climate extremes in California.

They have linked devastating drought to human-induced climate change; they have warned that such droughts could be “the new normal” for citizens; and that when the rains fall, they will bring ever more flooding.

”These are actually huge changes occurring: they are just on opposite ends of the spectrum”

The double impact of warming atmosphere and warming oceans means that more water will be deposited when the rains do arrive. And, say the researchers, the chance of a catastrophic flood to match the 1862 calamity that destroyed one-third of the state’s taxable land will grow three or fourfold.

If it happened again – after 150 years of population growth – it could be a trillion dollar disaster, and millions would have to abandon their homes.

“We may be going from a situation where an event as big as 1862 was unlikely to occur by the end of the century to a situation where it may happen more than once,” said Dr Swain.

“People tend not to die in droughts in places with a developed economy. People do still die in floods. It happened this year and last year in California. During an event of a magnitude similar to the 1862 flood, a lot of lives would be at risk.” – Climate News Network