(Also see “Manhattan-Size Ice Island Cracks in Half.”)

The crevasse stretches 19 miles (30 kilometers) long and up to 260 feet (80 meters) wide, as shown in a picture taken by NASA’s Terra satellite in October and featured this week as a NASA Image of the Day.

Snaking across the floating tongue of the Pine Island Glacier in West Antarctica, the crack is expected to create an iceberg 350 square miles (907 square kilometers)—versus 303 square miles (785 square kilometers) for Manhattan, Brooklyn, Queens, Staten Island, and the Bronx combined, according to NASA.

As for when the iceberg might shove off, “that is very difficult to predict,” said oceanographer Eric Rignot of NASA’s Jet Propulsion Laboratory, “but in the coming months for sure.”

Glacier “Contributing Most to Sea Level”

Usually there’s nothing extraordinary about a glacier calving, said glaciologist Ted Scambos of the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado.

Glaciers that flow into the sea, like the Pine Island Glacier, go through a normal cycle in which the floating section grows, stresses mount, and an iceberg breaks off, Scambos said.

“That is nothing unusual in most cases.”

But when the pattern deviates, glaciologists take notice. In this case, the crack is forming significantly farther “upstream” than has previously been the case. That “signifies that there are changes in the ice,” he said.

When “that point of rifting starts to climb upstream, generally you see some acceleration of the glacier.” That means that the ice will flow into the ocean at a faster rate, contributing even more to sea level rise.

(Related: “Hundreds of Glaciers Melting Faster in Antarctica.”)

 Such an acceleration is of particular concern at the Pine Island Glacier, because, among Antarctic glaciers, it’s “the one that’s contributing the most to sea level rise.”

In fact, he said, ice flows from that glacier alone account for a quarter to a third of Antarctica’s total contribution to sea level rise.

“It’s moving at about three kilometers [almost two miles] per year,” Scambos said. And, he noted, “it’s been accelerating quite a bit.”

(Pictures: Antarctica Warming.)

Cracking Glacier “Really Important”

As far as sea levels are concerned, changes in the Pine Island Glacier and other West Antarctic glaciers are far more important than shifts among the continent’s other glaciers, such as East Antarctica’s Mertz Glacier—despite Mertz’s much publicized release of a Luxembourg-size iceberg in early 2010.

That’s because the “Luxembourg” iceberg came from a glacial ice tongue that had just been “sitting there,” said oceanographer Doug Martinson of Columbia University’s Lamont-Doherty Earth Observatory.

By contrast, “West Antarctica has ice streams, of which Pine Island is one. Those are fast-flowing streams of ice,” said Martinson, who specializes in polar oceans.

When ice breaks off the Pine Island Glacier, he said, more ice can flow in faster from the mountains above—ice that will eventually wind up contributing to sea level rise.

“This glacier,” NSIDC’s Scambos added, “is really important.”

Source National Geographic

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

For two winters running, an Arctic chill has descended on Europe, burying that continent in snow and ice. Last year in the United States, historic blizzards afflicted the mid-Atlantic region. This winter the Deep South has endured unusual snowstorms and severe cold, and a frigid Northeast is bracing for what could shape into another major snowstorm this week.

Yet while people in Atlanta learn to shovel snow, the weather 2,000 miles to the north has been freakishly warm the past two winters. Throughout northeastern Canada and Greenland, temperatures in December ran as much as 15 to 20 degrees Fahrenheit above normal. Bays and lakes have been slow to freeze; ice fishing, hunting and trade routes have been disrupted.

Iqaluit, the capital of the remote Canadian territory of Nunavut, had to cancel its New Year’s snowmobile parade. David Ell, the deputy mayor, said that people in the region had been looking with envy at snowbound American and European cities. “People are saying, ‘That’s where all our snow is going!’ ” he said.

The immediate cause of the topsy-turvy weather is clear enough. A pattern of atmospheric circulation that tends to keep frigid air penned in the Arctic has weakened during the last two winters, allowing big tongues of cold air to descend far to the south, while masses of warmer air have moved north.

The deeper issue is whether this pattern is linked to the rapid changes that global warming is causing in the Arctic, particularly the drastic loss of sea ice. At least two prominent climate scientists have offered theories suggesting that it is. But others are doubtful, saying the recent events are unexceptional, or that more evidence over a longer period would be needed to establish a link.

Since satellites began tracking it in 1979, the ice on the Arctic Ocean’s surface in the bellwether month of September has declined by more than 30 percent. It is the most striking change in the terrain of the planet in recent decades, and a major question is whether it is starting to have an effect on broad weather patterns.

Ice reflects sunlight, and scientists say the loss of ice is causing the Arctic Ocean to absorb more heat in the summer. A handful of scientists point to that extra heat as a possible culprit in the recent harsh winters in Europe and the United States.

Their theories involve a fast-moving river of air called the jet stream that circles the Northern Hemisphere. Many winters, a strong pressure difference between the polar region and the middle latitudes channels the jet stream into a tight circle, or vortex, around the North Pole, effectively containing the frigid air at the top of the world.

“It’s like a fence,” said Michelle L’Heureux, a researcher in Camp Springs, Md., with the National Oceanic and Atmospheric Administration.

When that pressure difference diminishes, however, the jet stream weakens and meanders southward, bringing warm air into the Arctic and cold air into the midlatitudes — exactly what has happened the last couple of winters. The effect is sometimes compared to leaving a refrigerator door open, with cold air flooding the kitchen even as warm air enters the refrigerator. See * So what’s with the weather?

This has happened intermittently for many decades. Still, it is unusual for the polar vortex to weaken as much as it has lately. Last winter, one index related to the vortex hit its lowest wintertime value since record-keeping began in 1865, and it was quite low again in December.

James E. Overland, a climate scientist with NOAA in Seattle, has proposed that the extra warmth in the Arctic Ocean could be heating the atmosphere enough to make it less dense, causing the air pressure over the Arctic to be closer to that of the middle latitudes. “The added heat works against having a strong polar vortex,” he said.

But Dr. Overland acknowledges that his idea is tentative and needs further research. Many other climate scientists are not convinced, saying that a two-year span, however unusual, is not much on which to base a new theory. “We haven’t got sufficient insight to make definitive claims,” said Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research in Boulder, Colo.

Judah Cohen, director of seasonal forecasting at a company called Atmospheric and Environmental Research in Lexington, Mass., has spotted what he believes is a link between increasing snow in Siberia and the weakening of the polar vortex. In his theory, the extra snow is creating a dense, cold air mass over northern Asia in the late autumn, setting off a complex chain of cause and effect that ultimately perturbs the vortex.

Dr. Cohen said in an interview that the rising Siberian snow might, in turn, be linked to the decline of Arctic sea ice, with the open water providing extra moisture to the atmosphere — much as the Great Lakes produce heavy snows in cities like Buffalo and Syracuse. He is publishing seasonal forecasts based on his work, supported by the National Science Foundation. Those forecasts correctly predicted the recent harsh winters in the midlatitudes. But Dr. Cohen acknowledges, as does Dr. Overland, that some of his ideas are tentative and need further research.

The uncertainty about what is causing the strange winters highlights a core difficulty of climate science. While mainstream researchers are sure that greenhouse gases released by humans are warming the Earth, they acknowledge being on shakier ground in trying to predict the regional effects of that change. It is entirely possible, they say, that some regions will cool temporarily, because of disruption of the atmospheric and oceanic circulation, even as the Earth warms over all.

Bloggers who specialize in raising doubts about climate science have gleefully pointed to the recent winters in the United States and Europe as evidence that climatologists must be mistaken about a warming trend. These commentators have not been as eager to write about the strange warmth in parts of the Arctic, a region that scientists have long predicted will warm more rapidly than the planet as a whole.

Without doubt, the winter weather that began and ended 2010 was remarkable. Two of the 10 largest snowstorms in New York City history occurred last year, including the one that disrupted travel right after Christmas. The two snowstorms that fell on Washington and surrounding areas within a week in February had no known precedent in their overall impact on the region, with total accumulations of 40 inches in some places.

But the winters were not the whole story. Even without them, 2010 would have gone down as one of the strangest years in the annals of climatology, thanks in part to a weather condition known as El Niño, which dumped heat from the Pacific Ocean into the atmosphere early in the year. Later, the ocean surface cooled, a condition known as La Niña, contributing to heavy rainfall in many places.

Despite cooling from La Niña, newly compiled figures show that 2010 was among the two warmest years in the historical record. It featured a heat wave in Russia, all-time high temperatures in at least 17 countries, the hottest summer in New York City history, and devastating floods in Pakistan, China, Australia, the United States and other countries.

“It was a wild year,” said Christopher C. Burt, a weather historian for Weather Underground, an Internet site.

Still, however erratic the weather may have become, it is not obvious to most people how global warming could lead to frigid winters. Many scientists are hesitant to back such assertions, at least until they gain a better understanding of what is going on in the Arctic.

In interviews, several scientists recalled that in the decade ending in the mid-1990s, the polar vortex seemed to be strengthening, not weakening, producing mild winters in the eastern United States and western Europe.

At the time, some climate scientists wrote papers attributing that change to global warming. Newspapers, including this one, printed laments for winter lost. But soon after, the apparent trend went away, an experience that has made many researchers more cautious.

John M. Wallace, an atmospheric scientist at the University of Washington, wrote some of the earlier papers. This time around, he said, it will take a lot of evidence to convince him that a few harsh winters in London or Washington have anything to do with global warming.

“Just when you publish something and it looks like you’re seeing a connection,” Dr. Wallace said, “nature has a way of humbling us.”

Source NY Times

* Further reading on this topic from the Greenhouse Neutral Foundation 12^th of January 2010- ‘So what’s with the weather?’

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

Satellite imagery from the European Space Agency shows that a massive iceberg that calved from Greenland’s Petermann Glacier on August 4 has cruised into the Nares Strait, putting 28 kilometers between it and its source.

The 245-square-kilometer iceberg – that’s about four times the size of Manhattan – faces a fractured future. The satellite imagery shows it has hit a small island, which is slowing its journey but also threatening to break it up.

The berg is being tracked by the European Space Agency’s Envisat satellite, using both radar and photographs.

Related stories

Massive Ice Island Breaks off Greenland

Greenland Ice Sheet faces a tipping point in 10 years

We need to accept this moral responsibility. The following article which appeared in the Guardian I believe comes straight from James’s heart. Do you care enough to take an activist stance while we have the time?

Thank you – Bob Williamson Founder & Chair Greenhouse Neutral Foundation.

“How did you become an activist?” I was surprised by the question. I never considered myself an activist. I am a slow-paced taciturn scientist from the Midwest US. Most of my relatives are pretty conservative. I can imagine attitudes at home toward “activists”.

I was about to protest the characterisation – but I had been arrested, more than once. And I had testified in defence of others who had broken the law. Sure, we only meant to draw attention to problems of continued fossil fuel addiction. But weren’t there other ways to do that in a democracy? How had I been sucked into being an “activist?”

My grandchildren had a lot to do with it. It happened step by step. First, in 2004, I broke a 15-year self-imposed effort to stay out of the media. I gave a public lecture, backed by scientific papers, showing the need to slow greenhouse gas emissions – and I criticised the Bush administration for its lack of appropriate policies. My grandchildren came into the talk only as props – holding 1-watt Christmas tree bulbs to help explain climate forcings.

Fourteen months later I gave another public talk – connecting the dots from global warming to policy implications to criticisms of the fossil fuel industry for promoting misinformation. This time my grandchildren provided rationalisation for a talk likely to draw ire from the administration. I explained that I did not want my children to look back and say: “Opa understood what was happening, but he never made it clear.”

What had become clear was that our planet is close to climate tipping points. Ice is melting in the Arctic, Greenland and Antarctica, and on mountain glaciers worldwide. Many species are stressed by environmental destruction and climate change. Continuing fossil fuel emissions, if unabated, will cause sea levels to rise and species to become extinct beyond our control. Increasing atmospheric water vapour is already magnifying climate extremes, increasing overall precipitation, causing greater floods and stronger storms.

Stabilising climate requires restoring our planet’s energy balance. The physics is straightforward. The effect of increasing carbon dioxide on Earth’s energy imbalance is confirmed by precise measurements of ocean heat gain. The principal implication is defined by the geophysics, by the size of fossil fuel reservoirs. Simply put, there is a limit on how much carbon dioxide we can pour into the atmosphere. We cannot burn all fossil fuels. Specifically, we must (1) phase out coal use rapidly, (2) leave tar sands in the ground, and (3) not go after the last drops of oil.

Actions needed for the world to move on to clean energies of the future are feasible. The actions could restore clean air and water globally. But the actions are not happening.

At first I thought it was poor communication. Scientists must not have made the story clear enough to world leaders.

So I wrote letters to national leaders and visited more than half a dozen nations, as described in my book, Storms of My Grandchildren. What I found in each case was greenwash – a pretence of concern about climate but policies dictated by fossil fuel special interests.

The situation is epitomised by my recent trip to Norway. I hoped that Norway, because of its history of environmentalism, might be able to take real action to address climate change, drawing attention to the hypocrisy in the words and pseudo-actions of other nations.

So I wrote a letter to the prime minister suggesting that Norway, as majority owner of Statoil, should intervene in its plans to develop the tar sands of Canada. I received a polite response, by letter, from the deputy minister of petroleum and energy. The government position is that the tar sands investment is “a commercial decision”, that the government should not interfere, and that a “vast majority in the Norwegian parliament” agree that this constitutes “good corporate governance”. The deputy minister concluded his letter: “I can however assure you that we will continue our offensive stance on climate change issues both at home and abroad.”

A Norwegian grandfather, upon reading the deputy minister’s letter, quoted Saint Augustine: “Hypocrisy is the tribute that vice pays to virtue.”

The Norwegian position is a staggering reaffirmation of the global situation: even the greenest governments find it too inconvenient to address the implication of scientific facts.

It becomes clear that concerted action will happen only if the public, somehow, becomes forcefully involved. One way citizens can help is by blocking coal plants, tar sands, and the mining of the last drops of fossil fuels.

However, fossil fuel addiction can be solved only when we recognise an economic law as certain as the law of gravity: as long as fossil fuels are the cheapest energy they will be used. Solution therefore requires a rising fee on oil, gas and coal – a carbon fee collected from fossil fuel companies at the domestic mine or port of entry. All funds collected should be distributed to the public on a per capita basis to allow lifestyle adjustments and spur clean energy innovations. As the fee rises, fossil fuels will be phased out, replaced by carbon-free energy and efficiency.

A carbon fee is the only realistic path to global action. China and India will not accept caps, but they need a carbon fee to spur clean energy and avoid fossil fuel addiction.

Governments today, instead, talk of “cap-and-trade with offsets”, a system rigged by big banks and fossil fuel interests. Cap-and-trade invites corruption. Worse, it is ineffectual, assuring continued fossil fuel addiction to the last drop and environmental catastrophe.

Because the executive and legislative branches of our governments turn a deaf ear to the science, the judicial branch may provide the best opportunity to redress the situation. Our governments have a fiduciary responsibility to protect the rights of young people and future generations.

I look forward to standing with young people and their supporters, helping them develop their case, as they demand their proper due and fight for nature and their future. I guess that makes me an activist.

• The full version of this essay, entitled “Activist”, will appear in the book The Day After Tomorrow; Images of Our Earth in Crisis by J Henry Fair, to be published in November by PowerHouse Books. Dr James Hansen’s latest book is called Storms of my Grandchildren.

In the same way, the melting of sea ice in the Arctic, revealing the dark water below, has been shown by Australian scientists to be the main cause of unusually rapid warming at the top of the world.

Confirmation of this “feedback loop” means the region is likely to continue to warm strongly, with greater loss of sea ice and possible melting of the ice sheets.

James Screen and Ian Simmonds, of the University of Melbourne, said the rise in surface temperatures in the Arctic in the past 20 years had been more than double the global average.

The reasons for this enhanced warming have been “hotly debated” by scientists, with factors such as changes in cloud cover, and ocean and atmospheric circulation suggested as playing a role, along with sea ice loss, Dr Screen said.

To test these ideas, the researchers looked at the latest detailed atmospheric information, modelling and satellite measurements, including warming at different heights from the surface, for the period 1989 to 2008.

“Arctic warming is strongest at the surface during most of the year and is primarily consistent with reductions in sea ice cover,” said Dr Screen, whose study is published in the journal Nature.

Cloud cover did not have a big effect on recent warming, although increases in water vapour may have an impact in the lower part of the atmosphere in summer and early autumn.

Dr Screen said white ice reflects a lot of sunlight, but as it melts due to man-made warming from greenhouse gas emissions, the dark water that is exposed absorbs more heat, which in turn, melts more ice, and so on.

The amount of Arctic sea ice was at a record low in the summer of 2007, down about 40 per cent.

Although it has recovered slightly since, the long-term trend is down, he said. “We’re heading towards a situation where the Arctic Sea will be ice-free in summer.”

Source The Age

I’m talking at the University of Queensland next week so I thought I might use Skeptical Science to test-drive a new visual metaphor. Sometimes in the climate debate, we get a bit lost in the data and statistical analysis, forgetting the sheer scale of the impact we’re having on our climate. A vivid example is the amount of ice that Greenland is currently losing. When scientists talk about ice loss from the Greenland ice sheet, they refer to gigatonnes of ice. One gigatonne is one billion tonnes. To get a picture of how large this is, imagine a block of ice one kilometre high by one kilometer wide by one kilometre deep (okay, the edges are actually 1055 metres long as ice is slightly less dense than water but you get the idea). Borrowing from alien invasion movies, the scale is well illustrated by comparing a gigatonne block of ice to a famous, historical landmark like the Empire State Building:

How much ice is Greenland losing? This is monitored by satellites which have measured changes in gravity around the ice sheet over the last decade (Velicogna 2009). In 2002 to 2003, the Greenland ice sheet was losing mass at a rate of 137 gigatonnes per year.

However, the rate of ice loss has more than doubled in less than a decade. The rate of ice loss over the 2008 to 2009 period was 286 gigatonnes per year.

This is a vivid reminder that global warming isn’t a statistical abstraction cooked up in a climate lab. Greenland is just one example of the physical realities of climate change. On the other side of the planet, Antarctica is also losing ice at an accelerating rate. All over the globe, glaciers are retreating at an accelerating rate.

It’s also a reminder of the massive amount of inertia at play in our climate. It takes time for the massive Greenland ice sheet to respond to warming. But this inertia is not our friend. Now that Greenland is losing ice at an accelerating rate, it’s not like we can throw a rope around the ice sheet and hold it back. The steadily accelerating ice loss from Greenland is an ominous reminder that our actions now will have effects long into the future.

And for those who wish to watch it happen in real time, here it is!