The most detailed satellite information available shows that ice sheets in Greenland and western Antarctica are shrinking faster than scientists thought and in some places are already in runaway melt mode, a new study found….

Using 50 million laser readings from a NASA satellite, scientists for the first time calculated changes in the height of the vulnerable but massive ice sheets and found them especially worse at their edges. That’s where warmer water eats away from below. In some parts of Antarctica, ice sheets have been losing 30 feet a year in thickness since 2003, according to the study….

“To some extent it’s a runaway effect. The question is how far will it run?” said lead author Hamish Pritchard of the British Antarctic Survey. “It’s more widespread than we previously thought.”

That’s from “Study: ‘Runaway’ melt on Antarctica, Greenland,” the pull-no-punches MSNBC story last month.  The full study, “Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets,” was published in Nature (subs. req’d, excerpted below).

The British Antarctic Survey put out a news release with graphics.  Here are some satellite tracks, from NASA’s ICESat (Ice, Cloud, and land Elevation Satellite), revealing areas of dynamic thinning (red) in Antarctica and Greenland [click to enlarge].

The release notes that this “dynamic thinning”:

The authors conclude “Ice shelf collapse has triggered particularly strong thinning that has endured for decades.”  More of the MSNBC story:

Some of those areas are about a mile thick, so they’ve still got plenty of ice to burn through. But the drop in thickness is speeding up. In parts of Antarctica, the yearly rate of thinning from 2003 to 2007 is 50 percent higher than it was from 1995 to 2003.

These new measurements confirm what some of the more pessimistic scientists thought: The melting along the crucial edges of the two major ice sheets is accelerating and is in a self-feeding loop. The more the ice melts, the more water surrounds and eats away at the remaining ice.

What’s going on in Antarctica may be even more worrisome than what’s happening in Greenland, as I’ve noted (see Large Antarctic glacier thinning 4 times faster than it was 10 years ago: “Nothing in the natural world is lost at an accelerating exponential rate like this glacier” and “Q: How much can West Antarctica plausibly contribute to sea level rise by 2100?” [A:  3 to 5 feet]).

Antarctica is disintegrating much faster than almost anybody imagined.  In 2001, the IPCC “consensus” said neither Greenland nor Antarctica would lose significant mass by 2100. They both already are.  As Penn State climatologist Richard Alley said in March 2006, the ice sheets appear to be shrinking “100 years ahead of schedule.”

The warming of the WAIS is most worrisome (at least for this century) because it’s going to disintegrate long before the East Antarctic Ice Sheet does — since WAIS appears to be melting from underneath (i.e. the water is warming, too), and since, as I wrote in the “high water” part of my book, the WAIS is inherently less stable:

Perhaps the most important, and worrisome, fact about the WAIS is that it is fundamentally far less stable than the Greenland ice sheet because most of it is grounded far below sea level. The WAIS rests on bedrock as deep as two kilometers underwater. One 2004 NASA-led study found that most of the glaciers they were studying “flow into floating ice shelves over bedrock up to hundreds of meters deeper than previous estimates, providing exit routes for ice from further inland if ice-sheet collapse is under way.” A 2002 study in Science examined the underwater grounding lines–the points where the ice starts floating. Using satellites, the researchers determined that “bottom melt rates experienced by large outlet glaciers near their grounding lines are far higher than generally assumed.” And that melt rate is positively correlated with ocean temperature.

The warmer it gets, the more unstable WAIS outlet glaciers will become. Since so much of the ice sheet is grounded underwater, rising sea levels may have the effect of lifting the sheets, allowing more-and increasingly warmer-water underneath it, leading to further bottom melting, more ice shelf disintegration, accelerated glacial flow, and further sea level rise, and so on and on, another vicious cycle. The combination of global warming and accelerating sea level rise from Greenland could be the trigger for catastrophic collapse in the WAIS (see, for instance, here).

You can read every thing a laymen could possibly want to know about what the recent study on Antarctic warming does and doesn’t show at RealClimate here.

The authors of the Nature article find:

In Antarctica, we find significant dynamic thinning of fast-flowing ice at rates greater than plausible through interannual accumulation variability for drainage sectors….  On the glacier scale, thinning is strongest in the Amundsen Sea embayment (ASE), where it is confirmed as being localized on the fast-flowing glaciers and their tributaries (Fig. 3 [below]. The area close to the Pine Island Glacier grounding line thinned in the period 2003–2007 at up to 6 m yr-1, neighbouring Smith Glacier thinned at a rate in excess of 9 m yr-1 and Thwaites Glacier thinned at a rate of around 4 m yr-1. These rates are higher than those reported for the 2002–2004 period.

They conclude:

In Antarctica, dynamic thinning has accelerated at the grounding lines of the major glaciers of the Amundsen Sea embayment, and in places has penetrated to within 100 km of the ice divides. Ice-shelf-collapse glaciers show particularly strong thinning that has persisted for years to decades after collapse and in places has penetrated to their headwalls. Although losses are partly offset by strong gains on the spine and western flank of the Antarctic Peninsula, numerous glaciers feeding intact Antarctic Peninsula, West Antarctic and East Antarctic ice shelves are also thinning dynamically. We infer that grounded glaciers and ice streams are responding sensitively not only to ice-shelf collapse but to shelf thinning owing to ocean-driven melting. This is an apparently widespread phenomenon that does not require climate warming sufficient to initiate ice-shelf surface melt. Dynamic thinning of Greenland and Antarctic ice-sheet ocean margins is more sensitive, pervasive, enduring and important than previously realized.

Did I mention the time to act is now!

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Michael Mann updates the world on the latest climate science

Evolution of Evolution

First Things First: The journal Nature has published a study that attempts to find numerical “planetary boundaries” for global change, an effort that the authors believe will help policymakers better understand humanity’s impact on the planet and its life. A team of Earth scientists, led by the Stockholm Resilience Center, has identified and defined nine natural systems, and sifting through mountains of data and studies, assigned tentative thresholds beyond which environmental stress might cause them to fail. We have already tripped three such systems–climate change, extinction rate, and the nitrogen cycle, they contend. The study is likely to infuriate scientists who think assigning single numbers to such complex systems is absurd; confuse nonprofessionals trying to parse the value of boundaries so laden with caveats and lacunae in knowledge; and succeed in focusing the global conversation on the best available metrics for the speed at which civilization is swallowing the Earth.

New York Midtown Traffic Linked to Climate Change: The ultimate audience for whom the Nature study was conducted met in New York City two days before its publication. President Barack Obama addressed Tuesday’s day-long U.N. climate change summit. He noted the urgency of the issue and his administration’s role in turning around the U.S.’s policy. He outlined investment in renewable electricity and fuel economy and proposed a global phase-out of oil subsidies. But he couldn’t give the audience what it wanted: a U.S. climate policy to back up the president’s international goals.

U.N. Secretary-General Ban Ki-moon hosted the event, a political pick-me-up on what has otherwise been a muddy road to the December COP-15 talks in Copenhagen. The parade of world leaders past the podium set off the inevitable question of who is leading the global climate debate. Noble speeches and goals were largely deflated by vague language. Chinese President Hu Jintao vowed the world’s largest carbon dioxide emitter would cut down by a “notable” amount, without assigning a numerical target. India sent its environment minister, Jairam Ramesh, who talked up domestic legislation likely to appear in November that could set voluntary targets for fuel efficiency in 2011, building codes in 2012, and carbon capture and storage by 2020. The Wall Street Journal’s Environmental Capital blog asks, Has China suddenly become the “good guy” on climate?

All the activity may indicate that a new kind of global deal is emerging, in which individual nations design their own goals and programs, in what adds up to a more federalized system. More theoretically, if global emissions were limited to an amount thought to keep the Earth below 2 degrees Celsius of warming by 2050, and the access to these emissions were assigned out based on population, the U.S. would run out in six years and have to stop polluting.

A new series in ClimateWire will provide an in-depth look at development and climate issues inside China. The first piece cites U.S. climate envoy Todd Stern’s observation that parts of China resemble the developed world, even if most of the country is developing. Writer Lisa Friedman nails a central frustration with the status quo international climate regime: “Stern’s problem is that the current global climate change regime doesn’t allow for this kind of nuance.”

List of Lists to Grow: The Stockholm Resilience Institute is only the most rigorous attempt to list issues as a way for people to understand them better. U.K. Prime Minister Gordon Brown turns in a New York Times op-ed enumerating five global issues that need attention over the next six months -- the most consequential for global cooperation since 1945. Climate change tops the list. Sheila Olmstead and Robert Stavins, of Yale and Harvard respectively, identify three essential pillars of an international agreement: inclusion of key rich and poor nations; allowing enough time for emissions reductions; Tribune Newspapers points out nine potential stumbling blocks to a global treaty. Half of the top 10 most environmentally responsible companies are in information technology, according to a Newsweek study of the green 500.

Capitol Ideas: Conflict in the Senate made Washington a climate center this week, even as the war in Afghanistan distracted people from kicking back and reading Sen. Max Baucus’ centrist health-care legislation. Sen. Lisa Murkowski (R-Alaska), ranking member of the Energy Committee, threatened to introduce legislation that would delay enactment of the EPA’s new greenhouse gas regulations emissions, as they would affect stationary sources, such as power plants or manufacturing facilities. Though the situation is now resolved, it occupied senators on both sides of the aisle for several days.

Activity on climate activity proceeds in the Environment and Public Works Committee, where Sen. Barbara Boxer (D-Calif.), committee chairwoman, and Sen. John Kerry (D-Mass.) will introduce a bill next week. It is based on the legislation that passed the House of Representatives in June. Sen. Maria Cantwell (D-Wash.) is expected to introduce a stripped-down, 33-page “cap-and-refund” bill that would sell emissions credits at auction to energy companies. Seventy-five percent of the funds would return to consumers. The balance would go toward investment in new energy technology and other climate-related matters.

No (Science) News Is Good News: Upbeat climate-related stories abound, as venture capitalists plow funds into shiny and clean energy technologies and city managers find better ways of living. It is difficult to travel long in this space without acknowledging that dangerous climate change would be a bummer. Precise satellite measurements show that ice melt on Greenland and in Antarctica is accelerating. The Western U.S. may have a hard time planning for change, when officials don’t recognize scientific observations. Overall, the science can be characterized as, if not worrisome, then hard.

Naming Names: One upside to a failure at Copenhagen has gone unremarked upon, until the following conversation with Mrs. Climate Post occurred en route to work earlier this week:

MCP: “So wait … if they strike a deal in Copenhagen, then we’ll have to call it the Copenhagen Protocol, like the Kyoto Protocol?”
CP: “That’s pretty much the idea, yeah.”
MCP: “It’s kind of a mouthful.”
CP: “Next year is Mexico City.”
MCP: “Still a lot of syllables.”
CP: Maybe they can go back to Milan. The Milan Protocol.”
MCP: “That’s nice. I like that.”
CP: “Or Perm…”

Eric Roston is Senior Associate at the Nicholas Institute and author of The Carbon Age: How Life’s Core Element Has Become Civilization’s Greatest Threat. Prologue available at Grist.

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The Climate Post is a weekly roundup of climate news, produced by the The Nicholas Institute for Environmental Policy Solutions at Duke University.

First Things First: Cars, trucks, planes, and other things that go add more greenhouse gas to the atmosphere than any other sector where end-users burn their own fuel. And transportation added more energy-and-climate headlines this week than any other sector, driven by an emergency congressional payout to continue the "cash-for-clunkers" program and General Motors' promotional campaign for the Chevy Volt, its plug-in hybrid electric-and-gas car.

GM's message is simple enough: "230." That's the number of miles that the carmaker says the Volt can travel per gallon of gas, news greeted with a mix of exuberance and skepticism. Many reporters, analysts, and bloggers see symbolism in Chevy's very announcement, namely, that the company has chosen to speak of its future in the language of the past. By measuring the Volt against the traditional miles-per-gallon yardstick, GM is  fixing the electricity-powered car in the framework of gasoline. The Volt is expected to cost about $40,000 and go on sale at the end of 2011. Question: Could a "cash-for-chargers" program be far behind? Another question: If it's true, as a former GM official once famously said, that "you don't roll out a new product in August," what does an August roll-out say about GM's enthusiasm for this project?

GM faces nascent and possibly significant competition from upstart companies, such as Coda Automotive and Bright Automotive, who are trying to forego the Detroit business model of having all aspects of production and distribution under one corporate roof.

Department of Chickens and Eggs: The benefits of moving away from gasoline- and diesel-powered automobiles, toward non-polluting energy, are well-known: lower carbon dioxide emission levels; extrication from petro geopolitics; a diminishing numbers of car explosions in summertime Hollywood blockbusters. For a fleet of electric cars or hybrids to succeed in replacing them, there must be enough electricity. And the trouble with electricity is that producers find it difficult, once they've generated it, to pour it into a pipeline, supertanker, or a hazmat truck. What they need are power lines, which are unsightly, and batteries, which are commercially immature.

If Americans will charge their electric cars at home 90 percent of the time, as predicted, then electric and hybrid fleets will require that much more electricity be conveyed to homes. Power companies will need to both meet new demand for power and manage it wisely. That's where the "smart grid" comes in. The smart grid is a suite of technologies and behaviors to help power flow smoothly and predictably from generator, to grid, to users (and if they generate more than they need, back to the grid). The clean tech firm GridPoint's development of software to help utilities monitor and predict plug-in owners' charging habits is a quieter parallel development to GM's launch of its Volt campaign.

Beyond batteries and new generation transmission, there are plenty of "clean tech" stories to go around while the solar industry works out its monumental supply glut. And venture capitalists familiar with these developments are finding themselves in influential positions--even in the public sector public sector.

A Clunker of a Program (Full Stop?): An emergency $2 billion tranche will sustain the popular "cash for clunkers" program after it depleted its initial $1 billion treasury. Three criticisms tend to arise: the mileage of approved replacement cars is too low; the program rewards "bad" choices—buying inefficient cars; and marginal auto efficiency improvement are unlikely to produce benefits in financial savings as large as those generated by reducing buildings' energy waste, or promoting healthier lifestyles.

Part economic stimulus, clunkers-inspired car buying lifted sales 2.4 percent in July and led Ford to ramp up production. The auto sales spike could not alone carry overall retail sales into positive territory. The LAT lays out a loophole in the clunkers legislation, large enough to drive, um, a truck through. The Car Allowance Rebate System (CARS), the actual name of the legislation, exempts cars built before 1984, a request by the antique auto-parts lobby: "The final wording of the bill, including the provision requested by the interest group, was ironed out in a legislative conference committee and attached to a military spending bill." A New York Times lede and a Los Angeles Times photo suggest a marketing trend of dealerships displaying "clunkers" in dumpsters as a signal that they are participating in the program. The NYT Web headline, "A Clunker of a Program?", demonstrates the time-tested practice of a publication adding a question mark to a non-neutral statement of opinion to make it look like a neutral query.

Senate Climate Bill Goes Down Down Under: The Australian Senate defeated legislation that would have set up a national carbon emissions trading program. Climate change down under divides national political parties on a level the topic has not yet reached in the United States.

Though their political situations have little in common with the Australians, the Democratic leadership of the U.S. Senate also faces political obstacles to passage of a climate bill. For one, this week included an estimate that puts the program's ten-year bureaucratic price tag at $8 billion (The costs of inaction are more difficult to quantify with a pat number). Looming larger, president Obama faces opposition in the Senate from Democrats whose states rely on coal for electricity and manufacturing for jobs. Ten Democratic senators signed a letter to the Obama, requesting relief in legislation in the form of border tariffs on goods from countries without climate policies and rebates to offset higher energy costs.

New analyses of legislation by lobbying groups means, among other things, more fodder for he-said, she-said political rhetoric and subsequent reporting. (He said:) The National Association of Manufacturers rolled out its cost modeling of the House climate-and-energy bill that passed in June, projecting 2 million U.S. job losses and a 2 percent drop in GDP by 2020. The assumptions that went into the modeling are not yet released but (she said:) the Environmental Defense Fund is eager to discredit them. See this for a lengthy treatment about last year's tete-a-tete between NAM and EDF, and why not all economic models are equal but are sometimes presented that way in quickly written, grotesquely simplified paragraphs like this one.

Attention to the particulars of climate policy will ramp up as the fall legislative season begins, and the Senate tears into its version of the House bill. Seed magazine is ahead of the game, offering an explainer about "carbon offsetting," that includes views of five experts, including colleague Brian Murray, the Nicholas Institute's director of economic analysis and an IPCC economist

The Electric Kool-Aid Acid Bath: People enjoy the oceans both because they are pretty and because they absorb anthropogenic carbon dioxide, slowing its atmospheric accumulation and trapping of heat. Thanks, oceans. That said, ocean creatures do enjoy their water at specific temperatures, depths, salinity, and alkalinity.  As the seas absorb increased carbon dioxide from the atmosphere, oceans' chemistry changes, becoming less alkaline--or, as it has become commonly known, more acidic. Scientists are studying the effects of ocean acidification on creatures large and small, hoping to glean what this monumental change could mean for the fate of the human presence on and in oceans, marine ecosystems, and by extension the path of carbon from deep Earth, to power plant, to sky, to sea.

Coming off the Earth's second hottest July in recorded history (about 150 years), it's nice to think about ice, keeper of its own recorded history (about 800,000 years). One thing that makes climate so difficult to write about is that so much of potential change is clear and so much of it is not clear. If only there were a way to democratize science, so that sitting at your desktop you can see the ice for yourself, where it comes from, and how scientists study it.

Related Links:

Satellite data suggests “that EAST Antarctica is losing mass”

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Inhofe to Boxer: “We Won, You Lost, Now Get a Life!”

The Sermeq Kujalleq glacier (also known as the Jakobshavn Glacier) near where it flows into the sea in western Greeland. The photo was taken in the summer of 2008. Scientists have recorded the glacier's rapid melt over the past decade.Courtesy kriskaer via Flickr

Here's a tip for the ministers who are attending the latest of the long series of meetings preparing for the make-or-break climate negotiations in Copenhagen this December.

Go visit the valley of the dogs.

Yes, that's dogs, not dolls. Greenland sled dogs to be precise. For this week's meeting of 30 ministers from key countries is in Ilulissat, the third biggest settlement on the immense, increasingly melting island.

They have been invited there for informal "substantive and open" discussions, far from the media, by Connie Hedegaard the impressive Danish Minister for Climate and Energy. She has been holding such ministerial dialogues in different parts of the world for the past five years, but Ilulissat is her prime location, her secret weapon.

A former journalist, she well understands that "seeing is believing." And in this small coastal town overlooking a sea strewn with icebergs, the evidence of global warming is both unmistakable and overwhelming. She has hosted a whole series of key figures there over the last years, including House Speaker Nancy Pelosi, Sen. John McCain, and German Chancellor Angela Merkel. She wants President Obama to come too.

With her country hosting the next major international talks on climate change, Denmark's Connie Hedegaard has been bringing world leaders to Greenland in hopes that seeing global warming's effects up close will spur them to action.Courtesy Denmark's Ministry for Climate and EnergyI was there almost two years ago with Bartholomew I, the Ecumenical Patriarch of the Eastern Orthodox Church. Dubbed "the green pope" for his deep environmental concern, he has held a series of shipboard seminars on religion, science and the environment, on seas and rivers around the world, and this one started just off Ilulissat, home to 4,500 people and 2,500 sled dogs.

Ah yes, those dogs. I came across them on a trip ashore, when the whole shipload of us took a walk from the town to an ancient settlement on a nearby shore. In a valley, stretching as far as the eye could see, were countless scratching, sleeping, howling animals, tethered next to makeshift kennels. It must be the strangest settlement of the unemployed on the face of the warming Earth.

Until recently the dogs were busy and treasured, vital engines of transport in a land without roads, where the easiest routes from place to place -- or to the best hunting spots -- are often across the frozen ocean. But for five years before I was there the sea had failed to freeze, giving the hunters and their dogs nowhere to go.

It is much the same story hundreds of miles away at Qaanaak in the island's far northwest. The sea still freezes there, but the ice comes one and a half months later than a few years ago, and melts one and a half months earlier. For the local Inuit, who subsist by hunting over the ice with their sleds, it is -- as explained to me -- "like your boss taking away three months for your pay without giving you notice."

You can hear the howling of the idle dogs, reputedly descended from wolves, all over Ilulissat. But even this is not the most remarkable, or portentous, sound that fills the air. That sound -- loud booms that sometimes rumble like approaching thunder or other times crack sharply like a gunshot -- accompanies the calving of yet another iceberg from the giant Sermeq Kujalleq [see map at bottom of next page] glacier reaching the sea just beyond the canine valley.

The booms are ever more frequent these days, for the glacier is melting ever faster as Greenland warms up three times as fast as the rest of the world. Every day it now sheds enough fresh water, in the form of ice, to supply the whole of London or New York for an entire year.

The glacier, the biggest in Greenland, is racing towards the sea at a rate of nearly ten miles a year, five times as fast as a decade ago. And it can go even faster -- at one point scientists were shocked to find that part of it had surged three miles in just 90 minutes.

You can see the start of the process if you fly over the glacier. Melt water on the surface is finding its way down to the rock beneath, not in gentle trickles but in giant waterfalls that have carved great caverns in the ice; some are said to be as large as the Niagara Falls.

This has created a lake 500 meters deep under the glacier, lifting the ice and lubricating the glacier's passage. And much the same is happening all around Greenland, causing its ice-cap to melt far faster than anyone had expected, contributing to the inevitable rising of the world's seas.

I defy any rational person to see all this and not be struck with the urgency of combatting global warming. The ministers at this week's climate meeting will surely be shown the glacier; they have been promised "excursions to ... view first hand the consequences of climate change."

Rational people that they are, let's hope they get the point and act accordingly ... and fast.

--

Below: Video of the Ilulissat Icefjord from www.100places.com.

This video is from www.icescapes.tv

The Jakobshavn Glacier in western Greenland drains the central ice sheet, and it is retreating inland faster than any other. This image shows the glacier in 2001. The glacier flows from upper right to lower left. The fjord beyond the glacier terminus is packed with seasonal ice and icebergs. Terminus locations before 2001 were determined by surveys; more recent contours were derived from Landsat data. Without measurements of ice thickness, however, the picture of ice loss is incomplete. -- NASA image by Cindy Starr, based on data from Ole Bennike and Anker Weidick (Geological Survey of Denmark and Greenland) and Landsat data.Courtesy NASA's Earth Observatory

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December 19—the day after COP15

The eastern United States must plan on the very real possibility that total sea level rise by 2100 will exceed 6 feet on our current emissions path. Sadly, the Washington Post got the story only half right.

This week I'll focus on our best understanding of the impacts that Americans face from human-caused climate change. On Tuesday, the US Global Change Research Program is releasing its long-awaited comprehensive analysis of Global Climate Change Impacts in United States. We'll see how it matches up against my not-so-well-funded analysis, "Yes, the science says on our current emissions path we are projected to warm most of U.S. 10 - 15°F by 2100, with sea level rise of 5 feet or more, and the SW will be a permanent Dust Bowl."

First, though, let's do a comprehensive review of projected sea level rise (SLR), starting with two recent studies on what accelerated melting of the Greenland ice sheet might mean for us. The University of Alaska Fairbanks reports on a brand new study in the journal Hydrological Processes (subs. req'd):

The Greenland ice sheet is melting faster than expected according to a new study....

Study results indicate that the ice sheet may be responsible for nearly 25 percent of global sea rise in the past 13 years. The study also shows that seas now are rising by more than 3 millimeters a year-more than 50 percent faster than the average for the 20th century.

UAF researcher Sebastian H. Mernild and colleagues from the United States, United Kingdom and Denmark discovered that from 1995 to 2007, overall precipitation on the ice sheet decreased while surface ablation-the combination of evaporation, melting and calving of the ice sheet-increased. According to Mernild's new data, since 1995 the ice sheet lost an average of 265 cubic kilometers per year, which has contributed to about 0.7 millimeters per year in global sea level rise.

This research is consistent with data presented at the annual meeting of the American Geophysical Union in December (see "Two trillion tons of land ice lost since 2003, rate of Greenland summer ice loss triples 2007 record"). This staggering ice loss is all the more worrisome because it was not predicted by the IPCC's climate models. As Penn State climatologist Richard Alley said in March 2006, the ice sheets appear to be shrinking "100 years ahead of schedule." In 2001, the IPCC thought that neither Greenland nor Antarctica would lose significant mass by 2100. They both already are.

And, of course, Greenland is facing an almost incomprehensible amount of warming if we stay anywhere near our current emissions path - see "M.I.T. doubles its 2095 warming projection to 10°F - with 866 ppm and Arctic warming of 20°F."

Especially worrisome for North America is that a new study in Geophysical Research Letters (subs. req'd) finds that sustained high rates of Greenland ice loss could lead to staggering increases in coastal sea level rise. As reported:

If Greenland's ice melts at moderate to high rates, ocean circulation by 2100 may shift and cause sea levels off the northeast coast of North America to rise by about 12 to 20 inches (about 30 to 50 centimeters) more than in other coastal areas. The research builds on recent reports that have found that sea level rise associated with global warming could adversely affect North America, and its findings suggest that the situation is more threatening than previously believed.

"If the Greenland melt continues to accelerate, we could see significant impacts this century on the northeast U.S. coast from the resulting sea level rise," says NCAR scientist Aixue Hu, the lead author. "Major northeastern cities are directly in the path of the greatest rise."

All that is needed for the 20 inches of extra sea level rise is if Greenland's melt rate continues at its current rate through 2050.

And the key point of this study is that this 20 inches would be on top of what ever sea level rise is caused by the ice loss in Greenland, Antarctica, and the inland glaciers, plus thermal explanation of the ocean.

How much sea level rise is that? Well, if you read last week's WashPost story on the second study, "East Coast May Feel Rise in Sea Levels the Most," you'd get the bizarrely old SLR estimate from the 2007 IPCC report:

While the rest of the world might see seven to 23 inches of sea-level rise by 2100, the studies show this region might get that and more - 17 to 25 inches more - for a total increase that would submerge a beach chair.

[Note to WP: Sea level rise is one of the most potentially devastating impacts of global warming to human civilization -- so you need a more serious visual metaphor for it than submerging a "beach chair.]

The 7- to 23-inch estimate was out of date the minute it was published in 2007, since the IPCC froze virtually all new science inputs to its Fourth Assessment in 2005. Why would the WP write an article about the very latest study of possible extra SLR in 2100 and then add it to a very old SLR estimate that was based on an even older literature survey?

Last year, the Bush administration itself explained in great detail that the IPCC's projection, low-balled the sea level rise number - see US Geological Survey stunner: Sea-level rise in 2100 will likely "substantially exceed" IPCC projections. Since big media still gets this wrong, let's take a quick look at that study, which concluded "based on an assessment of the published scientific literature":

Recent rapid changes at the edges of the Greenland and West Antarctic ice sheets show acceleration of flow and thinning, with the velocity of some glaciers increasing more than twofold. Glacier accelerations causing this imbalance have been related to enhanced surface meltwater production penetrating to the bed to lubricate glacier motion, and to ice-shelf removal, ice-front retreat, and glacier ungrounding that reduce resistance to flow. The present generation of models does not capture these processes. It is unclear whether this imbalance is a short-term natural adjustment or a response to recent climate change, but processes causing accelerations are enabled by warming, so these adjustments will very likely become more frequent in a warmer climate. The regions likely to experience future rapid changes in ice volume are those where ice is grounded well below sea level such as the West Antarctic Ice Sheet or large glaciers in Greenland like the Jakobshavn Isbrae that flow into the sea through a deep channel reaching far inland. Inclusion of these processes in models will likely lead to sea-level projections for the end of the 21st century that substantially exceed the projections presented in the IPCC AR4 report (0.28 ± 0.10 m to 0.42 ± 0.16 m rise).

What does the recent published scientific literature now project?

And here's an extra update. The 2008 Science paper, "Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise" with its 0.8 and 2.0 m projection for 2100, is widely considered to be the most credible, comprehensive, and authoritative recent estimate. And yet consider just one piece of that analysis - the lower bound projection of the SLR contribution in 2100 from the ice caps and inland glaciers (other than Greenland and Antarctica), which the paper says is 0.17 meters (170 millimeters).

These inland glaciers are melting unexpectedly fast (see " Another climate impact comes faster than predicted: Himalayan glaciers "decapitated" and "Another one bites the dust, literally: Bolivia's 18,000 year-old Chacaltaya glacier is gone."

A 2009 Geophysical Research Letters paper, "Sea-level rise from glaciers and ice caps: A lower bound," (subs. req'd) concluded a detailed analysis of actual glacier data:

If the climate continues to warm along current trends, a minimum of 373 ± 21 mm of sea-level rise over the next 100 years is expected from glaciers and ice caps. When compared to recent estimates from all other sources, melt water from glaciers must be considered as a particularly important fraction of the total sea-level rise expected this century.

So you can add a minimum of 0.2 meters to the lower bound of the Science paper - taking that paper's lower bound to 1 meter. Given how fast the Arctic is projected to warm on the BAU path, I wouldn't be surprised if projections of the likely ice loss from Greenland will rise in the coming years. Same for Antarctica (see "Q: How much can West Antarctica plausibly contribute to sea level rise by 2100?").

Bottom line: The entire U.S. should be planning on SLR of 5 feet by 2100 on our current emissions path. And the eastern United States should plan on the very real possibility that total sea level rise will exceed 6 feet.

Related Links:

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Disappearing slave history

Today’s question:  How the heck does the Greenland ice sheet survive accelerated disintegration from projected 20°F warming by the 2090s?

I previously blogged on how the Massachusetts Institute of Technology Joint Program on the Science and Policy of Climate Change has joined the climate realists — the growing group of scientists who understand that the business as usual emissions path leads to unmitigated catastrophe (see “Hadley Center: “Catastrophic” 5-7°C warming by 2100 on current emissions path” and below).

Back in January, the Program issued a remarkable report in January, by over a dozen leading experts, doubling their 2095 warming projection to 5.2°C. The media mostly ignored it, which is no surprise, since the media generally ignores the realists in general (see U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm … the worst-case IPCC scenario trajectories (or even worse) are being realised” — 1000 ppm).

Now, the MIT study has been published in a peer-reviewed journal — The American Meteorological Society’s Journal of Climate (subs. req’d) — which obviously it makes it much more credible and high-profile.  Reuters has a good story on it, “Global warming could be twice as bad as forecast.”  The study concludes:

The MIT Integrated Global System Model is used to make probabilistic projections of climate change from 1861 to 2100. Since the model’s first projections were published in 2003 substantial improvements have been made to the model and improved estimates of the probability distributions of uncertain input parameters have become available. The new projections are considerably warmer than the 2003 projections, e.g., the median surface warming in 2091 to 2100 is 5.2°C compared to 2.4°C in the earlier study. Many changes contribute to the stronger warming; among the more important ones are taking into account the cooling in the second half of the 20th century due to volcanic eruptions for input parameter estimation and a more sophisticated method for projecting GDP growth which eliminated many low emission scenarios.

[Note:  That rise is compared to 1981-2000 temperature levels.  So you can add at least 0.5 °C and 1.0 °F for comparison with pre-industrial temperatures, which I did in the headline -- see "A (Hopefully) Clarifying Note on Temperature."]

The MIT press release calls for “rapid and massive” action to avoid this.  Study co-author Ronald Prinn, the co-director of the Joint Program and director of MIT’s Center for Global Change Science, says, it is important “to base our opinions and policies on the peer-reviewed science….  There’s no way the world can or should take these risks.”   Duh!

Their median projection for the atmospheric concentration of carbon dioxide in 2095 is a jaw-dropping 866 ppm.

Projected decadal mean concentrations of CO2. Red solid lines are median, 5% and 95% percentiles for present study: dashed blue line the same from their 2003 projection.

As grim as this prediction is, it is still almost certainly an underestimate of what will happen on our current path of unrestricted greenhouse gas emissions, as Prinn explains:

And the odds indicated by this modeling may actually understate the problem, because the model does not fully incorporate other positive feedbacks that can occur, for example, if increased temperatures caused a large-scale melting of permafrost in arctic regions and subsequent release of large quantities of methane, a very potent greenhouse gas. Including that feedback “is just going to make it worse,” Prinn says.

Speaking of feedbacks, the model shows staggering warming near the poles (see “What exactly is polar amplification and why does it matter?“):

Figure 9:  Latitudinal distribution of changes in SAT in the last decade of 21st century relative to 1981-2000. Red solid lines are median, 5% and 95% percentiles for present study: dashed blue line the same from Webster et al., (2003).

Median arctic warming — north of 70° latitude — (from 1981-2000 levels) is 20°F!  How could Greenland’s ice sheet possibly survive that?

Why the change in the 2009 modeling, compared to 2003? The Program’s website explains:

There is no single revision that is responsible for this change. In our more recent global model simulatations, the ocean heat-uptake is slower than previously estimated, the ocean uptake of carbon is weaker, feedbacks from the land system as temperature rises are stronger, cumulative emissions of greenhouse gases over the century are higher, and offsetting cooling from aerosol emissions is lower. No one of these effects is very strong on its own, and even adding each separately together would not fully explain the higher temperatures. Rather than interacting additively, these different affects appear to interact multiplicatively, with feedbacks among the contributing factors, leading to the surprisingly large increase in the chance of much higher temperatures.

The carbon sinks are saturating, and the amplifying feedbacks are worse than previously thought — that, of course, is a central understanding of all climate realists (see Study: Water-vapor feedback is “strong and positive,” so we face “warming of several degrees Celsius” for links to the various feedbacks that have been ignored by most climate models).

Andrew Freedman at washingtonpost.com had one of the very few stories on this important study back in February and reprints this useful figure from MIT:

He explains:

Results of the studies are depicted online in MIT’s “Greenhouse Gamble” exercise that conveys the “range of probability of potential global warming” via roulette wheel graphics (shown above). The modeling output showed that under both a “no policy” scenario and one in which nations took action beginning in the next few years to reduce greenhouse gas emissions, the odds have shifted in favor of larger temperature increases.

For the no policy scenario, the researchers concluded that there is now a nine percent chance (about one in 11 odds) that the global average surface temperature would increase by more than 7°C (12.6°F) by the end of this century, compared with only a less than one percent chance (one in 100 odds) that warming would be limited to below 3°C (5.4°F).

To repeat, on our current emissions path, we have a 9% chance of an incomprehensibly catastrophic warming of 7°C by century’s end, but less than a 1% chance of under 3°C warming.

“The take home message from the new greenhouse gamble wheels is that if we do little or nothing about lowering greenhouse gas emissions that the dangers are much greater than we thought three or four years ago,” said Ronald G. Prinn, professor of atmospheric chemistry at MIT. “It is making the impetus for serious policy much more urgent than we previously thought.”

The time to act is now.

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COPENHAGEN—Months before make-or-break climate negotiations, a conclave of scientists warned Tuesday that the impact of global warming was accelerating beyond a forecast made by U.N. experts two years ago.

Sea levels this century may rise several times higher than predictions made in 2007 that form the scientific foundation for policymakers today, the meeting heard.

In March 2007, the U.N.‘s Intergovernmental Panel on Climate Change concluded that global warming, if unchecked, would lead to a devastating amalgam of floods, drought, disease and extreme weather by the century end.

The world’s oceans would creep up 18 to 59 centimeters (7 to 23 inches), enough to wipe out several small island nations and wreak havoc for tens of millions living in low-lying deltas in east Asia, the Indian subcontinent and Africa.

But a new study, presented at the Copenhagen meeting on Tuesday, factored in likely water runoff from disintegrating glaciers in Greenland and Antarctica, and found the rise could be much higher.

The IPCC estimate had been based largely on the expansion of oceans from higher temperatures, rather than meltwater and the impact of glaciers tumbling into the sea.

Using the new model, “we get a range of sea level rise by 2100 between 75 and 190 centimeters when we apply the IPCC’s temperature scenarios for the future,” said climate expert Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research.

Even if the world manages to dramatically cut the emission of greenhouse gases driving global warming, the “best estimate” is about one meter (3.25 feet), he said.

“A few years ago, those of us who talked about the impact of the ice sheets were seen as extremists. Today it is recognized as the central issue,” said glaciologist Eric Rignot of the University of California at Irvine.

“The world has very little time,” IPCC chief Rajendra Pachauri told the meeting after the new findings were presented.

Participants also spoke out about fears that greenhouse gases—mainly emissions from oil, gas and coal—could trigger tipping points that would be nearly impossible to reverse.

The shrinking of the Arctic ice cap, and the release of billions of tonnes of greenhouse gases trapped in melting permafrost are two such “positive feedbacks” that could become both cause and consequence of global warming.

“We need to look at what is a ‘reasonable worst case’ in the lifetime of people alive today,” said John Ashton, Britain’s top climate negotiator, noting even rich nations had yet to take such scenarios seriously.

“A sea level rise of one or two meters would not just be damaging for China, it would be an absolute catastrophe. And what is catastrophic for China is catastrophic for the world,” he said.

More than 2,000 researchers from 80 countries responded to the open invitation to present their findings, which were then vetted by a panel of climate experts, many of them top figures in the IPCC.

“I and a lot of scientists see this meeting as an opportunity to update the science that has come out since the last IPCC report,” said William Howard, a researcher from the University of Tasmania in Hobart, Australia.

“The huge response from scientists comes from a sense of urgency, but also a sense of frustration,” said Katherine Richardson, head of the Danish government’s Commission on Climate Change Policy.

“Most of us have been trained as scientists to not get our hands dirty by talking to politicians. But we now realize that what we are dealing with is so complicated and urgent that we have to help to make sure the results are understood,” she told AFP.

Richardson said the 2007 IPCC report, called the Fourth Assessment Report, was an invaluable document but it would be years out of date when negotiators convene in Copenhagen in December to hammer out a global climate treaty.

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GENEVA—Icecaps around the North and South Poles are melting faster and in a more widespread manner than expected, raising sea levels and fuelling climate change, a major scientific survey showed Wednesday.

The International Polar Year survey found that warming in the Antarctic is “much more widespread than was thought,” while Arctic sea ice is diminishing and the melting of Greenland’s ice cover is accelerating.

Rising sea levels and changes in ocean temperatures triggered by the melting ice also heralded shifts in weather patterns worldwide and potentially more coastal storm surges, scientists said.

“We’re beginning to get hints of change in ocean circulation, that’ll have a dramatic impact on the global climate system,” IPY director David Carlson told journalists.

The frozen and often inaccessible polar regions have long been regarded as some of the most sensitive barometers of environmental change and global warming because of their influence on the world’s oceans and atmosphere.

Preliminary findings from the two year survey by thousands of scientists revealed new evidence that the ocean around the Antarctic has warmed more rapidly than the global average, the World Meteorological Organization and the International Council for Science said in a statement.

Meanwhile, shifts in temperature patterns deep underwater indicated that the continent’s land ice sheet is melting faster than reckoned.

“These changes are signs that global warming is affecting the Antarctic in ways not previously suspected,” the statement added.

“These assessments continue to be refined, but it now appears that both the Greenland and the Antarctic ice sheets are losing mass and thus raising sea level, and that the rate of ice loss from Greenland is growing.”

Shrinking sea ice was expected around Antarctica, while Arctic sea ice decreased to its lowest level since satellite records began.

Special IPY expeditions in the Arctic in 2007 and 2008 also found an “unprecedented rate” of floating drift ice.

But the focus was on the erosion of land-based ice sheets of Greenland and the Antarctic, which hold the bulk of the world’s freshwater reserves and can generate sea level changes of global scale as they melt.

“That was an urgent question three years ago and I think today it’s now a more urgent question,” Carlson said.

When the survey began in 2007, Greenland and Antarctica’s land areas were viewed as largely stable despite some worrying signs of fringe melting.

The joint statement concluded: “The message of IPY is loud and clear: what happens in the polar regions affects the rest of the world and concerns us all.”

The survey also revealed that the melting has the potential to feed more global warming in turn as the permafrost melts faster.

Permafrost, the expanse of continuously frozen soil in polar land areas, was found to have larger pools of carbon than expected and the melting could unleash more greenhouse gases into the atmosphere.

The scientists also found that global warming caused substantial changes that were tantamount to a greening of the Arctic landscape.

Vegetation and soil were changing in the region, with shrubbery taking over grassland and tree growth shifting according to changing snowfall, while insect infestation increased and species move from lower latitudes into polar regions.

Those shifts also disrupted native animals, hunting and local livelihoods, while building was taking place in previously uninhabited areas, the scientists found.

The survey around both poles was the first of its kind for half a century, revisiting areas that have not been seen since the 1950s and mobilizing 10,000 scientists around the world.

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Nature: “Dynamic thinning of Greenland and Antarctic ice-sheet”

The recent acceleration of glacier melt-off in Greenland, which some scientists fear could dramatically raise sea levels, may only be a temporary phenomenon, according to a study published Sunday.

Researchers in Britain and the United States devised computer models to test three scenarios that could account for rapid—by the standards applied to glaciers—melting of the Helheim Glacier, one of Greenland’s largest.

Two were based on changes caused directly by global warming: an increase in the flow of water that greases the underbelly of the glacier as it slides toward the sea, and a general thinning due to melting.

If confirmed, either of these explanations would point to a sustained increase in runoff over the coming decades, fueling speculation that sea level could rise faster and higher than once thought.

The stakes are enormous: the rate at which the global ocean water mark rises could have a devastating impact on hundreds of millions of people living in low-lying areas around the world.   But a team led by Faezeh Nick of Durham University in Britain found that neither of these scenarios matched the data.

“They simply don’t fit what we have observed,” said colleague and co-author Andreas Vieli in an interview.   By contrast, the third computer model—which hypothesised that melt-off was triggered by changing conditions in the confined area where the glacier meets the sea—fit like a glove, he said.

“Whatever happens at the terminus provokes a strong and rapid reaction in the rest of the glacier. The result has been a significant loss of mass” as huge chunks of ice drop into the ocean, a process known as calving, Vieli explained.

These changes are also set in motion by global warming, but are not likely to last, he said.   “You cannot maintain these very high rates of peak mass loss for very long.

The glaciers start to retreat and settle into a new an relatively stable state,” he said.

The Helheim Glacier, along with several others in Greenland, started to slow down in 2007.   Vieli also noted that the data alarming the scientific community only covers a span of a few years. It may be ill-advised, he suggested, to project a trend on the basis of what may turn out to be a short-term phenomenon.

The UN Intergovernmental Panel on Climate Change (IPCC) predicted in 2007 that sea levels could creep up by 18 to 59 centimeters (7.2 to 23.2 inches) by 2100 due to thermal expansion driven by global warming.

Such an increase would be enough to wipe out several small island nations and seriously disrupt mega-deltas home in Asia and Africa.

But IPCC failed to take into account recent studies on the observed and potential impact of the melting ice sheets in Greenland and Antarctica, prompting the Nobel-winning body to later remove the upward bracket from its end-of-century forecast.

A new consensus has formed among experts that levels could rise by a metre or more by 2100, according to Mark Serreze of the National Now and Ice Data Center in Boulder, Colorodo.

“What has puzzled us is that the changes are even faster than we would have though possible,” he said in a recent interview.

Vieli cautioned that his findings, published in Nature Geoscience, are narrowly focused on one glacier, and that sea levels could still rise higher than the IPCC’s original projections.

Other Greenland glaciers behave differently, and the dynamics of the Antarctic ice sheet are still poorly understood, he noted.

Nor should the new study “be taken out of context to suggest that climate change is not a serious threat—it is,” he added.

The ice sitting atop Greenland could lift oceans by seven meters, though even the gloomiest of climate change projections do not include such a scenario.

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Disappearing slave history

Wrapping up its annual meeting this week, the International Whaling Commission decided to defer decision-making on various controversial issues. The IWC took only one vote at the meeting, deciding to disallow Greenland's request to take a higher quota of humpback whales. It also agreed to research the impact of climate change on cetaceans. But with the commission polarized by fierce disagreement between pro- and anti-whaling countries, no decisions were made on whether to end a 22-year-old ban on commercial whaling, whether to continue letting Japan kill whales for alleged scientific purposes, whether to create a whale sanctuary in the south Atlantic, or whether to issue permits for coastal whaling. A 24-nation committee of the 81-member commission will try to come up with compromises on contentious issues, and will bring a report to next year's conference.

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The Greenland ice sheet is melting at an alarming rate! As in, faster than it has since satellite measurements began in 1979, and with 10 percent more melting in 2007 than in the previous record year of 2005. Allow researcher Konrad Steffen to put it into perspective for you: "The amount of ice lost by Greenland over the last year is the equivalent of two times all the ice in the Alps, or a layer of water more than one-half mile deep covering Washington D.C." Yes, we think that qualifies as alarming.

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Even while Greenland's melting ice is slowly destroying the viability of subsistence hunting, it offers new economic opportunities that could ultimately fund the island country's bid for independence from Denmark. Diamond hunters from North America have been coming to Greenland to search for the precious stones in rock uncovered by glacial retreat. Melting ice offers new opportunities for hydroelectric power. Gold found recently is already being mined. The government is in talks with aluminum giant Alcoa to build the world's second-largest smelter in the country. And oil companies are vying to drill off Greenland's expansive coastline. The country achieved a measure of independence with its successful push for self-governance in 1979, but Denmark still handles defense and foreign policy and sends much-needed funds. Yet if Greenland's mining rush could effectively displace those funds, the country's population of about 56,000 has a shot at full independence.

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It gets lost in all the gloom and doom, but global warming does have its upside. In the sub-Arctic south of Greenland, rising temperatures over the last five to 10 years have brought residents more potatoes, broccoli, and flowers, and have made officials optimistic about economically beneficial opportunities for drilling and mining as sea ice melts. Of course, melting sea ice is also ravaging the hunting and fishing that provide cultural identity and livelihood to many residents -- but the broccoli! Did we mention the broccoli?

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Twice as many girls as boys are being born in Arctic communities across Greenland and northern Russia, where Inuit villagers are known to have high levels of human-made chemicals in their blood. Many babies are being born premature; baby boys tend to be small. Hormone-mimicking chemicals originate in industrialized countries, travel to the Arctic by wind and water, and rise up the food chain to reach high levels in traditional Inuit fare of seals, whales, and polar bears. Greenland resident Aqqaluk Lynge tells it like it is: "This has become a critical question of people's survival but few governments want to talk about the problem of hormone mimickers because it means thinking about the chemicals you use." More food for thought: Recent research has also shown the gender ratio favoring girls for the first time in the U.S. and Japan. We're all about girl power, but this is ridiculous.

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