It's all six of the ghgs out there already, doing things like this:
A number of news reports and commentary on Hurricanes Katrina and Rita have linked the disasters to global warming. Almost nobody noticed a crucial scientific finding, two weeks earlier, that foreshadows disasters on a far greater scale in the decades to come.
According to August 11 articles in the magazine New Scientist and the British newspaper the Guardian, a pair of scientists, one Russian and one British, report that global warming is melting the permafrost in the West Siberian tundra. The news made a little blip in the international media and the blogosphere, and then it disappeared.
Why should anyone care? Because melting of the Siberian permafrost will, over the next few decades, release hundreds of millions of tons of methane from formerly frozen peat bogs into the atmosphere. Methane from those bogs is at least twenty times more potent as a greenhouse gas than the carbon dioxide that currently drives global warming. Dumping such a huge quantity of methane on top of already soaring CO2 levels will drive global temperatures to the upper range of increases forecast for the remainder of this century.
According to the most recent forecast by the UN's Intergovernmental Panel on Climate Change (IPCC), compiled in 2001, human industrial emissions are on course to raise global temperatures between 1.4 and 5.8 degrees Celsius by the year 2100. The IPCC models didn't account for methane releases from the Arctic, nor did they consider other natural sources of greenhouse gases that could be released by human activity. The agency judged Arctic methane releases to be a real but remote possibility, not likely to emerge for decades. Now we find that it could very well be happening today.
The news of melting Siberian permafrost means, in all likelihood, that global warming is accelerating much faster than climatologists had predicted. The finding from Siberia comes amidst evidence, presented at Tony Blair's special climate change conference last February, that the West Antarctic Ice Sheet could be in danger of disintegrating -- another warming-induced event once thought to be decades or centuries away. Meanwhile, according to a September 29, 2005 report in the Guardian, scientists at the University of Colorado, Boulder's National Snow and Ice Data Center have measured a drastic shrinking of ice floes in the Arctic Ocean. Arctic waters are now expected to be ice-free well before the end of this century.
EDIT
http://www.alternet.org/envirohealth/25351/And this:
If emissions of heat-trapping gases continue to accumulate in the atmosphere at the current rate, there may be many centuries of warming and a near-total loss of Arctic tundra, according to a new climate study. Over all, the world would experience profound transformations, some potentially beneficial but many disruptive, and all at a pace rarely seen in nature, said the authors of the new study, which is being published on Tuesday in The Journal of Climate.
"The question is no longer whether we will need to address this problem, but when we will need to address the problem," said Kenneth Caldeira, an author of the study and a climate expert at the Carnegie Institution's Department of Global Ecology, based at Stanford University. "We can either address it now, before we severely and irreversibly damage our climate, or we can wait until irreversible damage manifests itself strongly," Dr. Caldeira said. "If all we do is try to adapt, things will get worse and worse."
The paper's lead author, Bala Govindasamy of the Energy Department's Lawrence Livermore National Laboratory, said it might take 20 or 30 years before the scope of the human-caused changes becomes evident, but from then on there is likely to be no debate. The researchers ran a computer model that simulates both the climate system and the flow of heat-trapping carbon into the air in the form of carbon dioxide, then back into soils and the ocean.
EDIT
In the simulation, at least one ecosystem, the scrubby Arctic tundra largely vanishes as climate zones shift hundreds of miles north. Tundra would decline from about 8 percent of the world’s land area to 1.8 percent. Alaska, in the model, loses almost all of its evergreen boreal forests and becomes a largely temperate state. But vast stretches of land that were once locked beneath permanent ice cover would open up. The area locked beneath ice would diminish from 13.3 percent of the planet’s total land area to 4.8 percent. Conditions that nurture tropical and temperate forests could expand substantially, so that the two forest types could grow on nearly 65 percent of land surfaces instead of 44 percent now. But the pH of the oceans would fall because of a buildup of carbonic acid from dissolving carbon dioxide, eroding coral reefs and the shells of plankton and other marine life, Dr. Caldeira said.
EDIT
http://www.nytimes.com/2005/10/31/science/earth/01warm_... And this:
FAIRBANKS -- Interior Alaska's permafrost has warmed in some places to the highest level since the ice age ended 10,000 years ago, its temperature now within a degree or two of thawing. Earth frozen since woolly mammoths and bison wandered Interior steppes has been turning to mush. Lakes have been shrinking. Trees are stressed. Prehistoric ice has melted underground, leaving voids that collapse into sinkholes.
Largely concentrated where people have disturbed the surface, such damage can be expensive, even heartbreaking. It's happening now in Fairbanks: Toppled spruce, roller-coaster bike trails, rippled pavement, homes and buildings that sag into ruin. And the meltdown is spreading in wild areas: sinkholes, dying trees, eroding lakes. These collapses bode ill: They are omens of what scientists fear will happen on a large scale across the Arctic if water and air continue to warm as fast as climate models predict.
"So far, we have only some local places where permafrost is thawing naturally," said expert Vladimir Romanovksy, a Russian-born geophysicist at the Geophysical Institute of the University of Alaska Fairbanks. "But we are very, very close to this point when it (all) starts to thaw." After record high temperatures during the summer of 2004 and last winter's deep insulating snow, Romanovsky said he expects Interior permafrost will again be significantly warmer than normal this year -- still closer to melting.
EDIT
For a glimpse of that future, look no farther than the hills north of Fairbanks, near where Romanovsky lives with his wife and two of his three sons. In a meadow on his mother-in-law's property, weird six-foot-deep channels and holes crisscross the ground, trenches and bomb pits from what amounts to thermal warfare. A small hole opened up in the sod a few years ago, curving down into the earth like some gopher den. This spring, his sons and other children playing near the house discovered the bottom had fallen out. The cavity was now large enough to bury a person. No one has crawled down to see where it ends. Romanovksy discourages his sons playing in the field. "It is not safe," he said.
EDIT
http://www.adn.com/news/environment/story/6815494p-6707... We could stop emitting
tomorrow and the accumulated ghgs already in the atmosphere would, in all likelihood, be enough to keep powering up these sorts of natural positive feedback loops. Once they get going, they're very hard to stop.
At this point, I'm pretty much in the camp that catastrophic climate destabilization is inevitable.
I'm not saying this to be cool and portentuous like an art student, and not to look "hip" in a back-to-the-Pleistocene" way, but just because I think that's what the facts bear out.
It's not gloom - it's an appreciation of reality.
Printer-friendly format
Email this thread to a friend
Bookmark this thread
(1000+ posts)
Send PM |
Profile |
Ignore
