Polar bears weakened by pollution as well as warmth

Polar bears weakened by pollution as well as warmth

Climate change causing habitat loss and reduced food is the main problem for polar bears, but plastic waste and other pollutants are growing risks.

LONDON, 17 April, 2015 − Greenland’s polar bears have a thyroid problem. Their endocrine systems, too, are being disrupted. In both cases the culprit agency is environmental pollution by a range of long-lived industrial chemicals and pesticides.

Kristin Møller Gabrielsen of the Norwegian University of Science and Technology in Trondheim and colleagues report in the journal Environmental Research that they examined the liver, muscle and kidney tissues taken from seven polar bears killed by Inuit hunters in East Greenland in 2011 and analysed the effect of more than 50 contaminants in plasma samples from Ursus maritimus, to see what effect organohalogen compounds could have on the bears’ thyroid systems.

All mammals have thyroid systems, and these are physiologically essential for growth, development, reproduction, stress response, tissue repair, metabolism and thermoregulation (an animal’s ability to keep its body temperature within limits): disruption at any stage of life can be damaging, but thyroid regulation is vital in the earlier stages of life.

But the researchers found high concentrations of plastic pollution and pesticide contamination in the creatures’ tissues, many of which could affect the hormonal systems.

Retreating ice

Polar bears face an uncertain future: the Arctic’s most iconic predator depends on sea ice for access to the most nourishing prey – seals − but thanks to global warming driven by greenhouse gases discharged by humankind since the start of the Industrial Revolution, the ice is in retreat. The bears can and do forage on land for small prey, eggs, berries and so on, but new research suggests that this is unlikely to help them much.

“The health of the Arctic polar bear is being attacked from all fronts, but among many other factors is the exposure to environmental contaminants,” said Maria Jesus Obregon, of the Biomedical Research Institute in Madrid, one of the authors.

“A wide variety of organochlorine compounds and pesticides have an effect on the thyroid hormones in plasma, tissues and deiodinase enzymes, which are in charge of stabilising the thyroid hormones in tissues.”

The biggest problem that confronts Ursus maritimus is still climate change, loss of habitat and a more precarious food supply. But as a marine mammal, the bear is exposed to a huge range of pollutants delivered by modern industry, transport and commerce.

Conservation guidelines

Researchers in February calculated that in 2010, around eight million tons of plastic waste
ended up in the world’s oceans.

A second team of researchers has framed guidelines for the conservation of the polar bear, and proposed 15 measures that could determine the factors important in saving the creature from ultimate extinction.

They report in the journal Science of the Total Environment that they questioned 13 specialists from four nations to propose ways of measuring polar bear health. Not surprisingly, climate change topped the list of threats, but the list also included nutritional stress, chronic physiological stress, diseases and parasites, and increasing exposure to competitors. Exposure to contaminants was the third largest threat.

“We still don’t know to what extent environmental changes will affect polar bear health and therefore its conservation,” say the authors. − Climate News Network

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Permafrost holds key to release of trapped carbon

Permafrost holds key to release of trapped carbon

The frozen soil of the northern polar regions holds billions of tonnes of organic carbon – and global warming could speed its escape into the atmosphere.

LONDON, 14 April, 2015 − Three sets of scientists in the same week have helped narrow the uncertainties about how the natural world will respond to extra carbon dioxide in the atmosphere caused by the burning of fossil fuels.

Carbon locked in the frozen earth will escape gradually as the Arctic permafrost melts – but the scientists say the process could accelerate.

As greenhouse gas levels soar, and soils warm, and plant roots tap down into the carbon stored there by centuries of ancient growth, they will release potent chemicals that will accelerate microbial attack – and speed up the release of carbon dioxide into the atmosphere.

The soil carbon cycle is one of the great headaches of climate science. And the Arctic is the first place to look for answers about it, and about how the Earth and oceans that store atmospheric carbon will respond to global warming.

Locked away

Around half of the world’s buried organic carbon is locked away in the soils of the northern circumpolar permafrost, and this huge vault of deep-frozen peat and leaf litter – more than 1,000 billion metric tonnes in the top three metres, at the latest estimate − contains twice as much carbon as is held in the atmosphere.

But the Arctic is the fastest-warming region on the planet, so what will happen as the permafrost thaws and plants begin to move north? Would it all be surrendered to the atmosphere in one devastating exhalation, triggering an explosion in global warming and causing trillions of dollars in economic damage?

An international team within the Permafrost Carbon Network thinks not. Their verdict, published in Nature journal, is that the current evidence suggests “a gradual and prolonged release of greenhouse gas emissions in a warming climate”. That is, humankind would have time to adapt.

“The data from our team’s syntheses don’t support the permafrost carbon bomb view,” says one of the team members, David McGuire, professor of landscape ecology at the University of Alaska Fairbanks.

“What our syntheses do show is that permafrost carbon is likely to be released in a gradual and prolonged manner, and that the rate of release through 2100 is likely to be of the same order as the current rate of tropical deforestation in terms of its effects on the carbon cycle.”

Since the tropical forests are already under pressure, this is hardly good news. And the picture is not a simple one.

“Even small changes will have serious effects on carbon concentrations in the atmosphere, and by extension on climate”

As the permafrost thaws, the soil microbes will get to work on the buried carbon, which will inevitably add to the soil warming, and provide an instance of what engineers call positive feedback, according to a team led by Jøgen Hollesen, senior researcher at the University of Copenhagen’s Centre for Permafrost.

He and colleagues report in Nature Climate Change that when they measured heat production in 21 contrasting organic permafrost soils, they found it to be between 10 and 130 times higher than in mineral soils measured in Greenland − and this would have “crucial implications for the amounts of carbon being decomposed”.

And in the same issue of Nature Climate Change, a team led by researchers from Oregon State University have confirmed that any kind of warming or plant growth is likely to get the soil microbes working as hard as they can – partly because the plants use chemistry to free the soil carbon so the bacteria can start to turn it back into carbon dioxide.

Neither of the two Nature Climate Change studies was directly concerned with climate change. The Danish scientists’ findings sprang from concern about what warming might do to the ancient middens that hold as-yet-unexamined evidence of early human settlement in the Arctic. The Oregon team were more concerned about the interactions that go on in the soil, and how they could be measured.

Chemical bonds

They found that plant roots released an exudate that acted to release the chemical bonds that keep a carbon bound to non-organic minerals in the soil. Warming could only speed the process, so more carbon dioxide will get into the atmosphere from the soil because of global warming.

This, again, is positive feedback at work. And it suggests climate scientists might be underestimating carbon loss from the soil by as much as 1% a year.

“Our main concern is that this is an important mechanism, and we are not presently considering it in global models of carbon cycling,” says soil and environmental geochemist Markus Kleber, one of the authors of the Oregon report.

“There is more carbon stored in the soil, on a global scale, than in vegetation, or even in the atmosphere. Since this reservoir is so large, even small changes will have serious effects on carbon concentrations in the atmosphere, and by extension on climate.” – Climate News Network

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Canada will lose many glaciers as climate warms

Canada will lose many glaciers as climate warms

Climate change could cause many glaciers in western Canada to start to disappear by 2040, affecting people and places that depend on their water.

LONDON, 10 April, 2015 − As the world warms, many of the great frozen rivers of Canada will not just retreat, but could vanish altogether.

New research suggests that maritime glaciers in the far northwest might survive, but more than two-thirds of Canada’s existing glaciers in British Columbia and Alberta could be lost altogether by 2100.

Garry Clarke, a glaciologist at the University of British Columbia in Vancouver, says: “Soon our mountains could look like those in Colorado or California, and you don’t see much ice in those landscapes.”

The consequences for the forests, grasslands, animals and communities that depend on glacial meltwater could be serious. The disappearance of the glaciers will also create problems for Canada’s hydroelectric industry, for agriculture and grazing, for the mining industry, for the salmon fishery, and for tourism.

Professor Clarke and his colleagues report in Nature Geoscience that they devised a model – a high-resolution computer simulation – of the glaciers of western Canada that explicitly mimicked glacial flow. Then they tested it with a range of scenarios for climate change, driven by human combustion of fossil fuels and rising atmospheric carbon dioxide levels in the last two centuries.

“Once the glaciers are gone, the streams will be a lot warmer and this will hugely change freshwater habitat”

There are more than 17,000 glaciers in British Columbia and Alberta, covering more than 26,000 square kilometres of the two provinces, and holding an estimated 2,980 cubic kilometres of ice. This puts western Canada as more glaciated than the Himalayas (which have less than 23,000 sq kms of glacier): the entire continent of South America has only 31,000 sq kms of glacier.

The researchers found that maritime glaciers in the northwest would endure, in a diminished state. But overall, the volume of the glaciers in western Canada would shrink by 70%, give or take 10%.

Right now glaciers, most of them between 100 and 200 metres thick, are thinning at a rate of about a metre a year. The peak flow of meltwater would most likely occur between 2020 and 2040. Thereafter, the rivers would be in decline.

Potential sea level rise as a consequence of this, the scientists say, would be “modest” at around 6mm, but the consequences for that part of Canada would be substantial.

The Columbia River, which flows from the interior to the Pacific coast of Washington and Oregon, yields the largest hydroelectric production of any river in North America. And the impact on freshwater ecosystems could be considerable.

“These glaciers act as a thermostat for freshwater systems,” said Professor Clarke. “Once the glaciers are gone, the streams will be a lot warmer and this will hugely change freshwater habitat. We could see some unpleasant surprises in terms of salmon productivity.” – Climate News Network

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Cut carbon now to avoid climate tipping points

Cut carbon now to avoid climate tipping points

The price to be paid for not cutting greenhouse gas emissions could push the planetary climate system closer to irreversible “tipping points”.

LONDON, 3 April, 2015 – An international team of scientists has tried a new approach to addressing the complex argument about the costs of climate change – and, once again, the prediction is that the costs of inaction will be so much greater than paying the bills now.

The researchers − from the UK, Switzerland and the US − conclude that policy-makers must apply the brakes and put a high price on carbon emissions “before it is too late”.

Much of the argument on this issue revolves around the perceived cost of carbon emissions and any tax that should be imposed on fossil fuel use. Social scientists and economists and climate modellers have tried a number of approaches.

One group tried to work out the interval between the burning of fossil fuels and the consequent greenhouse warming, and concluded it could be as little as 10 years.

Other groups have separately tried to calculate the true cost of emitted carbon dioxide. The US government works on the basis of $37 in social costs per tonne emitted, but two US scientists proposed that the true cost in future health and habitat losses was probably six times higher.

“The additional carbon tax that our model recommends can be thought of as an insurance premium levied on society”

And yet another researcher began to examine the costs of petrol, or coal, or methane gas if the long-term economic damage and health costs were factored in, and concluded that these made “expensive” renewables cheap by comparison.

Now researchers from the universities of Exeter in the UK, Zurich in Switzerland and Chicago and Stanford in the US report in Nature Climate Change that they considered the risk that emitted greenhouse gases from fossil fuels would push the planetary climate system closer to what climate scientists call “tipping points.”

These are outcomes that would irreversibly change regional climate patterns, disrupt agriculture, precipitate greater flooding in some places, more sustained droughts in others, and accelerate sea level rise.

And, once again, they find that governments have underestimated the price to be paid by society for carbon dioxide emissions from fossil fuels.

“We are calling on policy-makers to respond to the prospect of triggering future climate tipping points by applying the brakes now and putting a high price on carbon emissions before it is too late,” says one of the authors, Tim Lenton, professor of climate change and earth system science at the University of Exeter.

“The additional carbon tax that our model recommends can be thought of as an insurance premium levied on society to delay irreversible changes in the future.”

The researchers selected five potential tipping points − all of which have separately been in the news recently. They relate to:

The researchers say their act-now, save-future-costs model not only demonstrates the dangers of underestimating the cost of future climate change, but is the first one to emerge from a purely market-based approach. The considerations do not have to be based on moral judgements about sustainability and the wellbeing of future generations. – Climate News Network

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Climate-driven loss of habitat endangers marine mammals

Climate-driven loss of habitat endangers marine mammals

Global survey of threatened Arctic species warns that conservation won’t work without regulation of greenhouse gas emissions to halt climate change.

LONDON, 2 April, 2015 − Three kinds of whale, six varieties of seal, the walrus and the polar bear all have things in common: they are marine mammals, they depend on the Arctic for survival as species, they are vulnerable, and biologists know surprisingly little about them.

And since the Arctic is warming twice as fast as the rest of the planet, their future could become even more threatened as climate change increases habitat loss.

The stress, so far, is on the word “could”, as the first challenge is to establish the facts.

A global study team led by Kristin Laidre, principal scientist at the University of Washington Polar Science Centre in Seattle, reports in the journal Conservation Biology that marine mammals are “disproportionately threatened and data poor compared with their terrestrial counterparts”.

The narwhal, beluga and bowhead whales, the ringed, bearded, spotted, ribbon, harp and hooded seals, the walrus, and the polar bear are “particularly vulnerable due to their dependence on sea ice”.

Important predators

All these animals make their living on the ice and in waters north of the Arctic Circle, and all are important predators. They are also important to indigenous and settler peoples in the frozen North as many can be legally harvested, and others are iconic tourist attractions. Either way, they help communities survive.

“These species are not only icons of climate change, they are also indicators of ecosystem health, and key resources for humans,” Dr Laidre says. “Accurate scientific data – currently lacking for many species – will be key to making informed and efficient decisions about conservation challenges and trade-offs in the 21st century.”

So the researchers set out on what they believe is the first comprehensive global review of what is known about the populations of these animals, and about the way their local habitats may be changing.

“They need ice to find food, find mates, reproduce, and rear their young. It’s their platform of life.”

The study divided the Arctic into 12 regions and began to look at population numbers and trends, and the local pattern of seasonal change in the ice.

They identified 78 distinct populations of the 11 species, and began to assemble estimates of numbers. These range from millions for the ringed seals to a few hundred for the beluga whales of Ungava Bay in the Canadian Arctic.

In many cases, researchers had too little information even to make a guess about whether local populations of any species were stable, declining or increasing. In their table of the trends of the 11 species in the 78 populations, the word “unknown” occurs more than 60 times.

They also charted profound reductions in ice cover. The sea ice naturally advances each winter, and retreats each spring, but because of global warming driven by human emissions of greenhouse gases released by fossil fuel combustion, the pattern of advance and retreat has changed dramatically. By 2040, according to some projections, the Arctic could be more or less ice-free each summer.

Extended summer

But change is visible now. In most regions, the scientists found that the summer period was extended by between five and 10 weeks. In Russia’s Barents Sea, the summer ice period is now 20 weeks longer – five months – than it was 30 years ago.

This presents a threat to the polar bear, and to the seals on which they feed. “These animals require sea ice,” Dr Laidre says. “They need ice to find food, find mates, reproduce, and rear their young. It’s their platform of life. It is very clear those species are going to feel the effects the hardest.”

On the other hand, the whale species might benefit – at least for a while – from reduced ice cover. Open water could offer a wider feeding range and greater marine productivity, and therefore more food.

The scientists provide a set of general recommendations for biologists, local authorities, government agencies and international organisations concerned with conservation of Arctic marine mammals. They also have a message for the entire planet.

As Dr Laidre says: “We may introduce conservation measures or protected species legislation, but none of those things can really address the primary driver of Arctic climate change and habitat loss for these species. The only thing that can do that is regulation of greenhouse gases.” – Climate News Network

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Deep concerns as climate impacts on Gulf Stream flow

Deep concerns as climate impacts on Gulf Stream flow

Ocean scientists find evidence of an increasing slowdown in the Atlantic’s “invisible river” that could seriously affect weather and sea levels in the US and Europe.

LONDON, 25 March, 2015 − Climate scientists have once again confirmed an alarming slowdown in the circulation of the Atlantic Ocean − the process that drives the current that warms Europe, and powers the planetary climate.

And this time, they are prepared to say that the changes are recent − and may be linked to global warming.

The Atlantic Conveyor is a great invisible river that flows in two directions at the same time. The equatorial surface waters − warm, and therefore less dense − flow towards the north in the form of the Gulf Stream. Around Greenland, the denser and colder Arctic waters sink to the ocean bottom and begin their progress towards the south.

It is the difference in temperatures that maintains the turnover and keeps the climate engine going.

As a consequence, the two-way traffic of warm and cold water redistributes heat around the planet and keeps Britain and maritime Europe in relatively mild conditions.

But as global average temperatures rise, and the Greenland ice sheet melts, ocean scientists have warned that the speed of the ocean turnover could be put at risk.

Greater weakening

Stefan Rahmstorf, an ocean physicist at the Potsdam Institute for Climate Impact Research in Germany, is lead author of a report in Nature Climate Change that says they now have evidence of a slowdown during the 20th century, and greater weakening since the first alarms 40 years ago about the possible effects of greenhouse emissions.

“It is conspicuous that one specific area in the North Atlantic has been cooling in the past hundred years, while the rest of the world heats up,” Professor Rahmstorf says. “Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970.”

The paradox of the Atlantic current is that, in a warmer world, it could slow down or halt, which would deliver uncomfortable consequences for maritime Europe.

Fears of such an effect provided the scenario for the 2004 climate disaster movie, The Day After Tomorrow, which predicated a frozen Britain and a glaciated US.

“Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970”

No such extreme outcome was ever likely, but the Gulf Stream certainly makes a big difference to Britain. A former UK chief scientist once calculated that it delivered 27,000 times the warmth that Britain’s power stations could supply and, as a consequence, the UK is on average 5°C warmer than it might be, given its latitude.

Strength of current

At a number of points in the last two decades, researchers have wondered about the strength of the Atlantic current, but since systematic oceanographic record-keeping began only relatively recently, they had no way of distinguishing between a natural oceanic cycle and real change.

So the Potsdam team used all available data, and “proxy temperatures” derived from ice-cores, tree-rings, coral, and ocean and lake sediments, to reconstruct the story of the Atlantic current − and, in particular, the phenomenon called the Atlantic meridional overturning circulation (AMOC) − for the last 1,000 years.

The changes happening now have no precedent since 900 AD, they say. And the increasingly rapid melting of the Greenland icecap – bringing an increased flow of water that is less saline and also less dense, and therefore less likely to sink − could disturb the circulation.

The consequences of all this could, they say, “contribute to further weakening of the AMOC” in the coming decades.

Atlantic Conveyor: a graph of the Atlantic Meridional Overturning Circulation (AMOC). Image: Stefan Rahmstorf/PIK

Atlantic Conveyor: a graph of the Atlantic Meridional Overturning Circulation (AMOC).
Image: Stefan Rahmstorf/PIK

This is not the first such alarm. The same weakening was identified last year, but at the time researchers could not be sure they were not looking at a natural fluctuation.

Now they are sure, and they suspect that the cooling of the north Atlantic that they now observe is even stronger than most computer simulations have so far predicted.

“Common climate models are underestimating the change we’re facing, either because the Atlantic overturning is too stable in the models or because they don’t properly account for the Greenland ice sheet melt, or both,” says one of the co-authors, Michael Mann, professor of meteorology at Pennsylvania State University in the US.

Climate predictions

“That is another example where observations suggest that climate model predictions are in some respects still overly-conservative when it comes to the pace at which certain aspects of climate change are proceeding.”

Another of the authors, Jason Box, professor of glaciology at the Geological Survey of Denmark and Greenland, adds that “the human-caused mass loss of the Greenland ice sheet appears to be slowing down the Atlantic overturning − and this effect might increase if temperatures are allowed to rise further”.

The stakes are high. If the Atlantic conveyor system continues to weaken, ocean ecosystems will change, fishing communities will be affected, and some coastal cities – such as New York and Boston in the US − could be hit by additional regional sea level rises.

The 2004 Hollywood version – promoted with a huge poster of New York’s Statue of Liberty all but covered by ice – is not likely to happen. But if the ocean circulation weakens too much, there could be a relatively rapid and difficult-to-reverse change in the world’s climate system.

The Intergovernmental Panel on Climate Change estimates that there is a one-in-10 chance of this “tipping point” happening within the 21st century.

But the evidence from the Potsdam team is now likely to prompt other climate scientists to go back to their calculations and re-evaluate the risk. – Climate News Network

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Forecast of less stormy weather is not good news

Forecast of less stormy weather is not good news

Scientists say intense droughts and heatwaves are the likely climate-related outcome of less frequent summer storms in recent decades.

LONDON, 14 March, 2015 − Storms on fine summer days might be unwelcome to many, but at least the rain and winds does act like a big brush on the weather system − bringing fresh air and relief from oppressive heat.

And scientists now warn that a decrease in the frequency of such storms across much of the US, Europe and Russia in recent decades − with climate change the probable cause – could mean that summer heat waves and droughts are likely to become ever more persistent and intense.

Scientists from the Potsdam Institute for Climate Impact Research (PIK) in Germany report in Science journal that storm activity data they collected from weather stations and satellites shows a clear reduction in the frequency and intensity of summer storms in the mid-latitudes of the northern hemisphere over recent decades.

Heat extremes

This makes heat extremes – such as the period of intense heat that hit Russia in 2010, causing widespread crop failure and multiple wildfires – ever more likely.

“While you might expect reduced storm activity to be something good, it turns out that this reduction leads to a greater persistence of weather systems in the northern hemisphere mid-latitudes,” says Dim Coumou, an Earth systems analyst at PIK and lead author of the study.

“In summer, storms transport moist and cool air from the oceans to the continents, bringing relief after periods of oppressive heat. Slack periods, in contrast, make warm weather conditions endure, resulting in the build-up of heat and drought.”

The PIK study looks at a particular set of turbulences − called synoptic eddy − in weather systems over the summer months, and calculates the total energy of their wind speeds.

“Climate change disturbs airstreams that are
important for shaping our weather”

It shows that the level of this energy, which measures the interplay between the intensity and frequency of high and low pressure systems in the atmosphere, has dropped by approximately 10% over the past 35 years.

Previous studies have focused mostly on winter storms, which tend to do more damage than those in summer. The PIK study found that average storm activity in the winter months in many regions is largely unchanged.

The Arctic region probably holds the key to the drop in summer storm activity, say the scientists.

Temperatures around the globe are rising due to greenhouse gas emissions caused by the burning of fossil fuels, but the rate of warming is faster in the Arctic.

As the sea ice cover in the Arctic shrinks, the surface reflects less sunlight and absorbs more heat. The warmer waters then warm the air, setting in motion a process through which the relative difference in temperature is reduced between the cold polar region and the rest of the northern hemisphere.

Air circulation

Temperature differences drive air circulation. As the difference in temperatures between the two regions decreases, so does the rate of summer storm activity.

The study also found that this reduction in the temperature differential weakens the polar jet stream, which − often travelling at speeds of more than 200 miles per hour high up in the troposphere − acts as a boundary between the cold polar air and warmer air further south.

“From whichever angle we look at the heat extremes, the evidence we find points in the same direction,” Dim Coumou says.

“The heat extremes do not just increase because we’re warming the planet, but because climate change disturbs airstreams that are important for shaping our weather.

“The reduced day-to-day variability that we observed makes weather more persistent, resulting in heat extremes on monthly timescales. So the risk of high-impact heat waves is likely to increase.” – Climate News Network

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Temperature rise leaves dogs racing on thin ice

Temperature rise leaves dogs racing on thin ice

Alaska proudly boasts of hosting the “greatest dog sled race on Earth”, but climate change has forced a switch in the historic event’s course.

LONDON, 18 February, 2015 − The Iditarod sled race in Alaska is a 1,000-mile endurance test in which competing teams of dogs and their drivers race at dizzying speeds across the frozen tundra.

But this year’s race, due to be held in early March, has had to be re-routed due to a lack of snow. And Jake Crouch, a climate scientist with the National Climatic Data Center, says rising temperatures are to blame.

“This is a pretty big deal,” Crouch told the New York Times. “One of the things we’re seeing with climate change is that the high latitudes are experiencing the brunt of it. They’re very vulnerable.”

Seasonal increase

According to the US government’s Environmental Protection Agency (EPA), temperatures in Alaska have increased by an average of 3.4˚F over the last 50 years, with winter temperatures showing the biggest seasonal increase, rising by an average of 6.3˚F over the same period.

The EPA says the rate of warming in Alaska is double the national average. Estimates are that average temperatures in the state will increase a further 3.5˚F to 7˚F by mid-century.

Deep snow – vital for what is described by Iditarod’s organisers as the greatest dog sled race on Earth – has been in particularly short supply this year, with only 19 inches falling since August on the race start near Alaska’s capital, Anchorage, compared with 50 inches normally.

“This year, you can’t go through a rock,” one of the sled drivers – who are locally known as a “mushers” – told Alaska’s Fairbanks Daily News-Miner.

“There’s boulders and rocks that we’ve never seen there in 20 some years that are littering all the gorge, places that you’d never even see a rock because you’re going over feet of snow through there. This year, you’re looking at bare ground.”

For only the second time in its 43 year history, the start of the Iditarod has had to be moved away from close to Anchorage to near the city of Fairbanks, 360 miles further north.

“The Arctic environment is changing extremely rapidly. It is time for the rest of the world to take notice, and also to take action . . .”

Although there was more snow for last year’s race, several competitors were forced out through injuries sustained after encountering bare rocks and gravel on the course.

Alaska has been feeling the multiple impacts of climate change for some time. Coastal erosion is increasing as protective sea ice along the shoreline is being lost, and roads built across the state’s permafrost have fractured or collapsed due to ice melt. Other infrastructure, including oil and gas pipelines, is under threat.

Cracks in permafrost

Homes have collapsed due to cracks opening in the permafrost beneath them. And people are being forced to abandon traditional hunting practices due to changes in wildlife distribution brought about by changes in temperature.

At the end of last year, more than 35,000 walruses were found crowded together on a beach in northeast Alaska.

“Due to loss of ice in offshore areas, walruses are foraging in more coastal areas and using beaches for resting,” said a report by the National Oceanic and Atmospheric Administration.

“The walruses are telling us what the polar bears have told us and what many indigenous people have told us in the Artic,” Margaret Williams, the head of the World Wildlife Fund’s Arctic programme, told the Associated Press news agency. “And that is that the Arctic environment is changing extremely rapidly.

“It is time for the rest of the world to take notice, and also to take action to address the root cause of climate change.” – Climate News Network

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Arctic melting opens sea route to more pollution

Arctic melting opens sea route to more pollution

Increasing loss of Arctic sea ice is likely soon to mean more ships being able to use the polar passage affecting climate, health and air quality.

LONDON, 14 February, 2015 − As Arctic sea ice continues to melt at an alarming rate, maritime traffic is set to increase − and with it the pollution emitted by ships’ engines.

A paper published by the International Council on Clean Transportation (ICCT) says emissions of pollutants from vessels in the US area of the high Arctic could increase by between 150% and 600% by 2025.

Ships typically burn bunker fuel with a high sulphur content. As well as various greenhouse gases (GHGs), the engines also emit soot, or black carbon. And when this covers snow and ice, it reduces their ability to reflect sunlight away from the Earth, and so raises temperatures.

Human health

The ICCT paper says ship-borne pollutants − which include carbon dioxide, nitrous oxide (NOX), oxides of sulphur, particulate matter (PM) and soot − affect local air quality and human health, as well as the global climate.

Without new pollution controls, it is estimated that global soot emissions from shipping may more than quintuple from 2004 to 2050, to a total of more than 744,000 tonnes, because of increased shipping demand.

A growing share of those emissions will occur in the Arctic, because of vessels being diverted to the much shorter Northwest Passage and Northeast Passage to cut the length of voyages.

Earlier studies of increased shipping in the Arctic concentrated on infrastructure needs and estimates of shipping growth, based on potential oil and gas exploration and other development, but did not address air pollution or its effects.

The paper says: “The potential increases in vessel activity associated with oil and gas exploration . . . would increase emissions from vessels beyond those estimated in this paper.”

It also says that a change to higher quality low-sulphur fuel would cut pollution significantly.

“The lack of regional restrictions in the Arctic leaves the area vulnerable to increasing emissions from international traffic . . .”

Mark Jacobson, professor of civil and environmental engineering at Stanford University, US, advised as long ago as 2011 that controlling soot could reduce warming in the Arctic by about 2°C within 15 years.

“That would virtually erase all of the warming that has occurred in the Arctic during the last 100 years,” he said. “No other measure could have such an immediate effect.”

He said soot emissions were second only to carbon dioxide in promoting global warming, accounting for about 17% of the extra heat. But its contribution could be cut by 90% in five to 10 years with aggressive national and international policies.

The International Maritime Organisation (IMO], a UN body, said in the final report of its GHG Study 2014 that, by 2050, emissions of NOX could increase globally by as much as 300%, and PM by 280%.

The IMO has two sets of emission and fuel quality requirements, one for global shipping and the other a more stringent set of rules for ships in Emission Control Areas.

The global requirements include a limit on marine bunker fuel sulphur content, which is currently 3.5%, compared with an actual global average of 2.7%. This limit is due to be cut to 0.5% in 2020, although parts of the shipping industry are urging the IMO to delay the reduction until at least 2025.

International regulations do not directly restrict the emission of soot from vessels, although it is generally understood that improving fuel quality also controls soot.

Increasing impact

The ICCT paper says that, combined with the potential increases in marine emissions, “the current lack of regional environmental requirements for vessels transiting and operating in the US Arctic may lead to an increasing impact on human health for Arctic communities and for the global climate.

“Additional emissions of climate-forcing pollutants such as black carbon and carbon dioxide, combined with emissions of PM and NOX, which can be linked with respiratory health issues, may place additional stress on the Arctic environment and Arctic communities.

“The lack of regional restrictions in the Arctic leaves the area vulnerable to increasing emissions from international traffic that is less tightly regulated than under US law.”

There have also been calls to find alternatives to the many diesel generators currently in use throughout Arctic communities, and which are known to produce large amounts of greenhouse gases and soot. − Climate News Network

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Growing concern over Iceland’s rising landmass

Growing concern over Iceland’s rising landmass

Satellite data confirms a global warming link between the melting of icecaps and an accelerating increase in the height of Icelandic hills.

LONDON, 10 February, 2015 − Iceland is certainly going up in the world − but that’s not necessarily good news. As the ice melts and glaciers retreat, the mantle below the crust of the Atlantic island has responded, and the ice-capped hills are rising by an average of 30mm a year.

And scientists says that their analysis of precision data from a network of satellite stations indicates that this uplift is accelerating by one or two millimetres a year.

Isostasy is not a new idea. Geologists have known for more than a century that the rigid plates of the Earth’s crust − the lithosphere − ride on a viscous, springy mantle called the asthenosphere.

As crustal mass is lost – the erosion of mountains, for instance, or the retreat of Ice Age glaciers – the asthenosphere responds, and the landmass rises. Similarly, when a volcanic cone is built by a series of rapid eruptions, the asthenosphere below starts to respond to the new burden by sinking.

Heaving and sinking

The principle is well established, and there is geological evidence of this slow heaving and sinking everywhere. But nobody had expected to be able to measure it as it happens.

Kathleen Compton,  of the University of Arizona’s Department of Geosciences, and colleagues report in Geophysical Research Letters that they used a network of 62 global positioning satellite stations to measure ground movements with exquisite accuracy.

They chose a set of stable icecaps away from the more active volcanic zones, to eliminate the heaving and sighing of the bedrock that is connected with eruption. Enough data was available from early installations of GPS stations to confirm that uplift from the end of the last ice age about 9,000 years ago was more or less at an end.

“What we’re observing is climatically-induced change in the Earth’s surface”

A glacier year that began in October and ended in September was chosen, so that measurements would not be confused by spring melting or early snowfall.

In the last 30 years, the world has warmed and the high latitudes of the northern hemisphere have warmed the fastest. The Arctic melting season has been advancing at the rate of about 17 days a decade.

The researchers’ measurements show that uplift began about 30 years ago, with some sites in Iceland now rising at 35mm a year. And this rate is increasing.

“Our research makes the connection between recent accelerated uplift and the accelerated melting of the Icelandic ice caps,” said Compton, a doctoral student.

“Iceland is the first place we can say accelerated uplift means accelerated ice loss,” said her co-author, associate professor Richard Bennett. “What we’re observing is climatically-induced change in the Earth’s surface.”

Volcanic activity

There is a tantalising possibility that they may also be observing a change in volcanic activity. Geological evidence suggests that, as the glaciers began to retreat 12,000 years ago, Iceland’s eruptions increased thirty-fold.

Other researchers have raised the possibility that warming-induced ice loss could increase the frequency of eruptions now.

But the Arizona team simply wanted to establish a connection between the rate of melting and the rate of uplift, and used mathematical models to confirm the coupling.

Dr Bennett says: “There’s no way to explain that accelerated uplift unless the glacier is disappearing at an accelerating rate.” – Climate News Network

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