- ► 2014 (856)
- ► 2013 (1259)
- ► 2012 (1040)
- ► 2011 (2089)
- ► 2010 (1317)
- ► 2009 (1326)
- Arctic Sea Ice status: June 29, 2008
- Multi-year Arctic Sea Ice Gone, June 2008
- Rhode Island planning for rising sea levels
- Remote sensing: 1980-2008 Temperature Anomalies b...
- ANTARCTIC ICE LOSS SPEEDS UP, NEARLY MATCHES GREEN...
- CSIRO Global Mean Sea Level Rise Curves, 1992-June...
- Jim Rogers: A "Green" Coal Baron?
- Mark Lynas: Six Degrees -- Our Future on a Hotter...
- NOAA: 2008 Global Temperature Seventh Warmest for ...
- Greenland ice core data offer clues to last big me...
- Arctic thaw threatens Siberian permafrost
- Bangladesh is set to disappear under the waves by ...
- Anne de Vernal: Natural Variability of Greenland C...
- Greenland Ice Core Analysis Shows Drastic Climate ...
- Gavin Schmidt: Ocean heat content revision (realcl...
- Ocean Temperatures And Sea Level Increases 50% Hig...
- U.S. High Temperatures, June 15, 2008
- WAIS: Wilkins Ice Shelf breaking-up in winter
- Closing Ozone Hole May Have Major Impact On Global...
- Freshwater Runoff From Greenland Ice Sheet Will Mo...
- Permafrost Threatened by Rapid Retreat of Arctic S...
- Greenland, June 11, 2008
- China Hacking Capitol Computers of Human Rights Ac...
- National Snow and Ice Data Center -- Arctic sea ic...
- Fossil Fuels Generating Ozone Will Damage Crops, R...
- June 10, 2008: Arctic Sea Ice In Bad Shape
- Stratospheric ozone chemistry plays an important r...
- German carmakers welcome modified emissions target...
- Elevation changes of ice caps in the Canadian Arct...
- Northern Canada Temperatures Breaking Records, Jun...
- Mauna Loa monthly CO2 measurements, March 1958 to ...
- Upper troposphere is warming after all, research s...
- Arctic Sea Ice well on its way to disappearing thi...
- ▼ June (33)
Sunday, June 29, 2008
CLICK ON THE GRAPHS TO ENLARGE
From the University of Bremen's site, June 29, 2008: http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png
Quikscat Ice Mask from NOAA, June 29, 2008 -- have a look at the Hudson Bay compared to yesterday -- even though the ice seems to have disappeared, apparently, it is still hanging around, but it is really thinning very quickly:
It would appear that there are satellite images and then there are satellite images -- of note is the strong melting going on in north-northeastern Greenland:
OK, and someone please tell me that the grey patch there in the middle of Greenland is not an area of melt, like the one that formed on Antarctica in 2005:
Above: temperatures on June 28, 2008
Below: temperatures on June 29, 2008. Notice that there is only one area of the Arctic that is below freezing, near Siberia. Alert, on Ellesmere Island, went to 17.2 C (63 F).
500-hPa Height Anomalies -- 30-day animation
Link to animation (updated daily, I think): http://www.cpc.noaa.gov/products/intraseasonal/z500_nh_anim.shtml
Saturday, June 28, 2008
Thursday, June 26, 2008
Prepare now for future coastal climate change impacts
By Steven Stycos
Sea level rises of at least three to five feet by 2100 and the likely increase in the frequency and strength of major storms due to carbon dioxide emissions from burning oil and coal, require Rhode Island to plan for major coastal disruptions, said Rhode Island Coastal Resources Management Council Executive Director Grover Fugate at a climate change conference last week in Narragansett.
"We're vulnerable. We're low and we're flat," agreed University of Rhode Island Coastal Institute director Peter August.
In January, the CRMC, Rhode Island's coastal regulatory agency, decided its policies on zoning and design must recognize the expected sea level rise. Rising sea levels and strong coastal storms will push barrier dunes, like those on Quonochontaug, Ninigret and Green Hill Ponds, inland, they predicted. They will also contaminate clean water supplies, salinate septic systems and reduce salt marsh area, Fugate warned. Finally, rising seas will submerge low-lying bridges and roads like Block Island's Corn Neck Road. The CRMC must consider innovative steps, Fugate urged, including the increase of set backs for coastal buildings, the elevation of bridges and the acquisition of land that will be transformed to environmentally important salt marsh as sea levels rise.
The CRMC is also preparing a plan to regulate which ocean areas are best for wind power, Fugate said, by balancing the potential for electricity generation with fishing and recreational boating. Rhode Island Governor Donald Carcieri has proposed several off-shore sites near Block Island for building wind power turbines.
Just how much sea levels will rise during the next one hundred years is unclear, said URI Oceanography professor Kate Moran. Scientists are particularly puzzled, she said, by the behavior of melting ice sheets on Greenland and Antarctica. Most of the recent sea rise can be attributed to the melting of glaciers and expansion of oceans due to warming, she said, but scientists are puzzled by the effects of melting ice sheets on Greenland and Antarctica.
Their rapid melting would raise levels considerably more than the CRMC's projection of 3-5 ft. by 2100, according to CRMC Coastal Geologist Janet Freedman. The pace of global sea rise is increasing, she said. According to a tide gauge in Newport, Rhode Island, sea levels rose an average of 1.27 mm per year between 1970 and 1988, Freedman related, but an average of 4.06 mm per year between 1989 and 2008. Overall, Newport sea levels have risen about 8 inches since 1929.
But for coastal communities, the biggest threat is not sea level rise, insisted state Geologist John Boothroyd, but more frequent and more powerful storms. Southern New England has not had a series of major storms since Hurricane Bob in the early 1990s, he said, adding that he cannot predict when another set of erosion causing storms may hit. Fugate said that careful planning for big storms requires good maps with up-to-date elevations of coastal areas. The current U.S. Federal Emergency Management Agency maps are old and inaccurate, he said, and called on conference attendees to contact their Congressmen to get the federal government to produce better maps.
To battle shoreline erosion, Boothroyd advocated beach replenishment, but said it can be prohibitively expensive to local communities who must assume 30 to 50 percent of the cost under federal programs. Moving buildings inland to higher ground is more practical, he added. Fugate agreed, saying, "Our primary policy is retreat."
Because sea walls, or revetments, encourage beach erosion and potentially block shoreline access, Freedman said that the CRMC does not allow construction of new sea walls. Property owners may maintain existing walls, but if a storm destroys more than 50 percent of a wall, it cannot be rebuilt, she said.
While Fugate and Freedman discussed local precautions, Moran called for action on the causes of climate, "heavy consumerism in the West, plus [world] population growth." She endorsed a cap and trade system on carbon dioxide emissions like the plans advocated by Presidential candidates John McCain and Barack Obama, but rejected by the United States Senate earlier this month.
"The rest of the world gets it," Moran said, "It's time for the United States to stop believing editorials in the Wall Street Journal."
Link to article: http://www.jamestownpress.com/news/2008/0626/Front_Page/003.html
Tuesday, June 24, 2008
Graph of temperature anomalies, by latitude, over time. Note the seemingly 5-yr. natural cycles from 1980 to 1997, then after 2002, these seem to be overwhelmed by the warming, although the period of time is too short to be confident of a trend.
January 23, 2008
ANTARCTIC ICE LOSS SPEEDS UP, NEARLY MATCHES GREENLAND LOSS
Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by NASA and university scientists.
In a first-of-its-kind study, an international team led by Eric Rignot of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of California, Irvine, estimated changes in Antarctica's ice mass between 1996 and 2006 and mapped patterns of ice loss on a glacier-by-glacier basis. They detected a sharp jump in Antarctica's ice loss, from enough ice to raise global sea level by 0.3 millimeters (.01 inches) a year in 1996, to 0.5 millimeters (.02 inches) a year in 2006.
Rignot said the losses, which were primarily concentrated in West Antarctica's Pine Island Bay sector and the northern tip of the Antarctic Peninsula, are caused by ongoing and past acceleration of glaciers into the sea. This is mostly a result of warmer ocean waters, which bathe the buttressing floating sections of glaciers, causing them to thin or collapse. "Changes in Antarctic glacier flow are having a significant, if not dominant, impact on the mass balance of the Antarctic ice sheet," he said.
To infer the ice sheet's mass, the team measured ice flowing out of Antarctica's drainage basins over 85 percent of its coastline. They used 15 years of satellite radar data from the European Earth Remote Sensing-1 and -2, Canada's Radarsat-1 and Japan's Advanced Land Observing satellites to reveal the pattern of ice sheet motion toward the sea. These results were compared with estimates of snowfall accumulation in Antarctica's interior derived from a regional atmospheric climate model spanning the past quarter century.
The team found that the net loss of ice mass from Antarctica increased from 112 (plus or minus 91) gigatonnes a year in 1996 to 196 (plus or minus 92) gigatonnes a year in 2006. A gigatonne is one billion metric tons, or more than 2.2 trillion pounds. These new results are about 20 percent higher over a comparable time frame than those of a NASA study of Antarctic mass balance last March that used data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment. This is within the margin of error for both techniques, each of which has its strengths and limitations.
Rignot says the increased contribution of Antarctica to global sea level rise indicated by the study warrants closer monitoring.
"Our new results emphasize the vital importance of continuing to monitor Antarctica using a variety of remote sensing techniques to determine how this trend will continue and, in particular, of conducting more frequent and systematic surveys of changes in glacier flow using satellite radar interferometry," Rignot said. "Large uncertainties remain in predicting Antarctica's future contribution to sea level rise. Ice sheets are responding faster to climate warming than anticipated."
Rignot said scientists are now observing these climate-driven changes over a significant fraction of the West Antarctic Ice Sheet, and the extent of the glacier ice losses is expected to keep rising in the years to come. "Even in East Antarctica, where we find ice mass to be in near balance, ice loss is detected in its potentially unstable marine sectors, warranting closer study," he said.
Other organizations participating in the NASA-funded study, in addition to the University of California, Irvine, are Centro de Estudios Cientificos, Valdivia, Chile; University of Bristol, United Kingdom; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, The Netherlands; University of Missouri, Columbia, Mo.; and the Royal Netherlands Meteorological Institute, De Bilt, The Netherlands.
Results of the study are published in February's issue of Nature Geoscience.
Contact: Alan Buis, Jet Propulsion Laboratory, Pasadena, Calif.
This text is derived from: http://www.jpl.nasa.gov/news/news.cfm?release=2008-010
Monday, June 23, 2008
CSIRO Sea Level Rise Curves, 1992-June 2008
Click on the graph to enlarge it.
Link to site: http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html
Sunday, June 22, 2008
by Clive Thompson, New York Times, June 22, 2008
“So we have 500,000 solar units on the roofs of our customers,” he said. “We install them, we maintain them and we dispatch them, just like it was a power plant!” He did some quick math: he could get maybe 1,000 megawatts out of that system, enough to permanently shutter one of the company’s older power plants. He shot me a toothy grin.
Even in this era of green evangelism, Rogers is a genuine anomaly. As the head of Duke Energy, with its dozens of coal-burning electric plants scattered around the Midwest and the Carolinas, he represents one of the country’s biggest sources of greenhouse gases. The company pumps 100 million tons of carbon dioxide into the atmosphere each year, making it the third-largest corporate emitter in the United States.
Yet Rogers, who makes $10 million a year, is also one of the electricity industry’s most vocal environmentalists. For years, he has opened his doors to the kinds of green activists who would give palpitations to most energy C.E.O.’s. In March, he had breakfast with James Lovelock, the originator of the Gaia theory, which regards the earth as a single, living organism, to discuss whether species can adapt to a warmer earth. In April, James Hansen, a climatologist at NASA and one of the first scientists to publicly warn about global warming, wrote an open letter urging Rogers to stop burning coal — so Rogers took him out for a three-hour dinner in Manhattan. “I would dare say that no one in the industry would talk to Lovelock and Hansen,” Rogers told me. Last year, Rogers astonished his board when he presented his plan to “decarbonize” Duke Energy by 2050 — in effect, to retool the utility so that it emits very little carbon dioxide.
Perhaps most controversial, though, Rogers has long advocated stiff regulation of greenhouses gases. For the last few years, he has relentlessly lobbied Washington to create a “carbon cap” law that strictly limits the amount of carbon dioxide produced in the United States, one that would impose enormous costs on any company that releases more carbon than its assigned limit. That law is now on its way to becoming reality: last fall, Senators Joe Lieberman and John Warner introduced a historic “cap-and-trade” bill that would require the country to reduce its co2 emissions by 70 percent before 2050. Earlier this month, the bill failed to advance, but its sponsors will most likely reintroduce it next year once a new president is in office; meanwhile, a half-dozen other rival bills are currently being drawn up that all seek the same thing. One way or another, a carbon cap is coming.
Prominent environmentalists, thrilled, credit Rogers for clearing the way politically; many are his friends. “It’s fair to say that we wouldn’t be where we are in Congress if it weren’t for him,” says Eileen Claussen, head of the Pew Center on Global Climate Change. “He helped put carbon legislation on the map.” This should be a golden moment for Rogers: he has godfathered a bill that could significantly reshape the electricity industry, help balance the world’s climate and establish his legacy as a visionary C.E.O. — a “statesman,” as he puts it. Instead, he is very, very worried, fearful that the real-world version of his dream legislation may end up threatening the company he has spent so many years building.
Though the details are devilish, the basic cap-and-trade concept is simple. The government makes it expensive for companies to emit carbon dioxide, and then market forces work their magic: those companies aggressively seek ways to avoid producing the stuff, to try to get a competitive edge on one another.
This is precisely how the government dealt with acid rain, back in the late ’80s. Acid rain, like global warming to a great extent, was caused by dangerous byproducts from burning coal: the chemicals sulphur dioxide and nitrogen oxide, or “sox and nox,” as they were known colloquially. Environmentalists in the ’80s tried to get Ronald Reagan’s Environmental Protection Agency to crack down on sox and nox, but an antiregulatory mood prevailed. So a group of politicians and forward-thinking environmentalists turned to the marketplace instead.
Through legislation, the government first set a limit, or cap, on how much sox and nox could be discharged by the nation’s coal-burning utilities. These companies then regularly received allowances based on their historic levels of emissions. At the end of a predetermined period, every company had to possess enough in the way of allowances to cover the gases it released or face stiff penalties. Over time, the cap and the number of allowances were slowly reduced.
A system like this creates a carrot and a stick. An electrical utility that reduces its pollution below the cap has leftover allowances to sell to other companies. In theory, a virtuous cycle emerges: a company that invests money to clean up its emissions can more than recoup its outlay by selling unused allowances to its dirtier, laggard competitors. Furthermore, entrepreneurs have an incentive to develop cleanup technologies. And sure enough, following the Clean Air Act amendments in 1990, innovations emerged quickly, ranging from new coal blends to chemical “scrubbers” that removed sox and nox from the smokestacks. Government and industry officials predicted that solving the problem of acid rain could cost $4 billion in new investment — but the marketplace was so efficient that only an estimated $1 billion was needed.
A cap-and-trade program for co2 would try to harness the same dynamics. There are several bills under development — Lieberman-Warner is the most advanced, and the one most likely to pass next year — but they all take roughly the same approach. Greenhouse-gas emissions are capped in key carbon-dioxide-producing industries like gas, oil and electricity. Allowances are issued and companies are free to sell them to one another. Then the cap and number of allowances are ratcheted down over time, sparking, it’s hoped, the same Cambrian-like explosion in the development of cheaper, cleaner technologies.
If Rogers is keen on the idea of cap and trade, it’s because the acid-rain fight was one of his formative experiences as a C.E.O. His first job was a three-year stint as a journalist in Lexington, Ky. — “I was a journalist, so I’m allowed to be a little cynical at times,” he likes to joke — before heading to law school and working as a public advocate in his home state of Kentucky. In 1988, by then 40 years old, he switched sides — the Indiana electrical utility PSI Energy teetered on the verge of bankruptcy, and Rogers was offered the job of turning it around.
Part of what ruined PSI was a $2.7-billion write-off of its nuclear plant when local environmentalists forced PSI to halt its construction after the Three Mile Island accident. Rather than demonize the environmentalists, Rogers instead decided to “put on a flannel shirt” and meet with them in a cafe in Madison, Ind. Phil Sharp, a U.S. representative for Indiana at the time, recalls the activists’ astonishment. “They couldn’t believe it,” he says. “They were always used to taking on the big utility companies. Then he came in and instead of saying, What craziness is this, he said, O.K., let’s talk.” It was partly self-protection, of course; Rogers knew that public opinion could ruin a company. Aware that the environmentalists were also worried about acid rain, Rogers decided it was a problem he should head off.
When cap and trade was proposed as a solution to acid rain, most energy executives whose companies burned coal hated the idea and lobbied fiercely against it. It wasn’t merely that they tended to resist regulation. They also didn’t believe it would work: they didn’t trust that the necessary technology would evolve fast enough. If it didn’t, they worried, very few firms would have extra allowances to sell, and the price of those on the open market would skyrocket. Companies might go broke trying to buy extra allowances to meet their cap.
Rogers was the outlier. He loved the elegance of the market-based approach, and he had a nerd’s optimism that the technology would bloom quickly. “And we were right,” he says. “So that’s what gave me the faith that this approach works. All you have to do is set the market up right.” PSI spent only $250 million to clean up its smokestacks, and allowances were “cheap and plentiful,” Rogers says.
Even as acid rain was being confronted in 1990, climate change was entering the public debate. By this time, Rogers was friends with a number of environmentalists and decided to dive into the science of global warming. He began inviting climate experts from Harvard, NASA and various research firms to brief him. “Pretty soon, I could see that the science was persuasive,” Rogers recalls. Many policy makers behind the acid-rain cleanup suspected that a cap-and-trade program could whip the carbon problem too. Rogers agreed. “What’s unusual about Jim is that he recognized these problems not as a woe-is-me burden but as real growth opportunities, opportunities to change his industry,” says Tim Wirth, president of the United Nations Foundation and a former senator from Colorado who helped write the acid-rain legislation. “That allows him to be cheerful in the face of the opposition.”
And there was plenty of opposition. Back then, merely acknowledging the existence of global warming was a thought crime among coal-burning energy executives. But as early as 2001, Rogers told a meeting of fellow C.E.O.’s in the industry that they should all work to pass a federal carbon cap. “They were stunned,” recalls Ralph Cavanagh, an energy program director at the Natural Resources Defense Council, who was present at the meeting. “That was the first time I had heard a major energy executive say anything like this. But because he was chairman of their energy committee, he wasn’t just a flaky maverick.” Sharp, a longtime friend, chuckles when he remembers how much ire Rogers generated. “They hated him,” he says. “Nobody would invite him for golf.”
[BLOGGER'S NOTE: this article is rather long, but well worth the read -- the rest of the article can be found at the link below in my Reference Materials blog:
Saturday, June 21, 2008
Climate chaos is inevitable. We can only avert oblivion
At best we will limit the extent of global warming, but Kyoto barely helps. Does humanity have the foresight to save itself?
by Mark Lynas, The Guardian, Thursday, June 12, 2008
Sometimes we need to think the unthinkable, particularly when dealing with a problem as dangerous as climate change -- there is no room for dogma when considering the future habitability of our planet. It was in this spirit that I and a panel of other specialists in climate, economics and policy-making met under the aegis of the Stockholm Network thinktank to map out future scenarios for how international policy might evolve -- and what the eventual impact might be on the earth's climate.
We came up with three alternative visions of the future, and asked experts at the Met Office Hadley Centre to run them through its climate models to give each a projected temperature rise. The results were both surprising and profoundly disturbing.
We gave each scenario a name. The most pessimistic was labelled "agree and ignore" -- a world where governments meet to make commitments on climate change, but then backtrack or fail to comply with them. Sound familiar? It should: this scenario most closely resembles the past 10 years, and it projects emissions on an upward trend until 2045.
A more optimistic scenario was termed "Kyoto plus": here governments make a strong agreement in Copenhagen in 2009, binding industrialised countries into a new round of Kyoto-style targets, with developing countries joining successively as they achieve "first world" status. This scenario represents the best outcome that can plausibly result from the current process -- but ominously, it still sees emissions rising until 2030.
The third scenario -- called "step change" -- is worth a closer look. Here we envisaged massive climate disasters around the world in 2010 and 2011, causing a sudden increase in the sense of urgency surrounding global warming. Energised, world leaders ditch Kyoto, abandoning efforts to regulate emissions at a national level. Instead, they focus on the companies that produce fossil fuels in the first place -- from oil and gas wells and coal mines -- with the UN setting a global "upstream" production cap and auctioning tradable permits to carbon producers.
Instead of all the complexity of regulating squabbling nations and billions of people, the price mechanism does the work: companies simply pass on their increased costs to consumers, and demand for carbon-intensive products begins to fall. The auctioning of permits raises trillions of dollars to be spent smoothing the transition to a low-carbon economy and offsetting the impact of price rises on the poor. A clear long-term framework puts a price on carbon, giving business a strong incentive to shift investment into renewable energy and low-carbon manufacturing. Most importantly, a strong carbon cap means that global emissions peak as early as 2017.
This "upstream cap" approach is not a new idea, and our approach draws in particular on a forthcoming book by the environmental writer Oliver Tickell. However, conventional wisdom from governments and environmental groups alike insists that "Kyoto is the only game in town," and that proposing any alternative is dangerous heresy.
But let's look at the modelled temperature increases associated with each scenario.
"Agree and ignore" sees temperatures rise by 4.85C by 2100 (with a 90% probability); for "Kyoto plus," it's 3.31C; and "step change" 2.89C. This is the depressing bit: no politically plausible scenario we could envisage will now keep the world below the danger threshold of two degrees, the official target of both the EU and UK. This means that all scenarios see the total disappearance of Arctic sea ice; spreading deserts and water stress in the sub-tropics; extreme weather and floods; and melting glaciers in the Andes and Himalayas. Hence the need to focus far more on adaptation: these are impacts that humanity is going to have to deal with whatever now happens at the policy level.
But the other great lesson is that sticking with current policy is actually a very risky option, rather than a safe bet. Betting on Kyoto could mean triggering the collapse of the West Antarctic ice sheet and crossing thresholds that involve massive methane release from melting Siberian permafrost. If current policy continues to fail -- along the lines of the "agree and ignore" scenario -- then 50% to 80% of all species on earth could be driven to extinction by the magnitude and rapidity of warming, and much of the planet's surface left uninhabitable to humans. Billions, not millions, of people would be displaced.
So which way will it go? Ultimately the difference between the scenarios is one of political will: the question now is whether humanity can summon up the courage and foresight to save itself, or whether business as usual -- on climate policy as much as economics -- will condemn us all to climatic oblivion.
· Mark Lynas is the author of Six Degrees: Our Future on a Hotter Planethttp://www.guardian.co.uk/commentisfree/2008/jun/12/climatechange.scienceofclimatechange
Lynas' Six Degrees wins Royal Society award
by Lindesay Irvine, Tuesday, June 17, 2008, guardian.co.uk
Not just an accolade for me, but also for the work of the climate scientists on whose shoulders my writing rests... Mark Lynas
A grim exploration of the implications of global warming has won Britain's most prestigious prize for science writing. Writer and activist Mark Lynas's Six Degrees: Our Future on a Hotter Planet received the £10,000 Royal Society Science Book of the Year, last night.
Lynas's book walks readers through the hellish scenario implied by a warming planet, degree by degree. A single degree hotter, he shows, will bring severe droughts; two will see the US population fleeing a desiccated land, and so on. Beyond six degrees (which he explains may see huge fireballs crashing into cities), the story finishes, along with most of humanity. Drawing on a vast amount of research, Lynas's book tempers its pessimism by insisting that time remains for the world to avert the coming crisis.
Speaking after the ceremony at the Royal Society, Lynas said he was delighted with his prize, "not least because the bookmaker William Hill judged my book the least likely to win."
"It's not just an accolade for me," he added, "but also for the work of the climate scientists on whose shoulders my writing rests. The book is for a popular audience, and of course it hasn't been peer-reviewed, so to get this accolade from one of the most distinguished scientific bodies in the world means a lot."
The book saw off strong competition from shortlisted authors including the 1994 winner Steve Jones for Coral, J Craig Venter for A Life Decoded and Ian Stewart for Why Beauty is Truth. Chair of the judges professor Jonathan Ashmore said, "Six degrees is not just a great read, written in an original way, but also provides a good overview of the latest science on this highly topical issue. This is a book that will stimulate debate and that will, Lynas hopes, move us to action in the hope that this is a disaster movie that never happens. Everyone should read this book."
Link to article: http://books.guardian.co.uk/news/articles/0,,2286052,00.html
NOAA: Global Temperature Seventh Warmest for Spring, Eighth Warmest for May
June 13, 2008
The combined average global land and ocean surface temperatures for spring (March-May) ranked seventh warmest, while May was the eighth warmest since worldwide records began in 1880 according to an analysis by NOAA’s National Climatic Data Center in Asheville, N.C.
Spring (March-May) Highlights
- The combined global land and ocean surface temperature for spring 2008 was 0.94 degrees F above the 20th century mean of 56.7 degrees F and ranked seventh warmest based on the 1880-2008 record.
- The global land surface temperature for spring was 1.87 degrees F above the 20th century mean of 46.4 degrees F and tied with 2000 as third warmest.
- The global ocean surface temperature for spring was 0.59 degrees F above the 20th century mean of 61.0 degrees F and ranked 10th warmest.
- For May 2008, the combined global land and ocean surface temperature was 0.81 degrees F above the 20th century mean of 58.6 degrees F and ranked eighth warmest.
- The global land surface temperature for May was 1.26 degrees F above the 20th century mean of 52.0 degrees F and ranked seventh warmest.
- The global ocean surface temperature for May was 0.65 degrees F above the 20th century mean of 61.3 degrees F and ranked 10th warmest.
- The extent of spring 2008 snow cover over Eurasia was the lowest on record for any spring in the 42-year historical satellite record. Conversely, North American snow cover extent was slightly above average. For the Northern Hemisphere, spring 2008 was the third least extensive spring snow cover.
- Continued weakening of La Niña, the cold phase of the El Niño-Southern Oscillation (ENSO), occurred during May. The ENSO conditions are expected to trend toward neutral conditions during the next two months.
Link to NOAA page: http://www.noaanews.noaa.gov/stories2008/20080613_springtemp.html
Link to NOAA's Mauna Loa page: http://www.mlo.noaa.gov/livedata/livedata.html
by Nora Schultz, NewScientist.com new service, 20 June 2008
The most detailed Greenland ice-core analysis yet offers important clues about what caused the climate to change so rapidly at the end of the last ice age.
"We can now read the climate's history at unprecedented resolution, going 15,000 years into the past", says Jim White at the University of Colorado at Boulder, who studied the new ice core as part of an international team.
Around this time, temperatures in Greenland rose by 10 °C in just 50 years. The new ice-core data suggests that this change began with a very rapid retreat of the ice covering the Atlantic. It also shows that it was preceded by dramatic climate change on the other side of the planet.
White and his colleagues analysed the amount of dust and heavy oxygen and hydrogen isotopes in small sections of the ice core that each represent a few months of climate history.
This approach is only made possible using an automated analysis tool that continuously melts an ice core and measures its composition at the extraction site, not in the lab.
Most of the dust found in Greenland drifts there from China. The core reveals a sharp drop in dust levels at the end of the ice age, suggesting the Asian deserts suddenly became much wetter.
Following this, levels of the heavy hydrogen isotope deuterium indicate that atmospheric circulation in the North probably led to a retreat in the ice covering the Atlantic all the way from Portugal to Iceland over just one to three years. This was followed by a more gradual rise in Greenland temperatures over the next few decades.
White says that the rapid ice melt was most likely triggered by a sudden recuperation of the warm North Atlantic deep water circulation.
However, he is surprised that the climate changed in Asia just before or at the same time. Although he does not yet know how the two events could be connected, White says the data strongly suggest that we should take a broader view when looking for warning signs of rapid climate change today.
"Otherwise, if we are just staring at the North Atlantic looking for change then we may get smacked in the rear by something that happens on the other side of the world," he says.
Katrin Meissner at the Climate Modelling Lab at the University of Victoria in Canada says the study presents groundbreaking insights into the existence of tipping points in the planet's climate system.
"This knowledge is crucial to understand and predict future climate changes due to man-made perturbations such as greenhouse gas emissions", she says.
Journal Reference: Science Express (DOI: 10.1126/science.1157707)
Friday, June 20, 2008
Arctic thaw threatens Siberian permafrost
The permafrost belt stretching across Siberia to Alaska and Canada could start melting three times faster than expected because of the speed at which Arctic Sea ice is disappearing.
A study found that the effects of sea-ice loss – which reached an all-time record last summer – extend almost 1,000 miles inland to areas where the ground is usually frozen all year round.
The smaller the area of sea ice, the less sunlight is reflected and the more heat is absorbed. That means scientists expect a tripling in the rate of warming over the continental land mass surrounding the Arctic. "Our study suggests that, if sea ice continues to contract rapidly over the next several years, Arctic land warming and permafrost thaw are likely to accelerate," said David Lawrence of the US National Centre for Atmospheric Research in Boulder, Colorado.
Last September, the sea ice of the Arctic shrank to more than 30 per cent of its average extent for that time of the year. Meanwhile, air temperatures over the Arctic region rose by about 2C above the long-term average for the period 1978 to 2006.
Melting permafrost threatens to undermine the roads, oil pipelines and buildings that are built on the permanently frozen ground. It will also endanger the region's wildlife as well as triggering the possible release of the greenhouse gases locked in the soil, which would exacerbate global warming.
Dr Lawrence and researchers at National Snow and Ice Data Centre used computer models to analyse how the loss of sea ice could influence rising air temperatures and the melting of permafrost. They looked in particular at the creation of "taliks", which are patches of unfrozen ground sandwiched between layers of permanently frozen soil lower down and a seasonally frozen patch of soil above.
"Taliks form when the downwelling summer heating wave extends deeper than the corresponding winter cooling wave, thereby preventing the talik from refreezing in winter and permitting heat to accumulate at depth as soil ice melts," the scientists said in their study to be published in the journal Geophysical Research Letters.
Taliks allow heat to build up more quickly in the soil which increases the rate at which permafrost is subjected to a long-term thaw. "Taken together, these results imply a link between rapid sea ice loss and permafrost health," the scientists warned.
Dr Lawrence said that about a quarter of the northern hemisphere's land contains perma-frost and the Arctic region's soils are believed to hold about 30 per cent of all the carbon stored in the world's soil. "An important, unresolved question is how the delicate balance of life in the Arctic will respond to such a rapid warming," he said. "Will we see, for example, accelerated coastal erosion, or increased methane emissions, or faster shrub encroachment into tundra regions if sea ice continues to retreat rapidly?"
Andrew Slater, a co-author of the study, said: "The rapid loss of sea ice can trigger widespread changes that would be felt across the region."
Claire Parkinson of Nasa said the consequences of the loss of the permafrost were unknown. "They could be significant, both on the climate through release of greenhouse gases and on the local communities through damage to roads and buildings as the frozen ground underneath thaws and destabilises."
Bangladesh is set to disappear under the waves by the end of the century - A special report by Johann Hari
Bangladesh is set to disappear under the waves by the end of the century - A special report by Johann HariThe Independent, Friday, 20 June 2008
Bangladesh, the most crowded nation on earth, is set to disappear under the waves by the end of this century – and we will be to blame. Johann Hari took a journey to see for himself how western profligacy and indifference have sealed the fate of 150 million people went to see for himself the spreading misery and destruction as the ocean reclaims the land on which so many millions depend
This spring, I took a month-long road trip across a country that we – you, me and everyone we know – are killing. One day, not long into my journey, I travelled over tiny ridges and groaning bridges on the back of a motorbike to reach the remote village of Munshigonj. The surviving villagers – gaunt, creased people – were sitting by a stagnant pond. They told me, slowly, what we have done to them.
Ten years ago, the village began to die. First, many of the trees turned a strange brownish-yellow colour and rotted. Then the rice paddies stopped growing and festered in the water. Then the fish floated to the surface of the rivers, gasping. Then many of the animals began to die. Then many of the children began to die.
The waters flowing through Munshigonj – which had once been sweet and clear and teeming with life – had turned salty and dead.
Arita Rani, a 25-year-old, sat looking at the salt water, swaddled in a blue sari and her grief. "We couldn't drink the water from the river, because it was suddenly full of salt and made us sick," she said. "So I had to give my children water from this pond. I knew it was a bad idea. People wash in this pond. It's dirty. So we all got dysentery." She keeps staring at its surface. "I have had it for 10 years now. You feel weak all the time, and you have terrible stomach pains. You need to run to the toilet 10 times a day. My boy Shupria was seven and he had this for his whole life. He was so weak, and kept getting coughs and fevers. And then one morning..."
Her mother interrupted the trailing silence. "He died," she said. Now Arita's surviving three-year-old, Ashik, is sick, too. He is sprawled on his back on the floor. He keeps collapsing; his eyes are watery and distant. His distended stomach feels like a balloon pumped full of water. "Why did this happen?" Arita asked.
It is happening because of us. Every flight, every hamburger, every coal power plant, ends here, with this. Bangladesh is a flat, low-lying land made of silt, squeezed in between the melting mountains of the Himalayas and the rising seas of the Bay of Bengal. As the world warms, the sea is swelling – and wiping Bangladesh off the map.
Deep below the ground of Munshigonj and thousands of villages like it, salt water is swelling up. It is this process – called "saline inundation" – that killed their trees and their fields and contaminated their drinking water. Some farmers have shifted from growing rice to farming shrimp – but that employs less than a quarter of the people, and it makes them dependent on a fickle export market. The scientific evidence shows that unless we change now, this salt water will keep rising and rising, until everything here is ocean.
I decided to embark on this trip when, sitting in my air-conditioned flat in London, I noticed a strange and seemingly impossible detail in a scientific report. The International Panel on Climate Change (IPCC) – whose predictions have consistently turned out to be underestimates – said that Bangladesh is on course to lose 17 per cent of its land and 30 per cent of its food production by 2050. For America, this would be equivalent to California and New York State drowning, and the entire mid-West turning salty and barren.
Surely this couldn't be right? How could more than 20 million Bangladeshis be turned into refugees so suddenly and so silently? I dug deeper, hoping it would be disproved – and found that many climatologists think the IPCC is way too optimistic about Bangladesh. I turned to Professor James Hansen, the director of NASA's Goddard Institute for Space Studies, whose climate calculations have proved to be more accurate than anybody else's. He believes the melting of the Greenland ice cap being picked up by his satellites today, now, suggests we are facing a 2.5-metre rise in sea levels this century – which would drown Bangladesh entirely. When I heard this, I knew I had to go, and see.
1. The edge of a cliff
The first thing that happens when you arrive in Dhaka is that you stop. And wait. And wait. And all you see around you are cars, and all you hear is screaming. Bangladesh's capital is in permanent shrieking gridlock, with miles of rickshaws and mobile heaps of rust. The traffic advances by inches and by howling. Each driver screams himself hoarse announcing – that was my lane! Stay there! Stop moving! Go back! Go forward! It is a good-natured shrieking: everybody knows that this is what you do in Dhaka. If you are lucky, you enter a slipstream of traffic that moves for a minute – until the jams back up and the screaming begins once more.
Around you, this megalopolis of 20 million people seems to be screaming itself conscious. People burn rubbish by the roadside, or loll in the rivers. Children with skin deformities that look like infected burns try to thrust maps or sweets into your hand. Rickshaw drivers with thighs of steel pedal furiously as whole families cling on and offer their own high-volume traffic commentary to the groaning driver, and the groaning city.
I wanted to wade through all this chaos to find Bangladesh's climate scientists, who are toiling in the crannies of the city to figure out what – if anything – can be saved.
Dr Atiq Rahman's office in downtown Dhaka is a nest of scientific reports and books that, at every question, he dives into to reel off figures. He is a tidy, grey-moustached man who speaks English very fast, as if he is running out of time.
"It is clear from all the data we are gathering here in Bangladesh that the IPCC predictions were much too conservative," he said. He should know: he is one of the IPCC's leading members, and the UN has given him an award for his unusually prescient predictions. His work is used as one of the standard textbooks across the world, including at Oxford and Harvard. "We are facing a catastrophe in this country. We are talking about an absolutely massive displacement of human beings."
He handed me shafts of scientific studies as he explained: "This is the ground zero of global warming." He listed the effects. The seas are rising, so land is being claimed from the outside. (The largest island in the country, Bhola, has lost half its land in the past decade.) The rivers are super-charged, becoming wider and wider, so land is being claimed from within. (Erosion is up by 40%.) Cyclones are becoming more intense and more violent (2007 was the worst year on record for intense hurricanes here). And salt water is rendering the land barren. (The rate of saline inundation has trebled in the past 20 years.) "There is no question," Dr Rahman said, "that this is being caused primarily by human action. This is way outside natural variation. If you really want people in the West to understand the effect they are having here, it's simple. From now on, we need to have a system where for every 10,000 tons of carbon you emit, you have to take a Bangladeshi family to live with you. It is your responsibility." In the past, he has called it "climatic genocide."
The worst-case scenario, Dr Rahman said, is if one of the world's land-based ice-sheets breaks up. "Then we lose 70 to 80 per cent of our land, including Dhaka. It's a different world, and we're not on it. The evidence from Jim Hansen shows this is becoming more likely – and it can happen quickly and irreversibly. My best understanding of the evidence is that this will probably happen towards the end of the lifetime of babies born today."
I walked out in the ceaseless churning noise of Dhaka. Everywhere I looked, people were building and making and living: my eyes skimmed up higher and higher and find more and more activity. A team of workers were building a house; behind and above them, children were sewing mattresses on a roof; behind and above them, more men were building taller buildings. This is the most cramped country on earth: 150 million people living in an area the size of Iowa. Could all this life really be continuing on the crumbling edge of a cliff?
2. 'It is like the Bay is angry'
I was hurtling through the darkness at 120 mph with my new driver, Shambrat. He was red-eyed from chewing pan, a leaf-stimulant that makes you buzz, and I could see nothing except the tiny pools of light cast by the car. They showed we were on narrow roads, darting between rice paddies and emptied shack-towns, in the midnight silence. I kept trying to put on my seatbelt, but every time Shambrat would cry, "You no need seatbelt! I good driver!" and burst into hysterical giggles . . .
Anne de Vernal: Natural Variability of Greenland Climate, Vegetation, and Ice Volume During the Past Million Years
Science, 20 June 2008,
Natural Variability of Greenland Climate, Vegetation, and Ice Volume During the Past Million Years
The response of the Greenland ice sheet to global warming is a source of concern notably because of its potential contribution to changes in the sea level. We demonstrated the natural vulnerability of the ice sheet by using pollen records from marine sediment off southwest Greenland that indicate important changes of the vegetation in Greenland over the past million years. The vegetation that developed over southern Greenland during the last interglacial period is consistent with model experiments, suggesting a reduced volume of the Greenland ice sheet. Abundant spruce pollen indicates that boreal coniferous forest developed some 400,000 years ago during the "warm" interval of marine isotope stage 11, providing a time frame for the development and decline of boreal ecosystems over a nearly ice-free Greenland.firstname.lastname@example.org
Link to article: http://www.sciencemag.org/cgi/content/abstract/sci;320/5883/1622
Greenland Ice Core Analysis Shows Drastic Climate Change Near End Of Last Ice AgeRead the abstract at Science Express: http://www.sciencemag.org/cgi/content/abstract/1157707
ScienceDaily, June 19, 2008 — Information gleaned from a Greenland ice core by an international science team shows that two huge Northern Hemisphere temperature spikes prior to the close of the last ice age some 11,500 years ago were tied to fundamental shifts in atmospheric circulation.
The ice core showed the Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just 50 years, then plunged back into icy conditions before abruptly warming again about 11,700 years ago. Startlingly, the Greenland ice core evidence showed that a massive "reorganization" of atmospheric circulation in the Northern Hemisphere coincided with each temperature spurt, with each reorganization taking just one or two years, said the study authors.
The new findings are expected to help scientists improve existing computer models for predicting future climate change as increasing anthropogenic greenhouse gases in the atmosphere drive up Earth's temperatures globally.
The team used changes in dust levels and stable water isotopes in the annual ice layers of the two-mile-long Greenland ice core, which was hauled from the massive ice sheet between 1998 to 2004, to chart past temperature and precipitation swings. Their paper was published in the June 19 issue of Science Express, the online version of Science.
The ice cores -- analyzed with powerful microscopes -- were drilled as part of the North Greenland Ice Core Project led by project leader Dorthe Dahl-Jensen of the Centre for Ice and Climate at the Neils Bohr Institute of the University of Copenhagen. The study included 17 co-investigators from Europe, one from Japan and two from the United States -- Jim White and Trevor Popp from the University of Colorado at Boulder.
"We have analyzed the transition from the last glacial period until our present warm interglacial period, and the climate shifts are happening suddenly, as if someone had pushed a button," said Dahl-Jenson.
According to the researchers, the first abrupt warming period beginning at 14,700 years ago lasted until about 12,900 years ago, when deep-freeze conditions returned for about 1,200 years before the onset of the second sharp warming event. The two events indicate a speed in the natural climate change process never before seen in ice cores, said White, director of CU-Boulder's Institute for Arctic and Alpine Research.
"We are beginning to tease apart the sequence of abrupt climate change," said White, whose work was funded by the National Science Foundation's Office of Polar Programs. "Since such rapid climate change would challenge even the most modern societies to successfully adapt, knowing how these massive events start and evolve is one of the most pressing climate questions we need to answer."
Both dramatic warming events were preceded by decreasing Greenland dust deposition, indicating higher tropical temperatures and significantly more rain falling on the deserts of Asia at the time, said White. The team believes the ancient tropical warming caused large, rapid atmospheric changes at the equator, the intensification of the Pacific monsoon, sea-ice loss in the north Atlantic Ocean and more atmospheric heat and moisture over Greenland and much of the rest of the Northern Hemisphere.
"Here we propose a series of events beginning in the lower latitudes and leading to changes in the ocean and atmosphere that reveal for the first time the anatomy of abrupt climate change," the authors wrote. White likened the abrupt shift in the Northern Hemisphere circulation pattern to shifts in the North American jet stream as it steers storms around the continent.
"We know such events are in Earth's future, but we don't know when," said White. "One question is whether we can see the symptoms before big problems occur. Until we answer these questions, we are speeding blindly down a narrow road, hoping there are no curves ahead."
Each yearly record of ice can reveal past temperatures and precipitation levels, the content of ancient atmospheres and even evidence for the timing and magnitude of distant storms, fires and volcanic eruptions, said White. The cores from the site -- located roughly in the middle of Greenland at an elevation of about 9,850 feet -- are four-inch-diameter cylinders brought to the surface in 11.5-foot lengths, said White.
Record Warm Summers Cause Extreme Ice Melt In Greenland
ScienceDaily, Jan. 16, 2008 — An international team of scientists, led by Dr Edward Hanna at the University of Sheffield, has demonstrated that recent warm summers have caused the most extreme Greenland ice melting in 50 years.
The new research provides further evidence of a key impact of global warming and helps scientists place recent satellite observations of Greenland's shrinking ice mass in a longer-term climatic context.
Dr Hanna of the University's Department of Geography, alongside some of the world's leading Greenland glaciologists and climatologists, analysed a combination of key meteorological and glaciological records spanning a number of decades as part of the research.
The findings show how the Greenland Ice Sheet responded to more regional, rather than global, changes in climate between the 1960s and early 1990s. However the last fifteen years has seen an increase in ice melting and a striking correspondence of Greenland with global temperature variations, demonstrating Greenland's recent response to global warming.
Summer 2003 was exceptionally warm around the margins of the Greenland Ice Sheet, which resulted in the second-highest meltwater running off from the Ice Sheet of the last 50 years. Summer 2005 experienced a record-high melt, which was very recently superseded in summer 2007 – a year almost as warm as 2003.
The team of researchers includes some of the leading Greenland glaciologists and climatologists from the Free University of Brussels, University of Colorado, Danish Meteorological Institute and NASA Goddard Earth Science and Technology Center, University of Maryland Baltimore County, as well as four members of the University of Sheffield.
Dr Edward Hanna said: "Our work shows that global warming is beginning to take its toll on the Greenland Ice Sheet which, as a relict feature of the last Ice Age, has already been living on borrowed time and seems now to be in inexorable decline. The question is can we reduce greenhouse-gas emissions in time to make enough of a difference to curb this decay?"
The findings have been published in the 15 January 2008 issue of Journal of Climate.
Adapted from materials provided by University of Sheffield.
University of Sheffield (2008, January 16). Record Warm Summers Cause Extreme Ice Melt In Greenland. ScienceDaily. Retrieved June 20, 2008, from http://www.sciencedaily.com /releases/2008/01/080115102706.htm
Thursday, June 19, 2008
Hot on the heels of last months reporting of a discrepancy in the ocean surface temperatures, a new paper in Nature (by Domingues et al, 2008) reports on the revisions of the ocean heat content (OHC) data -- a correction required because of other discrepancies in measuring systems found last year.
Before we get to the punchline though, it's worth going over the saga of the OHC trends in the literature over the last 8 years. In 2001, Syd Levitus and colleagues first published their collation of ocean heat content trends since 1950 based on archives of millions of profiles taken by oceanographic researchers over the last 50 years. This showed a long term upward trend up, but with some very significant decadal variability -- particularly in the 1970s and 1980s. This long term trend was in reasonable agreement with model predictions, but the decadal variability was much larger in the observations.
As in all cases where there is a data-model mismatch, people go back to both in order to see what might be wrong. One of the first suggestions was that since the spatial sampling became much coarser in the early part of the record, there might be more noise earlier on that didn't actually reflect a real ocean-wide signal. Sub-sampling the ocean models at the same sampling density as the real observations did increase the decadal variability in the diagnostic but it didn't provide a significantly better match (AchutaRao et al, 2006).
Other problems came up when trying to tally the reasons for sea level rise (SLR) over that 50 year period. Global SLR is a product of (in rough order of importance) ocean warming, land ice melting, groundwater extraction/dam building, and remnant glacial isostatic adjustment (the ocean basins are still slowly adjusting to the end of the last ice age). The numbers from tide gauges (and later, satellites) were higher than what you got by estimating each of those terms separately. (Note that the difference is mainly due to the early part of the record -- more recent trends do fit pretty well). There were enough uncertainties in the various components so that it wasn't obvious where the problems were though.
[For the rest of this post by Gavin Schmidt, please go to the realclimate.org link provided below.]
Wednesday, June 18, 2008
ScienceDaily, June 18, 2008 — New research suggests that ocean temperature and associated sea level increases between 1961 and 2003 were 50 percent larger than estimated in the 2007 Intergovernmental Panel on Climate Change report.
An international team of researchers, including Lawrence Livermore National Laboratory climate scientist Peter Gleckler, compared climate models with improved observations that show sea levels rose by 1.5 millimeters per year in the period from 1961-2003. That equates to an approximately 2½-inch increase in ocean levels in a 42-year span.
Estimates of ocean heat content and sea surface temperature. Upper (a): Comparison of our upper-ocean heat content with previous estimates (red1 and blue12) for the upper 700 m. The straight lines are linear fits to the estimates. The global mean stratospheric optical depth(arbitrary scale) at the bottom indicates the timing of major volcanic eruptions. The brown curve is a three-year running average of these values, included for comparison with the smoothed observations. Lower (b): Comparison of thick black line, as in a with the thick red line; thin red lines indicate estimates of one standard deviation error) results with sea surface temperature (blue; right-hand scale). All time series were smoothed with a three-year running average and are relative to 1961. (Credit: Image courtesy of DOE/Lawrence Livermore National Laboratory)
The ocean warming and thermal expansion rates are more than 50 percent larger than previous estimates for the upper 300 meters of oceans.
The research corrected for small but systematic biases recently discovered in the global ocean observing system, and uses statistical techniques that “infill” information in data-sparse regions. The results increase scientists’ confidence in ocean observations and further demonstrate that climate models simulate ocean temperature variability more realistically than previously thought.
“This is important for the climate modeling community because it demonstrates that the climate models used for assessing sea-level rise and ocean warming tie in closely with the observed results,” Gleckler said.
The results are reported in the June 19 edition of the journal Nature.
Climate model data were analyzed from 13 different modeling groups. All model data were obtained from the WCRP CMIP3 multi-model dataset archived at the LLNL’s Program for Climate Model Diagnosis and Intercomparison (PCMDI).
Although observations and models confirm that recent warming is greatest in the upper ocean, there are widespread observations of warming deeper than 700 meters.
Results were compared with recent estimates of other contributions to sea-level rise including glaciers, ice caps, Greenland and Antarctic ice sheets, and thermal expansion changes in the deep ocean. When these independent lines of evidence are examined collectively, the story is more consistent than found in earlier studies.
The oceans store more than 90 percent of the heat in the Earth’s climate system and act as a temporary buffer against the effects of climate change. The ocean warming and thermal expansion rates are 50 percent larger than previous estimates for the upper 700 meters of oceans, and greater than that for the upper 300 meters.
“This is just the tip of the iceberg, so to speak,” Gleckler said. “Our ability to quantify structural uncertainties in observationally based estimates is critically important. This study represents important progress.”
The team involved researchers from the Centre for Australian Weather and Climate Research (CSIRO), the Antarctic Climate and Ecosystems Cooperative Research Centre and LLNL.
Link to article: http://www.sciencedaily.com/releases/2008/06/080618143301.htm
Monday, June 16, 2008
Link to updated conditions at the Weather Channel site (ALERT: a commercial site with popups): http://www.weather.com/maps/maptype/currentweatherusnational/usactualhightemps_large.html
Saturday, June 14, 2008
Watch the animation of the breakup at this site: http://www.esa.int/esaEO/SEMG58VG3HF_planet_0.html
European Space Agency, June 13, 2008
The Wilkins Ice Shelf has experienced further break-up with an area of about 160 sq. km breaking off from 30 May to 31 May 2008. ESA's Envisat satellite captured the event -- the first ever-documented episode to occur in winter. Wilkins Ice Shelf, a broad plate of floating ice south of South America on the Antarctic Peninsula, is connected to two islands, Charcot and Latady. In February 2008, an area of about 400 sq. km broke off from the ice shelf, narrowing the connection down to a 6 km strip; this latest event in May has further reduced the strip to just 2.7 km.
The animation, comprised of images acquired by Envisat's Advanced Synthetic Aperture Radar (ASAR) between 30 May and 9 June, highlights the rapidly dwindling strip of ice that is protecting thousands of kilometres of the ice shelf from further break-up.
According to Dr Matthias Braun from the Centre for Remote Sensing of Land Surfaces, Bonn University, and Dr Angelika Humbert from the Institute of Geophysics, Muenster University, who have been investigating the dynamics of Wilkins Ice Shelf for months, this break-up has not yet finished. 'The remaining plate has an arched fracture at its narrowest position, making it very likely that the connection will break completely in the coming days,' Braun and Humbert said.
Braun and Humbert are monitoring the ice sheet daily via Envisat acquisitions as part of their contribution to the International Polar Year (IPY) 2007-2008, a large worldwide science programme focused on the Arctic and Antarctic.
The ASAR images used to compile these animations were acquired as part of ESA's support to IPY. ESA is helping scientists during IPY to collect an increasing amount of satellite information, particularly to understand recent and current distributions and variations in snow and ice and changes in the global ice sheets.
ESA is also co-leading a large IPY project -- the Global Interagency IPY Polar Snapshot Year (GIIPSY) -- with the Byrd Polar Research Centre. The goal of GIIPSY is to make the most efficient use of Earth-observing satellites to capture essential snapshots that will serve as benchmarks for gauging past and future changes in the environment of the polar regions.
ASAR is extremely useful for tracking changes in ice sheets because it is able to see through clouds and darkness -- conditions often found in polar regions.
Long-term satellite monitoring over Antarctica is important because it provides authoritative evidence of trends and allows scientists to make predictions. Ice shelves on the Antarctic Peninsula are important indicators for on-going climate change because they are sandwiched by extraordinarily raising surface air temperatures and a warming ocean.
The Antarctic Peninsula has experienced extraordinary warming in the past 50 years of 2.5 C, Braun and Humbert explained. In the past 20 years, seven ice shelves along the peninsula have retreated or disintegrated, including the most spectacular break-up of the Larsen B Ice Shelf in 2002, which Envisat captured within days of its launch.
Source: European Space Agency
Friday, June 13, 2008
The Earth's ozone layer is located in the lower stratosphere, which lies just above the troposphere (which begins at the planet's surface and reaches up to about 12 km), catching harmful ultraviolet rays from the sun. Until late in the last century, widespread usage of household and commercial aerosols containing chlorofluorocarbons (CFC), unstable compounds which are carried into the stratosphere, lead to significant and rapid ozone depletion. Due to the Montreal Protocol, signed by 191 countries, CFC production worldwide was phased out in 1996.
Observations in the last few years indicate that ozone depletion has largely halted and is expected to fully reverse. As a consequence, the new study finds, the Southern Hemisphere climate change may also reverse. This would be a very tangible outcome of the Montreal Protocol, which has been called the single most successful international agreement to date, and would demonstrate how international treaties are able to make positive changes to the climate system.
"Our results suggest that stratospheric ozone is important for the Southern Hemisphere climate change, and ought to be more carefully considered in the next set of IPCC model integrations," said Seok-Woo Son, lead-author of the study and a postdoctoral research scientist at Columbia's Fu Foundation School of Engineering and Applied Science (SEAS).
The team of 10 scientists compared results from two sets of climate models, the first one used by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), released in late 2007, and the second from the Scientific Assessment of Ozone Depletion, published by the World Meteorological Organization in 2006. In their prediction of future climate, many IPCC models did not consider the expected ozone recovery and its potential impacts on climate change. The chemistry-climate models used for the 2006 Ozone Assessment, however, predict that the Antarctic ozone hole will achieve full recovery in the second half of this century, and that this may have profound impacts on the surface winds and, likely, on other aspects of the Earth's climate, including surface temperatures, locations of storm tracks, extent of dry zones, amount of sea ice, and ocean circulation.
In the past few decades, the tropospheric winds in the Southern Hemisphere have been accelerating closer to the planet's pole as a result of increasing greenhouse gases and decreasing ozone. This wind change has had a broad range of effects on the Earth's climate. The IPCC models predict that this effect will continue, albeit at a slower pace. In contrast, predictions made by the chemistry-climate models indicate that, as a consequence of ozone recovery -- a factor largely ignored by IPCC models -- the tropospheric winds in the Southern Hemisphere may actually decelerate in the high latitudes and move toward the equator, potentially reversing the direction of climate change in that hemisphere.
"We were surprised to find that the closing of the ozone hole, which is expected to occur in the next 50 years or so, shows significant effects on the global climate," said Lorenzo M. Polvani, one of two principle investigators and professor of applied physics and applied mathematics at SEAS. "This is because stratospheric ozone has not been considered a major player in the climate system."
Polvani and Son state that more research needs to be conducted to validate their results, and to fully understand how complete ozone recovery will impact the planet's changing climate. While previous studies have shown that ozone hole recovery could lead to a warming of the Antarctic, much work remains. For instance, the chemistry-climate models used in the 2006 Ozone Assessment Report do not include a full ocean circulation, which might affect surface temperatures. The interactions between a recovering ozone hole, increasing greenhouse gases, ocean currents, and other components of the climate system must still be explored in order to better understand how the Earth's climate will change in the future.
In addition to Polvani and Son, researchers from Johns Hopkins (Baltimore, MD), the National Institute for Environmental Studies (Tsukuba, Japan), the National Center for Atmospheric Research (Boulder, CO), the NASA Goddard Space Flight Center (Greenbelt, MD), the Institute for Atmospheric and Climate Sciences at ETH (Zurich, Switzerland), the Physical Meteorological Observatory (Davos, Switzerland), the University of Toronto (Toronto, Canada), and the Meteorological Research Institute (Tsukuba, Japan).
Mernild and his team found that the total amount of Greenland Ice Sheet freshwater input into the North Atlantic Ocean expected from 2071 to 2100 will be more than double what is currently observed. The current East Greenland Ice Sheet freshwater flux is 257 km3 per year from both runoff and iceberg calving. This freshwater flux is estimated to reach 456 km3 by 2100.
Mernild’s results further show a change in total Greenland freshwater flux from today’s values of 438 km3 per year to 650 km3 per year by 2100. This indicates an increase in global sea level rise estimates from 1.1 millimeters per year to 1.6 millimeters per year.
“The Greenland Ice Sheet mass balance is changing as a response to the altered climatic state,” said Mernild. “This is faster than expected. This affects freshwater runoff input to the North Atlantic Ocean, and plays an important role in determining the global sea level rise and global ocean thermohaline circulation.”
Mernild is conducting the research as part of the University of Alaska’s International Polar Year efforts. He was appointed a University of Alaska IPY postdoctoral fellow by UA president Mark Hamilton in 2007.
- Mernild et al. Climatic control on river discharge simulations, Zackenberg River drainage basin, northeast Greenland. Hydrological Processes, 2008, Vol. 22, No. 12, 1932. DOI: 10.1002/hyp.6777
Link to article: http://www.sciencedaily.com/releases/2008/06/080612090919.htm