The map, along with an associated animation (below) developed by NASA, reveals that ice is flowing fastest in coastal ice shelves and their tributaries, shown in this illustration in bright purple and blue. Though it’s ice that’s moving, not water, “you can imagine it like a river system,” says Bernd Scheuchl, one of the map’s creators. The fastest ice flows out to sea at a rate of a few kilometers a year. Pine Island and Thwaites Glaciers on the west coast are the most active.

The team was surprised by how far inland they found fast-moving ice, Scheuchl says. So, if Antarctica loses a great deal of its coastal ice to climate change in the coming decades, large quantities of interior ice could follow. “That’s critical knowledge for predicting future sea level rise,” NASA polar scientist Thomas Wagner said in a prepared statement.

To create this view of Antarctic ice flow, the UC Irvine researchers relied on data from satellites operated by Canada, Japan and the European Space Agency. Flow was tracked from 2007 to 2009 during a period of intense scientific monitoring of Earth’s poles that researchers all over the world had agreed to do. A report on the map was published online August 18 in Science.

Source Scientific America

An irreversible climate “tipping point” could occur within the next 20 years as a result of the release of huge quantities of organic carbon locked away as frozen plant matter in the vast permafrost region of the Arctic, scientists have found.Billions of tons of frozen leaves and roots that have lain undisturbed for thousands of years in the permanently frozen ground of the northern hemisphere are thawing out, with potentially catastrophic implications for climate change, the researchers said.

A study into the speed at which the permafrost is melting suggests that the tipping point will occur between 2020 and 2030 and will mark the point at which the Arctic turns from being a net “sink” for carbon dioxide into an overall source that will accelerate global warming, they said.

The study is the first global investigation of what will happen in a warmer world to the huge amounts of frozen plant matter that has remained undegraded in the soil since it was incorporated into the permafrost about 30,000 years ago.

It also found that by 2200 about two-thirds of the Earth’s permafrost will have melted, releasing an estimated 190 billion tons of carbon dioxide and methane into the air – about half of all the fossil fuel emissions of greenhouse gases since the start of the industrial revolution.

“Our results indicate that, as the Arctic warms up, this frozen carbon will thaw out, allowing microbial decay to resume and releasing carbon into the atmosphere,” said Kevin Schaefer of the US National Snow and Ice Data Centre in Boulder, Colorado.

“Our research shows that the release of carbon from permafrost will result in an irreversible climate tipping point in only 20 years… Once the frozen carbon thaws out and decays, there is no way to put it back into the permafrost,” Dr Schaefer said.

The Arctic has experienced some of the greatest climatic changes in the world over recent decades. Summer sea ice has melted back to record minimums, average temperatures have increased dramatically, and scientists have documented significant melting of the underground permafrost, from Alaska to eastern Siberia.

The rising temperatures have lengthened the growing season of the Arctic summer, which has increased plant growth and the consequent uptake of carbon dioxide. However, by around 2025 this will go into reverse and the thawing permafrost will release more carbon than is being taken up by the tundra growing above it, Dr Schaefer said.

“There are two important messages from this study. The first is that the melting permafrost can release huge amounts of carbon and, secondly, the process is irreversible on a human timescale and will affect our targets for reducing fossil fuel emissions,” he said.

“All our emission reduction strategies are designed to hit a target atmospheric carbon dioxide concentration corresponding to a target climate. If we do not account for carbon released from thawing permafrost, we will overshoot this target concentration and end up with a warmer climate than we want,” Dr Schaefer said.

Permanently frozen ground covers about a quarter of the northern hemisphere and starts about a metre below the surface, extending up to 500 metres. The top three metres contain most of the frozen plant matter, primarily grass roots caught up in the last ice age.

Source Independent UK

Economic recession has failed to curb rising emissions, undermining hope of keeping global warming to safe levels Photograph: Dave Reede/All Canada Photos/Corbis

Greenhouse gas emissions increased by a record amount last year, to the highest carbon output in history, putting hopes of holding global warming to safe levels all but out of reach, according to unpublished estimates from the International Energy Agency.

The shock rise means the goal of preventing a temperature rise of more than 2 degrees Celsius – which scientists say is the threshold for potentially “dangerous climate change” – is likely to be just “a nice Utopia”, according to Fatih Birol, chief economist of the IEA. It also shows the most serious global recession for 80 years has had only a minimal effect on emissions, contrary to some predictions.

Last year, a record 30.6 gigatonnes of carbon dioxide poured into the atmosphere, mainly from burning fossil fuel – a rise of 1.6Gt on 2009, according to estimates from the IEA regarded as the gold standard for emissions data.

“I am very worried. This is the worst news on emissions,” Birol told the Guardian. “It is becoming extremely challenging to remain below 2 degrees. The prospect is getting bleaker. That is what the numbers say.”

Professor Lord Stern of the London School of Economics, the author of the influential Stern Report into the economics of climate change for the Treasury in 2006, warned that if the pattern continued, the results would be dire. “These figures indicate that [emissions] are now close to being back on a ‘business as usual’ path. According to the [Intergovernmental Panel on Climate Change's] projections, such a path … would mean around a 50% chance of a rise in global average temperature of more than 4C by 2100,” he said.

“Such warming would disrupt the lives and livelihoods of hundreds of millions of people across the planet, leading to widespread mass migration and conflict. That is a risk any sane person would seek to drastically reduce.”

Birol said disaster could yet be averted, if governments heed the warning. “If we have bold, decisive and urgent action, very soon, we still have a chance of succeeding,” he said.

The IEA has calculated that if the world is to escape the most damaging effects of global warming, annual energy-related emissions should be no more than 32Gt by 2020. If this year’s emissions rise by as much as they did in 2010, that limit will be exceeded nine years ahead of schedule, making it all but impossible to hold warming to a manageable degree.

Emissions from energy fell slightly between 2008 and 2009, from 29.3Gt to 29Gt, due to the financial crisis. A small rise was predicted for 2010 as economies recovered, but the scale of the increase has shocked the IEA. “I was expecting a rebound, but not such a strong one,” said Birol, who is widely regarded as one of the world’s foremost experts on energy.

John Sauven, the executive director of Greenpeace UK, said time was running out. “This news should shock the world. Yet even now politicians in each of the great powers are eyeing up extraordinary and risky ways to extract the world’s last remaining reserves of fossil fuels – even from under the melting ice of the Arctic. You don’t put out a fire with gasoline. It will now be up to us to stop them.”

Most of the rise – about three-quarters – has come from developing countries, as rapidly emerging economies have weathered the financial crisis and the recession that has gripped most of the developed world.

But he added that, while the emissions data was bad enough news, there were other factors that made it even less likely that the world would meet its greenhouse gas targets.

• About 80% of the power stations likely to be in use in 2020 are either already built or under construction, the IEA found. Most of these are fossil fuel power stations unlikely to be taken out of service early, so they will continue to pour out carbon – possibly into the mid-century. The emissions from these stations amount to about 11.2Gt, out of a total of 13.7Gt from the electricity sector. These “locked-in” emissions mean savings must be found elsewhere.

“It means the room for manoeuvre is shrinking,” warned Birol.

• Another factor that suggests emissions will continue their climb is the crisis in the nuclear power industry. Following the tsunami damage at Fukushima, Japan and Germany have called a halt to their reactor programmes, and other countries are reconsidering nuclear power.

“People may not like nuclear, but it is one of the major technologies for generating electricity without carbon dioxide,” said Birol. The gap left by scaling back the world’s nuclear ambitions is unlikely to be filled entirely by renewable energy, meaning an increased reliance on fossil fuels.

• Added to that, the United Nations-led negotiations on a new global treaty on climate change have stalled. “The significance of climate change in international policy debates is much less pronounced than it was a few years ago,” said Birol.

He urged governments to take action urgently. “This should be a wake-up call. A chance [of staying below 2 degrees] would be if we had a legally binding international agreement or major moves on clean energy technologies, energy efficiency and other technologies.”

Governments are to meet next week in Bonn for the next round of the UN talks, but little progress is expected.

Sir David King, former chief scientific adviser to the UK government, said the global emissions figures showed that the link between rising GDP and rising emissions had not been broken. “The only people who will be surprised by this are people who have not been reading the situation properly,” he said.

Forthcoming research led by Sir David will show the west has only managed to reduce emissions by relying on imports from countries such as China.

Another telling message from the IEA’s estimates is the relatively small effect that the recession – the worst since the 1930s – had on emissions. Initially, the agency had hoped the resulting reduction in emissions could be maintained, helping to give the world a “breathing space” and set countries on a low-carbon path. The new estimates suggest that opportunity may have been missed.

Source Guardian

Extracted from the Greenhouse Neutral Foundations article in Green Lifestyle Magazine in 2010 Soy -SOy what are we doing?  - ‘The Amazon lost some 10,000 square miles of forest cover last year alone — 40 percent more than the year before.” Among the players responsible for this rainforest destruction are multinational, international agribusinesses such as Cargill, Bunge and Archer Daniels Midland, companies investing in growing genetically modified soy. The U.S. company, Cargill, built a soy processing and port facility in Santarém, Brazil, without the environmental impact assessment required by the Brazilian government.
   Wikipedia lists the main producers of soy around the world as the United States (32%), Brazil (28%), Argentina (21%), China (7%) and India (4%). Of the 32% of global production of soy in the U.S., 85% percent was genetically modified by 2004, accounting for some 63.6 million acres of soybeans.
   Who is driving this steam engine of environmental destruction?  You guessed it, Monsanto.

Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed.

Methane is about 20 times more potent than CO2 in trapping solar heat.

The findings come from measurements of carbon fluxes around the north of Russia, led by Igor Semiletov from the University of Alaska at Fairbanks.

“Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be],” he said.

Professor Semiletov has been studying methane seepage in the region for the last few decades, and leads the International Siberian Shelf Study (ISSS), which has launched multiple expeditions to the Arctic Ocean.

The preliminary findings of ISSS 2009 are now being prepared for publication, he told BBC News.

Methane seepage recorded last summer was already the highest ever measured in the Arctic Ocean.

High seepage

Acting as a giant frozen depository of carbon such as CO2 and methane (often stored as compacted solid gas hydrates), Siberia’s shallow shelf areas are increasingly subjected to warming and are now giving up greater amounts of methane to the sea and to the atmosphere than recorded in the past.

This undersea permafrost was until recently considered to be stable.

But now scientists think the release of such a powerful greenhouse gas may accelerate global warming.

Higher concentrations of atmospheric methane are contributing to global temperature rise; this in turn is projected to cause further permafrost melting and the release of yet more methane in a feedback loop.

A worst-case scenario is one where the feedback passes a tipping point and billions of tonnes of methane are released suddenly, as has occurred at least once in the Earth’s past.

Such sudden releases have been linked to rapid increases in global temperatures and could have been a factor in the mass extinction of species.

According to a report by the US National Oceanic and Atmospheric Administration (Noaa), the springtime air temperature across the region in the period 2000-2007 was an average of 4C higher than during 1970-1999.

That is the fastest temperature rise on the planet, claims the university.

The recent thaw over the last decade means that some of the large reserve of carbon from organic material such as dead animals and plants in sediments is now being released into the sea and into our atmosphere.

Trapped below that is the methane hydrate now warming and leaking through holes in the defrosting sediments.

Previously it was thought much of this gas was absorbed into the sea.

But according to a recent report that Professor Semiletov and his team compiled for the environmental group WWF, the shallow depth of arctic shelves means that methane is reaching the atmosphere without reacting to become CO2 dissolved in the ocean.

Professor Semiletov’s fellow researcher aboard the Russian icebreaker that carries the ISSS team each year is Professor Orjan Gustafsson from Stockholm University in Sweden.

He said that methane measured in the atmosphere around the region is 100 times higher than normal background levels, and in some cases 1,000 times higher.

‘No alarm’

Despite the high readings, Professor Gustafsson said that so far there was no cause for alarm, and stressed that further studies were still necessary to determine the exact cause of the methane seepage.

“It is important now to understand how fast it is being released and how much is being released,” he said.

However, there is a real fear that global warming may cause Siberia’s subsea permafrost to thaw.

Some estimates put the amount of carbon trapped in shelf permafrost at 1,600 billion tonnes – roughly twice as much carbon as in the atmosphere now.

The release of this once captive carbon from destabilised ocean sediments and permafrost would have catastrophic effect on our climate and life on Earth, warn the scientists.

Source BBC News

It is natural to be rattled by these observations. There is no immediately obvious reason why the rate of ice loss should not continue to increase. Indeed, the recent observations might presage even faster acceleration, perhaps involving the discharge of a substantial fraction of the 1500 mm of sea-level equivalent still stored in Pine Island Glacier and its neighbours. And we have a serious enough problem even if Pine Island Glacier simply maintains its present rate of loss.

Knowing what they know and what they don’t know, “alarmist” is therefore not a label about which glaciologists need to be embarrassed. But they also know that alarmist projections have a way of turning out to be exaggerated.

Consider the energy-balance models, that describe how the climate responds to changes in radiative forcing. The two first such models, published independently by Mikhail Budyko and William Sellers in 1969, projected that the Earth’s surface temperature would drop to tens of degrees below freezing if the output of the Sun were to decrease by only two percent. That made people sit up, and yielded a flurry of publications showing that there are plenty of ways in which the climate system moderates the severity of the negative feedback which was the basis for the original findings.

Even though they are based on measurement rather than on modelling, might our concerns about the recent behaviour of outlet glaciers in Antarctica and Greenland be similarly exaggerated? In a recent modelling study, Ian Joughin and co-authors suggest that the answer is “Probably, but not necessarily”.

The model is not quite state-of-the-art, in that it does not solve the full Stokes equation but a simpler form of the dynamical system that is appropriate for ice shelves and ice streams. The authors were obliged to handle the grounding line, where the grounded ice stream feeds into the floating ice shelf, somewhat roughly. Nevertheless the calculations allow for careful treatment of the rapid sliding at the base of the ice stream, and the implied very large rates of basal melting. And the model does a good job of reproducing the documented behaviour of Pine Island Glacier up to 2009.

Most of the ice in the Pine Island Glacier catchment is flowing very slowly indeed, at a few metres per year at most. But as it converges on the outlet of the catchment it accelerates spectacularly, and is moving at thousands of metres per year by the time it starts to float at the grounding line. Most of the speed is the result of basal sliding, so the ice stream is not unlike a rigid plug, punching its way through the much slower ice on its flanks. This peculiar setup is the core of the problem.

Joughin and his co-authors simulated responses of the glacier to a variety of scenarios that might or might not represent the next hundred years. Even the more extreme scenarios, featuring basal melting at four times the present rate, did not lead to flotation of the entire 200-kilometre length of the ice stream, as one earlier study had suggested. Nor did the model come anywhere close to an even simpler extrapolation of current behaviour, based on kinematics rather than dynamics.

Don’t breathe out yet, however. The results considered by the authors to be the most probable have Pine Island Glacier continuing to lose mass at rates comparable to the recent rates. It doesn’t continue to accelerate, but it doesn’t slow down either. The grounding line doesn’t continue to migrate inland, but the inland thinning implied by the fast flow does continue.

It would be wrong to write off this heroic but tentative modelling effort, which is an important step towards the goal of understanding Pine Island Glacier. Models like this one, and like the energy-balance models that followed up on Budyko and Sellers, are part of the learning process. They suggest that doomsday isn’t going to happen just yet. But, in short, doomsday scenarios are educational.

Source Environmental research web

Footnote – This situation and the broader picture of the grounding lines under the Pine Island Glacier and the Ross Ice Shelf are cover in the book ZERO Greenhouse Emissions – get the ebook here.

We are entering a new era, one of rapid and often unpredictable climate change. In fact, the new climate norm is change. The 25 warmest years on record have come since 1980. And the 10 warmest years since global recordkeeping began in 1880 have come since 1998.

The effects of rising temperature are pervasive. Higher temperatures diminish crop yields, melt the mountain glaciers that feed rivers, generate more-destructive storms, increase the severity of flooding, intensify drought, cause more-frequent and destructive wildfires, and alter ecosystems everywhere. We are altering the earth’s climate, setting in motion trends we do not always understand with consequences we cannot anticipate.

Crop-withering heat waves have lowered grain harvests in key food-producing regions in recent years. One with a profoundly direct human impact was the searing heat wave that broke temperature records across Europe in 2003. The intense heat, which contributed to the world grain harvest falling short of consumption by 90 million tons, also claimed more than 52,000 lives.

There has also been a dramatic increase in the land area affected by drought in recent decades. A team of scientists at the National Center for Atmospheric Research reports that the area of the globe experiencing very dry conditions expanded from less than 15 percent in the 1970s to roughly 30 percent by 2002. The scientists attribute part of the change to a rise in temperature and part to reduced precipitation, with high temperatures becoming progressively more important during the latter part of the period. A 2009 report published by the U.S. National Academy of Sciences reinforces these findings. It concludes that if atmospheric CO2 climbs to 450–600 ppm, the world will face irreversible dry-season rainfall reductions in several regions of the world. The study likened the conditions to those of the U.S. Dust Bowl era of the 1930s.

The warming is caused by the accumulation of heat-trapping “greenhouse” gases and other pollutants in the atmosphere. Of the greenhouse gases, CO2 accounts for 63 percent of the recent warming trend, methane 18 percent, and nitrous oxide 6 percent, with several lesser gases accounting for the remaining 13 percent. Carbon dioxide comes mostly from electricity generation, heating, transportation, and industry. In contrast, human-caused methane and nitrous oxide emissions come largely from agriculture—methane from rice paddies and cattle and nitrous oxide from the use of nitrogenous fertilizer.

Atmospheric concentrations of CO2, the principal driver of climate change, have climbed from nearly 280 parts per million (ppm) when the Industrial Revolution began around 1760 to 387 ppm in 2009. The annual rise in atmospheric CO2 level, now one of the world’s most predictable environmental trends, results from emissions on a scale that is overwhelming nature’s capacity to absorb carbon. In 2008, some 7.9 billion tons of carbon were emitted from the burning of fossil fuels and 1.5 billion tons were emitted from deforestation, for a total of 9.4 billion tons. But since nature has been absorbing only about 5 billion tons per year in oceans, soils, and vegetation, nearly half of those emissions stay in the atmosphere, pushing up CO2 levels.

Methane, a potent greenhouse gas, is produced when organic matter is broken down under anaerobic conditions, including the decomposition of plant material in bogs, organic materials in landfills, or forage in a cow’s stomach. Methane can also be released with the thawing of permafrost, the frozen ground underlying the tundra that covers nearly 9 million square miles in the northern latitudes. All together, Arctic soils contain more carbon than currently resides in the atmosphere, which is a worry considering that permafrost is now melting in Alaska, northern Canada, and Siberia, creating lakes and releasing methane. Once they get under way, permafrost melting, the release of methane and CO2, and rising temperature create a self-reinforcing trend, what scientists call a “ positive feedback loop.” The risk is that the release of a massive amount of methane into the atmosphere from melting permafrost could simply overwhelm efforts to stabilize climate.

Another unsettling development is the effect of atmospheric brown clouds (ABCs) consisting of soot particles from burning coal, diesel fuel, or wood. These particles affect climate in three ways. First, by intercepting sunlight, they heat the upper atmosphere. Second, because they also reflect sunlight, they have a dimming effect, lowering the earth’s surface temperature. And third, if particles from these brown clouds are deposited on snow and ice, they darken the surface and accelerate melting. These effects are of particular concern in India and China, where a large ABC over the Tibetan Plateau is contributing to the melting of glaciers that supply the major rivers of Asia. Soot deposition causes earlier seasonal melting of mountain snow in ranges as different as the Himalayas of Asia and the Sierra Nevada of California, and it is also believed to be accelerating the melting of Arctic sea ice.

In contrast to CO2, which may remain in the atmosphere for a century or more, soot particles in ABCs are typically airborne for only a matter of weeks. Thus, once coal-fired power plants are closed or wood cooking stoves are replaced with solar cookers, atmospheric soot disappears rapidly.

If we continue with business as usual, the Intergovernmental Panel on Climate Change’s (IPCC’s) projected rise in the earth’s average temperature of 1.1–6.4 degrees Celsius (2–11 degrees Fahrenheit) during this century seems all too possible. Unfortunately, during the several years since the IPCC study was released, both global CO2 emissions and atmospheric CO2 concentrations have exceeded those in its worst-case scenario. With each passing year the chorus of urgency from the scientific community intensifies. Each new report indicates that we are running out of time. For instance, a landmark 2009 study by a team of scientists from the Massachusetts Institute of Technology concluded that the effects of climate change will be twice as severe as those they projected as recently as six years prior. Instead of a likely global temperature rise of 2.4 degrees Celsius, they now see a rise exceeding 5 degrees.

Another report, this one prepared independently as a background document for the December 2009 international climate negotiations in Copenhagen, indicated that every effort should be made to hold the temperature rise to 2 degrees Celsius above pre-industrial levels. Beyond this, dangerous climate change is considered inevitable. To hold the temperature rise to 2 degrees, the scientists note that CO2 emissions should be reduced by 60–80 percent immediately, but since this is not possible, they note that, “To limit the extent of the overshoot, emissions should peak in the near future.”

The Pew Center on Global Climate Change sponsored an analysis of some 40 scientific studies that link rising temperature with changes in ecosystems. Among the many changes reported are spring arriving nearly two weeks earlier in the United States, tree swallows nesting nine days earlier than they did 40 years ago, and a northward shift of red fox habitat that has it encroaching on the Arctic fox’s range. Inuits have been surprised by the appearance of robins, a bird they have never seen before. Indeed, there is no word in Inuit for “robin.”

Douglas Inkley, National Wildlife Federation senior science advisor, notes, “We face the prospect that the world of wildlife that we now know—and many of the places we have invested decades of work in conserving as refuges and habitats for wildlife—will cease to exist as we know them, unless we change this forecast.” Unfortunately, this observation holds true for humans as well. If we cannot quickly reduce carbon emissions, it is civilization itself that is at risk.

Adapted from Chapter 3, “Climate Change and the Energy Transition,” in Lester R. Brown, Plan B 4.0: Mobilizing to Save Civilization (New York: W.W. Norton & Company, 2009), available online at www.earth-policy.org/books/pb4.

Additional data and information sources at http://www.earth-policy.org/.

Another sign from the research community that Earth’s temperature is rising: The volume of fresh water flowing down the world’s rivers has increased markedly since 1994, new satellite data confirms.

The study (also see here) led by the University of California, Irvine, appearing in the Proceedings of the National Academy of Sciences on October 4, “is the first to estimate global fresh-water flow into the world’s oceans using observations from new satellite technology rather than through computer or hydrological models,” Margot Roosevelt of the Los Angeles Times reported in a blog October 5. Science News, among other news outlets, also reported on the findings.

Annual fresh-water flow increased 18 percent from 1994 to 2006, the study found. The trend suggests that the global cycles of rainfall and evaporation are accelerating — a development that could intensify storms, floods, and droughts.

The U.C. Irvine findings coincide with other work by California researchers at the Scripps Institution of Oceanography and elsewhere who have tracked earlier snowmelt in the Sierra — one consequence of warming temperatures over several decades in the American West.

“Until now, we have had no continuous record of global-scale river discharge,” Jay Famiglietti, the principal investigator for the U.C. Irvine study, said in Roosevelt’s blog. “If these trends persist, they will be a smoking gun that the water cycle intensification, predicted by climate scientists, is already upon us.”

The new study showed ice sheets like the Greenland Ice Sheet can respond to such warming on the order of decades rather than the centuries projected by conventional thermal models. Ice flows more readily as it warms, so a warming climate can increase ice flows on ice sheets much faster than previously thought, said the study authors.

“We are finding that once such water flow is initiated through a new section of ice sheet, it can warm rather significantly and quickly, sometimes in just 10 years, ” said lead author Thomas Phillips, a research scientist with Cooperative Institute for Research in Environmental Sciences. CIRES is a joint institute between CU-Boulder and the National Oceanic and Atmospheric Administration.

Phillips, along with CU-Boulder civil, environmental and architectural engineering Professor Harihar Rajaram and CIRES Director Konrad Steffen described their results in a paper published online in Geophysical Research Letters.

Conventional thermal models of ice sheets do not factor in the presence of water within the ice sheet as a warming agent, but instead use models that primarily consider ice-sheet heating by warmer air on the ice sheet surface. In water’s absence, ice warms slowly in response to the increased surface temperatures from climate change, often requiring centuries to millennia to happen.

But the Greenland ice sheet is not one solid, smooth mass of ice. As the ice flows towards the coast, grating on bedrock, crevasses and new fractures form in the upper 100 feet of the ice sheet. Melt water flowing through these openings can create “ice caves” and networks of “pipes” that can carry water through the ice and spreading warmth, the authors concluded.

To quantify the influence of melt water, the scientists modeled what would happen to the ice sheet temperature if water flowed through it for eight weeks every summer — about the length of the active melt season. The result was a significantly faster-than-expected increase in ice sheet warming, which could take place on the order of years to decades depending on the spacing of crevasses and other “pipes” that bring warmer water into the ice sheet in summer.

“The key difference between our model and previous models is that we include heat exchange between water flowing through the ice sheet and the ice,” said Rajaram.

Several factors contributed to the warming and resulting acceleration of ice flow, including the fact that flowing water into the ice sheets can stay in liquid form even through the winter, slowing seasonal cooling. In addition, warmer ice sheets are more susceptible to increases of water flow, including the basal lubrication of ice that allows ice to flow more readily on bedrock.

A third factor is melt water cascading downward into the ice, which warms the surrounding ice. In this process the water can refreeze, creating additional cracks in the more vulnerable warm ice, according to the study.

Taken together, the interactions between water, temperature, and ice velocity spell even more rapid changes to ice sheets in a changing climate than currently anticipated, the authors concluded. After comparing observed temperature profiles from Greenland with the new model described in the paper, the authors concluded the observations were unexplainable unless they accounted for warming.

“The fact that the ice temperatures warm rather quickly is really the key piece that’s been overlooked in models currently being used to determine how Greenland responds to climate warming,” Steffen said. “However, this process is not the ‘death knell’ for the ice sheet. Even under such conditions, it would still take thousands of years for the Greenland ice sheet to disappear, Steffen said.

This study was funded by NASA’s Cryosphere Science Program.

Source Science Daily

UXBRIDGE, Sep 20 (IPS) – The carbon dioxide emissions from burning fossil fuels have melted the Arctic sea ice to its lowest volume since before the rise of human civilisation, dangerously upsetting the energy balance of the entire planet, climate scientists are reporting.

“The Arctic sea ice has reached its four lowest summer extents (area covered) in the last four years,” said Mark Serreze, director of the National Snow and Ice Data Center in the U.S. city of Boulder, Colorado.

The volume – extent and thickness – of ice left in the Arctic likely reached the lowest ever level this month, Serreze told IPS.

“I stand by my previous statements that the Arctic summer sea ice cover is in a death spiral. It’s not going to recover,” he said.

There can be no recovery because tremendous amounts of extra heat are added every summer to the region as more than 2.5 million square kilometres of the Arctic Ocean have been opened up to the heat of the 24-hour summer sun. A warmer Arctic Ocean not only takes much longer to re-freeze, it emits huge volumes of additional heat energy into the atmosphere, disrupting the weather patterns of the northern hemisphere, scientists have now confirmed.

“The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic,” James Overland of the NOAA Pacific Marine Environmental Laboratory in the United States told IPS in Oslo, Norway last June in an exclusive interview. Paradoxically, a warmer Arctic means “future cold and snowy winters will be the rule rather than the exception” in these regions, Overland told IPS.

There is growing evidence of widespread impacts from a warmer Arctic, agreed Serreze. “Trapping all that additional heat has to have impacts and those will grow in the future,” he said.

One local impact underway is a rapid warming of the coastal regions of the Arctic, where average temperatures are now three to five degrees C warmer than they were 30 years ago. If the global average temperature increases from the present 0.8 C to two degrees C, as seems likely, the entire Arctic region will warm at least four to six degrees and possibly eight degrees due to a series of processes and feedbacks called Arctic amplification.

A similar feverish rise in our body temperatures would put us in hospital if it didn’t kill us outright.

“I hate to say it but I think we are committed to a four- to six-degree warmer Arctic,” Serreze said.

If the Arctic becomes six degrees warmer, then half of the world’s permafrost will likely thaw, probably to a depth of a few metres, releasing most of the carbon and methane accumulated there over thousands of years, said Vladimir Romanovsky of the University of Alaska in Fairbanks and a world expert on permafrost.

Methane is a global warming gas approximately 25 times more potent than carbon dioxide (CO2).

That would be catastrophic for human civilisation, experts agree. The permafrost region spans 13 million square kilometres of the land in Alaska, Canada, Siberia and parts of Europe and contains at least twice as much carbon as is currently present in the atmosphere – 1,672 gigatonnes of carbon, according a paper published in Nature in 2009. That’s three times more carbon than all of the worlds’ forests contain.

“Permafrost thawing has been observed consistently across the entire region since the 1980s,” Romanovsky said in an interview.

A Canadian study in 2009 documented that the southernmost permafrost limit had retreated 130 kilometres over the past 50 years in Quebec’s James Bay region. At the northern edge, for the first time in a decade, the heat from the Arctic Ocean pushed far inland this summer, Romanovsky said.

There are no good estimates of how much CO2 and methane is being released by the thawing permafrost or by the undersea permafrost that acts as a cap over unknown quantities of methane hydrates (a type of frozen methane) along the Arctic Ocean shelf, he said.

“Methane is always there anywhere you drill through the permafrost,” Romanovsky noted.

Last spring, Romanovsky’s colleagues reported that an estimated eight million tonnes of methane emissions are bubbling to the surface from the shallow East Siberian Arctic shelf every year in what were the first-ever measurements taken there. If just one percent of the Arctic undersea methane reaches the atmosphere, it could quadruple the amount of methane currently in the atmosphere.

Abrupt releases of large amounts of CO2 and methane are certainly possible on a scale of decades, he said. The present relatively slow thaw of the permafrost could rapidly accelerate in a few decades, releasing huge amounts of global warming gases.

Another permafrost expert, Ted Schuur of the University of Florida, has come to the same conclusion. “In a matter of decades we could lose much of the permafrost,” Shuur told IPS.

Those losses are more likely to come rapidly and upfront, he says. In other words, much of the permafrost thaw would happen at the beginning of a massive 50-year meltdown because of rapid feedbacks.

Emissions of CO2 and methane from thawing permafrost are not yet factored into the global climate models and it will be several years before this can be done reasonably well, Shuur said.

“Current mitigation targets are only based on anthropogenic (human) emissions,” he explained.

Present pledges by governments to reduce emissions will still result in a global average temperature increase of 3.5 to 3.9 C by 2100, according to the latest analysis. That would result in an Arctic that’s 10 to 16 degrees C warmer, releasing most of the permafrost carbon and methane and unknown quantities of methane hydrates.

This is why some climate scientists are calling for a rapid phaseout of fossil fuels, recommending that fossil fuel emissions peak by 2015 and then decline three per cent per year. But even then there’s still a 50-percent probability of exceeding two degrees C current studies show. If the emissions peak is delayed until 2025, then global temperatures will rise three degrees C, the Arctic will be eight to 10 degrees warmer and the world will lose most its permafrost.

Meanwhile, a new generation of low-cost, thin-film solar roof and outside wall coverings being made today has the potential to eliminate burning coal and oil to generate electricity, energy experts believe – if governments have the political will to fully embrace green technologies.