Tag Archives: Australia

Call to unravel basic climate change

Science still cannot provide satisfactory explanations for some features of basic climate change, experts argue – and they want a global search for answers.

LONDON, 5 February, 2017 – A group of distinguished climate scientists has called for a massive international co-operation to understand absolutely basic climate change. And their call exposes the uncertainties that still make long-term climate predictions uncertain, unsatisfactory and sometimes unconvincing.

“Knowing that the globe is warming through human activity is like understanding that cancer is caused by runaway cell division,” said Christian Jakob, a climate scientist at Monash University in Australia, and one of the authors.

“It is just the start of the challenge. While global mean temperature provides the canvas, the details of future changes will emerge at regional levels. It’s at these levels that we will feel and need to adapt to the impact of climate change, economically and socially.”

The point is that there is no doubt that human action has set off a process of accelerating climate change, by clearing the forests, changing the natural cycles of the terrestrial landscape, and by excavating and burning colossal quantities of fossil fuels to release rising proportions of carbon dioxide into the Earth’s atmosphere.

But within that global understanding there remain three profound questions that have yet to be answered in the kind of detail that would permit accurate prediction.

Vanishing carbon

One is: where does the carbon go? For the last 10,000 years or so, carbon dioxide levels in the atmosphere remained more or less the same: plants photosynthesised tissues from atmospheric carbon, oceans dissolved atmospheric gases, rocks reacted with the atmosphere to form mineral carbonates, herbivores consumed plants, man and other carnivores devoured grazing animals, but the overall ratio of the greenhouse gas carbon dioxide remained the same.

But now, to make sense of the precise link between greenhouse gases and climate change, researchers must first understand in much greater detail how the oceans and the land absorb atmospheric carbon, and in what quantities.

The second question they outline, in an essay in the journal Nature Climate Change, is: how will the weather change with climate?

Climate is what farmers bank on when they plant rice rather than rye, weather is what they get with a sudden sustained summer drought, or a late spring ice storm, or torrential harvest time floods. So what, in a world 2°C warmer, or 4°C, would that mean for a community?

Regional focus

“To put it in a particularly Australian way, we don’t plan for a bushfire season based on what is happening to global average temperatures, we look at the temperature and humidity in our area instead,” said Professor Jakob.

Which raises the third great question: how does climate affect the habitability of the Earth and its regions? There have been warnings that climate change could bring lethal extremes of heat and humidity to parts of the Gulf region, and render conditions in parts of North Africa and the Middle East intolerable

There have been predictions that extremes of drought and flood could increase, too, in Australia. But scientists don’t yet understand precisely the way overall climatic conditions play out in regional geography.

“Until we focus on regional phenomena, in a place like Australia we may struggle to know exactly how rainfall, heat waves and sea level rise will change in different parts of our country,” said Sarah Perkins-Kirkpatrick, of the University of New South Wales, and a  co-author.

“We need to reveal these impacts so we can protect regional agriculture, infrastructure and the Australian environments we have all come to know and love, such as the Great Barrier Reef.”

“ . . . a growing influx of the best scientists’ talent is needed to prepare for the surprises to come” 

The scientists, from Germany, France, Australia, the US, the UK and Switzerland, want to build a global co-operation of the kind launched decades ago at CERN in Geneva to understand basic climate change as CERN worked to understand particle physics.

They call for advanced climate simulation systems that can model outcomes with ever greater precision and ever smaller scales, and for sustained, long-term observation of the machinery of the planetary climate system: among them the complexities of the water cycle, involving the evaporation of soil moisture, the formation of clouds and the conditions for rain and snow fall.

Only then could researchers understand why climate continues to surprise: why so much of the Arctic sea ice disappeared in the summer of 2007; why almost all of the surface of Greenland started to melt in 2012; why drought and heat waves hit Russia so harshly in 2010.

“The human spirit is alive in climate research, as witnessed by the responses to the surprises encountered in the past,” they conclude, “but a growing influx of the best scientists’ talent is needed to prepare for the surprises to come.” – Climate News Network

Science still cannot provide satisfactory explanations for some features of basic climate change, experts argue – and they want a global search for answers.

LONDON, 5 February, 2017 – A group of distinguished climate scientists has called for a massive international co-operation to understand absolutely basic climate change. And their call exposes the uncertainties that still make long-term climate predictions uncertain, unsatisfactory and sometimes unconvincing.

“Knowing that the globe is warming through human activity is like understanding that cancer is caused by runaway cell division,” said Christian Jakob, a climate scientist at Monash University in Australia, and one of the authors.

“It is just the start of the challenge. While global mean temperature provides the canvas, the details of future changes will emerge at regional levels. It’s at these levels that we will feel and need to adapt to the impact of climate change, economically and socially.”

The point is that there is no doubt that human action has set off a process of accelerating climate change, by clearing the forests, changing the natural cycles of the terrestrial landscape, and by excavating and burning colossal quantities of fossil fuels to release rising proportions of carbon dioxide into the Earth’s atmosphere.

But within that global understanding there remain three profound questions that have yet to be answered in the kind of detail that would permit accurate prediction.

Vanishing carbon

One is: where does the carbon go? For the last 10,000 years or so, carbon dioxide levels in the atmosphere remained more or less the same: plants photosynthesised tissues from atmospheric carbon, oceans dissolved atmospheric gases, rocks reacted with the atmosphere to form mineral carbonates, herbivores consumed plants, man and other carnivores devoured grazing animals, but the overall ratio of the greenhouse gas carbon dioxide remained the same.

But now, to make sense of the precise link between greenhouse gases and climate change, researchers must first understand in much greater detail how the oceans and the land absorb atmospheric carbon, and in what quantities.

The second question they outline, in an essay in the journal Nature Climate Change, is: how will the weather change with climate?

Climate is what farmers bank on when they plant rice rather than rye, weather is what they get with a sudden sustained summer drought, or a late spring ice storm, or torrential harvest time floods. So what, in a world 2°C warmer, or 4°C, would that mean for a community?

Regional focus

“To put it in a particularly Australian way, we don’t plan for a bushfire season based on what is happening to global average temperatures, we look at the temperature and humidity in our area instead,” said Professor Jakob.

Which raises the third great question: how does climate affect the habitability of the Earth and its regions? There have been warnings that climate change could bring lethal extremes of heat and humidity to parts of the Gulf region, and render conditions in parts of North Africa and the Middle East intolerable

There have been predictions that extremes of drought and flood could increase, too, in Australia. But scientists don’t yet understand precisely the way overall climatic conditions play out in regional geography.

“Until we focus on regional phenomena, in a place like Australia we may struggle to know exactly how rainfall, heat waves and sea level rise will change in different parts of our country,” said Sarah Perkins-Kirkpatrick, of the University of New South Wales, and a  co-author.

“We need to reveal these impacts so we can protect regional agriculture, infrastructure and the Australian environments we have all come to know and love, such as the Great Barrier Reef.”

“ . . . a growing influx of the best scientists’ talent is needed to prepare for the surprises to come” 

The scientists, from Germany, France, Australia, the US, the UK and Switzerland, want to build a global co-operation of the kind launched decades ago at CERN in Geneva to understand basic climate change as CERN worked to understand particle physics.

They call for advanced climate simulation systems that can model outcomes with ever greater precision and ever smaller scales, and for sustained, long-term observation of the machinery of the planetary climate system: among them the complexities of the water cycle, involving the evaporation of soil moisture, the formation of clouds and the conditions for rain and snow fall.

Only then could researchers understand why climate continues to surprise: why so much of the Arctic sea ice disappeared in the summer of 2007; why almost all of the surface of Greenland started to melt in 2012; why drought and heat waves hit Russia so harshly in 2010.

“The human spirit is alive in climate research, as witnessed by the responses to the surprises encountered in the past,” they conclude, “but a growing influx of the best scientists’ talent is needed to prepare for the surprises to come.” – Climate News Network

Less mild weather ahead as world warms

The warming atmosphere will mean a rise in mild weather for parts of the US, scientists find, but a gradual global drop. 

LONDON, 30 January, 2017 – Thanks to climate change, there will be more perfect days in President Trump’s America. Those will be the days that areneither too hot, too cold, too humid nor rainy”, when the highest temperatures hover between 18°C and 30°C, and when less than 1mm of rain falls.

This is the weather for walks, bicycle rides, picnics and music festivals. But the mellow moments will not be evenly distributed. The number of mild winter days will go up, but for many the number of mild summer days will fall, and Donald Trump’s Florida in particular will experience less benign weather overall as global temperatures rise.

Meanwhile, in a world 2°C warmer, Australia will confront a different experience: extreme rainfall events that will be up to 30% rainier, even in those regions that, overall, will become more drought-prone, according to a separate study.

US scientists report in the journal Climatic Change that rather than make any further predictions about hurricanes, blizzards, droughts or floods they would look in the climate models for the future incidence of good weather around the world: days ideal for walking the dog, watching a football match or going fishing.

Different approach

And they found that although there would be winners in the mid-latitude, temperate zones, globally by the century’s end the number of mild days would drop by between 10 and 13%, thanks to global warming as a consequence of rising levels of greenhouse gases in the atmosphere.

Right now, worldwide, there is an average of 74 mellow days a year: by 2035, this will drop to 70, and in the last decade of the century the average will be 64.

“Extreme weather is difficult to relate to because it may happen only once in your lifetime,” said Karin van der Wiel, of the US National Oceanic and Atmospheric Administration’s geophysical fluid dynamics laboratory at Princeton University.

“We took a different approach here and studied a positive meteorological concept, weather that occurs regularly, and that’s easier to relate to.”

So Seattle in the US, with 88 good days a year now, can expect 97 by late in the century. Miami, which can bank on 97 mellow days a year now, will experience only 69 after 2081. 

England and northern Europe could gain another 10 or 15 good days, but some regions in Africa, Asia and Latin America could become a great deal more uncomfortable, with from 15 to 50 fewer mild days.

And across the Pacific, Australian scientists used computer simulations to predict the pattern of change in a world in which temperatures rise, and with them the capacity of the atmosphere to hold moisture.

They were looking not at overall change, but at the likelihood of extreme rainfall in a land that seems to specialise in extended droughts and devastating floods.  

They report in Nature Climate Change that if the world sticks to the Paris Agreement – which would limit average global warming to 2°C – then extreme precipitation would increase by from 11.3% to 30%.

“The long and the short of it is that with 2°C of global warming Australia is stuck with either more aridity, much heavier extreme rains, or some combination of the two”

If the world abandoned the attempt to rein in fossil fuel combustion, and global average temperatures rose by 4°C, then the projected increase in rainfall for extreme events could be between 22% and 60% higher.

“Extreme precipitation is projected to increase almost everywhere in Australia, from tropical regions in the north to mid-latitudes in the south and from dry deserts in the centre to wet places along the coast,” said Jiawei Bao of the Climate Change Research Centre at the University of New South Wales.

And his co-author Steven Sherwood said: “There is no chance that rainfall in Australia will remain the same as the climate warms. The only way that this intensification of extreme rainfall falls at the lower end of the scale is if the continent becomes drier overall.

“The long and the short of it is that with 2°C of global warming Australia is stuck with either more aridity, much heavier extreme rains, or some combination of the two.” – Climate News Network

The warming atmosphere will mean a rise in mild weather for parts of the US, scientists find, but a gradual global drop. 

LONDON, 30 January, 2017 – Thanks to climate change, there will be more perfect days in President Trump’s America. Those will be the days that areneither too hot, too cold, too humid nor rainy”, when the highest temperatures hover between 18°C and 30°C, and when less than 1mm of rain falls.

This is the weather for walks, bicycle rides, picnics and music festivals. But the mellow moments will not be evenly distributed. The number of mild winter days will go up, but for many the number of mild summer days will fall, and Donald Trump’s Florida in particular will experience less benign weather overall as global temperatures rise.

Meanwhile, in a world 2°C warmer, Australia will confront a different experience: extreme rainfall events that will be up to 30% rainier, even in those regions that, overall, will become more drought-prone, according to a separate study.

US scientists report in the journal Climatic Change that rather than make any further predictions about hurricanes, blizzards, droughts or floods they would look in the climate models for the future incidence of good weather around the world: days ideal for walking the dog, watching a football match or going fishing.

Different approach

And they found that although there would be winners in the mid-latitude, temperate zones, globally by the century’s end the number of mild days would drop by between 10 and 13%, thanks to global warming as a consequence of rising levels of greenhouse gases in the atmosphere.

Right now, worldwide, there is an average of 74 mellow days a year: by 2035, this will drop to 70, and in the last decade of the century the average will be 64.

“Extreme weather is difficult to relate to because it may happen only once in your lifetime,” said Karin van der Wiel, of the US National Oceanic and Atmospheric Administration’s geophysical fluid dynamics laboratory at Princeton University.

“We took a different approach here and studied a positive meteorological concept, weather that occurs regularly, and that’s easier to relate to.”

So Seattle in the US, with 88 good days a year now, can expect 97 by late in the century. Miami, which can bank on 97 mellow days a year now, will experience only 69 after 2081. 

England and northern Europe could gain another 10 or 15 good days, but some regions in Africa, Asia and Latin America could become a great deal more uncomfortable, with from 15 to 50 fewer mild days.

And across the Pacific, Australian scientists used computer simulations to predict the pattern of change in a world in which temperatures rise, and with them the capacity of the atmosphere to hold moisture.

They were looking not at overall change, but at the likelihood of extreme rainfall in a land that seems to specialise in extended droughts and devastating floods.  

They report in Nature Climate Change that if the world sticks to the Paris Agreement – which would limit average global warming to 2°C – then extreme precipitation would increase by from 11.3% to 30%.

“The long and the short of it is that with 2°C of global warming Australia is stuck with either more aridity, much heavier extreme rains, or some combination of the two”

If the world abandoned the attempt to rein in fossil fuel combustion, and global average temperatures rose by 4°C, then the projected increase in rainfall for extreme events could be between 22% and 60% higher.

“Extreme precipitation is projected to increase almost everywhere in Australia, from tropical regions in the north to mid-latitudes in the south and from dry deserts in the centre to wet places along the coast,” said Jiawei Bao of the Climate Change Research Centre at the University of New South Wales.

And his co-author Steven Sherwood said: “There is no chance that rainfall in Australia will remain the same as the climate warms. The only way that this intensification of extreme rainfall falls at the lower end of the scale is if the continent becomes drier overall.

“The long and the short of it is that with 2°C of global warming Australia is stuck with either more aridity, much heavier extreme rains, or some combination of the two.” – Climate News Network

Coral bleaching could spark annual reef havoc

Before 2100, almost every reef in the world will suffer severe coral bleaching annually unless fossil fuel consumption is sharply reduced.

LONDON, 14 January, 2017 – Some time this century, if humans go on burning fossil fuels at the present rate, severe bleaching will hit 99% of coral reefs every year. Coral bleaching happens when the organisms become uncomfortably hot, and reject the algae on which their lives ultimately depend.

Since it takes a reef five years to recover from any one bleaching event, the consequences for some of the world’s richest ecosystems could be catastrophic. But catastrophe could be delayed. Drastic cuts in emissions reductions could give reefs an average of another 11 years before they start bleaching every year, according to new research.

Right now, the world’s reefs are caught up in the longest global coral bleaching event ever recorded. It began in 2014, and could go on well into 2017, according to the journal Scientific Reports

Corals are acutely sensitive to ocean temperatures and when the thermometer rises, their symbiotic relationship with a mutual beneficiary, the zooxanthellae, breaks down. Some 90% of the Great Barrier Reef off Australia has been affected by the latest episode, and 20% of the coral killed.

“Bleaching that takes place every year will invariably cause major changes in the ecological function of coral reef ecosystems,” said Ruben van Hooidonk of the US National Oceanic and Atmospheric Administration and the University of Miami.

“Further, annual bleaching will greatly reduce the capacity of coral reefs to provide goods and services, such as fisheries and coastal protection, to human communities.”

Acid trend

The warning supports earlier studies that have already predicted problems for the world’s reefs by the century’s end. The reefs are being hit by changes in ocean chemistry, as carbon dioxide levels rise and as waters become more acidic

Changing conditions make reefs vulnerable to new predators. And biologists have warned, again and again, that reefs are home to around a quarter of all marine life, and worth an estimated $375bn a year to humans, as coastal protection, as fishery nurseries, and as a source of tourism.

And even if corals recover from bleaching, and pollution, they could still be vulnerable to drowning as sea levels rise. A new study in the journal Global and Planetary Change has identified a crisis at the Great Barrier Reef 125,000 years ago, when polar ice melted, sea levels rose by perhaps six metres, and the reef’s corals all but perished.

“The findings highlight the importance of increasing the reef’s resilience now,” said Belinda Dechnik of the University of Sydney, who led the research..

“In combination with climate change predictions by the Intergovernmental Panel on Climate Change and in the absence of improvements to reef management and human impacts, sea level pressures could tip the reef over the edge, potentially drowning it for good.”

But the latest computer model predictions revealed in Scientific Reports deliver even more urgency, more global detail and more alarm. There are 87 countries or territories that are home to 500 square kilometres or more of reef .

“ . . . annual bleaching will greatly reduce the capacity of coral reefs to provide goods and services, such as fisheries and coastal protection”

On average, these reefs will start to experience annual bleaching by 2043. This will leave the living corals vulnerable to starvation and disease.

About one reef system in twenty will already be hotter and have started bleaching a decade before that. Among the first will be reefs around Taiwan and the Turks and Caicos Islands. 

Some 11% of reefs will be affected a decade later than average, and these include the corals off Bahrain, Chile and French Polynesia.

If nations adhere to an international agreement made in Paris in December 2015 to limit global warming to 1.5°C, the annual bleaching experience could be delayed by another 11 years.

The low latitude reefs of the South Pacific, India, Florida and the Great Barrier off Australia could be protected for another 25 years. In effect, the research has identified the conservation priorities.

“These predictions are a treasure trove for those who are fighting to protect one of the world’s most magnificent and important ecosystems from the ravages of climate change,” said Erik Solheim, head of the UN Environment Programme.

“It is imperative that we take these predictions seriously and that, at the very minimum, we meet the targets of the Paris Agreement. Doing so will buy time for coral reefs and allow us to plan for the future and adapt to the present.” – Climate News Network

Before 2100, almost every reef in the world will suffer severe coral bleaching annually unless fossil fuel consumption is sharply reduced.

LONDON, 14 January, 2017 – Some time this century, if humans go on burning fossil fuels at the present rate, severe bleaching will hit 99% of coral reefs every year. Coral bleaching happens when the organisms become uncomfortably hot, and reject the algae on which their lives ultimately depend.

Since it takes a reef five years to recover from any one bleaching event, the consequences for some of the world’s richest ecosystems could be catastrophic. But catastrophe could be delayed. Drastic cuts in emissions reductions could give reefs an average of another 11 years before they start bleaching every year, according to new research.

Right now, the world’s reefs are caught up in the longest global coral bleaching event ever recorded. It began in 2014, and could go on well into 2017, according to the journal Scientific Reports

Corals are acutely sensitive to ocean temperatures and when the thermometer rises, their symbiotic relationship with a mutual beneficiary, the zooxanthellae, breaks down. Some 90% of the Great Barrier Reef off Australia has been affected by the latest episode, and 20% of the coral killed.

“Bleaching that takes place every year will invariably cause major changes in the ecological function of coral reef ecosystems,” said Ruben van Hooidonk of the US National Oceanic and Atmospheric Administration and the University of Miami.

“Further, annual bleaching will greatly reduce the capacity of coral reefs to provide goods and services, such as fisheries and coastal protection, to human communities.”

Acid trend

The warning supports earlier studies that have already predicted problems for the world’s reefs by the century’s end. The reefs are being hit by changes in ocean chemistry, as carbon dioxide levels rise and as waters become more acidic

Changing conditions make reefs vulnerable to new predators. And biologists have warned, again and again, that reefs are home to around a quarter of all marine life, and worth an estimated $375bn a year to humans, as coastal protection, as fishery nurseries, and as a source of tourism.

And even if corals recover from bleaching, and pollution, they could still be vulnerable to drowning as sea levels rise. A new study in the journal Global and Planetary Change has identified a crisis at the Great Barrier Reef 125,000 years ago, when polar ice melted, sea levels rose by perhaps six metres, and the reef’s corals all but perished.

“The findings highlight the importance of increasing the reef’s resilience now,” said Belinda Dechnik of the University of Sydney, who led the research..

“In combination with climate change predictions by the Intergovernmental Panel on Climate Change and in the absence of improvements to reef management and human impacts, sea level pressures could tip the reef over the edge, potentially drowning it for good.”

But the latest computer model predictions revealed in Scientific Reports deliver even more urgency, more global detail and more alarm. There are 87 countries or territories that are home to 500 square kilometres or more of reef .

“ . . . annual bleaching will greatly reduce the capacity of coral reefs to provide goods and services, such as fisheries and coastal protection”

On average, these reefs will start to experience annual bleaching by 2043. This will leave the living corals vulnerable to starvation and disease.

About one reef system in twenty will already be hotter and have started bleaching a decade before that. Among the first will be reefs around Taiwan and the Turks and Caicos Islands. 

Some 11% of reefs will be affected a decade later than average, and these include the corals off Bahrain, Chile and French Polynesia.

If nations adhere to an international agreement made in Paris in December 2015 to limit global warming to 1.5°C, the annual bleaching experience could be delayed by another 11 years.

The low latitude reefs of the South Pacific, India, Florida and the Great Barrier off Australia could be protected for another 25 years. In effect, the research has identified the conservation priorities.

“These predictions are a treasure trove for those who are fighting to protect one of the world’s most magnificent and important ecosystems from the ravages of climate change,” said Erik Solheim, head of the UN Environment Programme.

“It is imperative that we take these predictions seriously and that, at the very minimum, we meet the targets of the Paris Agreement. Doing so will buy time for coral reefs and allow us to plan for the future and adapt to the present.” – Climate News Network

Speed of Arctic changes defies scientists

The Arctic climate is changing so quickly that science can barely keep track of what is happening and predict the global consequences, the UN says.

LONDON, 29 September, 2016 In an unusually stark warning a leading international scientific body says the Arctic climate is changing so fast that researchers are struggling to keep up. The changes happening there, it says, are affecting the weather worldwide.

The World Meteorological Organisation (WMO) says: Dramatic and unprecedented warming in the Arctic is driving sea level rise, affecting weather patterns around the world and may trigger even more changes in the climate system.

The rate of change is challenging the current scientific capacity to monitor and predict what is becoming a journey into uncharted territory. 

The WMO is the United Nations’ main agency responsible for weather, climate and water.    

Its president, David Grimes, said: The Arctic is a principal, global driver of the climate system and is undergoing an unprecedented rate of change with consequences far beyond its boundaries.

Arctic collaboration

The changes in the Arctic are serving as a global indicator – like a canary in the coal mine – and are happening at a much faster rate than we would have expected.

He was speaking before addressing the first White House Science Ministerial meeting in Washington DC, held to develop international collaboration on Arctic science.

Climate change is causing global average temperatures to rise: 2014, 2015 and the first eight months of 2016 have all been record-breakers. The Arctic is warming at least twice as fast as the global average, in places even faster: the Canadian town of Inuvik has warmed by almost 4°C since 1948, about four times more than the global figure.

The increasing loss of Arctic sea ice is threatening polar bears across their range; melting sea ice is affecting the Arctic climate in a feedback loop; and scientists expect melting permafrost will release more carbon dioxide and methane

The WMO secretary-general, Petteri Taalas, said the Arctic changes had also been a factor in unusual winter weather patterns in North America and Europe. He said the thawing of the permafrost could release vast quantities of greenhouse gases into the atmosphere.

These are part of the vicious circles of climate change which are the subject of intense scientific research, he said.

The Arctic is a principal, global driver of the climate system and is undergoing an unprecedented rate of change with consequences far beyond its boundaries

Despite its certainty that the Arctic is in trouble, the WMO says it is hard to establish the implications of what is happening there. The Arctic makes up about 4% of the Earth’s surface, but the WMO says it is one of the most data-sparse regions in the world because of its remoteness and previous inaccessibility.

Lack of data and forecasts in the Arctic does impact on the quality of weather forecasts in other parts of the world. 

That’s a worry which is echoed at the other end of the planet. A study led by Dr Julie Jones, from the department of geography at the University of Sheffield, UK, says limited data on Antarctica’s climate is making it difficult for researchers to disentangle changes caused by human activity from natural climate fluctuations.

It was only when regular satellite observations began in 1979 that measurement of surface climate over the Antarctic and the Southern Ocean became possible, says the study, published in the journal Nature Climate Change

To gain a longer view, Dr Jones and her colleagues used a compilation of records from natural archives such as ice cores from the Antarctic ice sheet, which show how the region’s climate has changed over the last 200 years.

Separating signals

They confirmed that human-induced changes have caused the belt of prevailing westerly winds over the Southern Ocean to shift towards Antarctica.

But they conclude that for other changes, including regional warming and sea ice changes, the observations since 1979 are not yet long enough for the signal of human activity to be clearly separated from the strong natural variability.

The shift in the westerly winds has moved rainfall away from southern Australia. This year is set to be the country’s hottest on record.

Dr Jones said: “The Antarctic climate is like a giant jigsaw puzzle with most of the pieces still missing.

“There are some parts of the picture which are clear, particularly the way that climate change is causing westerly winds to shift southwards, but there are still huge gaps that we need to fill in order to fully understand how much human activity is changing weather in the region.” – Climate News Network

The Arctic climate is changing so quickly that science can barely keep track of what is happening and predict the global consequences, the UN says.

LONDON, 29 September, 2016 In an unusually stark warning a leading international scientific body says the Arctic climate is changing so fast that researchers are struggling to keep up. The changes happening there, it says, are affecting the weather worldwide.

The World Meteorological Organisation (WMO) says: Dramatic and unprecedented warming in the Arctic is driving sea level rise, affecting weather patterns around the world and may trigger even more changes in the climate system.

The rate of change is challenging the current scientific capacity to monitor and predict what is becoming a journey into uncharted territory. 

The WMO is the United Nations’ main agency responsible for weather, climate and water.    

Its president, David Grimes, said: The Arctic is a principal, global driver of the climate system and is undergoing an unprecedented rate of change with consequences far beyond its boundaries.

Arctic collaboration

The changes in the Arctic are serving as a global indicator – like a canary in the coal mine – and are happening at a much faster rate than we would have expected.

He was speaking before addressing the first White House Science Ministerial meeting in Washington DC, held to develop international collaboration on Arctic science.

Climate change is causing global average temperatures to rise: 2014, 2015 and the first eight months of 2016 have all been record-breakers. The Arctic is warming at least twice as fast as the global average, in places even faster: the Canadian town of Inuvik has warmed by almost 4°C since 1948, about four times more than the global figure.

The increasing loss of Arctic sea ice is threatening polar bears across their range; melting sea ice is affecting the Arctic climate in a feedback loop; and scientists expect melting permafrost will release more carbon dioxide and methane

The WMO secretary-general, Petteri Taalas, said the Arctic changes had also been a factor in unusual winter weather patterns in North America and Europe. He said the thawing of the permafrost could release vast quantities of greenhouse gases into the atmosphere.

These are part of the vicious circles of climate change which are the subject of intense scientific research, he said.

The Arctic is a principal, global driver of the climate system and is undergoing an unprecedented rate of change with consequences far beyond its boundaries

Despite its certainty that the Arctic is in trouble, the WMO says it is hard to establish the implications of what is happening there. The Arctic makes up about 4% of the Earth’s surface, but the WMO says it is one of the most data-sparse regions in the world because of its remoteness and previous inaccessibility.

Lack of data and forecasts in the Arctic does impact on the quality of weather forecasts in other parts of the world. 

That’s a worry which is echoed at the other end of the planet. A study led by Dr Julie Jones, from the department of geography at the University of Sheffield, UK, says limited data on Antarctica’s climate is making it difficult for researchers to disentangle changes caused by human activity from natural climate fluctuations.

It was only when regular satellite observations began in 1979 that measurement of surface climate over the Antarctic and the Southern Ocean became possible, says the study, published in the journal Nature Climate Change

To gain a longer view, Dr Jones and her colleagues used a compilation of records from natural archives such as ice cores from the Antarctic ice sheet, which show how the region’s climate has changed over the last 200 years.

Separating signals

They confirmed that human-induced changes have caused the belt of prevailing westerly winds over the Southern Ocean to shift towards Antarctica.

But they conclude that for other changes, including regional warming and sea ice changes, the observations since 1979 are not yet long enough for the signal of human activity to be clearly separated from the strong natural variability.

The shift in the westerly winds has moved rainfall away from southern Australia. This year is set to be the country’s hottest on record.

Dr Jones said: “The Antarctic climate is like a giant jigsaw puzzle with most of the pieces still missing.

“There are some parts of the picture which are clear, particularly the way that climate change is causing westerly winds to shift southwards, but there are still huge gaps that we need to fill in order to fully understand how much human activity is changing weather in the region.” – Climate News Network

Humans sparked warming nearly 200 years ago

Human activity prompted an early start to global warming, scientists say – nearly 200 years ago, long before previous studies had suggested.

LONDON, 30 August, 2016 – Global warming may have started far earlier than anyone has so far imagined. The first signs of climate change driven by rising levels of atmospheric carbon dioxide may have been there in the year the world’s first intercity railway link opened between Manchester and Liverpool, when the Duke of Wellington was still Prime Minister of Britain, when an angry Parisian mob overturned the French monarchy in 1830.

But if so – and climate scientists and modellers will argue whether in fact humans sparked warming so early – the evidence is available only with benefit of a long time series and twenty-twenty hindsight.

Nerilie Abramclimate scientist at the Australian National University, and international colleagues in the Past Global Changes consortium known as PAGES report in the journal Nature that they looked once again at all the climate data – records and proxy evidence from ice cores and ocean sediments – since 1500 AD.

What they saw there was that the sustained trend of warming in the 20th century may have shown its first signs in the tropical oceans and over some parts of the land surfaces of the Northern Hemisphere as early as the 1830s.

Before the first novels of Charles Dickens, before Queen Victoria, there may have been the first signs of anthropogenic warming. This is earlier than anybody expected, including the scientists who have just published the research.

Surprise

“It was an extraordinary finding,” said Dr Abram. “It was one of those moments where science really surprised us. But the results were clear. What we are witnessing today started about 180 years ago.”

Corals, like trees, have annual growth rings, and these too can tell a story of climate change. By bringing together coral measurements and evidence from sea floor sediments, the scientists recorded a steady turn for the warmer in ocean temperatures early in the 19th century.

“Somebody living in the 1830s or even the 1890s would not have been able to distinguish that there was this change afoot,” she said. “It’s by having this long record now that extends almost 200 years from that point that we can go back and say ‘Well, this was when the changes first started.’”

The observation had to be backed up by computer simulation: the very early 19th century had been marked by catastrophic volcanic eruptions, one of which – Mount Tambora in Indonesia in 1815 – led to the notorious “Year without a Summer”.

That followed in 1816, when the poets Byron, Shelley and  Mary Shelley and young Dr Polidori shivered away in a villa in Geneva, and left the world the legacy of Frankenstein and the first vampire novel.

“In some ways it is really a positive message, because it suggests that the climate system can respond very quickly to relatively small changes in greenhouse gases”

Theoretically, the warming could have been a response to the recovery after the eruptions. But, said Nicholas McKay, a climate scientist at Northern Arizona University, and one of the authors, this is not the case.

”If you run the models with only volcanoes and no increase in greenhouse gases, you see a warming, starting in the early 1800s. But then it levels off, and you don’t see that warming continue through the 20th century,” he said.

But once the increases in greenhouse gases were incorporated, the globe started warming around 1830 and carried on warming, just as the coral records showed.

“In some ways it is really a positive message, because it suggests that the climate system can respond very quickly to relatively small changes in greenhouse gases,” he said.

“It means that our actions as a society, both positive and negative, can result in an immediate impact.” – Climate News Network

Human activity prompted an early start to global warming, scientists say – nearly 200 years ago, long before previous studies had suggested.

LONDON, 30 August, 2016 – Global warming may have started far earlier than anyone has so far imagined. The first signs of climate change driven by rising levels of atmospheric carbon dioxide may have been there in the year the world’s first intercity railway link opened between Manchester and Liverpool, when the Duke of Wellington was still Prime Minister of Britain, when an angry Parisian mob overturned the French monarchy in 1830.

But if so – and climate scientists and modellers will argue whether in fact humans sparked warming so early – the evidence is available only with benefit of a long time series and twenty-twenty hindsight.

Nerilie Abramclimate scientist at the Australian National University, and international colleagues in the Past Global Changes consortium known as PAGES report in the journal Nature that they looked once again at all the climate data – records and proxy evidence from ice cores and ocean sediments – since 1500 AD.

What they saw there was that the sustained trend of warming in the 20th century may have shown its first signs in the tropical oceans and over some parts of the land surfaces of the Northern Hemisphere as early as the 1830s.

Before the first novels of Charles Dickens, before Queen Victoria, there may have been the first signs of anthropogenic warming. This is earlier than anybody expected, including the scientists who have just published the research.

Surprise

“It was an extraordinary finding,” said Dr Abram. “It was one of those moments where science really surprised us. But the results were clear. What we are witnessing today started about 180 years ago.”

Corals, like trees, have annual growth rings, and these too can tell a story of climate change. By bringing together coral measurements and evidence from sea floor sediments, the scientists recorded a steady turn for the warmer in ocean temperatures early in the 19th century.

“Somebody living in the 1830s or even the 1890s would not have been able to distinguish that there was this change afoot,” she said. “It’s by having this long record now that extends almost 200 years from that point that we can go back and say ‘Well, this was when the changes first started.’”

The observation had to be backed up by computer simulation: the very early 19th century had been marked by catastrophic volcanic eruptions, one of which – Mount Tambora in Indonesia in 1815 – led to the notorious “Year without a Summer”.

That followed in 1816, when the poets Byron, Shelley and  Mary Shelley and young Dr Polidori shivered away in a villa in Geneva, and left the world the legacy of Frankenstein and the first vampire novel.

“In some ways it is really a positive message, because it suggests that the climate system can respond very quickly to relatively small changes in greenhouse gases”

Theoretically, the warming could have been a response to the recovery after the eruptions. But, said Nicholas McKay, a climate scientist at Northern Arizona University, and one of the authors, this is not the case.

”If you run the models with only volcanoes and no increase in greenhouse gases, you see a warming, starting in the early 1800s. But then it levels off, and you don’t see that warming continue through the 20th century,” he said.

But once the increases in greenhouse gases were incorporated, the globe started warming around 1830 and carried on warming, just as the coral records showed.

“In some ways it is really a positive message, because it suggests that the climate system can respond very quickly to relatively small changes in greenhouse gases,” he said.

“It means that our actions as a society, both positive and negative, can result in an immediate impact.” – Climate News Network

Fossil fuels are now a bad bet, investors told

Owning fossil fuel deposits was once like having money in the bank – but not any longer, investors are being warned.

LONDON, 14 February, 2016 – Investors in fossil fuels are being warned that they may risk losing their money, because the markets for coal and liquefied natural gas are disappearing.

In both cases it is competition from renewables, principally wind and solar power, that is being blamed for the threat. The cost of electricity from renewables continues to fall in Europe and Asia as the numbers of wind and solar installations grow in both continents, cutting demand for imported gas and coal.

Two separate reports on coal and gas were published at the same time as a round of annual financial reports from oil companies showed that this third fossil fuel could be in serious trouble too. 

Despite massive cutbacks on exploration and development, companies like Shell and BP still need a price of US$60 a barrel by the end of this year if they are to break even on many of their current projects – almost double the current market price. 

Long lead-time

Overproduction of coal, gas and oil spells trouble for investors in mines, pipelines, ports and the other infrastructure needed to transport fossil fuels round the globe. The cost of development requires a long lifetime for the equipment and a high long-term guaranteed price for the fuels if investors are to get their money back.

The first report, Stranded Assets and Thermal Coalfound that Australian and US coal assets were the most vulnerable. Australian mines were particularly at risk because of their heavy reliance on exporting coal to markets that were rapidly shrinking. 

Australia exports three times as much coal as it consumes locally, but two of the world’s largest markets for coal, India and China, are cutting imports. India’s imports fell by 34% last year and China’s by 31%. Australia’s mines were also seen as high-risk because of environmental regulations and the widespread opposition to their development.

US coal assets were risky because of competition from cheap gas for the same markets. This meant exporting coal and competing in a world market where there is already a significant surplus.

In the dark

The report said company statements made it clear that investors were not being given the full picture of the risks from environmental regulation and policy.

Many countries pledged in the Paris Agreement reached last December to cut their coal use. If these pledges were kept, the report said, then much of the coal currently shown as an asset would have to be left in the ground.

A separate report, on liquefied petroleum gas (LPG), also raises the possibility that investors may lose their money. The trade is based on the fact that gas is cheap in the US and expensive in Europe, so the expense of liquefying it and transporting it to Europe is offset. Large investments are being made in the pipelines, ships and ports required to transport it.

There are two problems outlined in the report, LNG and Renewable Power. The first is that the price of gas, which is tied to that of oil, has dropped in Europe, squeezing the margins of the companies that are spending large sums setting up the supply line.

No recovery

The second is that the market for gas is itself shrinking as the output of the solar panels and wind farms increases. Unless gas investors can see a long-term return from a stable market they will not make a profit, and LPG becomes high-risk.

Predictions on the future of fossil fuel investments all hinge on the price of oil. With big oil companies – and many countries – needing the current price to double to more than $60 a barrel to break even on their current investments. Everybody in the business believes it is only a matter of time before prices double again.

Paul Spedding, former global co-head of oil and gas research at HSBC, an adviser to Carbon Tracker, says he believes the price of oil may never recoverStructural changes in the energy markets, more efficient electric cars, batteries and hybrid solutions no longer favour oil. The European Union for example is already reducing its demand by 1.5% a year.

Similar drops can be expected elsewhere as governments strive to meet their targets under the Paris Agreement. If that happens, an oil surplus will become the new normal and investors in major oil companies will face a difficult future. Climate News Network

Owning fossil fuel deposits was once like having money in the bank – but not any longer, investors are being warned.

LONDON, 14 February, 2016 – Investors in fossil fuels are being warned that they may risk losing their money, because the markets for coal and liquefied natural gas are disappearing.

In both cases it is competition from renewables, principally wind and solar power, that is being blamed for the threat. The cost of electricity from renewables continues to fall in Europe and Asia as the numbers of wind and solar installations grow in both continents, cutting demand for imported gas and coal.

Two separate reports on coal and gas were published at the same time as a round of annual financial reports from oil companies showed that this third fossil fuel could be in serious trouble too. 

Despite massive cutbacks on exploration and development, companies like Shell and BP still need a price of US$60 a barrel by the end of this year if they are to break even on many of their current projects – almost double the current market price. 

Long lead-time

Overproduction of coal, gas and oil spells trouble for investors in mines, pipelines, ports and the other infrastructure needed to transport fossil fuels round the globe. The cost of development requires a long lifetime for the equipment and a high long-term guaranteed price for the fuels if investors are to get their money back.

The first report, Stranded Assets and Thermal Coalfound that Australian and US coal assets were the most vulnerable. Australian mines were particularly at risk because of their heavy reliance on exporting coal to markets that were rapidly shrinking. 

Australia exports three times as much coal as it consumes locally, but two of the world’s largest markets for coal, India and China, are cutting imports. India’s imports fell by 34% last year and China’s by 31%. Australia’s mines were also seen as high-risk because of environmental regulations and the widespread opposition to their development.

US coal assets were risky because of competition from cheap gas for the same markets. This meant exporting coal and competing in a world market where there is already a significant surplus.

In the dark

The report said company statements made it clear that investors were not being given the full picture of the risks from environmental regulation and policy.

Many countries pledged in the Paris Agreement reached last December to cut their coal use. If these pledges were kept, the report said, then much of the coal currently shown as an asset would have to be left in the ground.

A separate report, on liquefied petroleum gas (LPG), also raises the possibility that investors may lose their money. The trade is based on the fact that gas is cheap in the US and expensive in Europe, so the expense of liquefying it and transporting it to Europe is offset. Large investments are being made in the pipelines, ships and ports required to transport it.

There are two problems outlined in the report, LNG and Renewable Power. The first is that the price of gas, which is tied to that of oil, has dropped in Europe, squeezing the margins of the companies that are spending large sums setting up the supply line.

No recovery

The second is that the market for gas is itself shrinking as the output of the solar panels and wind farms increases. Unless gas investors can see a long-term return from a stable market they will not make a profit, and LPG becomes high-risk.

Predictions on the future of fossil fuel investments all hinge on the price of oil. With big oil companies – and many countries – needing the current price to double to more than $60 a barrel to break even on their current investments. Everybody in the business believes it is only a matter of time before prices double again.

Paul Spedding, former global co-head of oil and gas research at HSBC, an adviser to Carbon Tracker, says he believes the price of oil may never recoverStructural changes in the energy markets, more efficient electric cars, batteries and hybrid solutions no longer favour oil. The European Union for example is already reducing its demand by 1.5% a year.

Similar drops can be expected elsewhere as governments strive to meet their targets under the Paris Agreement. If that happens, an oil surplus will become the new normal and investors in major oil companies will face a difficult future. Climate News Network

Australia’s crocodiles face flight from growing heat

Rising temperatures in northern Australia could force its predatory crocodiles to seek refuge in cooler waters further south.

LONDON, 25 December, 2015 – Global warming poses a challenge to some of Australia’s scariest citizens – the saltwater or estuarine crocodiles of the far north. These cold-blooded killers could find tomorrow’s world just too hot for comfort.

Crocodiles, like other amphibians and reptiles, are ectotherms: cold-blooded creatures that become sluggish in cold weather and must warm up in the sunshine before they can hunt and eat.

But new research by Essie Rodgers, a PhD student at the University of Queensland and colleagues, published in the journal Conservation Physiology, suggests that these top predators could face a world in which it becomes too warm to take to the water to kill.

The news is not entirely a surprise: other research has established that lizards, for example, have a narrow range of heat tolerance.  

But Rodgers and her colleagues put juvenile crocodiles to the test. They submerged them in water at temperatures likely to occur under different climate change scenarios.

Too hot

Right now, summer water temperatures in northern Queensland’s rivers reach 28°C. Under a moderate rise, these could get to 31.5°C. If humans go on burning ever more fossil fuels and releasing greenhouse gases that warm the atmosphere even more, then the waters could reach 35°C.

The scientists found, to their surprise, that the animals spent less time submerged as temperatures rose. “Acute increases in water temperatures resulted in significantly shorter crocodile dives,” Rodgers said. “Their submergence times halved with every 3.5°C increase in water temperatures.”

The lethal temperature for crocodiles was in the high 30s to low 40s: air temperatures could easily get higher in the region, which is why crocodiles need to spend so much time submerged: up to 11 hours a day.

Craig Franklin, of the University of Queensland, professor of zoology and a co-author, said he and his colleagues had thought that the predators would be able to adjust to changing temperatures. But that didn’t seem to be the case.

On the move

“We are not sure what this means, but it’s likely that if the water is too hot, crocodiles might move to cooler regions, or will seek refuge in deep, cool water pockets to defend their dive times,” he said.

The study is unfinished. Dive times are only part of the crocodile’s survival equipment. The next step, the researchers say, is to see what rising water temperatures will do for the swimming capacity, bite force and aerobic scope of the air-breathing, submarine hunter Crocodylus porosus.

As a class of animals, the crocodiles survived when the dinosaurs perished: they have faced a lot of climate change in the last 200 million years, and individual saltwater crocodiles can live for as long as 70 years.

But, the scientists warn, the Australian estuarine crocodiles are unlikely to acclimatise to what they call “the negative consequences of elevated temperatures on dive capacity.” So to survive, the animals may have to become climate migrants, and move south. – Climate News Network

Rising temperatures in northern Australia could force its predatory crocodiles to seek refuge in cooler waters further south.

LONDON, 25 December, 2015 – Global warming poses a challenge to some of Australia’s scariest citizens – the saltwater or estuarine crocodiles of the far north. These cold-blooded killers could find tomorrow’s world just too hot for comfort.

Crocodiles, like other amphibians and reptiles, are ectotherms: cold-blooded creatures that become sluggish in cold weather and must warm up in the sunshine before they can hunt and eat.

But new research by Essie Rodgers, a PhD student at the University of Queensland and colleagues, published in the journal Conservation Physiology, suggests that these top predators could face a world in which it becomes too warm to take to the water to kill.

The news is not entirely a surprise: other research has established that lizards, for example, have a narrow range of heat tolerance.  

But Rodgers and her colleagues put juvenile crocodiles to the test. They submerged them in water at temperatures likely to occur under different climate change scenarios.

Too hot

Right now, summer water temperatures in northern Queensland’s rivers reach 28°C. Under a moderate rise, these could get to 31.5°C. If humans go on burning ever more fossil fuels and releasing greenhouse gases that warm the atmosphere even more, then the waters could reach 35°C.

The scientists found, to their surprise, that the animals spent less time submerged as temperatures rose. “Acute increases in water temperatures resulted in significantly shorter crocodile dives,” Rodgers said. “Their submergence times halved with every 3.5°C increase in water temperatures.”

The lethal temperature for crocodiles was in the high 30s to low 40s: air temperatures could easily get higher in the region, which is why crocodiles need to spend so much time submerged: up to 11 hours a day.

Craig Franklin, of the University of Queensland, professor of zoology and a co-author, said he and his colleagues had thought that the predators would be able to adjust to changing temperatures. But that didn’t seem to be the case.

On the move

“We are not sure what this means, but it’s likely that if the water is too hot, crocodiles might move to cooler regions, or will seek refuge in deep, cool water pockets to defend their dive times,” he said.

The study is unfinished. Dive times are only part of the crocodile’s survival equipment. The next step, the researchers say, is to see what rising water temperatures will do for the swimming capacity, bite force and aerobic scope of the air-breathing, submarine hunter Crocodylus porosus.

As a class of animals, the crocodiles survived when the dinosaurs perished: they have faced a lot of climate change in the last 200 million years, and individual saltwater crocodiles can live for as long as 70 years.

But, the scientists warn, the Australian estuarine crocodiles are unlikely to acclimatise to what they call “the negative consequences of elevated temperatures on dive capacity.” So to survive, the animals may have to become climate migrants, and move south. – Climate News Network

Climate change boosted Australia’s 2010 floods

Warming oceans helped to worsen Australia’s floods five years ago by intensifying rainfall, researchers find.

LONDON, 21 November, 2015 – For the first time, researchers have linked the catastrophic floods in Australia in the summer of 2010 with global warming. And they warn that the double hazard of long-term ocean warming and rising atmospheric temperatures makes the risk of extreme rainfall greater in years to come.

In 2010, during a natural cyclic Pacific phenomenon called La Niña, sea surface temperatures in the Indian Ocean and the western Pacific were high, and the air became saturated with moisture.

When the clouds billowed over Queensland, they deposited so much water that 35 people died, 28,000 homes were flooded and 100,000 people were left without electricity. Lake Eyre, a normally dry lakebed in the country’s interior, filled with water.

The economic damage amounted to US $2.38 bn. Altogether so much water fell on the normally arid landscape that global sea levels dropped perceptibly.

Rapid warming

“The sea surface temperatures around Australia during 2010/2011 were on average 0.5°C warmer than they were 60 years ago,” said Caroline Ummenhofer, a physical oceanographer at the Woods Hole Oceanographic Institution in the US. “While many past studies have found a global warming link to heat extremes, this study is one of the first to show how ocean warming can impact a heavy rainfall event.”

She and her Australian colleagues report in the journal Geophysical Research Letters that they had identified the mechanisms that increase the likelihood of extreme rainfall. “Additional ocean warming enhanced onshore moisture transport into Australia and ascent and precipitation over the northeast,” they write.

“Our results highlight the role of long-term ocean warming for modifying rain-producing atmospheric circulation conditions, increasing the likelihood of extreme precipitation for Australia during future La Niña events.”

La Niña is the supposedly cooler little sister of the notorious El Niño, associated with warmer than usual waters in the eastern equatorial Pacific.  Researchers have already warned that it could play a role in future floods: Dr Ummenhofer and her colleagues have looked back in time to find that it has already done so.

Climatologists are normally reluctant to ascribe any one weather event to climate change driven by rising carbon dioxide levels as a consequence of the human combustion of fossil fuels: that is because climate is what people expect, but weather is what happens.

Repeated warnings

But Australian researchers have separately warned of storms ahead as global temperatures rise, and have identified the fingerprint of global warming in record temperatures in the southern continent.

They have also found that human greenhouse gas emissions may be contributing to the sustained droughts that periodically cripple Australia’s agriculture.

But this is the first direct link with any one episode of flooding. One prediction of the Woods Hole team’s modelling experiments is that because of warmer sea surface temperatures, Australia is now three times more likely to experience unprecedented rainfall during a strong La Niña event.

“The additional warming of the oceans has profound impacts on the atmosphere. It increases the amount of moisture in the atmosphere and can intensify rain-producing circulation conditions,” said Matthew England, of the Australian Research Council’s Centre of Excellence for Climate System Science, and a co-author.

“This is why in 2010/11 more moisture was brought onshore along Australia’s east coast. Stronger rising motion over the northeast resulted in higher rainfall, making it more likely for Australia to suffer extreme rainfall conditions during this strong La Niña.”  – Climate News Network

Warming oceans helped to worsen Australia’s floods five years ago by intensifying rainfall, researchers find.

LONDON, 21 November, 2015 – For the first time, researchers have linked the catastrophic floods in Australia in the summer of 2010 with global warming. And they warn that the double hazard of long-term ocean warming and rising atmospheric temperatures makes the risk of extreme rainfall greater in years to come.

In 2010, during a natural cyclic Pacific phenomenon called La Niña, sea surface temperatures in the Indian Ocean and the western Pacific were high, and the air became saturated with moisture.

When the clouds billowed over Queensland, they deposited so much water that 35 people died, 28,000 homes were flooded and 100,000 people were left without electricity. Lake Eyre, a normally dry lakebed in the country’s interior, filled with water.

The economic damage amounted to US $2.38 bn. Altogether so much water fell on the normally arid landscape that global sea levels dropped perceptibly.

Rapid warming

“The sea surface temperatures around Australia during 2010/2011 were on average 0.5°C warmer than they were 60 years ago,” said Caroline Ummenhofer, a physical oceanographer at the Woods Hole Oceanographic Institution in the US. “While many past studies have found a global warming link to heat extremes, this study is one of the first to show how ocean warming can impact a heavy rainfall event.”

She and her Australian colleagues report in the journal Geophysical Research Letters that they had identified the mechanisms that increase the likelihood of extreme rainfall. “Additional ocean warming enhanced onshore moisture transport into Australia and ascent and precipitation over the northeast,” they write.

“Our results highlight the role of long-term ocean warming for modifying rain-producing atmospheric circulation conditions, increasing the likelihood of extreme precipitation for Australia during future La Niña events.”

La Niña is the supposedly cooler little sister of the notorious El Niño, associated with warmer than usual waters in the eastern equatorial Pacific.  Researchers have already warned that it could play a role in future floods: Dr Ummenhofer and her colleagues have looked back in time to find that it has already done so.

Climatologists are normally reluctant to ascribe any one weather event to climate change driven by rising carbon dioxide levels as a consequence of the human combustion of fossil fuels: that is because climate is what people expect, but weather is what happens.

Repeated warnings

But Australian researchers have separately warned of storms ahead as global temperatures rise, and have identified the fingerprint of global warming in record temperatures in the southern continent.

They have also found that human greenhouse gas emissions may be contributing to the sustained droughts that periodically cripple Australia’s agriculture.

But this is the first direct link with any one episode of flooding. One prediction of the Woods Hole team’s modelling experiments is that because of warmer sea surface temperatures, Australia is now three times more likely to experience unprecedented rainfall during a strong La Niña event.

“The additional warming of the oceans has profound impacts on the atmosphere. It increases the amount of moisture in the atmosphere and can intensify rain-producing circulation conditions,” said Matthew England, of the Australian Research Council’s Centre of Excellence for Climate System Science, and a co-author.

“This is why in 2010/11 more moisture was brought onshore along Australia’s east coast. Stronger rising motion over the northeast resulted in higher rainfall, making it more likely for Australia to suffer extreme rainfall conditions during this strong La Niña.”  – Climate News Network

Coral reefs die as El Niño hots up

The third mass coral bleaching in recent history is under way, as record ocean warmth creates a crisis in the tropics.

LONDON, 11 October, 2015 – Record sea temperatures combined with a strong El Niño are causing widespread coral bleaching, which is threatening to kill over 12,000 square kilometres of reefs.

The US National Oceanic and Atmospheric Administration (NOAA) has declared a global bleaching event, making this only the third such crisis in recorded history.

NOAA’s declaration has implications for the livelihoods of 500 million people worldwide and income worth $30 billion, because reefs support 25% of all marine species and are a nursery ground for many species of fish.

The bleaching is directly connected to climate change: it is the warmer water that causes the problem. The first global bleaching event was in 1998 and the second in 2010, both in years marked by El Niños, the periodic climate phenomenon in the Pacific. 

Each time the potential for damage has been greater because the sea has been warmer before the start of the El Niño. This August the ocean was the warmest on record – and this time NOAA’s estimate is that 38% of the world’s reefs may be affected.

Huge losses

Coral bleaching this year began in the Florida Keys and South Florida in August. Record bleaching is now taking place in Hawaii; it is spreading to the Caribbean and may last until the New Year.

As the exceptionally warm water spreads across the Pacific the bleaching event is expected to hit the Great Barrier Reef in Australia in early 2016, causing more damage, some of it permanent.

Mark Eakin, NOAA’s Coral Reef Watch coordinator, said: “The coral bleaching and disease brought on by climate change, and coupled with events like the current El Niño, are the largest and most pervasive threats to coral reefs around the world.

“As a result, we are losing huge areas of coral across the US, as well as internationally. What really has us concerned is this event has been going on for more than a year and our preliminary model projections indicate it’s likely to last well into 2016.”

Corals live in symbiosis with algae, and the two creatures depend on each other for survival. The apparent bleaching happens because as sea temperatures rise above coral comfort levels, the increasingly stressed corals and the colourful algae part company. 

Protection lost

As a result, the corals whiten, lose their source of nutrients and – if the bleaching goes on for too long – will die.

Minor bleaching can be repaired and reefs recover, but at high temperatures and on this scale large areas can die. Apart from the loss of the corals, damage to the tourist industry and fishing, it also increases flood risk, because healthy reefs act as a storm barrier for many islands and low-lying coasts.

Graphic illustrations of bleaching can be seen on a website set up to alert people to the dangers and record the event. 

There is particular concern on Hawaii at the moment. It suffered bad bleaching in 2014, which is currently getting worse.

Record warming

Eakin said the bleaching was a crisis. “Hawaii is getting hit with the worst coral bleaching they have ever seen, right now. It’s severe. It’s extensive. And it’s on all the islands.

“In one part of northwestern Hawaii the reef just completely bleached and all of the coral is dead and covered with scuzzy algae.”

The bleaching has also struck Cuba, Haiti and the Dominican Republic and is about to hit Puerto Rico and the Virgin Islands, he said. Oceans worldwide are by far the warmest on record – August 2015 was two-fifths of a degree warmer than August 1998. Eakin said: “Next year may be as bad as this year or even worse.”

Gregor Hodgson, who heads the group Reef Check Australia, is concerned about the forecast that the warm blob of water caused by El Niño will hit the country’s Great Barrier Reef early next year.

The reef is the planet’s biggest, a world heritage site and a magnet for tourists. The computer model forecasts “this horrendous, dramatic” impact on the reef, Hodgson said. “It’s truly terrifying.” – Climate News Network

The third mass coral bleaching in recent history is under way, as record ocean warmth creates a crisis in the tropics.

LONDON, 11 October, 2015 – Record sea temperatures combined with a strong El Niño are causing widespread coral bleaching, which is threatening to kill over 12,000 square kilometres of reefs.

The US National Oceanic and Atmospheric Administration (NOAA) has declared a global bleaching event, making this only the third such crisis in recorded history.

NOAA’s declaration has implications for the livelihoods of 500 million people worldwide and income worth $30 billion, because reefs support 25% of all marine species and are a nursery ground for many species of fish.

The bleaching is directly connected to climate change: it is the warmer water that causes the problem. The first global bleaching event was in 1998 and the second in 2010, both in years marked by El Niños, the periodic climate phenomenon in the Pacific. 

Each time the potential for damage has been greater because the sea has been warmer before the start of the El Niño. This August the ocean was the warmest on record – and this time NOAA’s estimate is that 38% of the world’s reefs may be affected.

Huge losses

Coral bleaching this year began in the Florida Keys and South Florida in August. Record bleaching is now taking place in Hawaii; it is spreading to the Caribbean and may last until the New Year.

As the exceptionally warm water spreads across the Pacific the bleaching event is expected to hit the Great Barrier Reef in Australia in early 2016, causing more damage, some of it permanent.

Mark Eakin, NOAA’s Coral Reef Watch coordinator, said: “The coral bleaching and disease brought on by climate change, and coupled with events like the current El Niño, are the largest and most pervasive threats to coral reefs around the world.

“As a result, we are losing huge areas of coral across the US, as well as internationally. What really has us concerned is this event has been going on for more than a year and our preliminary model projections indicate it’s likely to last well into 2016.”

Corals live in symbiosis with algae, and the two creatures depend on each other for survival. The apparent bleaching happens because as sea temperatures rise above coral comfort levels, the increasingly stressed corals and the colourful algae part company. 

Protection lost

As a result, the corals whiten, lose their source of nutrients and – if the bleaching goes on for too long – will die.

Minor bleaching can be repaired and reefs recover, but at high temperatures and on this scale large areas can die. Apart from the loss of the corals, damage to the tourist industry and fishing, it also increases flood risk, because healthy reefs act as a storm barrier for many islands and low-lying coasts.

Graphic illustrations of bleaching can be seen on a website set up to alert people to the dangers and record the event. 

There is particular concern on Hawaii at the moment. It suffered bad bleaching in 2014, which is currently getting worse.

Record warming

Eakin said the bleaching was a crisis. “Hawaii is getting hit with the worst coral bleaching they have ever seen, right now. It’s severe. It’s extensive. And it’s on all the islands.

“In one part of northwestern Hawaii the reef just completely bleached and all of the coral is dead and covered with scuzzy algae.”

The bleaching has also struck Cuba, Haiti and the Dominican Republic and is about to hit Puerto Rico and the Virgin Islands, he said. Oceans worldwide are by far the warmest on record – August 2015 was two-fifths of a degree warmer than August 1998. Eakin said: “Next year may be as bad as this year or even worse.”

Gregor Hodgson, who heads the group Reef Check Australia, is concerned about the forecast that the warm blob of water caused by El Niño will hit the country’s Great Barrier Reef early next year.

The reef is the planet’s biggest, a world heritage site and a magnet for tourists. The computer model forecasts “this horrendous, dramatic” impact on the reef, Hodgson said. “It’s truly terrifying.” – Climate News Network

Risk of new Katrinas rises as climate warms

Climate change may drastically increase the risk of simultaneous cyclones and storm surges striking populous coastlines around the world. LONDON, 1 September, 2015 – Perfect storms are by definition improbable. But climate scientists now think that the devastating combination of extreme tropical cyclone and unprecedented storm surge is going to get a whole lot less improbable by the end of the century. The chances that the city of Tampa, in Florida, will be hit by a devastating hurricane and an 11-metre wall of ocean water by 2100 could have increased by up to fourteen-fold, they report in Nature Climate Change. All climate modelling involves a calculation of probabilities. Ning Lin, a civil engineer at Princeton University in New Jersey in the US, and Kerry Emanuel, a climate scientist at Massachusetts Institute of Technology in Cambridge, Massachusetts, started exploring the idea of events that are highly improbable, but worth trying to predict anyway because their consequences could be so calamitous. If storms that could not be expected are “black swan” events, then they have identified a second category: “grey swan” events that are worse than any in recorded history, but are nevertheless foreseeable, using knowledge of atmospheric physics, topography and the climate record. So – on the tenth anniversary of Hurricane Katrina’s assault on New Orleans, the most costly disaster in American history – they decided to see how bad things could really get.

Advance warnings

The horror of Katrina was that although it was a storm surge without precedent, engineers and meteorologists had repeatedly warned that New Orleans could be vulnerable. And when it arrived, New Orleans, the state of Louisiana and the Washington Administration were all taken by surprise. For their study, the two scientists selected three vulnerable bits of coastline and set about modelling the worst that could happen, and the probabilities that it might happen. They chose Dubai in the Persian Gulf – an area never before hit by a tropical cyclone – Cairns on the coast of Australia, and Tampa in Florida. They found that a “grey swan” cyclone right now could cause a storm surge of six metres in Tampa, Cairns 5.7 metres and Dubai four metres. The chances of such a thing happening in any one year, however, were as low as one in 10,000. That is, not very likely. And then they factored in continuing climate change, driven by global warming as a consequence of prodigal fossil fuel combustion by humankind, and started to consider the long-term consequences. By the end of the century, the hazard to Dubai had increased to seven metres, and to Tampa to 11 metres. And the probabilities had increased too: the likelihood of a devastating storm and an overwhelming wall of water in the Persian Gulf had become “non-negligible”: the extreme in Tampa’s case was one in 700.

“The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon”

But such research is based only on known hazards now and projections for the future. In fact, hurricane conditions in one region can be matched by awful hazards in places far away according to a team from the University of California, Irvine, and the US space agency Nasa. They report in Geophysical Research Letters that they have identified a link between catastrophic wildfires in the Amazon and hurricanes such as Katrina that devastate the northern hemisphere coasts. Yang Chen, an earth system scientist from UC Irvine, and colleagues looked at years of sea surface temperature and other climate data to find the connection. In years of high numbers of hurricanes and high fire risk, warm waters in the North Atlantic help hurricanes develop and gather strength and speed on their way to North American shores. These same warm waters drag rainfall away from the southern Amazon, leaving the rainforests increasingly vulnerable to fire. Since the Amazon forests are a vital repository of stored carbon, any fires there can only fuel global warming still further, increasing sea surface temperatures and stepping up yet more the probability of tropical cyclones, typhoons or hurricanes. “Hurricane Katrina is, indeed, part of this story”, said UCI earth system scientist James Randerson, senior author of the paper. “The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon. The timing of these events is perfectly consistent with our research findings.” – Climate News Network

Climate change may drastically increase the risk of simultaneous cyclones and storm surges striking populous coastlines around the world. LONDON, 1 September, 2015 – Perfect storms are by definition improbable. But climate scientists now think that the devastating combination of extreme tropical cyclone and unprecedented storm surge is going to get a whole lot less improbable by the end of the century. The chances that the city of Tampa, in Florida, will be hit by a devastating hurricane and an 11-metre wall of ocean water by 2100 could have increased by up to fourteen-fold, they report in Nature Climate Change. All climate modelling involves a calculation of probabilities. Ning Lin, a civil engineer at Princeton University in New Jersey in the US, and Kerry Emanuel, a climate scientist at Massachusetts Institute of Technology in Cambridge, Massachusetts, started exploring the idea of events that are highly improbable, but worth trying to predict anyway because their consequences could be so calamitous. If storms that could not be expected are “black swan” events, then they have identified a second category: “grey swan” events that are worse than any in recorded history, but are nevertheless foreseeable, using knowledge of atmospheric physics, topography and the climate record. So – on the tenth anniversary of Hurricane Katrina’s assault on New Orleans, the most costly disaster in American history – they decided to see how bad things could really get.

Advance warnings

The horror of Katrina was that although it was a storm surge without precedent, engineers and meteorologists had repeatedly warned that New Orleans could be vulnerable. And when it arrived, New Orleans, the state of Louisiana and the Washington Administration were all taken by surprise. For their study, the two scientists selected three vulnerable bits of coastline and set about modelling the worst that could happen, and the probabilities that it might happen. They chose Dubai in the Persian Gulf – an area never before hit by a tropical cyclone – Cairns on the coast of Australia, and Tampa in Florida. They found that a “grey swan” cyclone right now could cause a storm surge of six metres in Tampa, Cairns 5.7 metres and Dubai four metres. The chances of such a thing happening in any one year, however, were as low as one in 10,000. That is, not very likely. And then they factored in continuing climate change, driven by global warming as a consequence of prodigal fossil fuel combustion by humankind, and started to consider the long-term consequences. By the end of the century, the hazard to Dubai had increased to seven metres, and to Tampa to 11 metres. And the probabilities had increased too: the likelihood of a devastating storm and an overwhelming wall of water in the Persian Gulf had become “non-negligible”: the extreme in Tampa’s case was one in 700.

“The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon”

But such research is based only on known hazards now and projections for the future. In fact, hurricane conditions in one region can be matched by awful hazards in places far away according to a team from the University of California, Irvine, and the US space agency Nasa. They report in Geophysical Research Letters that they have identified a link between catastrophic wildfires in the Amazon and hurricanes such as Katrina that devastate the northern hemisphere coasts. Yang Chen, an earth system scientist from UC Irvine, and colleagues looked at years of sea surface temperature and other climate data to find the connection. In years of high numbers of hurricanes and high fire risk, warm waters in the North Atlantic help hurricanes develop and gather strength and speed on their way to North American shores. These same warm waters drag rainfall away from the southern Amazon, leaving the rainforests increasingly vulnerable to fire. Since the Amazon forests are a vital repository of stored carbon, any fires there can only fuel global warming still further, increasing sea surface temperatures and stepping up yet more the probability of tropical cyclones, typhoons or hurricanes. “Hurricane Katrina is, indeed, part of this story”, said UCI earth system scientist James Randerson, senior author of the paper. “The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon. The timing of these events is perfectly consistent with our research findings.” – Climate News Network