Greenland’s hidden meltwater lakes store up trouble

Greenland’s hidden meltwater lakes store up trouble

Scientists find evidence of vast “storage tanks” of water deep below the melting Greenland ice sheet that could have a major effect on sea level rise.

LONDON, 5 February, 2015 − One small mystery that surrounds Greenland’s melting ice is a little closer to being solved as scientists in the US confirm that surface meltwater can drain all the way down to fill concealed lakes under the ice.

This means that atmospheric warming can reach thousands of metres below the ice sheet − warming the glacial base and potentially increasing its rate of flow.

One group, led by geologist Michael Willis, of Cornell University, and another team led by glaciologist Ian Howat, of Ohio State University, report in two different journals on separate but related studies of Greenland’s plumbing system: what happens to meltwater.

The ice sheet of Greenland adds up to about four-fifths of the mass of the vast frozen island, and there is evidence that, as a consequence of global warming, the rate of melting has begun to accelerate.

Measurable difference

This has already begun to make a measureable difference to global sea levels, and were the entire island to shed its burden of ice – a process that would take a considerable time − then sea levels would rise by seven metres or more.

So what exactly happens to the water that forms on the surface and collects in lakes each summer, and how much of it gets into the sea, has become an important but perplexing problem. Surface lakes are now appearing much further inland, and at higher altitudes, than recorded in the past.

Dr Howat and his colleagues report in The Cryosphere that they measured a two kilometre-wide depression 70 metres deep in the icecap of southwest Greenland, which they then identified as “the first direct evidence for concentrated long-term storage and sudden release of meltwater at the bed”.

The slumped crater suggested a holding capacity of more than 30 million cubic metres of water, which had suddenly drained away.

“If we are going to do something to mitigate sea level rise, we need to do it earlier rather than later”

“The fact that our lake appears to have been stable for at least several decades, and then drained in a matter of weeks – or less – after a few very hot summers, may signal a fundamental change happening to the ice sheet,” Dr Howat said.

The Cornell team worked in northeast Greenland, and in 2011 found a collapsed basin 70 metres deep. Dr Willis and colleagues report in Nature journal that between 2011 and 2014 they watched as summer meltwater made its way down fissures in the depression and refilled a lake basin at the base of the icecap. When this in turn emptied, the researchers calculated that the flow from the subglacial lake was at a rate of 215 cubic metres per second.

“We’re seeing surface meltwater make its way to the base of the ice where it can get trapped and stored at the boundary between the bedrock beneath the ice sheet and the ice itself,” they say.

“As the lake beneath the ice fills with surface meltwater, the heat released by this trapped meltwater can soften surrounding ice, which may eventually cause an increase in ice flow.”

Glacial flow

The researchers do not yet know whether the draining water is increasing glacial flow, and nor can they be sure how many such depressions in the Greenland ice mask buried meltwater storage tanks.

But melting of glacial ice is likely to accelerate anyway, according to new research in the journal Climate Dynamics.

Earth scientist Patrick Applegate, of Penn State University, reports that computer models confirm that the more temperatures increase, the faster the ice will melt.

Were all Greenland’s ice to melt, sea levels would rise catastrophically. At least one billion people live on coasts and estuaries vulnerable to a mere one metre rise.

The Arctic is already the fastest warming place in the northern hemisphere, and the Penn State scientists wanted to see how present warming could play back into future warming. Engineers call this positive feedback.

“If we are going to do something to mitigate sea level rise, we need to do it earlier rather than later,” Dr Applegate said. “The longer we wait, the more rapidly the changes will take place and the more difficult it will be to change.” − Climate News Network

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Arctic glacier’s galloping melt baffles scientists

Arctic glacier’s galloping melt baffles scientists

New satellite data analysis has produced evidence that rapid melting in the last three years has caused dramatic shrinkage of an Arctic ice cap.

LONDON, 31 January, 2015 – An ice cap in the high Arctic has lost what British scientists say is a significant amount of ice in an unusually short time.

It has thinned by more than 50 metres since 2012 – about one sixth of its original thickness – and the ice flow is now 25 times faster, accelerating to speeds of several kilometres per year.

Over the last two decades, thinning of the Austfonna ice cap in the Svalbard archipelago − , roughly half way between Norway and the North Pole − has spread more than 50km inland, to within 10km of the summit. .

A team led by the scientists from the UK Centre for Polar Observation and Modelling (CPOM) at the University of Leeds combined observations from eight satellite missions, including Sentinel-1A and CryoSat, with results from regional climate models, to understand what was happening.

Sea level rise

The study’s lead author, geophysicist Dr Mal McMillan, a member of the CPOM team, said: “These results provide a clear example of just how quickly ice caps can evolve, and highlight the challenges associated with making projections of their future contribution to sea level rise.”

The study, published in Geophysical Research Letters, is the first to make use of measurements from the European Space Agency’s latest Earth observation satellite, Sentinel-1A.

Dr McMillan said: “New satellites, such as the Sentinel-1A and CryoSat missions, are essential for enabling us to systematically monitor ice caps and ice sheets, and to better understand these remote polar environments.”

“Whether or not the warmer ocean water
and ice cap behaviour are directly linked
remains an unanswered question”

Melting ice caps and glaciers account for about a third of recent global sea level rise. Although scientists predict that they will continue to lose ice in the future, determining the exact amount is difficult, because of a lack of observations and the complex nature of how they interact with the climate around them.

The 20 years of satellite data that the scientists have amassed show some fairly small changes at the start of the study period, but these have since increased.

“Glacier surges, similar to what we have observed, are a well-known phenomenon”, said Professor Andrew Shepherd, the director of CPOM. “What we see here is unusual because it has developed over such a long period of time, and appears to have started when ice began to thin and accelerate at the coast.”

There is evidence that the surrounding ocean temperature has increased in recent years, which may have been the original trigger for the ice cap thinning.

Flow models

Prof Shepherd said: “Whether or not the warmer ocean water and ice cap behaviour are directly linked remains an unanswered question. Feeding the results into existing ice flow models may help us to shed light on the cause, and also improve predictions of global ice loss and sea level rise in the future.”

The team says long-term observations by satellites are the key to monitoring such climate-related phenomena.

Dr McMillan told Climate News Network he did not think what was happening in Austfonna suggested any sort of tipping point in the Arctic, which scientists say is warming more than twice as fast as anywhere else on Earth.

He said: “What I take from this work is that we don’t understand well enough what’s caused this sort of behaviour − natural variability, ocean temperatures or atmospheric temperatures. It reinforces the complexities and the challenges of the future.” – Climate News Network

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Scientists say rise in sea levels is faster than feared

Scientists say rise in sea levels is faster than feared

Harvard researchers find that there has been an almost threefold annual increase in global sea levels over the last quarter of a century.

LONDON, 22 January, 2015 − Sea level rise for most of the 20th century may have been over-estimated by as much as 30%. But the less welcome news is that, if that’s the case, then sea levels since 1990 have started to accelerate more sharply than anyone had ever expected.

Scientists at Harvard University, in the US, report in the journal Nature that they came to the conclusions after deciding that old data needed fresh analysis − using sophisticated mathematical filtering techniques for handling the uncertainties and gaps in such data.

Estimating and accounting for global mean sea level (GMSL) rise is critical to characterising current and future human-induced changes. The catch is that sea level measurement hasn’t been going on for very long, so not all measurement techniques have been the same. In addition, reliable, systematic and sustained sets of data are relatively sparse.

Rise and fall

The term “sea level” sounds pretty basic, but the oceans are hardly ever level. Tides swell and ebb, regions of sea rise and fall according to temperature and salinity, and the shorelines at which researchers take measurements can also go up because of tectonic movement or sink because of the abstraction of groundwater.

Measurements along some of the world’s great estuary systems can be skewed because of human interference over the decades with the flow downstream, and great tracts of ocean cannot be measured directly at all.

The challenge, then, is to arrive at an average sea level rise for the whole planet.

“We know that sea level is changing for a variety of reasons,” said Dr Carling Hay, post-doctoral fellow in Harvard’s Department of Earth and Planetary Sciences (EPS).

“There are ongoing effects due to the last ice age, heating and expansion of the ocean due to global warming, changes in ocean circulation, and present day melting of land-ice − all of which result in unique patterns of sea level change. These processes combine to produce the observed global mean sea level rise.”

So the Harvard scientists, working with colleagues from Rutgers University in New Jersey, made estimates for the meltwater from glaciers and dwindling ice caps, from ocean thermal expansion and factors. They then “smoothed” the data, using a mathematical modelling algorithm.

Earlier estimates put mean sea level rise in the 20th century at between 1.5 and 1.8 millimetres a year. Dr Hay and her colleagues now think that, between 1901 and 1990, the true figure was probably closer to 1.2mm a year.

But since 1990, global sea level has risen by 3mm a year on average. So, in fact, the acceleration since then has been faster than anybody expected – and this in turn could affect future projections.

Question of accuracy

“Another concern with this is that many efforts to project sea level change into the future use estimates of sea level rise over the time period from 1900 to 1990,” said co-author Eric Morrow, a recent Ph.D graduate of Harvard’s EPS

“If we’ve been over-estimating the sea level change during that period, it means that these models are not calibrated appropriately, and that calls into question the accuracy of projections out to the end of the century.”

Dr Hay added: “We expected that we would estimate the individual contributions, and that their sum would get us back to the 1.5 to 1.8mm a year that other people had predicted. But the math doesn’t work out that way.

“Unfortunately, our new lower rate of sea level rise prior to 1990 means that sea level acceleration that resulted in higher rates over the last 20 years is really much larger than anyone thought.” – Climate News Network

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Science gains from clearer sight of Greenland’s ice melt

Science gains from clearer sight of Greenland's ice melt

Research into how Greenland’s ice melts should lead to more accurate predictions of sea level rise and global warming.

LONDON, 18 January, 2015 − Scientists in the US have used on-the-ice measurements and military-grade satellite imagery to take a much closer look at just how Greenland’s icesheet melts.

They already knew that huge icebergs fall from the glaciers into the ocean, and that surface lakes drain suddenly in the summer warmth. But now they know considerably more about what happens to the network of streams, rivers and ponds that collect in the summer sunshine, and then flow across the top of the icesheet into moulins, or sinkholes.

They report in the Proceedings of the National Academy of Sciences that they used the data collected to chart 523 streams in a catchment area of about 6,800 square kilometres during the freak thaw of 2012, when almost the whole of the Greenland icecap was covered in slush. They measured the run-off at between 1,550 and 1,700 cubic metres per second − twice the average flow of the Colorado River.

Thereafter, all this water drained into moulins, and began to filter towards the base of the icesheet. What happened to it then is not yet certain, but the guess is that a percentage was soaked up within the iceshelf, while a proportion reached the sea.

Only the start

The study placed 11 researchers on the ice for six days in July 2012, during a massive and unusual melt. Only on one other occasion in the last 700 years, in 1889, did Greenland’s ice melt on such a scale.

The scientists were moved around by helicopter and equipped with a specially-designed automaton boat, buoys fitted with GPS technology, and sophisticated satellite imagery.

“It was a real preview of just how quickly that ice sheet can melt and the meltwater can escape”, said lead author Laurence Smith, Professor of Earth, Planetary, and Space Sciences at University of California Los Angeles. “The question was whether the ice sheet acts like a sponge or like Swiss cheese.”

The provisional answer is: both. Some meltwater stays, and some certainly escapes altogether. But it will take more than just one visit to arrive at more precise calculations.

“Greenland is really the big player for sea level rise in the future, so improving climate models is extremely crucial”

The scientists also took measurements of Greenland’s Isortoq river − just one of about 100 large terrestrial rivers delivering Greenland meltwater to the oceans.

They found that the Isortoq carries water from the ice sheet to the ocean at between 650 and 1,300 cubic metres per second, which is less than models have projected.

Such direct measurements are important because they make predictions of melt rate and sea level rise more accurate − and more credible.

“If we can get better estimates, then we can have better projections for the extent and impact of global warming”, said another of the report’s authors, Marco Tedesco, founder and director of the City College of New York’s Cryospheric Processes Laboratory. “Greenland is really the big player for sea level rise in the future, so improving climate models is extremely crucial.” – Climate News Network

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US coastal cities warned of daily high tide floods

US coastal cities warned of daily high tide floods

Scientists report that many cities near the coasts of the US should prepare for daily flooding at high tide by mid-century because of rising sea levels.

LONDON, 5 January, 2015 − Oceanographers have just identified the US coastal regions likely to experience 30 days or more of “nuisance” flooding every year. And the answer is that most of the American coast will experience high waters that are 30-60 cms above local high tides, at least 30 times a year.

Nuisance flooding means just that − somewhere between an inconvenience and modest damage. But climate change, and its attendant sea-level rise, will make them much more frequent, and possibly more damaging.

William Sweet and Joseph Park, scientists at the National Oceanic and Atmospheric Administration (NOAA), report in the journal Earth’s Future that sea level rise has accelerated from 1.7mm a year in the last century to 3.2mm a year in the last two decades, and flooding events that were once extreme could become the mean.

The oceanographers wanted to establish what they call “regional tipping points” – places where extra high waters would wash across streets and promenades normally above water and start to do so frequently.

Detailed picture

New York was inundated when Superstorm Sandy hit the city in 2012, and studies have repeatedly warned that coastal inundations will cost communities colossal sums each year by 2050, and even more by 2100. Nor is the US alone in this respect. There have been ominous calculations for the UK as well.

The NOAA scientists add detail to the big picture. They started with the projections for global sea level rise delivered by the Intergovernmental Panel on Climate Change and then included the more local factors such as land subsidence or settlement, and cyclic weather patterns that exacerbate the tidal highs. Such floods have already increased, and are now five to 10 times more likely than 50 years ago.

They looked at all those tidal stations with a continuous 50-year record of measurement. This does not include the city of Miami, where the tide stations were destroyed in 1992 by Hurricane Andrew.

Coastal changes

And they warn that Boston, New York City, Philadelphia, Baltimore and many other places along the Atlantic Coast, Galveston and Port Isabel in the Gulf of Mexico, and San Francisco Bay and San Diego along the Pacific Coast will all see a lot more seawater in city streets.

“Coastal communities are beginning to experience sunny-day nuisance flooding, much more so than in decades past,” said Dr Sweet. “This is due to sea level rise.

“Unfortunately, once impacts are noticed, they will become commonplace rather quickly. We find that in 30 to 40 years, even modest projections of global sea level rise – 1.5 feet by the year 2100 – will increase instances of daily high tide flooding to a point requiring an active and potentially costly response.

“And by the end of the century, our projections show that there will be near-daily nuisance flooding in most of the locations that we reviewed.” – Climate News Network

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Satellite provides sharper picture of shrinking ice sheet

Satellite provides sharper picture of shrinking ice sheet

The most detailed study yet of the Greenland ice sheet illustrates the complex process that is causing billions of tonnes to melt ever year.

LONDON, 27 December, 2014 − Greenland’s ice sheet shrank by an average of 243 billion tonnes a year between 2003 and 2009 – a rate of melting that is enough to raise the world’s sea levels by 0.68 mm per year.

In what is claimed as the first detailed study, geologist Beata Csatho, of the University of Buffalo in the US, and colleagues report in the Proceedings of the National Academy of Sciences that they used satellite and aerial data to reconstruct changes in the ice sheet at 100,000 places, and to confirm that the process of losing 277 cubic kilometres of ice a year is more complex than anyone had predicted.

The Greenland ice sheet is the second biggest body of ice on Earth − second only to Antarctica − and its role in the machinery of the northern hemisphere climate is profound.

Careful measurements

It has been closely studied for decades, but such are the conditions in the high Arctic that researchers have tended to make careful measurements of ice melt and glacier calving in fixed locations – in particular, at four glaciers − and then try to estimate what that might mean for the island as a whole.

“The great importance of our data is that, for the first time, we have a comprehensive picture of how all of Greenland’s glaciers have changed over the past decade,” Dr Csatho said.

The study looked at readings from NASA’s ice, cloud and land elevation satellite ICESat, and from aerial surveys of 242 glaciers wider than 1.5 km at their outlets, to get a more complete picture of melting, loss and – in some cases – thickening of the ice sheet as a whole.

“When the ice sheet is thinner, it is at a slightly lower elevation and at the mercy of warmer air temperatures”

Previous studies have focused on the four glaciers. One of them, Jakobshavn, has doubled its speed of flow since 2003, and closer studies have begun to reveal more about the dynamics of individual flows.

But the real strength of the study is that it establishes the pattern of ice melt in more detail, and suggests that climate models may not give a clear enough picture of the future of the ice cap. To put it crudely, Greenland could lose ice faster in the future than any of today’s predictions suggest.

Meanwhile, a team from the UK has been trying to work out what is happening on the surface of the ice sheet. Each summer, of course, some of the ice melts. Some of this gets to the sea, but some freezes again in the natural seasonal order of things.

But glaciology researcher Amber Leeson, of the University of Leeds, and colleagues report in Nature Climate Change that the “supraglacial” lakes that form each summer could also affect ice flow.

Their computer simulations suggest that these lakes will migrate further inland as the century wears on and the world continues to warm. Ice reflects heat, water absorbs it. So the process could trigger further melting. Some of this extra meltwater could slide or drain to the base of the glacier, lubricating its flow and accelerating the process yet again.

Thin pancake

“Our research shows that, by 2060, the area of Greenland covered by them will double,” Dr Leeson said. “When you pour pancake batter into a pan, if it rushes quickly to the edge of the pan, you end up with a thin pancake. It’s similar to what happens with ice sheets. The faster it flows, the thinner it will be.

“When the ice sheet is thinner, it is at a slightly lower elevation and at the mercy of warmer air temperatures than it would be if it were thicker, increasing the size of the melt zone around the edge of the ice sheet.”

In the last 40 years, the band in which such supraglacial lakes can form has crept 56 km inland. By 2060, the simulations now suggest, it could reach 110km inland, doubling the area of coverage and delivering yet more meltwater to fuel further warming.

Once again, the research suggests that current models underestimate the rate of ice loss. – Climate News Network

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Climate change’s threat of space centre invasion

Climate change's threat of space centre invasion

Rising sea levels and repeated storm damage to natural coastal defences pose an increasing threat to the famous Cape Canaveral rocket launch site in Florida.

LONDON, 15 December, 2014 − Climate change has begun to make its mark on one of America’s most iconic sites – the Kennedy Space Centre at Cape Canaveral in Florida.

Within a decade, according to geologists, the combination punch of rising sea levels and increasing wave energy could start to affect operations at the site where, more than five decades ago, astronauts were launched towards a landing on the Moon.

Peter Adams and John Jaeger, of the University of Florida, have since 2009 been studying the dunes and the beach at Cape Canaveral that historically screened the launch site from even the worst tropical storms.

These dunes were levelled in 2008 during Tropical Storm Fay, in 2011 during Hurricane Irene, and again in 2012 during Hurricane Sandy.

Washed away

Storm waves repeatedly covered a stretch of railroad track built by the US space agency NASA during the 1960s. The line is no longer used, and part of it has been removed to make room for a protective man-made dune. NASA’s own prediction in 2010 was that the line could be permanently breached by 2016.

Hurricane Sandy, the superstorm  that brought catastrophic flooding to New York and caused damage along almost all the US Atlantic seaboard, washed away a section of Cape Canaveral shoreline so close to a US Air Force launch pad that the surrounding fence was left near collapse.

“When you put immovable infrastructure right next to a dynamic environment, something has to give”

Coastal erosion is an enduring fact of life, but during the 1960s the Cape seemed a secure site for one of the great 20th-century adventures.

The two geologists, working as partners with NASA and the US Geological Survey, began looking at a problem that seemed to have been getting worse since 2004: chronic erosion of a six-mile stretch between the two launch pads used for the Apollo missions and space shuttle launches.

According to Dr Adams, the slow rise in sea levels and the increased energy of the ocean’s storm waves – both symptoms of global warming – are almost certainly to blame. He said: “Is it affecting NASA’s infrastructure? The answer’s yes.”

Although man-made dunes will protect the site for the immediate future, the space agency has already spoken of a “managed retreat”. And Dr Jaeger  said: “When you put immovable infrastructure right next to a dynamic environment, something has to give.”

Evidence of flooding

As a coastal facility, Cape Canaveral is naturally vulnerable to hurricanes, which tend to lose their energy as they hit the coasts. But University of Iowa scientists report in the Bulletin of the American Meteorological Society that they have found evidence of flooding by tropical cyclones as far inland as Iowa, in the Midwest.

Gabriele Villarini, a civil and environmental engineer, found the evidence in 30 years’ worth of discharge records from more than 3,000 US Geological Survey stream measurement stations.

Between 1981 and 2011, the US was hit by more than 100 tropical cyclones or hurricanes that did their worst damage at the coast, but could also be linked with major flooding far inland.

“Our results indicate that flooding from tropical cyclones affects large areas of the US and the Midwest, as far inland as Illinois, Wisconsin and Michigan,” Villarini said. – Climate News Network

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Deep concern over invisible threat to Antarctic glaciers

Deep concern over invisible threat to Antarctic glaciers

As ocean temperatures rise, warmer currents are attacking the Antarctic ice sheet from below and adding to the threats posed by a melting rate that has trebled in the last two decades.

LONDON, 13 December, 2014 − The Antarctic ice shelf is under threat from a silent, invisible agency – and the rate of melting of glaciers has trebled in the last two decades.

The ocean waters of the deep circumpolar current that swirl around the continent have been getting measurably warmer and nearer the ocean surface over the last 40 years, and now they could be accelerating glacier flow by melting the ice from underneath, according to new research.

And a separate study reports that the melting of the West Antarctic glaciers has accelerated threefold in the last 21 years.

Calamitous consequences

If the West Antarctic ice sheet were to melt altogether – something that is not likely to happen this century – the world’s sea levels would rise by 4.8 metres, with calamitous consequences for seaboard cities and communities everywhere.

Researchers from Germany, Britain, Japan and the US report in Science journal that they base their research on long-term studies of seawater temperature and salinity sampled from the Antarctic continental shelf.

This continued intrusion of warmer waters has accelerated the melting of glaciers in West Antarctica, and there is no indication that the trend is likely to reverse.

Other parts of the continent so far are stable – but they could start melting for the first time.

“The Antarctic ice sheet is a giant water reservoir,” said Karen Heywood, professor of environmental sciences at the University of East Anglia, UK. “The ice cap on the southern continent is on average 2,100 metres thick and contains 70% of the world’s fresh water. If this ice mass were to melt completely, it could raise global sea level by 60 metres. That is not going to happen, but it gives you an idea of how much water is stored there.”

“These waters have warmed . . . and  are significantly shallower than 50 years ago”

Temperatures in the warmest waters in the Bellinghausen Sea in West Antarctica have risen from 0.8°C in the 1970s to about 1.2°C in the last few years.

“This might not sound much, but it is a large amount of extra heat available to melt the ice,” said Sunke Schmidtko, an oceanographer at the Geomar Helmholtz Centre for Ocean Research in Kiel, Germany, who led the study. “These waters have warmed in West Antarctica over 50 years. And they are significantly shallower than 50 years ago.”

The apparent rise of warm water, and the observed melting of the West Antarctic ice shelf, could be linked to long-term changes in wind patterns in the southern ocean. Although melting has not yet been observed in other parts of the continent, there could be serious consequences for other ice shelves.

The shelf areas are where the Antarctic krill – the little shrimp that plays a vital role in the Antarctic ocean food chain – are getting warmer, with unpredictable consequences for spawning cycles, and then for ocean biodiversity.

Meanwhile, according to US scientists writing in Geophysical Research Letters, the glaciers of the Amundsen Sea in West Antarctica are shedding ice faster than any other part of the region.

Tyler Sutterley, a climate researcher at the University of California Irvine, and NASA space agency colleagues used four sets of observations to confirm the threefold acceleration.

They took their data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites, from a NASA airborne project called Operation IceBridge, from an earlier satellite called ICESat, and from readings by the European Space Agency’s Envisat satellite.

Loss calculated

The observations spanned the period 1992 to 2013 and enabled the researchers to calculate the total loss of ice, and also the rate of change of that loss.

In all, during that period the continent lost 83 gigatonnes, or 83 billion metric tonnes, of ice per year on average. Since Mount Everest weighs an estimated 161 billion tonnes, this is as if the ice cap lost an Everest’s worth of ice every two years.

After 1992, the rate of loss accelerated by 6.1 billion tonnes a year, and between 2003 and 2009 the melt rate increased by 16.3 gigatonnes a year on average. So the increasing rate of loss is now nearly three times the original figure.

“The mass loss of these glaciers is increasing at an amazing rate,” said Isabella Velicogna, Earth system scientist at both UC Irvine and the NASA Jet Propulsion Laboratory. – Climate News Network

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Plea for South Asia to unite in fight against climate risks

Plea for South Asia to unite in fight against climate risks

South Asia, one of the world’s most populous and disaster-prone regions, faces dire impacts from climate change. So why are its nations not working together to tackle the many shared threats they face?

LIMA, 8 December, 2014 − The countries of South Asia need to stand together in their efforts to push for more finance from the developed world to help them adapt to and mitigate the impacts of climate change,  a prominent regional expert says.

Saleemul Huq, from Bangladesh, a lead negotiator for the group of Least Developed Countries told a fringe meeting at the UN climate change conference in Lima, Peru, that South Asia countries face a range of climate-related events.

“Countries in the region must co-ordinate climate action to cope with adverse climate impacts, such as flash floods, forest fires, cyclones, migration and sea-level rise.” said Huq, senior fellow in the Climate Change Group at the International Institute for Environment and Development.

The South Asia region is home to more than one-fifth of the globe’s population, but is also regarded as one of the most disaster-prone regions in the world, Huq told delegates.

Substantial rise

Temperature projections for the region for the 21st century indicate a substantial rise in warming, with recent modelling showing that the warming would be particularly significant in the high Himalayas, on the Tibetan Plateau, and across arid regions of Asia.

“Extreme weather events are also forecast across the region” said Huq. “This is likely to include an increase in the interannual variability of precipitation during the Asian summer monsoon period.”

In turn, Huq said, this will negatively impact on crop yields throughout the region, as already crops in many areas are already being grown at close to their temperature tolerance threshold.

In its latest assessment, the UN’s Intergovernmental Panel on Climate Change identified the South Asia region as one of the areas most vulnerable to warming.

“Developing states have to have technical support in order to hammer out their climate adaptation plans”

In the high Himalayas and on the Tibetan Plateau, rates of glacial melting are increasing. The incidence of flooding is likely to grow, although there is the possibility, over the long term, of drought affecting billions of people in one of the most densely-populated areas on Earth.

Co-operation between the region’s countries on climate change is minimal. Pakistan and India, for example, remain deeply suspicious of each other, and data on such key issues as river flows and erosion rates are classified as state secrets.

China and India are competing for water resources, and large-scale dam building programmes in both countries are creating environmental tensions in the region.

Competing interests

Less powerful countries in the area – such as Bangladesh and Nepal – are squeezed between the competing interests of their powerful neighbours.

Harjeet Singh, a New Delhi-based representative of the Action Aid  charity, told delegates that South Asian countries must use their combined influence to pressure world leaders to reach a legally-binding climate agreement in 2015.

Singh told the Climate News Network that a new agreement was a matter of urgency, and  that developed countries must also fulfill their commitments to help developing countries with adaptation measures.

Manjeet Dhakal, a director of the Clean Energy Nepal research organisation, said a new agreement must address the needs of the vulnerable. “The regional countries and other developing states,” he said, “have to have technical support in order to hammer out their climate adaptation plans. They also need the financial support to put those plans into action.” – Climate News Network

  • Saleem Shaikh is a freelance climate change and science journalist based in Islamabad, Pakistan.

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Yellow submarine is a big hit for Antarctic records

Yellow submarine is a big hit for Antarctic records

A new underwater robot is revolutionising important research into the thickness of the sea ice floating off Antarctica’s coasts by looking up from the depths to create detailed 3-D maps.

LONDON, 27 November, 2014 − For the first time, researchers have begun to collect accurate data on the thickness of the sea ice around Antarctica.

A new underwater robot called SeaBED has begun to deliver a clear picture of the greatest mass of floating frozen water on the planet. And the first evidence is that the ice is thicker than anyone had realised: on average somewhere between 1.4 and 5.5 metres, but sometimes as much as 16 metres or more.

Although scientists can keep an eye on the precise extent of the seasonal ice, thanks to consistent satellite data, looking beneath the rim of floating ice that surrounds the enormous continent has been more of a problem. But it’s a problem SeaBED is now addressing by producing the first detailed, high-resolution 3-D maps of Antarctic sea ice.

Baseline measurement

Ice thickness measurements are not easy. During the Cold War, nuclear submarines routinely cruised under the Arctic Ocean ice, making measurements – for navigational safety reasons, rather than climate research. But, in consequence, when the Arctic ice sheet started to melt and dwindle, researchers had a baseline of accurate measurement.

The Antarctic, however, is a partly-submerged rocky continent that bears a huge burden of snow and ice. Shipboard and shore-based studies can provide only a limited set of measurements of ice thickness off its coasts.

Now Guy Williams, a polar oceanographer at theUniversity of Tasmania Institute for Marine and Antarctic Studies, and colleagues from the British Antarctic Survey  and other institutions, report in Nature Geoscience that at last they have a clearer picture of the ice thickness, and therefore a better chance of calculating how sea ice is likely to change as the planet’s climate continues to warm.

“We can now measure in far greater detail, and were excited to measure ice up to 17 metres thick”

SeaBED, technically described as an autonomous underwater vehicle (AUV), is a little yellow submarine two metres long and weighing 200 kg. It was designed and built by the Woods Hole Oceanographic Institution in the US.

In 2010 and 2012 it made a series of autonomous underwater traverses in lawnmower fashion, at depths of 20-30 metres. Most surveying instruments look down, but this one looks up at the ice above it.

There has been a level of alarm at change in Antarctica in recent years. Although the sea ice during recent polar winters has been greater than ever there has been concern about the rate at which some Antarctic glaciers are melting − with worrying consequences for the rate of sea level rise.

Accurate estimates

So the more accurate the information about the volumes of ice formed and lost, the more accurate the estimates of future sea level rise, and the better the understanding of the polar climate machinery.

The AUV measurements – especially when backed up by direct measurements, radar and satellite studies – promise to provide a real insight into the nature of Antarctic sea ice.

Jeremy Wilkinson, lead investigator at the British Antarctic Survey, says: “We can now measure in far greater detail, and were excited to measure ice up to 17 metres thick.”

David Ferreira, an oceanographer at the University of Reading, who is not one of the authors, called the study “a formidable benchmark” in formulating climate models of the region.

“We strongly depend on the simulation of the sea ice in these models to test possible causes of the Antarctic sea ice expansion,” he said. “Effects of the ozone hole, of melt water from the Antarctic ice sheet, or of sea ice movements are among the plausible candidates, but we are limited by the quality of our models in this poorly-observed region of the world to discriminate between them.” – Climate News Network

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