Tag Archives: arctic melt

Arctic warming gives US and Europe the chills

The effects of Arctic climate change on the jet stream could mean harsher winters for some of the most highly populated regions of the world.

LONDON, 2 November, 2016 Warming in the Arctic – one of the fastest-warming regions on the planet – could be heightening the chances of extreme winters in Europe and the US.

As the Arctic warms, the stratospheric jet stream that brings occasionally catastrophic ice storms and record snow falls to the eastern United States could also be on the move, according to new research in the journal Nature Climate Change.

The phenomenon is a natural one. Some years the track of the jet stream is wavy, and delivers severe cold weather to the mid-latitudes of the northern hemisphere. Some years the pattern alters, and Europe in particular experiences mild winters. The temperate zones have always experienced occasional extremes. But climate change could be tilting the balance.

Extreme spells

“We’ve always had years with wavy and not so wavy jet-stream winds, but in the last one or two decades the warming Arctic could well have been amplifying the effects of the wavy patterns.

“This may have contributed to some recent extreme cold winter spells along the eastern seaboard of the United States, in western Asia and at times over the UK,” says Edward Hanna, a geographer at the University of Sheffield, UK, and one of a team of British, European and US scientists behind the study.

“Improving our ability to predict how climate change
is affecting the jet stream will help improve
our long-term prediction of winter weather”

The study doesn’t claim to settle the question: notoriously, climate is what you expect but weather is what you get, and it may be impossible to prove that this or that unexpected event happened because the global average temperatures are now at least 1°C higher than they used to be, before the human combustion of fossil fuels began to increase the concentration of the greenhouse gas carbon dioxide in the atmosphere from 280 parts per million to 400 ppm.

But there are changes in the Arctic that are happening because of global warming, and meteorologists have been watching the knock-on effect on the stratospheric winds, especially the jet stream.

In the same issue of the journal one group identified a persistent shift and a weakening in the Arctic winter polar vortex, a meteorological monster that plays a role in temperate zone weather patterns.

Others identified a link between Arctic changes and the speed of the jet stream, and its effect on transatlantic airline timetables.

Yet others have linked Arctic warming to dangerous extremes of heat further south, and yet another group has linked polar climate change to both ice storms and heatwaves.

Arctic signals

The debate continues. The important thing is to monitor the melting sea ice, the rising sea-surface temperatures and the emerging pattern of severe winter weather. If meteorologists can learn to read the signals from the Arctic, then communities could plan more effectively for the consequences.

“Improving our ability to predict how climate change is affecting the jet stream will help improve our long-term prediction of winter weather in some of the most highly populated regions of the world,” Professor Hanna says. “This would be highly beneficial for communities, businesses and entire economies in the northern hemisphere.

“The public could better prepare for severe winter weather and have access to extra crucial information that could help make life-saving and cost-saving decisions.” Climate News Network

The effects of Arctic climate change on the jet stream could mean harsher winters for some of the most highly populated regions of the world.

LONDON, 2 November, 2016 Warming in the Arctic – one of the fastest-warming regions on the planet – could be heightening the chances of extreme winters in Europe and the US.

As the Arctic warms, the stratospheric jet stream that brings occasionally catastrophic ice storms and record snow falls to the eastern United States could also be on the move, according to new research in the journal Nature Climate Change.

The phenomenon is a natural one. Some years the track of the jet stream is wavy, and delivers severe cold weather to the mid-latitudes of the northern hemisphere. Some years the pattern alters, and Europe in particular experiences mild winters. The temperate zones have always experienced occasional extremes. But climate change could be tilting the balance.

Extreme spells

“We’ve always had years with wavy and not so wavy jet-stream winds, but in the last one or two decades the warming Arctic could well have been amplifying the effects of the wavy patterns.

“This may have contributed to some recent extreme cold winter spells along the eastern seaboard of the United States, in western Asia and at times over the UK,” says Edward Hanna, a geographer at the University of Sheffield, UK, and one of a team of British, European and US scientists behind the study.

“Improving our ability to predict how climate change
is affecting the jet stream will help improve
our long-term prediction of winter weather”

The study doesn’t claim to settle the question: notoriously, climate is what you expect but weather is what you get, and it may be impossible to prove that this or that unexpected event happened because the global average temperatures are now at least 1°C higher than they used to be, before the human combustion of fossil fuels began to increase the concentration of the greenhouse gas carbon dioxide in the atmosphere from 280 parts per million to 400 ppm.

But there are changes in the Arctic that are happening because of global warming, and meteorologists have been watching the knock-on effect on the stratospheric winds, especially the jet stream.

In the same issue of the journal one group identified a persistent shift and a weakening in the Arctic winter polar vortex, a meteorological monster that plays a role in temperate zone weather patterns.

Others identified a link between Arctic changes and the speed of the jet stream, and its effect on transatlantic airline timetables.

Yet others have linked Arctic warming to dangerous extremes of heat further south, and yet another group has linked polar climate change to both ice storms and heatwaves.

Arctic signals

The debate continues. The important thing is to monitor the melting sea ice, the rising sea-surface temperatures and the emerging pattern of severe winter weather. If meteorologists can learn to read the signals from the Arctic, then communities could plan more effectively for the consequences.

“Improving our ability to predict how climate change is affecting the jet stream will help improve our long-term prediction of winter weather in some of the most highly populated regions of the world,” Professor Hanna says. “This would be highly beneficial for communities, businesses and entire economies in the northern hemisphere.

“The public could better prepare for severe winter weather and have access to extra crucial information that could help make life-saving and cost-saving decisions.” Climate News Network

Early springs surprise many species

FOR IMMEDIATE RELEASE As seasonal change suffers ever more disruption, many species are struggling to adapt quickly enough. LONDON, 7 April – Spring is arriving earlier. This is not necessarily welcome news for Arctic creatures or the roe deer of France. It could be awkward for flower festival organisers as well. Julienne Stroeve of the US National Snow and Ice Data Centre and colleagues will report in Geophysical Research Letters that the length of the Arctic melt season is growing by several days each decade. When the melt starts earlier, the Arctic Ocean absorbs more radiation: enough in some places to melt four feet in thickness from the Arctic ice cap. “The lengthening of the melt season is allowing for more of the sun’s energy to get stored in the oceans and increase ice melt during the summer, overall weakening the sea ice cover,” says Stroeve. The Arctic sea ice has now been in decline for four decades. The seven lowest September sea ice extents in the satellite record have all occurred in the last seven years. A new examination of satellite imagery and data from 1979 to the present shows that the Beaufort and Chukchi Seas are freezing up between six and 11 days later per decade. But the earlier melt is more ominous than the later freeze: the sun is higher and brighter, and delivers more warmth to the seas.

Festival disruption

The earlier spring presents no problems for many plants but it may not be much fun for the organisers of flower festivals who like to announce their events well in advance. Tim Sparks of Coventry University reports in the journal Climate Research that over its 46-year history, the Thriplow Daffodil Weekend in Cambridgeshire in eastern England has been forced to bring its dates forward by 26 days. The event can attract up to 10,000 visitors, and has raised £300,000 (US $500,000) for charity, so it clearly helps the organisers to set up some advance publicity. Since 1969, mean temperatures in March and April in the UK have risen by 1.8°C. “The study represents one of the first solid pieces of evidence of flower tourism having to adapt to climate change,” said Professor Sparks. “The issues faced by Thriplow are a microcosm of the wider picture.” Flower festivals may be able to adapt. Sadly, the roe deer of Champagne have yet to get the message about climate change. To flourish, both nectar seekers and herbivores have to time their breeding patterns to the surge in plant growth. Three French scientists looked at records of a population of roe deer in the Champagne region of France, and found that although spring has been arriving increasingly earlier, the fawns are being born at around the same dates as they were 27 years ago, and their survival rate is falling, they report in the Public Library of Science journal PLOS Biology. Overall, the roe deer population in the region is also in decline. Great tits have kept up with climate change, because reproduction is cued by temperature, so they are around at the same time as the explosion in food sources. What sets the biological pace for roe deer is day length, the authors think, and this is not affected by climate change. – Climate News Network

FOR IMMEDIATE RELEASE As seasonal change suffers ever more disruption, many species are struggling to adapt quickly enough. LONDON, 7 April – Spring is arriving earlier. This is not necessarily welcome news for Arctic creatures or the roe deer of France. It could be awkward for flower festival organisers as well. Julienne Stroeve of the US National Snow and Ice Data Centre and colleagues will report in Geophysical Research Letters that the length of the Arctic melt season is growing by several days each decade. When the melt starts earlier, the Arctic Ocean absorbs more radiation: enough in some places to melt four feet in thickness from the Arctic ice cap. “The lengthening of the melt season is allowing for more of the sun’s energy to get stored in the oceans and increase ice melt during the summer, overall weakening the sea ice cover,” says Stroeve. The Arctic sea ice has now been in decline for four decades. The seven lowest September sea ice extents in the satellite record have all occurred in the last seven years. A new examination of satellite imagery and data from 1979 to the present shows that the Beaufort and Chukchi Seas are freezing up between six and 11 days later per decade. But the earlier melt is more ominous than the later freeze: the sun is higher and brighter, and delivers more warmth to the seas.

Festival disruption

The earlier spring presents no problems for many plants but it may not be much fun for the organisers of flower festivals who like to announce their events well in advance. Tim Sparks of Coventry University reports in the journal Climate Research that over its 46-year history, the Thriplow Daffodil Weekend in Cambridgeshire in eastern England has been forced to bring its dates forward by 26 days. The event can attract up to 10,000 visitors, and has raised £300,000 (US $500,000) for charity, so it clearly helps the organisers to set up some advance publicity. Since 1969, mean temperatures in March and April in the UK have risen by 1.8°C. “The study represents one of the first solid pieces of evidence of flower tourism having to adapt to climate change,” said Professor Sparks. “The issues faced by Thriplow are a microcosm of the wider picture.” Flower festivals may be able to adapt. Sadly, the roe deer of Champagne have yet to get the message about climate change. To flourish, both nectar seekers and herbivores have to time their breeding patterns to the surge in plant growth. Three French scientists looked at records of a population of roe deer in the Champagne region of France, and found that although spring has been arriving increasingly earlier, the fawns are being born at around the same dates as they were 27 years ago, and their survival rate is falling, they report in the Public Library of Science journal PLOS Biology. Overall, the roe deer population in the region is also in decline. Great tits have kept up with climate change, because reproduction is cued by temperature, so they are around at the same time as the explosion in food sources. What sets the biological pace for roe deer is day length, the authors think, and this is not affected by climate change. – Climate News Network

Arctic melt speeding up

FOR IMMEDIATE RELEASE It’s long been established that Arctic ice is on the retreat but it’s the pace of change that’s surprising scientists: latest studies show the region is at its warmest for 40,000 years.  LONDON, 9 March – Ice in the Arctic continues to retreat. The season without ice is getting longer by an average of five days every 10 years, according to a new study in Geophysical Research Letters.  And in some regions of the Arctic, the autumn freeze is now up to 11 days later every decade. This means that a greater proportion of the polar region for a longer timespan no longer reflects sunlight but absorbs it. This change in albedo – the scientist’s term for a planet’s reflectivity – means that open sea absorbs radiation, stays warmer, and freezes again ever later.

Warming accelerates

None of this is news: sea ice in the Arctic has been both retreating and thinning in volume for four decades. Researchers have tracked the retreat of the snow line to find tiny plants exposed that had been frozen over 40,000 years ago: the implication is that the Arctic is warmer now than it has been for 40 millennia. This warming threatens the animals that depend for their existence on a stable cycle of seasons  and is accelerating at such a rate that the polar ocean could be entirely free of ice in late summer in the next four decades. So Julienne Stroeve, of University College London and her colleagues have provided yet further confirmation of an increasing rate of change in the region in their latest study. The scientists examined satellite imagery of the Arctic for the last 30 years, on 25 square kilometer grid, to work out the albedo of each square for every month they had data. Their headline figure of five days is an average: in fact the pattern of freeze and thaw in the Arctic varies. In one region the melt season has been extended by 13 days, in another the melt season is actually getting shorter.

Energy increases

This increasing exposure to summer sunlight means that ever greater quantities of energy are being absorbed: several times the energy of the atomic bomb dropped on Hiroshima hits every square kilometer of the open Arctic Ocean. “The extent of sea ice in the Arctic has been declining for the last four decades,” said Professor Stroeve, “and the timing of when melt begins and ends has a large impact on the amount of ice lost each summer. With the Arctic region becoming more accessible for longer periods of time, there is a growing need for improved prediction of when the ice retreats and reforms in the water.” – Climate News Network  

FOR IMMEDIATE RELEASE It’s long been established that Arctic ice is on the retreat but it’s the pace of change that’s surprising scientists: latest studies show the region is at its warmest for 40,000 years.  LONDON, 9 March – Ice in the Arctic continues to retreat. The season without ice is getting longer by an average of five days every 10 years, according to a new study in Geophysical Research Letters.  And in some regions of the Arctic, the autumn freeze is now up to 11 days later every decade. This means that a greater proportion of the polar region for a longer timespan no longer reflects sunlight but absorbs it. This change in albedo – the scientist’s term for a planet’s reflectivity – means that open sea absorbs radiation, stays warmer, and freezes again ever later.

Warming accelerates

None of this is news: sea ice in the Arctic has been both retreating and thinning in volume for four decades. Researchers have tracked the retreat of the snow line to find tiny plants exposed that had been frozen over 40,000 years ago: the implication is that the Arctic is warmer now than it has been for 40 millennia. This warming threatens the animals that depend for their existence on a stable cycle of seasons  and is accelerating at such a rate that the polar ocean could be entirely free of ice in late summer in the next four decades. So Julienne Stroeve, of University College London and her colleagues have provided yet further confirmation of an increasing rate of change in the region in their latest study. The scientists examined satellite imagery of the Arctic for the last 30 years, on 25 square kilometer grid, to work out the albedo of each square for every month they had data. Their headline figure of five days is an average: in fact the pattern of freeze and thaw in the Arctic varies. In one region the melt season has been extended by 13 days, in another the melt season is actually getting shorter.

Energy increases

This increasing exposure to summer sunlight means that ever greater quantities of energy are being absorbed: several times the energy of the atomic bomb dropped on Hiroshima hits every square kilometer of the open Arctic Ocean. “The extent of sea ice in the Arctic has been declining for the last four decades,” said Professor Stroeve, “and the timing of when melt begins and ends has a large impact on the amount of ice lost each summer. With the Arctic region becoming more accessible for longer periods of time, there is a growing need for improved prediction of when the ice retreats and reforms in the water.” – Climate News Network  

Poles apart: sea ice melts – and grows

FOR IMMEDIATE RELEASE While climate change is clearly strongly affecting Arctic sea ice, scientists are uncertain what links the rise in global temperatures and the continuing small increase in the Antarctic ice sheet. LONDON, 4 October – It’s one of the most closely-watched questions in climate science: how fast is the Arctic sea ice melting? The definitive answer is that it is still melting rapidly, though not quite as fast it did in 2012, when the extent of the ice sheet was lower than ever recorded. At the other end of the world, though, the Antarctic ice sheet has continued to grow, reaching a new record extent. Some experts believe this is the result not of cooling but of stronger polar winds pushing the ice further outward from the pole. Others have suggested that increased fresh water from summer icecap melting means the sea ice can form at a higher temperature in winter since the salt water is diluted. The details are published by the US National Snow and Ice Data Center (NSIDC), based at the University of Colorado Boulder, in Arctic Sea Ice News and Analysis. This September, sea ice covering the Arctic Ocean fell to its sixth lowest extent in the satellite record, which dates from 1979. All of the seven lowest extents have occurred in the last seven years. The NSIDC says cooler conditions in the Arctic this summer helped to retain more sea ice. Satellite data analysed by NSIDC scientists shows the sea ice cover at its lowest extent on 13 September. Averaging the extent for the whole of September also showed it to be the sixth lowest in the satellite record. Julienne Stroeve, an NSIDC scientist, says: “A relatively cool and stormy summer helped slow ice loss compared to the last few summers. This summer’s extent highlights the complex interaction between natural climate variability and long-term thinning of the ice cover.” Mark Serreze, the director of the NSIDC, said: “For Earth’s ice and snow cover taken as a whole, this year has been a bit of a bright spot within a long-term sobering trend.”

Thinning ice

But the Arctic sea ice continues to be thinner than in past years, as confirmed both by direct satellite observations and estimates of ice age, and so it is more vulnerable to breakup by storms, circulating currents and thawing. “While Earth’s cryosphere, its snow and ice cover, got a shot of hope this year, it’s likely to be only a short-term boost,” Serreze said. The NSIDC says that although most of the ice cover now consists of young, thin ice, a pack of multi-year ice (ice that has survived more than one melt season and is thicker than first-year ice) remains in the central Arctic. At its lowest point this year on 13 September sea ice extent dropped to 5.10 million square kilometers (1.97 million square miles). September ice extent was 1.17 million sq km (452,000 sq m) below the 1981 to 2010 average. This summer’s low ice extent continues the downward trend seen since 1979, with September sea ice extent declining by 13.7% per decade. Summer sea ice extent is important because, among other things, it reflects sunlight, keeping the Arctic region cool and tempering global climate. As well as declining in extent the ice cover has grown thinner and less resistant to summer melt. Recent data on the age of sea ice, which scientists use to estimate the thickness of the ice cover, shows that the youngest, thinnest ice, which has survived only one or two melt seasons, now makes up most of the cover. But in the Antarctic the sea ice has reached record high levels – a Southern Hemisphere winter maximum extent of 19.47 million sq kms (7.52 million sq m) on 22 September. The September monthly average was also a record high, at 19.77 million sq kms (7.63 million sq m), slightly higher than last year’s previous record. Antarctic September sea ice has been increasing at 1.1% a decade relative to the 1981 to 2010 average. “The tiny gain in Antarctica’s ice is an interesting puzzle for scientists,” said NSIDC lead scientist Ted Scambos. “The rapid loss of ice in the Arctic should be ringing alarm bells for everyone.” – Climate News Network

FOR IMMEDIATE RELEASE While climate change is clearly strongly affecting Arctic sea ice, scientists are uncertain what links the rise in global temperatures and the continuing small increase in the Antarctic ice sheet. LONDON, 4 October – It’s one of the most closely-watched questions in climate science: how fast is the Arctic sea ice melting? The definitive answer is that it is still melting rapidly, though not quite as fast it did in 2012, when the extent of the ice sheet was lower than ever recorded. At the other end of the world, though, the Antarctic ice sheet has continued to grow, reaching a new record extent. Some experts believe this is the result not of cooling but of stronger polar winds pushing the ice further outward from the pole. Others have suggested that increased fresh water from summer icecap melting means the sea ice can form at a higher temperature in winter since the salt water is diluted. The details are published by the US National Snow and Ice Data Center (NSIDC), based at the University of Colorado Boulder, in Arctic Sea Ice News and Analysis. This September, sea ice covering the Arctic Ocean fell to its sixth lowest extent in the satellite record, which dates from 1979. All of the seven lowest extents have occurred in the last seven years. The NSIDC says cooler conditions in the Arctic this summer helped to retain more sea ice. Satellite data analysed by NSIDC scientists shows the sea ice cover at its lowest extent on 13 September. Averaging the extent for the whole of September also showed it to be the sixth lowest in the satellite record. Julienne Stroeve, an NSIDC scientist, says: “A relatively cool and stormy summer helped slow ice loss compared to the last few summers. This summer’s extent highlights the complex interaction between natural climate variability and long-term thinning of the ice cover.” Mark Serreze, the director of the NSIDC, said: “For Earth’s ice and snow cover taken as a whole, this year has been a bit of a bright spot within a long-term sobering trend.”

Thinning ice

But the Arctic sea ice continues to be thinner than in past years, as confirmed both by direct satellite observations and estimates of ice age, and so it is more vulnerable to breakup by storms, circulating currents and thawing. “While Earth’s cryosphere, its snow and ice cover, got a shot of hope this year, it’s likely to be only a short-term boost,” Serreze said. The NSIDC says that although most of the ice cover now consists of young, thin ice, a pack of multi-year ice (ice that has survived more than one melt season and is thicker than first-year ice) remains in the central Arctic. At its lowest point this year on 13 September sea ice extent dropped to 5.10 million square kilometers (1.97 million square miles). September ice extent was 1.17 million sq km (452,000 sq m) below the 1981 to 2010 average. This summer’s low ice extent continues the downward trend seen since 1979, with September sea ice extent declining by 13.7% per decade. Summer sea ice extent is important because, among other things, it reflects sunlight, keeping the Arctic region cool and tempering global climate. As well as declining in extent the ice cover has grown thinner and less resistant to summer melt. Recent data on the age of sea ice, which scientists use to estimate the thickness of the ice cover, shows that the youngest, thinnest ice, which has survived only one or two melt seasons, now makes up most of the cover. But in the Antarctic the sea ice has reached record high levels – a Southern Hemisphere winter maximum extent of 19.47 million sq kms (7.52 million sq m) on 22 September. The September monthly average was also a record high, at 19.77 million sq kms (7.63 million sq m), slightly higher than last year’s previous record. Antarctic September sea ice has been increasing at 1.1% a decade relative to the 1981 to 2010 average. “The tiny gain in Antarctica’s ice is an interesting puzzle for scientists,” said NSIDC lead scientist Ted Scambos. “The rapid loss of ice in the Arctic should be ringing alarm bells for everyone.” – Climate News Network

Greenland’s great melt is pinned on climate change

FOR IMMEDIATE RELEASE The forensic search for the mysterious agent that almost melted Greenland goes on. The latest suspect to be rounded up for questioning is the jet stream, according to scientists in Sheffield, in the UK. LONDON, 18, June – First: the story so far. For a few days in July 2012, almost 97% of the surface of Greenland began suddenly to thaw. This was a melt on an unprecedented scale. Greenland carries a burden of three million cubic kilometres of ice and even in the summer, most of it stays frozen, partly because of the island’s high latitude and partly because ice reflects sunlight, and tends normally to serve as its own insulator. The event was so unusual, and so unexpected, and on such a scale that nobody seriously suggested that the dramatic conversion of snow to slush was direct evidence of climate change because of human-induced global warming. Soot, smoke and heat At first, climatologists were inclined to see the thaw as a consequence of the record-breaking heat waves and forest fires that afflicted North America last summer: snow could have been darkened by columns of soot and smoke from forest fires, just enough to start absorbing the sunlight, some reasoned. Then in April a team at the University of Wisconsin-Madison suggested that freak cloud behaviour over Greenland at the time might have caused the melting. Clouds normally block sunlight and keep the terrain below them cool. But these clouds could have been thin enough to let solar radiation through, but thick enough to trap the consequential infra-red radiation from the ground, and raise the local temperature levels. Now Edward Hanna and colleagues at Sheffield report in the International Journal of Climatology that they have another explanation. Unusual atmospheric circulation and changes in the jet stream – the same changes that almost washed away summer in England – sent a blister of warm air sweeping over the ice sheet. Hanna and his team analysed all the weather data collected by the Danish Meteorological Institute and by US researchers, and then employed satellite readings and a computer simulation called SnowModel to reconstruct the strange turn of events. And climate change may after all be a suspect.   High melt years The Greenland Ice Sheet is a highly sensitive indicator of regional and global change, and, says Prof Hanna, been undergoing rapid warming, and losing ice, for at least the last five years and probably the last 20. “Our research found that a ‘heat dome’ of warm southerly winds over the ice sheet led to widespread surface melting.” This was not predicted by the climate models used by the Intergovernmental Panel on Climate Change, and perhaps that indicated a deficiency in those models, he suggested. The event seemed to be linked to changes in a phenomenon known to oceanographers and meteorologists as the summer North Atlantic Oscillation (NAO), another well-observed high pressure system called the Greenland Blocking Index, and the polar jet stream, all of which sent warm southerly winds sweeping over Greenland’s western coast. “The next five to 10 years will reveal whether or not 2012 was a rare event resulting from natural variability of the NAO or part of an emerging pattern of new extreme high melt years.” It was hard to predict future changes in the Greenland climate in the current state of knowledge, but important to keep on trying. There is an awful lot of ice on top of Greenland. Once it starts to melt, it is likely to be, say the Sheffield scientists,  “dominant contributor to global sea level change over the next 100 to 1,000 years.”- Climate News Network

FOR IMMEDIATE RELEASE The forensic search for the mysterious agent that almost melted Greenland goes on. The latest suspect to be rounded up for questioning is the jet stream, according to scientists in Sheffield, in the UK. LONDON, 18, June – First: the story so far. For a few days in July 2012, almost 97% of the surface of Greenland began suddenly to thaw. This was a melt on an unprecedented scale. Greenland carries a burden of three million cubic kilometres of ice and even in the summer, most of it stays frozen, partly because of the island’s high latitude and partly because ice reflects sunlight, and tends normally to serve as its own insulator. The event was so unusual, and so unexpected, and on such a scale that nobody seriously suggested that the dramatic conversion of snow to slush was direct evidence of climate change because of human-induced global warming. Soot, smoke and heat At first, climatologists were inclined to see the thaw as a consequence of the record-breaking heat waves and forest fires that afflicted North America last summer: snow could have been darkened by columns of soot and smoke from forest fires, just enough to start absorbing the sunlight, some reasoned. Then in April a team at the University of Wisconsin-Madison suggested that freak cloud behaviour over Greenland at the time might have caused the melting. Clouds normally block sunlight and keep the terrain below them cool. But these clouds could have been thin enough to let solar radiation through, but thick enough to trap the consequential infra-red radiation from the ground, and raise the local temperature levels. Now Edward Hanna and colleagues at Sheffield report in the International Journal of Climatology that they have another explanation. Unusual atmospheric circulation and changes in the jet stream – the same changes that almost washed away summer in England – sent a blister of warm air sweeping over the ice sheet. Hanna and his team analysed all the weather data collected by the Danish Meteorological Institute and by US researchers, and then employed satellite readings and a computer simulation called SnowModel to reconstruct the strange turn of events. And climate change may after all be a suspect.   High melt years The Greenland Ice Sheet is a highly sensitive indicator of regional and global change, and, says Prof Hanna, been undergoing rapid warming, and losing ice, for at least the last five years and probably the last 20. “Our research found that a ‘heat dome’ of warm southerly winds over the ice sheet led to widespread surface melting.” This was not predicted by the climate models used by the Intergovernmental Panel on Climate Change, and perhaps that indicated a deficiency in those models, he suggested. The event seemed to be linked to changes in a phenomenon known to oceanographers and meteorologists as the summer North Atlantic Oscillation (NAO), another well-observed high pressure system called the Greenland Blocking Index, and the polar jet stream, all of which sent warm southerly winds sweeping over Greenland’s western coast. “The next five to 10 years will reveal whether or not 2012 was a rare event resulting from natural variability of the NAO or part of an emerging pattern of new extreme high melt years.” It was hard to predict future changes in the Greenland climate in the current state of knowledge, but important to keep on trying. There is an awful lot of ice on top of Greenland. Once it starts to melt, it is likely to be, say the Sheffield scientists,  “dominant contributor to global sea level change over the next 100 to 1,000 years.”- Climate News Network

As Arctic ice melts diseases spread

EMBARGOED until 2301 on Friday 7 June There’s strong evidence that with rising temperatures and reductions in ice cover, the Arctic is seeing a spike in the rate of various diseases.  LONDON, 7 June – A cow grazing on the lush pasturelands of Cornwall in southwest England and a seal swimming in the ice cold waters of the Arctic might not appear to have much in common. The link between the two is tuberculosis, with a strain of the disease threatening cattle populations in Britain and elsewhere now showing up among  seals in the high Arctic. Dr Claire Heffernan, a trained vet and a specialist in global health and disease interaction between animals and humans, says that as the climate warms in Arctic regions, more and more diseases from Europe and elsewhere are spreading there, threatening both animal and human populations. “In the past diseases might not have survived in the cold temperatures and the ice of the Arctic but as the region warms a new dynamic is introduced” Heffernan told Climate News Network. “We need to fundamentally alter the way we look at disease in the context of climate change. We should recognise disease as a harbinger of a warming world.” Dr Heffernan, a senior fellow at the Smith School for Enterprise and the Environment in Oxford and director of the livestock development group at the University of Reading says a wide variety of diseases have recently become evident among Arctic animal populations. Toxoplasma, a parasite common in European cat populations, is now being found in polar bears in Greenland. Erysipelas, a disease of domestic pigs, is being found in Musk Oxen in the Canadian Arctic: the animals have also been found to have contracted Giardiasis, an intestinal parasite of humans. Meanwhile West Nile virus has been found in wolf pups in the Canadian Arctic. Transmission Such diseases could have been transmitted in a variety of ways, says Heffernan. The spread of Toxoplasma, for example, might be the result of people flushing cat faeces down toilets in the US and Europe which are then carried by tides to the Arctic. More people are visiting the region. Tourists defecating in the wilds might be the cause of the spread of Erysipelas. “The Arctic is like a Heathrow airport in terms of bird, seal and other migration patterns so that’s another way disease is easily spread” says Heffernan.  “And the disease pathway is not all one way – they can also be transmitted from the Arctic to elsewhere in the world. “The point is no one is really joining up the dots between climate change and the spread of disease. There’s a whole new disease transmission cycle appearing in the Arctic which we just don’t understand.” Impact on humans Human disease levels in the Arctic are a continuing concern says Heffernan. Rates of TB among the Inuit of northern Canada are far higher than in the general population. Major economic change and development now taking place in the Arctic means previously nomadic people are moving to towns in search jobs. Ice melt is also forcing more into settlements. With people living in close proximity to each other, disease tends to spread faster. Infant mortality in the Arctic, much of it due to diseases curable elsewhere in the world, is considerably higher than elsewhere. “In 1930s there was a temperature spike in the Arctic which led to an outbreak of malaria” says Heffernan. “In subsequent years chloroquine was used to combat it. But what happens now, with temperatures rising and the prevalence of chloroquine resistant malaria?” Athrax alert Early in the last century there were periodic outbreaks of anthrax in the Russian Arctic, resulting in the deaths of thousands of deer and cattle. Some Russian scientists and officials have warned that burial sites of those anthrax infected animals are now being exposed. “As the Arctic melts, ancient pathogens can suddenly escape” says Heffernan. “No one knows for certain how many livestock burial sites there are in the Russian Arctic – I’ve seen estimates ranging from 400 to 13,000.” In recent years there have been several anthrax outbreaks affecting both cattle and people reported in the region, particularly among communities of the indigenous Yakut, who often live near to such burial sites. With Arctic temperatures rising at more than twice the rate of the rest of the world, Heffernan says there’s an urgent need to link disease and climate change and tackle health issues. But there are a number of problems preventing concerted action: the Arctic is governed by different states with different laws. There’s not even a common agreement among Arctic nation states on the region’s boundaries. There’s a dearth of trained medical staff and research across the region. When it comes to statistics, the Arctic is something of a black hole with health data subsumed into  more general country wide statistics. “There’s very little biosecurity work going on in the Arctic” says Heffernan. “Yet we have the means to control so many of these diseases. There must be urgent, concerted, joined up action.” – Climate News Network

EMBARGOED until 2301 on Friday 7 June There’s strong evidence that with rising temperatures and reductions in ice cover, the Arctic is seeing a spike in the rate of various diseases.  LONDON, 7 June – A cow grazing on the lush pasturelands of Cornwall in southwest England and a seal swimming in the ice cold waters of the Arctic might not appear to have much in common. The link between the two is tuberculosis, with a strain of the disease threatening cattle populations in Britain and elsewhere now showing up among  seals in the high Arctic. Dr Claire Heffernan, a trained vet and a specialist in global health and disease interaction between animals and humans, says that as the climate warms in Arctic regions, more and more diseases from Europe and elsewhere are spreading there, threatening both animal and human populations. “In the past diseases might not have survived in the cold temperatures and the ice of the Arctic but as the region warms a new dynamic is introduced” Heffernan told Climate News Network. “We need to fundamentally alter the way we look at disease in the context of climate change. We should recognise disease as a harbinger of a warming world.” Dr Heffernan, a senior fellow at the Smith School for Enterprise and the Environment in Oxford and director of the livestock development group at the University of Reading says a wide variety of diseases have recently become evident among Arctic animal populations. Toxoplasma, a parasite common in European cat populations, is now being found in polar bears in Greenland. Erysipelas, a disease of domestic pigs, is being found in Musk Oxen in the Canadian Arctic: the animals have also been found to have contracted Giardiasis, an intestinal parasite of humans. Meanwhile West Nile virus has been found in wolf pups in the Canadian Arctic. Transmission Such diseases could have been transmitted in a variety of ways, says Heffernan. The spread of Toxoplasma, for example, might be the result of people flushing cat faeces down toilets in the US and Europe which are then carried by tides to the Arctic. More people are visiting the region. Tourists defecating in the wilds might be the cause of the spread of Erysipelas. “The Arctic is like a Heathrow airport in terms of bird, seal and other migration patterns so that’s another way disease is easily spread” says Heffernan.  “And the disease pathway is not all one way – they can also be transmitted from the Arctic to elsewhere in the world. “The point is no one is really joining up the dots between climate change and the spread of disease. There’s a whole new disease transmission cycle appearing in the Arctic which we just don’t understand.” Impact on humans Human disease levels in the Arctic are a continuing concern says Heffernan. Rates of TB among the Inuit of northern Canada are far higher than in the general population. Major economic change and development now taking place in the Arctic means previously nomadic people are moving to towns in search jobs. Ice melt is also forcing more into settlements. With people living in close proximity to each other, disease tends to spread faster. Infant mortality in the Arctic, much of it due to diseases curable elsewhere in the world, is considerably higher than elsewhere. “In 1930s there was a temperature spike in the Arctic which led to an outbreak of malaria” says Heffernan. “In subsequent years chloroquine was used to combat it. But what happens now, with temperatures rising and the prevalence of chloroquine resistant malaria?” Athrax alert Early in the last century there were periodic outbreaks of anthrax in the Russian Arctic, resulting in the deaths of thousands of deer and cattle. Some Russian scientists and officials have warned that burial sites of those anthrax infected animals are now being exposed. “As the Arctic melts, ancient pathogens can suddenly escape” says Heffernan. “No one knows for certain how many livestock burial sites there are in the Russian Arctic – I’ve seen estimates ranging from 400 to 13,000.” In recent years there have been several anthrax outbreaks affecting both cattle and people reported in the region, particularly among communities of the indigenous Yakut, who often live near to such burial sites. With Arctic temperatures rising at more than twice the rate of the rest of the world, Heffernan says there’s an urgent need to link disease and climate change and tackle health issues. But there are a number of problems preventing concerted action: the Arctic is governed by different states with different laws. There’s not even a common agreement among Arctic nation states on the region’s boundaries. There’s a dearth of trained medical staff and research across the region. When it comes to statistics, the Arctic is something of a black hole with health data subsumed into  more general country wide statistics. “There’s very little biosecurity work going on in the Arctic” says Heffernan. “Yet we have the means to control so many of these diseases. There must be urgent, concerted, joined up action.” – Climate News Network