From AFP: "Earth's climate appears to be changing more quickly and deeply than a benchmark UN report for policymakers predicted, top scientists said ahead of international climate talks starting Monday in Poland.
More from the article:
But the new studies, they say, indicate that human activity may be triggering powerful natural forces that would be nearly impossible to reverse and that could push temperatures up even further. At the top of the list for virtually all of the scientists canvassed was the rapid melting of the Arctic ice cap...
"In the last couple of years, Arctic Sea ice is at an all-time low in summer, which has got a lot of people very, very concerned," commented Robert Watson, Chief Scientific Advisor for Britain's department for environmental affairs and chairman of the IPCC's previous assessment in 2001. "This has implication's for Earth's climate because it can clearly lead to a positive feedback effect," he said in an interview. When the reflective ice surface retreats, the Sun's radiation -- heat -- is absorbed by open water rather than bounced back into the atmosphere, creating a vicious circle of heating.
"We had always known that the Arctic was going to respond first," said Mark Serreze of the National Snow and Ice Data Center in Boulder, Colorado. "What has us puzzled is that the changes are even faster than we would have thought possible," he said by phone...
New data on the rate at which oceans might rise has also caused consternation.
"The most recent IPCC report was prior to ... the measurements of increasing mass loss from Greenland and Antarctica, which are disintegrating much faster than IPCC estimates," said climatologist James Hansen, head of NASA's Goddard Institute for Space Studies in New York. Unlike the Arctic ice cap, which floats on water, the world's two major ice sheets -- up to three kilometers (two miles) thick -- sit on land. Runaway sea level rises, Hansen said, would put huge coastal cities and agricultural deltas in Bangladesh, Egypt and southern China under water, and create hundreds of millions of refugees...
The accelerating concentration of greenhouse gases in the atmosphere, and signs of the planet's dwindling ability to absorb them, are also causing some scientists to lose sleep. During the 1970s, there were on average 1.3 parts per million (ppm) of carbon dioxide -- the main greenhouse gas -- in the air. In the 1980s the figure was 1.6 ppm, and in the 1990s 1.5 ppm. In the period 2000-2007, however, the concentration jumped to an average 2.0 ppm, with a high of 2.2 last year, according to the Global Carbon Project, based in Australia. "The present concentration is the highest during the last 650,000 years and probably during the last 20 million years," said the Global Carbon Project's Pep Canadell, a researcher at Australia's Commonwealth Scientific and Industrial Research Organisation.
And in 2008, he said, there has been an "exponential growth" in the atmospheric concentration of methane, another greenhouse gas that is an even more potent driver of global warming than CO2. One potential source of both gases is frozen tundra in the Arctic and sub-Arctic regions, where temperatures have risen faster than anywhere else on Earth. "The amount of carbon that is locked up in permafrost that could be released into the atmosphere is just about on a par with the atmospheric load the world has right now," said Serreze. These higher concentrations of greenhouse gases come at a time when Earth's two major "carbon sinks" -- forests and especially oceans -- are showing signs of saturation.
The December 1-12 forum of 192-member UN Framework Convention on Climate Change (UNFCCC) comes midway through a two-year process launched in Bali for braking the juggernaut of global warming. Scheduled to run until December 12, the talks are a stepping stone towards a new pact -- due to be sealed in Copenhagen in December 2009 -- for reducing emissions and boosting adaptation funds beyond 2012, when the current provisions of the UN's Kyoto Protocol expire.
Meanwhile global levels of CO2 set records this year, according to the Environmental News Service. They write:
Climate-heating greenhouse gases continue to increase in the atmosphere, and last year, global concentrations of carbon dioxide again reached the highest levels ever recorded, according to an annual report released Tuesday by the World Meteorological Organization...
The WMO Global Atmosphere Watch coordinates the measurement of greenhouse gases in the atmosphere through a network of observatories located in more than 65 countries. The measurements are published annually in the WMO's "Greenhouse Gas Bulletin." "Population growth and urban development worldwide continue to increase the use of fossil fuels, such as oil, coal and natural gas, which emit carbon dioxide and other gases into the atmosphere. At the same time, the clearing of land for agriculture, including deforestation, is releasing carbon dioxide into the air and reducing carbon uptake by the biosphere," the WMO states in its report...
An ecologist who studies the carbon cycle, [Jay Gulledge, senior scientist with the Pew Center for Global Climate Change in Arlington, Virginia] says greenhouse gas emissions must peak by 2015 to have "a good shot at stabililzing the climate at a safe level." After water vapor, the four most prevalent greenhouse gases in the atmosphere are carbon dioxide, methane, nitrous oxide and chlorofluorocarbons, CFCs, ozone-damaging chemicals once widely used as refrigerants. CFC levels are now slowly dropping due to emissions reductions set under the United Nations Montreal Protocol on Substances that Deplete the Ozone Layer that entered into force in 1989. Carbon dioxide reached 383.1 parts per million (ppm), an increase of 0.5 percent from 2006, according to the latest numbers in the World Meteorological Organization report. Concentrations of nitrous oxide also reached record highs in 2007, up 0.25 percent from the year before. Methane levels increased 0.34 percent, exceeding the highest value so far, which was recorded in 2003. Using the annual greenhouse gas index issued by the U.S. National Oceanic and Atmospheric Administration, NOAA, the total warming effect of all long-lived greenhouse gases was calculated to have increased by 24.2 percent since 1990 and by 1.06 percent from the previous year. Since the mid-18th century, carbon dioxide concentrations in the atmosphere have risen 37 percent, the WMO report shows. Gulledge points out that greenhouse gas concentrations will continue to rise for some decades even after emissions continue to drop. "We wouldn't expect concentrations to level off until the middle of the century even with effective policy," he said...
There is a glimmer of good news concerning the greenhouse gas methane in the WMO report. While the atmospheric concentrations of other gases are increasing steadily, the growth rate of methane concentrations has slowed over the past decade, with some variations from one year to the next. The rise of six parts per billion from 2006 to 2007 is the highest annual methane increase observed since 1998. It is still too early to state with certainty, however, that this latest increase is the start of a new upward trend in methane levels...
Meanwhile, a consortium including the UN Food and Agriculture Organization said Tuesday that Africa could be absorbing more carbon dioxide from the atmosphere than the continent is releasing. CarboAfrica found that Africa contributes less than four percent of the global emissions from fossil fuels, but accounts for 17 percent and 40 percent respectively of gas emissions emanating from deforestation and fires, according to the research conducted by scientists from 15 institutions. The most important element is the balance between carbon captured through photosynthesis by Africa's forests and savannas and gas released into the atmosphere, said Riccardo Valenti, coordinator of CarboAfrica.
More Coyote Gulch coverage here.
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