Tag Archives: Australia

Savage heat engulfs temperate Tasmania

One Australian state hit severely this ferocious summer is normally temperate Tasmania. A resident with vivid experience describes its ordeal.

TASMANIA, 14 February, 2019 − Australia has been going through one of its hottest and stormiest summers on record and usually temperate Tasmania, its island state, has taken a battering..

Climate change-related weather events have brought cyclones and raging floods to the north-east of the country, while drought and temperatures exceeding 40°C have resulted in parched lands and rivers drying up in areas of New South Wales.

Summer on the island of Tasmania, Australia’s most southerly state, with a generally temperate climate, is usually a time for BBQs and beach swimming. This summer has been very different.

A prolonged drought and record high temperatures have caused a series of devastating fires, destroying unique forests and vegetation and forcing people to leave their homes.

Critics of the Australian government say it’s clear climate change is wreaking havoc; meanwhile politicians continue to pander to the interests of the country’s powerful mining and fossil fuel industries.

“It’s a giant, macabre game of cat and mouse”

Mike Willson is a Tasmania resident, a fire equipment specialist and a volunteer with the Tasmania Fire Service. Here he tells Climate News Network what life has been like on the island over recent weeks.

“There is menace in the air. Days full of thick brown smoke. The clouds of smoke have even been swept across 2,500 kilometres of ocean to as far away as New Zealand – itself trying to cope with its own forest fires.

“A new phenomenon has arrived in Tasmania – lightning storms without rain. In one day in mid-January there were over 2,000 dry lightning strikes over the south-west and central highlands here, starting up to 70 bush fires.

““ Even with water bombing by planes and helicopters, the fires – which have already burned out 3% of the area of the island – are virtually impossible to control.

Leaping ahead

“Dealing with these fires is like fighting a snarling dragon. Small flakes of grey ash fall everywhere. Embers can trigger spot fires several kilometres ahead of the main fire.

“The fire can seem to disappear but still burns in logs and stumps. You have to always be on the lookout for tell-tale wisps of smoke. Walking across with a hose line to investigate, it’s a moonscape, the soil collapsing under your feet.

““ It’s like trudging through powder snow, sinking up to mid-calf in places, with the earth under your feet turning to hot dust. Aiming at a puff of smoke, the ground erupts and hisses like a volcano when we spray water.

“It’s a giant, macabre game of cat and mouse. If conditions are right, a controlled back burn can effectively starve the fire of fuel, but then the wind might whip up and the fire can jump – even across large rivers and bays – and rampage on.

Disaster avoided

“Luckily, so far there have been no casualties, and few homes have been lost. At least the drought and high temperatures have not come with very high winds – a cocktail for disaster.

“Firefighter and helicopter crews are being constantly rotated – it all takes a considerable physical and mental toll.”

*

In recent days rainfall over much of Tasmania has eased the fire risk, though the authorities are warning people that there is still a danger of further fire outbreaks.

Among the areas threatened or partially destroyed by fire are the world’s largest remaining forest of thousand-year-old King Billy pines. − Climate News Network

One Australian state hit severely this ferocious summer is normally temperate Tasmania. A resident with vivid experience describes its ordeal.

TASMANIA, 14 February, 2019 − Australia has been going through one of its hottest and stormiest summers on record and usually temperate Tasmania, its island state, has taken a battering..

Climate change-related weather events have brought cyclones and raging floods to the north-east of the country, while drought and temperatures exceeding 40°C have resulted in parched lands and rivers drying up in areas of New South Wales.

Summer on the island of Tasmania, Australia’s most southerly state, with a generally temperate climate, is usually a time for BBQs and beach swimming. This summer has been very different.

A prolonged drought and record high temperatures have caused a series of devastating fires, destroying unique forests and vegetation and forcing people to leave their homes.

Critics of the Australian government say it’s clear climate change is wreaking havoc; meanwhile politicians continue to pander to the interests of the country’s powerful mining and fossil fuel industries.

“It’s a giant, macabre game of cat and mouse”

Mike Willson is a Tasmania resident, a fire equipment specialist and a volunteer with the Tasmania Fire Service. Here he tells Climate News Network what life has been like on the island over recent weeks.

“There is menace in the air. Days full of thick brown smoke. The clouds of smoke have even been swept across 2,500 kilometres of ocean to as far away as New Zealand – itself trying to cope with its own forest fires.

“A new phenomenon has arrived in Tasmania – lightning storms without rain. In one day in mid-January there were over 2,000 dry lightning strikes over the south-west and central highlands here, starting up to 70 bush fires.

““ Even with water bombing by planes and helicopters, the fires – which have already burned out 3% of the area of the island – are virtually impossible to control.

Leaping ahead

“Dealing with these fires is like fighting a snarling dragon. Small flakes of grey ash fall everywhere. Embers can trigger spot fires several kilometres ahead of the main fire.

“The fire can seem to disappear but still burns in logs and stumps. You have to always be on the lookout for tell-tale wisps of smoke. Walking across with a hose line to investigate, it’s a moonscape, the soil collapsing under your feet.

““ It’s like trudging through powder snow, sinking up to mid-calf in places, with the earth under your feet turning to hot dust. Aiming at a puff of smoke, the ground erupts and hisses like a volcano when we spray water.

“It’s a giant, macabre game of cat and mouse. If conditions are right, a controlled back burn can effectively starve the fire of fuel, but then the wind might whip up and the fire can jump – even across large rivers and bays – and rampage on.

Disaster avoided

“Luckily, so far there have been no casualties, and few homes have been lost. At least the drought and high temperatures have not come with very high winds – a cocktail for disaster.

“Firefighter and helicopter crews are being constantly rotated – it all takes a considerable physical and mental toll.”

*

In recent days rainfall over much of Tasmania has eased the fire risk, though the authorities are warning people that there is still a danger of further fire outbreaks.

Among the areas threatened or partially destroyed by fire are the world’s largest remaining forest of thousand-year-old King Billy pines. − Climate News Network

Flash floods increase as mercury climbs

Heavy rain must fall somewhere. The danger lies in where it falls and on what kind of terrain. As cities grow, the risk of flash floods rises.

LONDON, 9 November, 2018 – Scientists once again have confirmed that humankind’s actions have triggered ever-greater extremes of rainfall – and an ever-greater rise in disastrous flash floods.

The study comes close on the heels of a warning by UN scientists of a dramatic increase in economic losses from climate-related disasters. Between 1998 and 2017, natural disasters cost the world’s nations direct losses of $2.9 trillion, and although earthquake and tsunami accounted for most deaths, floods, storms and other climate-related catastrophes accounted for 77% of the economic damage.

Scientists and engineers from China and the US report in the journal Nature Communications that flash floods now cause more deaths as well as more property and agricultural losses than any other severe weather-related hazards. These losses have been increasing for the last 50 years and over the last decade worldwide have topped $30bn a year.

And, they find, extremes in run–off from increasing extremes of rainfall are driven by what humans have done, and continue to do, to their planet: in the race for economic growth, people have burned ever more coal, oil and gas to dump ever-increasing levels of carbon dioxide emissions into the atmosphere.

Heat hazard rises

They have driven up global average temperatures by around 1°C in the last century, and without drastic action this average could reach 3°C by the century’s end.

As average temperatures rise, so does the hazard of extremes of heat. With every rise of 1°C the capacity of the atmosphere to absorb moisture rises by about 7%: higher temperatures are linked to ever-harder falls of rain. And rain that falls must go somewhere.

Moisture once naturally absorbed by forests, extensive wetlands or rich natural grasslands now increasingly lands on tarmacadam, brick, cement, tile or glass, to race down city streets, threaten ever more lives and sweep away costly homes, offices and bridges.

“Those who are suffering the most from climate change are those who are contributing least to greenhouse gas emissions”

Altogether one billion people are now settled in floodplains: the lives at risk are on the increase. And, the researchers warn, the losses will go on rising.

Most researchers have been unwilling to link specific floods directly to global warming. That cautious attitude shifted in the last few years as separate teams of climate scientists made connections between global warming and disastrous flooding and destructive storms in Europe, in India and in the US.

Australia – more often linked with extended drought and wildfire hazards than floods – has identified ever greater dangers from extreme rainfall.

The Nature study was based on decades of rainfall, run-off and temperature data collected on a daily basis and forms part of a widening search for ways to adapt to a danger that, inevitably, looks set to increase, particularly in the US.

Growth in extremes

“We were trying to find the physical mechanisms behind why precipitation and run-off extremes are increasing all over the globe,” said Jiabo Yin, a Wuhan University student working at the Earth Institute in the University of Columbia, who led the research.

“We know that precipitation and run-off extremes will increase significantly in the future, and we need to modify our infrastructures accordingly. Our study establishes a framework for investigating the runoff response.”

Altogether, according to the UN Office for Disaster Risk Reduction’s latest survey, the world experienced more than 7,000 major disasters in the last two decades: floods and storms accounted for 43% and 28.2% of them and were the most frequent kinds of disaster.

Together, such disasters claimed 1.3 million lives – almost 750,000 of these to a total of 563 earthquakes and tsunamis. An estimated 4.4 billion people were hurt, or lost their homes, or were displaced or placed in need of emergency help.

Biggest losers

The greatest economic losers were the US, with almost $945 billion, and China with $492bn. Storms, floods and earthquakes put three European nations in the top ten, with France, Germany and Italy losing around $50bn each in those two decades.

Once again, the UN study highlights the gap between rich and poor. “Those who are suffering the most from climate change are those who are contributing least to greenhouse gas emissions,” said Deberati Guha-Sapir, head of the UN’s Centre for Research on the Epidemiology of Disasters at the Catholic University of Louvain in Belgium.

“Clearly there is great room for improvement in data collection on economic losses, but we know from our analysis … that people in low income countries are six times more likely to lose all their worldly possessions or suffer injury in a disaster than people in high income countries.” – Climate News Network

Heavy rain must fall somewhere. The danger lies in where it falls and on what kind of terrain. As cities grow, the risk of flash floods rises.

LONDON, 9 November, 2018 – Scientists once again have confirmed that humankind’s actions have triggered ever-greater extremes of rainfall – and an ever-greater rise in disastrous flash floods.

The study comes close on the heels of a warning by UN scientists of a dramatic increase in economic losses from climate-related disasters. Between 1998 and 2017, natural disasters cost the world’s nations direct losses of $2.9 trillion, and although earthquake and tsunami accounted for most deaths, floods, storms and other climate-related catastrophes accounted for 77% of the economic damage.

Scientists and engineers from China and the US report in the journal Nature Communications that flash floods now cause more deaths as well as more property and agricultural losses than any other severe weather-related hazards. These losses have been increasing for the last 50 years and over the last decade worldwide have topped $30bn a year.

And, they find, extremes in run–off from increasing extremes of rainfall are driven by what humans have done, and continue to do, to their planet: in the race for economic growth, people have burned ever more coal, oil and gas to dump ever-increasing levels of carbon dioxide emissions into the atmosphere.

Heat hazard rises

They have driven up global average temperatures by around 1°C in the last century, and without drastic action this average could reach 3°C by the century’s end.

As average temperatures rise, so does the hazard of extremes of heat. With every rise of 1°C the capacity of the atmosphere to absorb moisture rises by about 7%: higher temperatures are linked to ever-harder falls of rain. And rain that falls must go somewhere.

Moisture once naturally absorbed by forests, extensive wetlands or rich natural grasslands now increasingly lands on tarmacadam, brick, cement, tile or glass, to race down city streets, threaten ever more lives and sweep away costly homes, offices and bridges.

“Those who are suffering the most from climate change are those who are contributing least to greenhouse gas emissions”

Altogether one billion people are now settled in floodplains: the lives at risk are on the increase. And, the researchers warn, the losses will go on rising.

Most researchers have been unwilling to link specific floods directly to global warming. That cautious attitude shifted in the last few years as separate teams of climate scientists made connections between global warming and disastrous flooding and destructive storms in Europe, in India and in the US.

Australia – more often linked with extended drought and wildfire hazards than floods – has identified ever greater dangers from extreme rainfall.

The Nature study was based on decades of rainfall, run-off and temperature data collected on a daily basis and forms part of a widening search for ways to adapt to a danger that, inevitably, looks set to increase, particularly in the US.

Growth in extremes

“We were trying to find the physical mechanisms behind why precipitation and run-off extremes are increasing all over the globe,” said Jiabo Yin, a Wuhan University student working at the Earth Institute in the University of Columbia, who led the research.

“We know that precipitation and run-off extremes will increase significantly in the future, and we need to modify our infrastructures accordingly. Our study establishes a framework for investigating the runoff response.”

Altogether, according to the UN Office for Disaster Risk Reduction’s latest survey, the world experienced more than 7,000 major disasters in the last two decades: floods and storms accounted for 43% and 28.2% of them and were the most frequent kinds of disaster.

Together, such disasters claimed 1.3 million lives – almost 750,000 of these to a total of 563 earthquakes and tsunamis. An estimated 4.4 billion people were hurt, or lost their homes, or were displaced or placed in need of emergency help.

Biggest losers

The greatest economic losers were the US, with almost $945 billion, and China with $492bn. Storms, floods and earthquakes put three European nations in the top ten, with France, Germany and Italy losing around $50bn each in those two decades.

Once again, the UN study highlights the gap between rich and poor. “Those who are suffering the most from climate change are those who are contributing least to greenhouse gas emissions,” said Deberati Guha-Sapir, head of the UN’s Centre for Research on the Epidemiology of Disasters at the Catholic University of Louvain in Belgium.

“Clearly there is great room for improvement in data collection on economic losses, but we know from our analysis … that people in low income countries are six times more likely to lose all their worldly possessions or suffer injury in a disaster than people in high income countries.” – 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

Alien seaweed arrives in Antarctica

For more than a century, scientists believed that only humans could cross the hostile oceans to reach Antarctica. Some strands of alien seaweed tell another story.

LONDON, 19 July, 2018 – A foreign invader, a species of alien seaweed, has managed to cross the oceans to reach the frozen Antarctic shores. So scientists may have to give up a cherished belief: that Antarctica is inviolate.

For a century, researchers have assumed that the mix of ocean currents, distance and temperature have kept the Great White Continent shielded from invasion by Pacific or Atlantic flotsam.

But the discovery of strands of kelp on an Antarctic beach – seaweed that may have drifted for considerable periods and a distance of 20,000 kms before becoming stranded far from home – brings an end to that belief. And the discovery suggests that global warming could bring serious changes to Antarctic ecosystems.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected”

“This finding shows us that living plants and animals can reach Antarctica across the ocean, with temperate and sub-Antarctic marine species probably bombarding Antarctic coastlines all the time,” said Ceridwen Fraser, of the Australian National University.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research now suggests these differences are almost entirely due to environmental extremes, not isolation.”

Dr Fraser and her colleagues report in the journal Nature Climate Change that strands of southern bull kelp, Durvillaea antarctica, found by a Chilean scientist, must have floated 20,000 km from the Kerguelen Islands and South Georgia. The kelp was encrusted with barnacles, evidence of a long time adrift.

In fact, researchers believe, it may be evidence of the longest episode of “biological rafting” ever confirmed. The word raft is significant: such floating platforms could provide shelter and transport for other biological invaders.

Plastic next?

Until now, the assumption has been that the pattern of surface currents and westerly winds tends to drive drifting material northwards from Antarctica. The discovery suggests that if kelp can get there, so can floating driftwood, or plastic debris, or any other unwelcome visitor.

The researchers think large waves driven by Southern Ocean storms may have steered the kelp rafts over what had been considered a natural ocean barrier. Global warming has begun to change conditions in Antarctica, and the continent – considered the last great tract of terrain unmarked by human colonisation – could become increasingly vulnerable to change.

“This is an unequivocal demonstration that marine species from the north can reach Antarctica. To get there the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable,” Dr Fraser said.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected.” – Climate News Network

For more than a century, scientists believed that only humans could cross the hostile oceans to reach Antarctica. Some strands of alien seaweed tell another story.

LONDON, 19 July, 2018 – A foreign invader, a species of alien seaweed, has managed to cross the oceans to reach the frozen Antarctic shores. So scientists may have to give up a cherished belief: that Antarctica is inviolate.

For a century, researchers have assumed that the mix of ocean currents, distance and temperature have kept the Great White Continent shielded from invasion by Pacific or Atlantic flotsam.

But the discovery of strands of kelp on an Antarctic beach – seaweed that may have drifted for considerable periods and a distance of 20,000 kms before becoming stranded far from home – brings an end to that belief. And the discovery suggests that global warming could bring serious changes to Antarctic ecosystems.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected”

“This finding shows us that living plants and animals can reach Antarctica across the ocean, with temperate and sub-Antarctic marine species probably bombarding Antarctic coastlines all the time,” said Ceridwen Fraser, of the Australian National University.

“We always thought Antarctic plants and animals were distinct because they were isolated, but this research now suggests these differences are almost entirely due to environmental extremes, not isolation.”

Dr Fraser and her colleagues report in the journal Nature Climate Change that strands of southern bull kelp, Durvillaea antarctica, found by a Chilean scientist, must have floated 20,000 km from the Kerguelen Islands and South Georgia. The kelp was encrusted with barnacles, evidence of a long time adrift.

In fact, researchers believe, it may be evidence of the longest episode of “biological rafting” ever confirmed. The word raft is significant: such floating platforms could provide shelter and transport for other biological invaders.

Plastic next?

Until now, the assumption has been that the pattern of surface currents and westerly winds tends to drive drifting material northwards from Antarctica. The discovery suggests that if kelp can get there, so can floating driftwood, or plastic debris, or any other unwelcome visitor.

The researchers think large waves driven by Southern Ocean storms may have steered the kelp rafts over what had been considered a natural ocean barrier. Global warming has begun to change conditions in Antarctica, and the continent – considered the last great tract of terrain unmarked by human colonisation – could become increasingly vulnerable to change.

“This is an unequivocal demonstration that marine species from the north can reach Antarctica. To get there the kelp had to pass through barriers created by polar winds and currents that were, until now, thought to be impenetrable,” Dr Fraser said.

“Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we suspected.” – Climate News Network

Slowing tropical cyclones bring more mayhem

Tropical cyclones are slowing down. Hurricanes have lost their hurry. Paradoxically, this is bad news: they have more time to work their mischief.

LONDON, 15 June, 2018 – Tropical cyclones are moving more slowly. As temperatures rise, the pace at which a hurricane storms across a landscape has slowed perceptibly in the last 70 years. But the slowdown means each hurricane has more time to do more damage and deliver more flooding.

“Tropical cyclones over land have slowed down 20% in the Atlantic, 30% in the northwestern Pacific and 19% in the Australian region,” said James Kossin, of the US National Oceanic and Atmospheric Administration’s national centres for environmental information.

“These trends are almost certainly increasing local rainfall totals and freshwater flooding, which is associated with a very high mortality risk.”

He reports in the journal Nature that thanks to atmospheric warming as a consequence of the profligate combustion of fossil fuels in the last century, the summer tropical circulation has slowed and, along with it, hurricane and typhoon speeds. Overall, since 1940, cyclone movements have slowed by 10%; over some land areas, they have slowed much more.

But as the temperature goes up, the capacity of the atmosphere to hold moisture increases – by at least 7% with each degree Centigrade. That means a tropical cyclone – a whirling system of terrifying winds bearing huge quantities of water – has both more water, and more time to drop it over land.

Harvey’s warning

And Dr Kossin cites the example of Hurricane Harvey which in 2017 dumped more than 1.25 metres of water on Houston, Texas and the surrounding countryside in just five days. Devastating floods displaced 30,000 people, and 89 died. Economic losses were assessed at more than $126bn.

This shift in what researchers call the translation speed is new – and is only the latest study in a procession of alarming findings about the response of the winds in a warming world.

Researchers have already established that hurricanes are gaining in ferocity – that is, becoming more intense – at a faster rate than they did decades ago. They have warned that windstorms’ capacity to damage the world’s economy is on the increase directly because of global warming and consequent climate change, and they have identified a trend in hurricane geography: the storms are moving further north, in the northern hemisphere.

The combination of rising sea levels and fiercer storms could create, some argue, a new class of climate refugee in the US. And they have bad news for Texas: more storms like Harvey could be on the way.

“These trends are almost certainly increasing local rainfall totals and freshwater flooding, which is associated with a very high mortality risk”

In the course of the last century, global average temperatures have, as a consequence of the notorious greenhouse effect, gone up by around 1°C. Around 195 nations agreed in Paris in 2015 to attempt to contain global warming to 1.5°C in total by 2100, but gloomy forecasts suggest that unless action becomes urgent, temperatures will rise much higher.

And that means that hurricanes will go on slowing, to deliver ever more damage as they linger over coastal cities and farmlands.

“The observed 10% slowdown occurred in a period when the planet warmed by 0.5°C, but this does not provide a true measure of climate sensitivity, and more study is needed to determine how much more slowing will occur with continued warming,” Dr Kossin said.

“Still, it’s entirely plausible that local rainfall increases could actually be dominated by this slowdown rather than that the expected rain-rate increases due to global warming”. – Climate News Network

Tropical cyclones are slowing down. Hurricanes have lost their hurry. Paradoxically, this is bad news: they have more time to work their mischief.

LONDON, 15 June, 2018 – Tropical cyclones are moving more slowly. As temperatures rise, the pace at which a hurricane storms across a landscape has slowed perceptibly in the last 70 years. But the slowdown means each hurricane has more time to do more damage and deliver more flooding.

“Tropical cyclones over land have slowed down 20% in the Atlantic, 30% in the northwestern Pacific and 19% in the Australian region,” said James Kossin, of the US National Oceanic and Atmospheric Administration’s national centres for environmental information.

“These trends are almost certainly increasing local rainfall totals and freshwater flooding, which is associated with a very high mortality risk.”

He reports in the journal Nature that thanks to atmospheric warming as a consequence of the profligate combustion of fossil fuels in the last century, the summer tropical circulation has slowed and, along with it, hurricane and typhoon speeds. Overall, since 1940, cyclone movements have slowed by 10%; over some land areas, they have slowed much more.

But as the temperature goes up, the capacity of the atmosphere to hold moisture increases – by at least 7% with each degree Centigrade. That means a tropical cyclone – a whirling system of terrifying winds bearing huge quantities of water – has both more water, and more time to drop it over land.

Harvey’s warning

And Dr Kossin cites the example of Hurricane Harvey which in 2017 dumped more than 1.25 metres of water on Houston, Texas and the surrounding countryside in just five days. Devastating floods displaced 30,000 people, and 89 died. Economic losses were assessed at more than $126bn.

This shift in what researchers call the translation speed is new – and is only the latest study in a procession of alarming findings about the response of the winds in a warming world.

Researchers have already established that hurricanes are gaining in ferocity – that is, becoming more intense – at a faster rate than they did decades ago. They have warned that windstorms’ capacity to damage the world’s economy is on the increase directly because of global warming and consequent climate change, and they have identified a trend in hurricane geography: the storms are moving further north, in the northern hemisphere.

The combination of rising sea levels and fiercer storms could create, some argue, a new class of climate refugee in the US. And they have bad news for Texas: more storms like Harvey could be on the way.

“These trends are almost certainly increasing local rainfall totals and freshwater flooding, which is associated with a very high mortality risk”

In the course of the last century, global average temperatures have, as a consequence of the notorious greenhouse effect, gone up by around 1°C. Around 195 nations agreed in Paris in 2015 to attempt to contain global warming to 1.5°C in total by 2100, but gloomy forecasts suggest that unless action becomes urgent, temperatures will rise much higher.

And that means that hurricanes will go on slowing, to deliver ever more damage as they linger over coastal cities and farmlands.

“The observed 10% slowdown occurred in a period when the planet warmed by 0.5°C, but this does not provide a true measure of climate sensitivity, and more study is needed to determine how much more slowing will occur with continued warming,” Dr Kossin said.

“Still, it’s entirely plausible that local rainfall increases could actually be dominated by this slowdown rather than that the expected rain-rate increases due to global warming”. – Climate News Network

Humans put conservation reserves at risk

In theory conservation reserves are set aside to preserve wild creatures. But then the humans move in. Land almost twice the area of India is threatened.

LONDON, 8 June, 2018 – Many of the world’s conservation reserves, intended to safeguard species at risk of survival, are increasingly unable to provide effective refuge.

At least one third of all the forests, grasslands, wetlands and mangroves notionally protected by laws to safeguard the wild things that evolved with them are under intense human pressure, according to the first detailed study for 25 years.

Major road systems criss-cross African wildlife reserves, cities have grown up in national park areas, and farmland and buildings blight landscapes supposedly reserved for endemic species at hazard from extinction. Altogether 6 million square kilometres (2.3m square miles) of protected land, researchers say, are “under intense human pressure.”

Since the global Convention on Biological Diversity (CBD) was agreed in 1992, the area of the world declared as protected has doubled in size, and more than 202,000 patches of conservation area and national park cover 14.7% of the Earth’s land surface.

“A well-run protected area network is essential in saving species. If we allow our protected area network to be degraded there is no doubt biodiversity losses will be exacerbated”

Some of these areas are strictly for conservation of biodiversity; some permit limited human exploitation but are still intended mainly to provide habitat for the wild creatures.

Australian and Canadian scientists report in the journal Science that they examined what they call “human footprint” maps of the globe to make their assessment. The human footprint metric incorporates built environments, intensive agriculture, pasture lands, human population density, night-time lights, roads, railways and navigable waterways.

The scientists found that only 42% of these lands were free of measurable human pressure. But 32.8%, an area of more than 6m sq km – almost twice the size of India – counted as under intense pressure.

What worried the scientists most was what happened to some landscapes that were intact and in a natural state when declared as protected: since 1993, around 280,000 square kilometres of such wilderness had shifted from low disturbance to intense human pressure: this is an area almost as large as Italy.

Complete human dependence

Almost three fourths of the world’s nations – that is, 137 countries – have 50% of their protected land under intense human pressure. “If one assumes that protected land under intense human pressure does not contribute towards conservation targets,” the scientists write, “we show that 74 of 111 nations that have reached a level of 17% protected coverage would drop out of that list.”

Almost all human resources – including food and drink, fabrics and medicines – are derived from the planet’s biodiversity: even the coal, natural gas and petrol that drives the human economy was once wild forest and reed bed. Researchers have repeatedly stressed the importance of biodiversity to all human economic activity – they call it natural capital – and warned that continued loss of wild native plants and animals could have catastrophic consequences. The authors of the Science study warn that if human pressure increases, the goals of the CBD will be severely undermined.

“A well-run protected area network is essential in saving species,” said Kendall Jones of the University of Queensland. “If we allow our protected area network to be degraded there is no doubt biodiversity losses will be exacerbated.”

And his co-author James Watson of the World Conservation Society said: “Most importantly, we’ve got to recognise that these jewels in the crown need support – there are some protected areas that are safeguarding nature and that still haven’t got any evidence of human encroachment in them. We must ensure these values are maintained.” – Climate News Network

In theory conservation reserves are set aside to preserve wild creatures. But then the humans move in. Land almost twice the area of India is threatened.

LONDON, 8 June, 2018 – Many of the world’s conservation reserves, intended to safeguard species at risk of survival, are increasingly unable to provide effective refuge.

At least one third of all the forests, grasslands, wetlands and mangroves notionally protected by laws to safeguard the wild things that evolved with them are under intense human pressure, according to the first detailed study for 25 years.

Major road systems criss-cross African wildlife reserves, cities have grown up in national park areas, and farmland and buildings blight landscapes supposedly reserved for endemic species at hazard from extinction. Altogether 6 million square kilometres (2.3m square miles) of protected land, researchers say, are “under intense human pressure.”

Since the global Convention on Biological Diversity (CBD) was agreed in 1992, the area of the world declared as protected has doubled in size, and more than 202,000 patches of conservation area and national park cover 14.7% of the Earth’s land surface.

“A well-run protected area network is essential in saving species. If we allow our protected area network to be degraded there is no doubt biodiversity losses will be exacerbated”

Some of these areas are strictly for conservation of biodiversity; some permit limited human exploitation but are still intended mainly to provide habitat for the wild creatures.

Australian and Canadian scientists report in the journal Science that they examined what they call “human footprint” maps of the globe to make their assessment. The human footprint metric incorporates built environments, intensive agriculture, pasture lands, human population density, night-time lights, roads, railways and navigable waterways.

The scientists found that only 42% of these lands were free of measurable human pressure. But 32.8%, an area of more than 6m sq km – almost twice the size of India – counted as under intense pressure.

What worried the scientists most was what happened to some landscapes that were intact and in a natural state when declared as protected: since 1993, around 280,000 square kilometres of such wilderness had shifted from low disturbance to intense human pressure: this is an area almost as large as Italy.

Complete human dependence

Almost three fourths of the world’s nations – that is, 137 countries – have 50% of their protected land under intense human pressure. “If one assumes that protected land under intense human pressure does not contribute towards conservation targets,” the scientists write, “we show that 74 of 111 nations that have reached a level of 17% protected coverage would drop out of that list.”

Almost all human resources – including food and drink, fabrics and medicines – are derived from the planet’s biodiversity: even the coal, natural gas and petrol that drives the human economy was once wild forest and reed bed. Researchers have repeatedly stressed the importance of biodiversity to all human economic activity – they call it natural capital – and warned that continued loss of wild native plants and animals could have catastrophic consequences. The authors of the Science study warn that if human pressure increases, the goals of the CBD will be severely undermined.

“A well-run protected area network is essential in saving species,” said Kendall Jones of the University of Queensland. “If we allow our protected area network to be degraded there is no doubt biodiversity losses will be exacerbated.”

And his co-author James Watson of the World Conservation Society said: “Most importantly, we’ve got to recognise that these jewels in the crown need support – there are some protected areas that are safeguarding nature and that still haven’t got any evidence of human encroachment in them. We must ensure these values are maintained.” – Climate News Network

Global warming grows less nutritious rice

One consequence of more carbon dioxide in the atmosphere will be less nutritious rice, despite growth gains for some other crops.

LONDON, 25 May, 2018 – Global warming could bring a serious problem for the two billion people on the planet who depend on one grain for their staple diet: less nutritious rice to sustain them. Scientists have found that rice grown at higher levels of carbon dioxide has an overall lower nutritional value.

The grain contains lower levels of protein, and iron and zinc – metals vital for health in trace form – and also consistent declines in vitamin B.

This finding is not based on computer simulation of a plant’s response to notionally higher atmospheric levels of the greenhouse gas CO2, nor on laboratory studies under glass and in artificial conditions. It is based on open air field trials.

That is, extra carbon dioxide is piped to the plants to mimic the ratios expected at the end of the century as ever more people burn ever greater quantities of fossil fuels. And it has been tested in many locations in rice-growing countries over many years.

The finding remains true – although at different levels of impact – for the 18 varieties or hybrids of rice tested so far.

levels were down 30%.

“People say more CO2 is more plant food – and it is. But how plants respond to that sudden increase in food will impact human health as well”

Ten nations depend upon rice for daily food supplies. The people most likely to feel the consequences of reduced nutritional support – and these include impaired cognitive development, a feebler immune system, obesity and diabetes – are likely to be those who are poorest. The researchers estimate that 600 million people for whom rice provides more than half their daily diet could be affected.

Scientists from China, Japan, the US and Australia report in the journal Science Advances that they began their research, using what they call the technique of free air carbon dioxide enrichment, in 1998, to recreate what they expect to be the conditions under which farmers will grow crops a few decades from now.

They found on average that the test rice had 10% less protein, 8% less iron and 5.1% less zinc compared with rice grown by farmers under existing conditions. There were also declines of 17% in the vitamins B1 (thiamine) and of more than 16% in vitamin B2 (riboflavin). Vitamin B5, or pantothenic acid levels, were down more than 12%. Folate or vitamin B9 levels were down 30%.

“People say more CO2 is more plant food – and it is. But how plants respond to that sudden increase in food will impact human health as well, from nutritional deficits, to ethnopharmacology, to seasonal pollen allergies – in ways we don’t yet understand,” said Lewis Ziska, a plant physiologist with the US Department of Agriculture research service, one of the authors.

Hungry billion

Up to a billion people in the world are what bureaucrats politely call “food insecure.” There has already been concern about the impact of higher levels of carbon dioxide on protein in potatoes, maize and other cereals.

As global temperatures rise in response to ever greater levels of CO2 and other greenhouse gases in the atmosphere, harvests of all the staple cereals could in any case decline – sometimes as a response to ever wilder extremes of heat, rain and windstorm – by between 20 and 40%. But so far, there has been little research on the impact of climate change on the nutritional qualities of each staple.

The study puts the case more coolly: “For those populations that are highly rice-dependent, any CO2-induced change in the integrated nutritional value of rice grains could disproportionately affect human health.” And the scientists end their study by saying:

“Overall, these results indicate that the role of rising CO2 on reducing rice quality may represent a fundamental, but under-appreciated, human health effect associated with anthropogenic climate change.” – Climate News Network

One consequence of more carbon dioxide in the atmosphere will be less nutritious rice, despite growth gains for some other crops.

LONDON, 25 May, 2018 – Global warming could bring a serious problem for the two billion people on the planet who depend on one grain for their staple diet: less nutritious rice to sustain them. Scientists have found that rice grown at higher levels of carbon dioxide has an overall lower nutritional value.

The grain contains lower levels of protein, and iron and zinc – metals vital for health in trace form – and also consistent declines in vitamin B.

This finding is not based on computer simulation of a plant’s response to notionally higher atmospheric levels of the greenhouse gas CO2, nor on laboratory studies under glass and in artificial conditions. It is based on open air field trials.

That is, extra carbon dioxide is piped to the plants to mimic the ratios expected at the end of the century as ever more people burn ever greater quantities of fossil fuels. And it has been tested in many locations in rice-growing countries over many years.

The finding remains true – although at different levels of impact – for the 18 varieties or hybrids of rice tested so far.

levels were down 30%.

“People say more CO2 is more plant food – and it is. But how plants respond to that sudden increase in food will impact human health as well”

Ten nations depend upon rice for daily food supplies. The people most likely to feel the consequences of reduced nutritional support – and these include impaired cognitive development, a feebler immune system, obesity and diabetes – are likely to be those who are poorest. The researchers estimate that 600 million people for whom rice provides more than half their daily diet could be affected.

Scientists from China, Japan, the US and Australia report in the journal Science Advances that they began their research, using what they call the technique of free air carbon dioxide enrichment, in 1998, to recreate what they expect to be the conditions under which farmers will grow crops a few decades from now.

They found on average that the test rice had 10% less protein, 8% less iron and 5.1% less zinc compared with rice grown by farmers under existing conditions. There were also declines of 17% in the vitamins B1 (thiamine) and of more than 16% in vitamin B2 (riboflavin). Vitamin B5, or pantothenic acid levels, were down more than 12%. Folate or vitamin B9 levels were down 30%.

“People say more CO2 is more plant food – and it is. But how plants respond to that sudden increase in food will impact human health as well, from nutritional deficits, to ethnopharmacology, to seasonal pollen allergies – in ways we don’t yet understand,” said Lewis Ziska, a plant physiologist with the US Department of Agriculture research service, one of the authors.

Hungry billion

Up to a billion people in the world are what bureaucrats politely call “food insecure.” There has already been concern about the impact of higher levels of carbon dioxide on protein in potatoes, maize and other cereals.

As global temperatures rise in response to ever greater levels of CO2 and other greenhouse gases in the atmosphere, harvests of all the staple cereals could in any case decline – sometimes as a response to ever wilder extremes of heat, rain and windstorm – by between 20 and 40%. But so far, there has been little research on the impact of climate change on the nutritional qualities of each staple.

The study puts the case more coolly: “For those populations that are highly rice-dependent, any CO2-induced change in the integrated nutritional value of rice grains could disproportionately affect human health.” And the scientists end their study by saying:

“Overall, these results indicate that the role of rising CO2 on reducing rice quality may represent a fundamental, but under-appreciated, human health effect associated with anthropogenic climate change.” – Climate News Network

Kelp forests under threat from acid seas

The kelp forests – those towering submarine tangles of brown seaweeds – may not survive the steady change of ocean chemistry.

LONDON, 17 May, 2018 – Australian scientists have identified a risk to the kelp forests of the oceans, a new way in which carbon dioxide can change the world. Ever more acidic oceans could encourage weedy submarine grasslands to replace the rich habitats of the coastal kelp forests.

Although most climate change forecasts are based on computer simulation, this one has been tested in the real world. The scientists used natural volcanic seeps rich in carbon dioxide to observe the changes to sea floor ecosystems as water chemistry changes with greater levels of dissolved CO2.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally,” said Sean Connell, of the Environment Institute at the University of Adelaide.

“Weedy species are quicker to capitalise on nutrients, such as carbon, and can grow faster than their natural predators can consume them.

Weedy turf wins

“Unfortunately, the CO2 that humans are pumping into the atmosphere by burning fossil fuels gets absorbed by the ocean and favours weedy turfs, which replace kelp forests that support higher coastal productivity and biodiversity.”

He and colleagues from Australia, the US, New Zealand, Italy and Hong Kong report in the journal Ecology that they made a series of samples of submarine plant growth at natural volcanic vents in New Zealand’s Bay of Plenty: they looked at rocky reefs on which grew a mosaic of kelp and turf algae, along barren stretches grazed by sea urchins and a native New Zealand mollusc.

They chose the sites because the levels of carbon dioxide – and therefore the measures of acidity – in the water were roughly what climate scientists would predict for the end of this century, if humans go on releasing greenhouse gases.

They found that ecosystems changed with shifts in water chemistry. “While elevated CO2 caused some weeds to be eaten in greater amounts, the dominant sea urchin predator ate these weeds at reduced amounts. This enabled the weeds to escape their natural controls and expand across coasts near the elevated CO2,” Professor Connell said.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally”

The slow but inexorable changes in ocean acidity will have inevitable consequences for coastal protection offered by natural ecosystems. Kelp forests provide habitat or nourishment for seals, sea otters, sea lions, whales, cormorants, gulls, terns and shore birds as well as fish. There is evidence that warming has already damaged some of Australia’s kelp forests.

Researchers have been issuing such warnings for years: among them Professor Connell and his co-author from Adelaide, Ivan Nagelkerken, who, three years ago, surveyed 632 scientific studies of a huge range of marine habitats to conclude that the overall effect of acidification was to impoverish ocean life.

“Under the level of acidification we will find in the oceans in a few decades, marine life is likely to be dominated by fast-growing and opportunistic species at the expense of longer-lived species with specialist lifestyles, unless we set some change in place,” said Professor Nagelkerken.

“We need to consider how natural enemies might be managed so that those weedy species are kept under control.” – Climate News Network

The kelp forests – those towering submarine tangles of brown seaweeds – may not survive the steady change of ocean chemistry.

LONDON, 17 May, 2018 – Australian scientists have identified a risk to the kelp forests of the oceans, a new way in which carbon dioxide can change the world. Ever more acidic oceans could encourage weedy submarine grasslands to replace the rich habitats of the coastal kelp forests.

Although most climate change forecasts are based on computer simulation, this one has been tested in the real world. The scientists used natural volcanic seeps rich in carbon dioxide to observe the changes to sea floor ecosystems as water chemistry changes with greater levels of dissolved CO2.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally,” said Sean Connell, of the Environment Institute at the University of Adelaide.

“Weedy species are quicker to capitalise on nutrients, such as carbon, and can grow faster than their natural predators can consume them.

Weedy turf wins

“Unfortunately, the CO2 that humans are pumping into the atmosphere by burning fossil fuels gets absorbed by the ocean and favours weedy turfs, which replace kelp forests that support higher coastal productivity and biodiversity.”

He and colleagues from Australia, the US, New Zealand, Italy and Hong Kong report in the journal Ecology that they made a series of samples of submarine plant growth at natural volcanic vents in New Zealand’s Bay of Plenty: they looked at rocky reefs on which grew a mosaic of kelp and turf algae, along barren stretches grazed by sea urchins and a native New Zealand mollusc.

They chose the sites because the levels of carbon dioxide – and therefore the measures of acidity – in the water were roughly what climate scientists would predict for the end of this century, if humans go on releasing greenhouse gases.

They found that ecosystems changed with shifts in water chemistry. “While elevated CO2 caused some weeds to be eaten in greater amounts, the dominant sea urchin predator ate these weeds at reduced amounts. This enabled the weeds to escape their natural controls and expand across coasts near the elevated CO2,” Professor Connell said.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally”

The slow but inexorable changes in ocean acidity will have inevitable consequences for coastal protection offered by natural ecosystems. Kelp forests provide habitat or nourishment for seals, sea otters, sea lions, whales, cormorants, gulls, terns and shore birds as well as fish. There is evidence that warming has already damaged some of Australia’s kelp forests.

Researchers have been issuing such warnings for years: among them Professor Connell and his co-author from Adelaide, Ivan Nagelkerken, who, three years ago, surveyed 632 scientific studies of a huge range of marine habitats to conclude that the overall effect of acidification was to impoverish ocean life.

“Under the level of acidification we will find in the oceans in a few decades, marine life is likely to be dominated by fast-growing and opportunistic species at the expense of longer-lived species with specialist lifestyles, unless we set some change in place,” said Professor Nagelkerken.

“We need to consider how natural enemies might be managed so that those weedy species are kept under control.” – Climate News Network

Hopes rise for some coral survival

US scientists have good news about prospects for coral survival on one of the world’s great reefs, threatened by climate change.

LONDON, 25 April, 2018 – Researchers have raised hopes that limited coral survival may be possible, allowing one of the world’s best-known reefs to survive a little longer.

Although corals are highly sensitive to ocean warming, and notoriously bleach when temperatures exceed a certain limit, a new study has shown that at least one coral can evolve tolerance to excessive temperatures.

The implication is that even though other teams have repeatedly warned that the world’s reefs are in peril as the world warms because of ever-greater ratios of greenhouse gases in the atmosphere, as a consequence of human combustion of fossil fuels at a profligate rate, the world’s great reefs may survive for perhaps another century, rather than perish within the next 50 years.

“It means these corals will still go extinct if we do nothing,” said Misha Matz, of the University of Texas at Austin, who led the study. “But it also means we have a chance to save them. It buys us time to actually do something about global warming, which is the main problem.”

The argument is based on Darwinian logic: coral colonies produce colossal numbers of larvae each year, set adrift on ocean currents to colonise new reefs. As conditions change, those corals that by an accident of genetic inheritance have the traits needed to cope with environmental challenge will get a foothold, and flourish. Those that don’t will fade out. Natural selection will respond.

”While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers”

And this is hopeful news, if only because the world’s reefs are under threat as never before. Bleaching – the response to heat in which coral rejects the algae with which it normally lives in symbiosis – has always happened: research earlier this year suggests it could become five times more frequent, and reefs such as Australia’s Great Barrier would have no time to recover.

Some reefs have already been pronounced too damaged ever to be restored. This is bad news not just for the coral animals: the tropical reefs are just about the richest habitats on the planet, and of profound economic importance to humans too.

A partnership of US and Australian scientists reports in the Public Library of Science journal PLOS Genetics that computer simulation models and genetic evidence of variation from one species of staghorn coral, called Acropora millepora, together show that the coral could in theory adapt over a stretch of 20 to 50 generations.

“This genetic variation is like fuel for natural selection,” Dr Matz said. “If there is enough of it, evolution can be remarkably fast, because all it needs to do is reshuffle the existing variants between the populations.

“It doesn’t have to wait for a new mutation to appear; it’s already there. The problem is, when the genetic variation is exhausted, it is over and the future is unclear.”

Tentative conclusions

There are problems with such studies. This one is based on genetic evidence from one species of coral. But the 2,300 km Great Barrier Reef of Australia is home to at least 411 species of hard coral. It is based on a mathematical model, not on observed change in the reefs.

And global warming is not the only challenge to coral reefs, which are also threatened by human exploitation, pollution and increasing acidification  of the surrounding seas, again as a consequence of ever higher levels of carbon dioxide in the atmosphere.

“Corals live in a symbiotic relationship with zooxanthellae, which are plant-like cells hosted in surface tissues that provide up to 90% of the energy to the colony,” said Stephen Simpson, a marine biologist at the University of Exeter in the UK, commenting on the study.

“Whether there is also sufficient genotypic variation in the zooxanthellae to tolerate further warming remains to be seen. While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers, threatening the functional integrity of reef ecosystems.” – Climate News Network

US scientists have good news about prospects for coral survival on one of the world’s great reefs, threatened by climate change.

LONDON, 25 April, 2018 – Researchers have raised hopes that limited coral survival may be possible, allowing one of the world’s best-known reefs to survive a little longer.

Although corals are highly sensitive to ocean warming, and notoriously bleach when temperatures exceed a certain limit, a new study has shown that at least one coral can evolve tolerance to excessive temperatures.

The implication is that even though other teams have repeatedly warned that the world’s reefs are in peril as the world warms because of ever-greater ratios of greenhouse gases in the atmosphere, as a consequence of human combustion of fossil fuels at a profligate rate, the world’s great reefs may survive for perhaps another century, rather than perish within the next 50 years.

“It means these corals will still go extinct if we do nothing,” said Misha Matz, of the University of Texas at Austin, who led the study. “But it also means we have a chance to save them. It buys us time to actually do something about global warming, which is the main problem.”

The argument is based on Darwinian logic: coral colonies produce colossal numbers of larvae each year, set adrift on ocean currents to colonise new reefs. As conditions change, those corals that by an accident of genetic inheritance have the traits needed to cope with environmental challenge will get a foothold, and flourish. Those that don’t will fade out. Natural selection will respond.

”While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers”

And this is hopeful news, if only because the world’s reefs are under threat as never before. Bleaching – the response to heat in which coral rejects the algae with which it normally lives in symbiosis – has always happened: research earlier this year suggests it could become five times more frequent, and reefs such as Australia’s Great Barrier would have no time to recover.

Some reefs have already been pronounced too damaged ever to be restored. This is bad news not just for the coral animals: the tropical reefs are just about the richest habitats on the planet, and of profound economic importance to humans too.

A partnership of US and Australian scientists reports in the Public Library of Science journal PLOS Genetics that computer simulation models and genetic evidence of variation from one species of staghorn coral, called Acropora millepora, together show that the coral could in theory adapt over a stretch of 20 to 50 generations.

“This genetic variation is like fuel for natural selection,” Dr Matz said. “If there is enough of it, evolution can be remarkably fast, because all it needs to do is reshuffle the existing variants between the populations.

“It doesn’t have to wait for a new mutation to appear; it’s already there. The problem is, when the genetic variation is exhausted, it is over and the future is unclear.”

Tentative conclusions

There are problems with such studies. This one is based on genetic evidence from one species of coral. But the 2,300 km Great Barrier Reef of Australia is home to at least 411 species of hard coral. It is based on a mathematical model, not on observed change in the reefs.

And global warming is not the only challenge to coral reefs, which are also threatened by human exploitation, pollution and increasing acidification  of the surrounding seas, again as a consequence of ever higher levels of carbon dioxide in the atmosphere.

“Corals live in a symbiotic relationship with zooxanthellae, which are plant-like cells hosted in surface tissues that provide up to 90% of the energy to the colony,” said Stephen Simpson, a marine biologist at the University of Exeter in the UK, commenting on the study.

“Whether there is also sufficient genotypic variation in the zooxanthellae to tolerate further warming remains to be seen. While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers, threatening the functional integrity of reef ecosystems.” – Climate News Network

Coral reefs face infection risk from plastic

Plastic flotsam provides a liferaft for deadly bacteria – and a way of colonising coral reefs with killer infections.

LONDON, 29 January, 2018 – Scientists have established yet another hazard from the millions of tons of plastic waste that tip into the sea: it delivers microbial infection to the world’s coral reefs.

When plastic pollutants snag on coral reefs, the likelihood of disease rises from 4% to 89%, they calculate. That is an increase in risk of more than twentyfold.

And the impact on the world’s reefs – already under increasing hazard from ocean acidification and from bleaching in extremes of heat – could be devastating.

“Plastic debris acts like a marine motor home for microbes,” said Joleah Lamb, a researcher at Cornell University in the US. She began gathering data while at James Cook University in Australia.

“Plastics make ideal vessels for colonising microscopic organisms that could trigger disease if they come into contact with corals.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions”

“Plastic items – commonly made of polypropylene, such as bottle caps and toothbrushes – have been shown to become heavily inhabited by bacteria. This is associated with the globally devastating group of coral diseases known as white syndromes.”

She and colleagues from the US, Canada, Australia, Myanmar, Thailand and Indonesia report in the journal Science that between 2011 and 2014 they surveyed 124,000 reef-building corals from 159 reefs in the Asia-Pacific region.

One third of the reefs surveyed were polluted with plastic waste, the highest in Indonesian waters, the lowest off the Australian coast.

They calculate that, right now, the number of plastic bags, cups, bottles, toothbrushes and bits of packaging snagged on the reefs in the region could be 11.1 billion. By 2025, there could be 15.7 bn plastic objects stuck on the same reefs.

No return

And, they report, the presence of plastic was associated with a 20-fold increase in risk of disease, and in particular infections know to marine biologists as skeletal eroding band disease, white syndrome and black band disease.

The items snagged on the corals deprived them of sunlight and oxygen, and weakened the coral to the point at which invasive pathogens could gain a hold.

“What’s troubling about coral disease is that once the coral tissue loss occurs, it’s not coming back,” Dr Lamb said. “It’s like getting gangrene on your foot and there is nothing you can do to stop it from affecting your whole body.”

The Asia-Pacific region is home to more than 55% of the world’s coral reefs. Complex reef structures – reefs with branching corals, for instance – were eight times more likely to trap floating plastic waste.

An estimated 12 billion metric tons of indestructible plastic waste is in the world’s landfills. Somewhere between 4.8 million and 12.7 million metric tons of plastic waste gets into the oceans in a single year.

Rich resource

Coral reefs are among the richest habitats on the planet: a diseased or dying reef can no longer provide food and shelter for a vast range of sea creatures.

Pollution and disease also put at risk much of the estimated $375bn value that reefs offer to 275 million people as sources of fisheries, tourism and coastal protection.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions,” said Drew Harvell, professor of ecology and evolutionary biology at Cornell, and one of the authors.

“While we can’t stop the huge impact of global warming on coral health in the short term, this new work should drive policy toward reducing plastic pollution.” – Climate News Network

Plastic flotsam provides a liferaft for deadly bacteria – and a way of colonising coral reefs with killer infections.

LONDON, 29 January, 2018 – Scientists have established yet another hazard from the millions of tons of plastic waste that tip into the sea: it delivers microbial infection to the world’s coral reefs.

When plastic pollutants snag on coral reefs, the likelihood of disease rises from 4% to 89%, they calculate. That is an increase in risk of more than twentyfold.

And the impact on the world’s reefs – already under increasing hazard from ocean acidification and from bleaching in extremes of heat – could be devastating.

“Plastic debris acts like a marine motor home for microbes,” said Joleah Lamb, a researcher at Cornell University in the US. She began gathering data while at James Cook University in Australia.

“Plastics make ideal vessels for colonising microscopic organisms that could trigger disease if they come into contact with corals.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions”

“Plastic items – commonly made of polypropylene, such as bottle caps and toothbrushes – have been shown to become heavily inhabited by bacteria. This is associated with the globally devastating group of coral diseases known as white syndromes.”

She and colleagues from the US, Canada, Australia, Myanmar, Thailand and Indonesia report in the journal Science that between 2011 and 2014 they surveyed 124,000 reef-building corals from 159 reefs in the Asia-Pacific region.

One third of the reefs surveyed were polluted with plastic waste, the highest in Indonesian waters, the lowest off the Australian coast.

They calculate that, right now, the number of plastic bags, cups, bottles, toothbrushes and bits of packaging snagged on the reefs in the region could be 11.1 billion. By 2025, there could be 15.7 bn plastic objects stuck on the same reefs.

No return

And, they report, the presence of plastic was associated with a 20-fold increase in risk of disease, and in particular infections know to marine biologists as skeletal eroding band disease, white syndrome and black band disease.

The items snagged on the corals deprived them of sunlight and oxygen, and weakened the coral to the point at which invasive pathogens could gain a hold.

“What’s troubling about coral disease is that once the coral tissue loss occurs, it’s not coming back,” Dr Lamb said. “It’s like getting gangrene on your foot and there is nothing you can do to stop it from affecting your whole body.”

The Asia-Pacific region is home to more than 55% of the world’s coral reefs. Complex reef structures – reefs with branching corals, for instance – were eight times more likely to trap floating plastic waste.

An estimated 12 billion metric tons of indestructible plastic waste is in the world’s landfills. Somewhere between 4.8 million and 12.7 million metric tons of plastic waste gets into the oceans in a single year.

Rich resource

Coral reefs are among the richest habitats on the planet: a diseased or dying reef can no longer provide food and shelter for a vast range of sea creatures.

Pollution and disease also put at risk much of the estimated $375bn value that reefs offer to 275 million people as sources of fisheries, tourism and coastal protection.

“Our work shows that plastic pollution is killing corals. Our goal is to focus less on measuring things dying and more on finding solutions,” said Drew Harvell, professor of ecology and evolutionary biology at Cornell, and one of the authors.

“While we can’t stop the huge impact of global warming on coral health in the short term, this new work should drive policy toward reducing plastic pollution.” – Climate News Network