Unlimited emissions would result in ice-free Antarctica

Unlimited emissions would result in ice-free Antarctica

Scientists warn that burning up the planet’s remaining fossil fuel would cause all Antarctic ice to melt and lead to devastating sea level rise.

LONDON, 15 September, 2015 – German and US scientists have worked out how to melt almost all the ice in Antarctica, raise sea levels by up to 60 metres, and flood cities that are now home to more than a billion people.

The answer is simple: just burn all the planet’s remaining fossil fuel resources, which would pump another 10,000 billion tons of carbon into the atmosphere in the form of the greenhouse gas, carbon dioxide.

The West Antarctic ice sheet would become unstable by the end of the century, although it might take another 10,000 years to melt the much larger East Antarctic sheet.

But the release of carbon on such a scale would mean that sea levels could rise by three metres a century − and once the planet’s average temperatures had risen beyond 2°C, the process might be impossible to stop, according to a study published in the journal Science Advances.

Much larger loss

“Our findings show that if we do not want to melt Antarctica, we can’t keep taking fossil fuel carbon out of the ground and just dumping it into the atmosphere as CO2, like we’ve been doing,” says one of the report’s authors, Ken Caldeira, an atmospheric scientist at Stanford University’s Carnegie Institution for Science, California .

“Most previous studies have focused on the loss of the West Antarctic ice sheet. Our study demonstrates that burning coal, oil and gas also risks loss of the much larger East Antarctic ice sheet.”

Chart of how Antarctic ice would be affected by different emissions scenarios (GTC = gigatons of carbon). Image: Ken Caldeira and Ricarda Winkelmann

How Antarctic ice would be affected by different emissions scenarios (GTC = gigatons of carbon).     Image: Ken Caldeira and Ricarda Winkelmann

The report’s lead author, Ricarda Winkelmann, climate system analyst at the Potsdam Institute for Climate Impact Research, says such action would cause global sea level rise on a scale unprecedented in human history.

“This would not happen overnight,” she says, “but the mind-boggling point is that our actions today are changing the face of planet Earth as we know it, and will continue to do so for tens of thousands of years to come.”

The study, although led by German scientists, started in Professor Caldeira’s global ecology lab in the US, and in every sense bears his signature. It takes a big, simple idea, strips away all the difficult short-term questions, and follows it to a logical conclusion.

“The mind-boggling point is that our actions today are changing the face of planet Earth
as we know it, and will continue to do so
for tens of thousands of years”

People working with Caldeira in the last two years have settled a number of such big and never-before-asked questions − for instance, whether geo-engineering could save the Arctic ice cap (it would not) or whether treating the ocean as a renewable energy source would actually accelerate global warming (it would).

The same style of thinking has established that it could take just 45 days for the heat from released carbon dioxide to outpace the initial combustion that released it, and that at current fossil fuel emission rates, all the ocean’s coral reefs would be at risk within this century.

The bottom line of the latest research is that unrestrained fossil fuel burning could cause extreme sea level rise over the next thousand years, and put crowded mega-cities such as New York, Tokyo, London, Shanghai and Calcutta at serious risk.

Complex calculation

The timing is no great surprise: the world’s political leaders will gather at the UN climate change conference in Paris in December to decide on an international programme to limit global warming.

But though the question the scientists asked themselves is a simple one, it still involved some complex calculation.

“It is much easier to predict that an ice cube in a warming room is going to melt eventually than it is to say precisely how quickly it will vanish,” Dr Winkelmann says.

“Our results show that the currently attainable carbon resources are sufficient to eliminate the Antarctic ice sheet, and that major coastal cities are threatened at much lower amounts of cumulative emissions.

“In a world beyond two degrees, long-term sea level rise would likely be dominated by ice loss from Antarctica.” – Climate News Network

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Clean energy plans may increase toxins in plankton

Clean energy plans may increase toxins in plankton

Environmental assessment of a proposed hydroelectric dam in Canada sheds new light on the cause of high levels of a potent neurotoxin in Arctic marine life.

LONDON, 10 September, 2015 – Scientists in the US think they may now have the explanation to a conundrum that has puzzled them for a long time − why there are high levels of methylmercury, which can damage the nervous system, in Arctic marine life.

The answer, they report, appears to be one of those examples of worsening a problem by trying to solve it: human attempts to mitigate climate change have inadvertently altered the eating habits of Arctic plankton.

Researchers from the Harvard John A.Paulson School of Engineering and Applied Science and Harvard T.H. Chan School of Public Health suggest in the Proceedings of the National Academy of Sciences that the high levels of methylmercury, a potent neurotoxin, are a byproduct of global warming and the melting of sea ice in Arctic and sub-Arctic regions.

To tackle global warming, many governments are turning to hydro-electric power to replace fossil fuels.

Impact review

This latest research was part of a review of the environmental impact assessment for the Muskrat Falls hydroelectric dam in Labrador, Canada, which in 2017 will flood a large region upstream from an estuarine fjord called Lake Melville. The communities along the shores of Lake Melville are predominantly indigenous and rely on the lake for much of their food.

The researchers spent 10 days criss-crossing the lake to measure baseline methylmercury levels. They found that concentrations in the plankton peaked between one and 10 metres below the surface, closely matching findings from the central Arctic Ocean.

When fresh and salt water meet – in estuaries, or when sea ice melts in the ocean – salinity increases as water deepens, allowing organic matter − which typically sinks to the bottom − to reach a neutral buoyancy so that it cannot float either up or down in the water.

“Scientists have a responsibility to understand and explain how environmental systems
will react before they are modified”

This layer collects other small pieces of debris and concentrates them into a feeding zone for marine plankton. The bacteria stuck in this zone then complete a complex chemical process that turns naturally-occurring mercury into dangerous and readily-accumulated methylmercury.

Plankton in the Arctic and sub-Arctic are not choosy eaters: once in the debris layer, they go on a feeding frenzy that can last several weeks. The methylmercury they produce accumulates in other organisms and magnifies as it works its way up the food chain.

Amina Schartup, a biogeochemist at Harvard and lead author of the paper, says: “This system is incredibly efficient at accumulating methylmercury.” She adds that the same system is mirrored in the Arctic, where fresh water from melting ice mixes with salt water.

To find out what happens when methylmercury levels increase because of reservoir flooding upstream, the researchers collected soil cores from the inland areas due to be flooded in 2017 for the hydro-electric plant.

Simulated flooding

The team simulated flooding by covering the cores with river water. And, within five days, mercury levels in the water covering the cores increased 14-fold.

One of the communities along the shores of Lake Melville – and two-thirds of the lake itself – is part of Nunatsiavut, the first autonomous region in Canada governed by Inuit.

“Any kind of contamination is going to disrupt how we live as Inuit and impact our health and lifestyle,” says Sarah Leo, president of the Nunatsiavut government.

“We need more research to understand the downstream effects, and we need to develop strategies to mitigate those effects. How are we, as a community, going to adjust our lifestyle if we can no longer live off the land? These are all questions we need answered before flooding.”

Schartup says: “Scientists have a responsibility to understand and explain how environmental systems will react before they are modified, because once the damage is done, you can’t take it back.” – Climate News Network

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Hi-tech analysis pinpoints Antarctic ice sheet dangers

Hi-tech analysis pinpoints Antarctic ice sheet dangers

Precision mapping of West Antarctica’s melting glaciers could help climate scientists to predict potentially calamitous effects on sea levels.

LONDON, 25 August, 2015 – Scientists have used high-resolution computing techniques to calculate the future of the West Antarctic ice sheet over the next two or three centuries.

The West Antarctic peninsula right now is about the fastest-warming place on Earth. And, in the worst case scenario, glaciers will retreat by hundreds of kilometres, and seas will rise everywhere.

An estimated 80,000 cubic kilometres of ice could flow into the sea by 2100, and by 2200 this could rise to 200,000 cubic kilometres. By the end of this century, sea levels could have risen by 20cms, and 50cms by 2200.

This is an extreme case, but the forecasts for West Antarctica’s glaciers have been consistently alarming. In the last two years, scientists have confirmed that the rates of melt and retreat have accelerated, and that, under the combined effects of warmer air and sea, this melting may be irreversible.

Vulnerable mass

Stephen Cornford, a researcher at the School of Geographical Sciences at the University of Bristol in the UK, and colleagues report in the European Geosciences Union journal The Cryosphere that their chief concern was to help climate science by fixing with greater precision the things that might happen to the most vulnerable mass of ice on the frozen continent.

The new study tests a range of climate predictions in greater detail than before, over a greater area, and a longer period of time. But the uncertainties remain. Will human-induced greenhouse gas levels continue to rise? How will the oceans respond? What will be the consequences for snowfall south of the Antarctic Circle?

“Other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently”

So the study looks at all the possibilities in more detail, and the pay-off could be more confident predictions of climate change as the circumstances begin to change.

Dr Cornford says: “We expect future change in the West Antarctic ice sheet to be dominated by thinning in the Amundsen Sea Embayment, just as it is today, until at least the 22nd century. But other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently.”

A computer-generated map of the projected glacial retreat in the Amundsen Sea Embayment by 2154. Image: S.Cornford et al/The Cryosphere

A computer-generated map of the projected glacial retreat in the Amundsen Sea Embayment by 2154.
Image: S.Cornford et al/The Cryosphere

Serious consequences

The worst-case predictions are disconcerting, and could have serious consequences for the hundreds of millions of people who live in cities and on productive land at or near sea level – for instance on the Nile Delta or in Bangladesh – or even below sea level, protected by sea walls, such as in the Netherlands.

But they remain just that: worst case predictions. The scientists were not concerned with establishing probabilities for any scenario, just with employing complex mathematical techniques to extend climate models.

The chief aim of the study has been to find ways of making sense of all possibilities − from no change to calamitous change − in the factors that govern glacier loss.

Co-author Dan Martin, a computational scientist at the Lawrence Berkeley National Laboratory in California, says: “Much like a higher-resolution digital camera transforms a blur into a flock of birds, higher resolution in a computer model often helps to capture details of the physics involved, which may be crucial to the broad picture.” – Climate News Network

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Central Asia’s glaciers may lose half their ice by mid-century

Central Asia’s glaciers may lose half their ice by mid-century

The speed at which the warming climate is melting glaciers in Central Asia may ruin the water supply of millions of people within 50 years.

LONDON, 22 August, 2015 – Glaciers in the largest mountain range in Central Asia, the Tien Shan, have lost over a quarter of their mass in the last 50 years, and nearly a fifth of their area.

An international team of researchers estimates that since the 1960s the glaciers have shrunk by almost 3,000 square kilometres, losing an average of 60 sq km of ice annually.

The Tien Shan reach almost 7,500 metres (24,500 feet) in height, and are a vital reservoir for the countries through which they pass – China, Kazakhstan, Kyrgyzstan and Uzbekistan.

The team, from the GFZ German Research Centre for Geosciences and France’s National Centre for Scientific Research (CNRS), report in the current online issue of Nature Geoscience that about half of the mountains’ glacier volume could be depleted by the 2050s.

The researchers say the Tien Shan (which in Chinese means “the celestial mountains”) have lost 27% of their mass and 18% of their area since 1960.

Glaciers worldwide are melting at unprecedented rates, which is serious because they are often irreplaceable sources of drinking water, hydropower and irrigation. The Tien Shan are no different.

Long-term storage

The mountains form a vital part of Central Asia’s water cycle. Snow and glacier melt from the Tien Shan is essential for the water supply of the four countries they traverse.

“Despite this importance, only a little was known about how glaciers in this region changed over the last century,” says the principal investigator, Daniel Farinotti. Most of the direct monitoring programmes, which were closed with the end of the Soviet Union, have been resumed only recently.

Farinotti, from GFZ, and his colleagues have completed a reconstruction of the glaciers’ evolution in the Tien Shan. “We combined various methods based on satellite gravimetry, laser altimetry and glaciological modelling”, he says.

This let them plot the evolution of every single glacier. They came up with some surprising findings: currently, the range is losing ice at a pace that equals roughly double the annual water consumption of the whole of Germany.

Glaciers can store water as ice for decades, transferring winter snow and rainfall to the summer months by releasing it as meltwater. This is particularly important in seasonally arid regions which have months with virtually no precipitation. Their local water supply depends on meltwater availability, as Central Asia knows from experience.

Increased temperature contributes to both increased melt and reduced glacier nourishment”

Many people in Central Asia depend on water seasonally impounded by the glaciers of the Tien Shan, not only for water itself but for hydro-electricity and for food.

The pace of glacier retreat in the Tien Shan accelerated noticeably in the decade from the 1970s. Daniel Farinotti says: “The long-term signal is clearly related to the overall rise in temperature”. The study shows that the rise in temperature, and summer temperature in particular, is a primary influence on the region’s glaciers.

“Since the winter months in Central Asia are very dry and the mountains are that high, glaciers receive most of their snowfall during the summer”, Farinotti explains. “This means that an increased temperature contributes to both increased melt and reduced glacier nourishment – and obviously, both contribute to glacier wastage.”

Using the latest climate projections, which expect an additional 2°C of warming in summer temperatures between 2021 and 2050, the authors suggest what the mountains’ future evolution may look like. Half of the total glacier ice volume of the Tien Shan today could be lost by the 2050s, they believe. – Climate News Network

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Global glacier melt reaches record levels

Global glacier melt reaches record levels

Scientists say tens of thousands of glaciers are melting faster than ever − and many will continue to do so even if climate change can be stabilised.

LONDON, 5 August, 2015 – The world’s glaciers are melting fast − probably faster than at any time in recorded history, according to new research.

Measurements show several hundred glaciers are losing between half and one metre of thickness every year − at least twice the average loss for the 20th century − and remote monitoring shows this rate of melting is far more widespread.

The World Glacier Monitoring Service (WGMS), based at the University of Zurich, Switzerland, has compiled worldwide data on glacier changes for more than 120 years.

Drawing on reports from its observers in more than 30 countries, it has published in the Journal of Glaciology a comprehensive analysis of global glacier changes.

Pictorial sources

The study compares observations of the first decade of this century with all available earlier data from field, airborne and satellite observations, and with reconstructions from pictorial and written sources.

Dr Michael Zemp, director of WGMS and lead author of the study, says the current annual loss of 0.5-1 metre of ice thickness observed on “a few hundred glaciers” through direct measurement is two to three times more than the average for the last century.

Evidence of how much the Rhone glacier in the Swiss Alps receded between 2007 (above) and 2014. Images: Simon Oberli

Evidence of how much the Rhone glacier in the Swiss Alps receded between 2007 (above) and 2014. Images: Simon Oberli


“However, these results are qualitatively confirmed from field and satellite-based observations for tens of thousands of glaciers around the world,” he adds.

The WGMS compiles the results of worldwide glacier observations in annual calls-for-data. The current database contains more than 5,000 measurements of glacier volume and mass changes since 1850, and more than 42,000 front variations from observations and reconstructions stretching back to the 16th century.

Intense ice loss of the last two decades has resulted in a strong imbalance of glaciers
in many regions of the world

Glaciers provide drinking water for millions of people, as well as irrigating crops and providing hydropower. When they melt, they also make a measurable contribution to sea level rise.

The researchers say the current rate of glacier melt is without precedent at the global scale − at least for the time period observed, and probably also for recorded history, as reconstructions from written and illustrated documents attest.

Long-term retreat

The study also shows that the long-term retreat of glacier tongues is a global phenomenon. Intermittent re-advance periods at regional and decadal scales are normally restricted to a smaller sample of glaciers and have not come close to achieving the Little Ice Age maximum positions reached between the 16th and 19th centuries.

Glacier tongues in Norway, for example, have retreated by some kilometres from their maximum extents in the 19th century. The intermittent re-advances of the 1990s were restricted to glaciers in coastal areas, and to a few hundred metres.

The study shows that the intense ice loss of the last two decades has resulted in what it calls “a strong imbalance of glaciers in many regions of the world”. And Dr Zemp warns: “These glaciers will suffer further ice loss, even if climate remains stable.”

He told Climate News Network: “Due to the strong ice loss over the past few decades, many glaciers are too big under current climatic conditions. They simply have not had enough time to react to the climatic changes of the past.

“So they will have to retreat further until they are in balance with climatic conditions again. In the European Alps, many glaciers would lose about 50% of their present surface area without further climate change.” – Climate News Network

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Arctic’s melting ice shrinks shipping routes

Arctic’s melting ice shrinks shipping routes

The opening up of waters north of Siberia as Arctic ice melts will change world trade patterns by cutting a third off distances between north-west Europe and the Far East.

LONDON, 4 August, 2015 – The disappearing Arctic ice cap will boost trade between north-west Europe and countries such as China, Japan and South Korea by making the sea routes far shorter, according to economic analysts.

The new sea route will alter world trade, making northern countries richer, but causing serious problems for Egypt, which will lose a large chunk of revenue currently gained from ships coming through the Suez Canal.

One advantage to the environment − according to a discussion paper from the Netherlands Bureau for Economic Policy Analysis − is that ships will burn far less fossil fuel to reach their destination.

However, this gain will be offset when the volume of trade increases because of the shorter sea route, making climate change slightly worse.

Open all year

The northern sea route is already open in the summer months, but the paper predicts that it will be available all year round by 2030, or possibly sooner. It says that Arctic ice is melting faster than predicted by scientists.

To police the new route, the Russian government has already formed a federal state institution and is building 10 “relief ports” along the Siberian coastline for ships that might need repairs or supplies. China has signed a free trade agreement with Iceland in anticipation of regularly using the route.

The paper estimates that trade between north-west Europe and China, Japan and Korea will increase by 10% as a result of the opening of the route, but that this will happen gradually.

The northern route will become one of the busiest shipping lanes in the world, increasing the economic and political importance of the Arctic

Since 90% of world trade by volume is carried by ship, the distance between ports is a vital consideration. The northern route reduces the distance from Japan to north European countries by 37%, from South Korea by 31%, China 23%, and Taiwan 17%.

The advantage of shorter distances applies only to countries in northern East Asia. For countries south of the equator, such as Singapore and Indonesia, the southern route via Suez is still shorter.

Similarly, southern European countries do not gain because they remain roughly the same distance away from their trading partners whichever route they use.

The countries in Europe that will gain most from the new sea route are those with access to ports on the North Sea and the Baltic. These include Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, Germany, Ireland, Latvia, the Netherlands, Poland, Slovakia, Sweden, the UK and Norway.

Drop in trade

Some countries in eastern and southern Europe would experience a drop in trade because of the comparatively longer distances their exports and imports would need to travel, according to the report. These include Bulgaria, Croatia, Hungary, Italy, Romania and Slovenia.

The report says that roughly 8% of world trade goes through the Suez Canal, and that two-thirds of this volume will go via the shorter Arctic route. The northern route will become one of the busiest shipping lanes in the world, increasing the economic and political importance of the Arctic.

At the same time, it will put huge economic pressure on Egypt and Singapore, who rely heavily on shipping using the southern route.

Over time, the opening of the Arctic route will have knock-on effects on jobs and prosperity in all the countries concerned, but it is predicted that this will be a gradual rather than sudden process. – Climate News Network

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Half of climate safety level has gone

Half of climate safety level has gone

Global temperatures have risen by 1°C in the past 150 years, and one scientist says doubling that level could unleash catastrophic sea level rise this century.

LONDON, 2 August, 2015 – The world is now halfway towards the internationally-agreed safety limit of a maximum 2°C rise in global average temperatures, researchers say.

That limit seeks to prevent the global warming caused by the burning of fossil fuels exceeding 2°C above the pre-industrial global temperature. The UN’s Paris climate summit later this year aims to ensure that it is not breached.

It appears that the human race has taken roughly 250 years to stoke global warming by 1°C. On present trends, we look likely to add the next 1°C far more quickly – across much of the world, many climate scientists believe, by the middle of this century.

The research is published in the journal New Scientist, which commissioned it. As so often with climate projections, it needs qualifying and teasing apart.

Some scientists, for example, warn that there’s uncertainty about just what the pre-industrial global temperature was. The New Scientist research is careful to be specific: it says global surface temperature is now passing 1°C of warming relative to the second half of the 19th century.

Farewell, hiatus

And one of the four main trackers of temperature thinks that milestone will be passed only if there is a strong El Niño, the cyclic Pacific weather phenomenon that periodically brings widespread chaos in its wake.

However, the research looks likely finally to lay to rest the argument that global warming is slowing and stuttering to a virtual halt, the so-called hiatus theory. Kevin Trenberth, of the US National Center for Atmospheric Research in Boulder, Colorado, told New Scientist: There’s a good chance the hiatus is over.”

The hottest year since records began was by a very small margin – 2014, and this year’s El Niño could mean a temperature rise of 0.1°C this year, an increase which usually takes about a decade to develop. Dr Trenberth thinks 2015 is likely also to be a record-breaker. 

Between 1984 and 1998 the Earth warmed at 0.26°C a decade, but the Intergovernmental Panel on Climate Change (IPCC)  says the rate then fell back until 2012 to about 0.04°C, for a number of reasons, including a less active Sun, more cooling aerosols from volcanoes and Asian factories, and more heat being absorbed by the oceans. The New Scientist findings suggest that warming may soon revert to the higher rate. 

From a quite different source comes a warning not only that temperatures may soon start a marked rise, but that sea level may also accelerate far faster than most scientists think likely.

It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable”

The prospect it holds out is at odds with most mainstream climate science, and might well be discounted as alarmist and fanciful. But the lead author of the discussion paper in which it appears is the highly respected James Hansen, former director of NASA’s Goddard Institute for Space Studies.

He and his colleagues say the ice melting around Greenland and Antarctica will cause sea level rises much faster than mainstream predictions suggest, by several metres this century. This will add to a process which they say has already begun, accelerating the melting of the undersides of Antarctic glaciers and ice shelves.

Another consequence, they think, will be the shutting down of ocean currents which carry heat from the tropics to the polar regions, leaving the tropics to warm fast and the high latitudes to cool. This temperature difference, they say, will spawn superstorms unlike any seen so far.

All this, Professor Hansen and his colleagues say, could happen with a 2°C temperature rise, with devastating consequences: It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilisation.”

Professor Hansen may of course be wrong, but it would be short-sighted to assume that he is. He has a strong record of ultimately being proved right. Climate News Network

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Global warming’s record-breaking trend continues

Global warming’s record-breaking trend continues

Detailed update by hundreds of scientists on climate indicators in 2014 reveals highest recorded rises in temperatures, sea levels and greenhouse gases.

LONDON, 22 July, 2015 – Forget talk of a slowdown in global warming. Scientists say the climate is heading smartly in the opposite direction, with 2014 proving to be a record-breaking year.

The US National Oceanic and Atmospheric Administration (NOAA), one of the most respected sources of climate science, says that last year “the most essential indicators of Earth’s changing climate continued to reflect trends of a warming planet”. Some − including rising land and ocean temperatures, sea levels and greenhouse gases − reached record highs.

The authoritative report by the NOAA’s Centre for Weather and Climate at the National Centres for Environmental Information (NCEI), published by the American Meterological Society, draws on contributions from 413 scientists in 58 countries to provide a detailed update on global climate indicators.

“The variety of indicators shows us how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere,” says Thomas R. Karl, director of the NCEI.

Rising concentrations

The authors report that concentrations of greenhouse gases continued to climb during the year. Atmospheric carbon dioxide concentrations rose by 1.9 parts per million (ppm), reaching a global average of 397.2 ppm for the year. This compares with a global average of 354ppm in 1990 when the first edition of this report was published. And levels of methane and nitrous oxide also went up.

“Variety of indicators shows how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere”

Four independent global datasets showed that 2014 was the warmest year on record, with the warmth widespread across land areas.

Europe experienced its warmest year; Africa had above-average temperatures across most of the continent throughout 2014; Australia recorded its third warmest year; and Mexico had its warmest. Eastern North America was the only major region to experience below-average annual temperatures.

Global average sea level rose to a record high, and the globally averaged sea surface temperature was also the highest recorded. The warmth was particularly notable in the North Pacific Ocean, where temperatures are in part probably driven by a transition of the Pacific decadal oscillation – a recurring pattern of ocean-atmosphere climate variability centred in the region.

Earlier snow melt

The Arctic continued to warm, and sea ice extent remained low. Arctic snow melt occurred 20–30 days earlier than the 1998–2010 average. On the North Slope of Alaska, record high temperatures at a 20-metre depth were measured at four of five permafrost observatories. The eight lowest minimum sea ice extents during this period have occurred in the last eight years.

But temperature patterns across the Antarctic showed strong seasonal and regional patterns of warmer-than-normal and cooler-than-normal conditions, resulting in near-average conditions for the year for the continent as a whole. Last year was the third consecutive year of record maximum sea ice extent in the Antarctic.

The El Niño-Southern Oscillation (ENSO), a periodic warming of the water in the central and eastern Pacific that disrupts weather over thousands of miles, was in a neutral state during 2014, although it was on the cool side of neutral at the beginning of the year and approached warm El Niño conditions by the end of the year. This pattern played a major role in several regional climate outcomes.

There were 91 tropical cyclones in 2014, well above the 1981-2010 average of 82 storms. But the North Atlantic season, as in 2013, was quieter than most years of the last two decades with respect to the number of storms. – Climate News Network

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Melting sea ice means shortage of bear necessities

Melting sea ice means shortage of bear necessities

Researchers explode theory that polar bears can use hibernation techniques to last without food as climate change reduces their summertime hunting habitat.

LONDON, 20 July, 2015 – Global warming is likely to leave the polar bear high and dry and very hungry as increasing loss of sea ice reduces the hunting grounds of the Arctic’s top predator.

Researchers have established that while Ursus maritimus can survive for months without eating during winter hibernation, in the summertime it is not much better at going without food than any other mammal.

The polar bear is capable of shutting its own metabolism down to astonishingly low levels during hibernation and, until now, zoologists have surmised that the bear could minimise energy losses by entering a hibernation-like state when deprived of food.

But John Whiteman, a doctoral student in ecology, zoology and physiology at the University of Wyoming, and colleagues report in Science journal that that theory is wrong. Once they are up and hunting, bears need food.

Energy expenditure

“We report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, non-hibernating mammals,” they write.

As carbon dioxide levels in the atmosphere creep up, as a consequence of the human combustion of fossil fuels, so Arctic temperatures have on average risen.

The loss of sea ice in the Arctic has, over the last decade, happened even faster than climate scientists predicted, which creates problems for bears that need to hunt and gorge on high-calorie diets in preparation for the winter.

The polar bear hunts on the ice, and its preferred diet is the blubber-rich flesh of seals and small whales. On shore, it must forage for scraps, berries and small mammals while waiting for the seas to freeze again.

“Polar bears appear unable to meaningfully prolong their reliance on stored energy”

But Arctic summers have stayed milder for longer, and the areas of summer sea ice have steadily dwindled. So the bears have spent increasing periods without their preferred diet.

The orthodoxy had been that bears, while waiting for the first freeze, had been able to enter a state called “walking hibernation”. Whiteman and his fellow researchers took a closer look.

With help from government agencies, a US coastguard icebreaker, helicopter pilots and a large number of other people, they captured two dozen polar bears, fitted satellite collars, and implanted little devices that recorded body temperature and tracked their movements on shore and on ice in the Beaufort Sea, north of Alaska and Canada, between 2008 and 2010.

Core temperature

They found that the bears could do something physiologically clever to keep warm while swimming – they could temporarily cool their outermost skin layers to insulate their inner selves and keep their core body temperatures at a healthy level, and one bear was reported to have survived a nine-day swim from shore to ice.

But they also found that the bears were not much better than other mammals at walking around on dry land, looking for food that wasn’t there.

“We found that polar bears appear unable to meaningfully prolong their reliance on stored energy, confirming their vulnerability to lost hunting opportunities on the sea ice − even as they surprised us by also exhibiting an unusual ability to minimise heat loss while swimming in Arctic waters,” Whiteman says.

The evidence, however, suggested that “walking hibernation” didn’t actually exist. The researchers conclude that the bears “are unlikely to avoid deleterious loss in body condition, and ultimately survival, that are expected with continuous ice loss and lengthening of the ice-melt period”. – Climate News Network

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Too few specialists to track loss of Himalayan glaciers

Too few specialists to track loss of Himalayan glaciers

Millions of people rely on meltwater from the Himalayas, but lack of expertise and manpower is hampering the study of climate change impacts.

DELHI, 11 July, 2015 − Studying ice loss in the vast, inhospitable region of the Himalayas can be a very tricky business as most glaciers are found above 12,000 feet.

While much of the data is derived from satellite surveys, reliable field data is also vital − but skill shortages mean that only four of the approximately 9,500 glaciers spread across the Indian section of the Himalayas are being studied in detail.

Gathering field data involves a combination of skills that include high-altitude mountaineering. Weather restricts such work to about four months of the year, and there is also the constant danger of avalanches.

The mighty Gangotri glacier, in the far northwest of the country, is one of the four glaciers monitored in detail by field researchers.

Rapidly disintegrating

Recent studies indicate that the Gangotri, one of the Himalayas’ largest glaciers and a primary source of the Ganges, is rapidly disintegrating. Nearly 30 kilometres long and between 0.5 and 2.5km wide, it is at present retreating by between 12 and 13 metres a year.

To analyse the impacts of climate change, and to predict what will happen in the future in glacial regions, it is necessary to carry out what glaciologists refer to as surveys of mass balance – analysing the relative difference between the accumulation and melting of ice and snow on a glacier over a given period.

Collecting and interpreting data – from satellite imagery and from field surveys – is highly specialised. And Indian institutions say a big knowledge gap has developed, with only limited field data being collected and a lack of trained personnel available to interpret the results of remote sensing and other data.

A determined effort is now being made by several institutions to produce more trained glaciologists.

“There is evidence of changing climatic patterns leading to changing water flow patterns that
could have serious impacts”

The Indian government’s Department of Science and Technology is undertaking a project with the Swiss Agency for Development and Co-operation to train young scientists in glaciology as part of a Himalayan climate change and adaptation programme.

The Indian Space Research Organisation, which has been collecting satellite data on glaciers for many years, has a fully-fledged climate change department that is becoming more involved in monitoring glacier size and mass balance data.

The Divecha Centre for Climate Change, part of the prestigious Indian Institute of Science, is also combining studies of glaciology and climate change.

The generally accepted view is that the majority of glaciers in the Himalayas – an area often referred to as “The Third Pole”, due to its vast ice mass – are in retreat.

Reliable conclusions

Yet in some areas, such as the Karakoram Range in the west of the Himalayas, satellite data indicates that glaciers are advancing.

The International Centre for Integrated Mountain Development (ICIMOD), a regional organisation based in Nepal and specialising in the Himalayas/Hindu Kush region, says much more field work is needed to draw reliable conclusions about the extent of glacial loss across the Himalayas.

It points to data collected in Nepal and to studies in China that clearly show a decrease in glacial area. At the same time, fragmentation means that more smaller glaciers are being created.

The world should be concerned about glacial melt in the Himalayas, ICIMOD says, because “there is evidence of changing climatic patterns leading to changing water flow patterns that could have serious impacts”. − Climate News Network

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