Sunday, January 29, 2006
Debate on Climate Shifts to Issue of Irreparable Change
By Juliet Eilperin
Washington Post Staff Writer
Sunday, January 29, 2006; Page A01
Now that most scientists agree human activity is causing Earth to warm, the central debate has shifted to whether climate change is progressing so rapidly that, within decades, humans may be helpless to slow or reverse the trend.
This "tipping point" scenario has begun to consume many prominent researchers in the United States and abroad, because the answer could determine how drastically countries need to reduce their greenhouse gas emissions in the coming years. While scientists remain uncertain when such a point might occur, many say it is urgent that policymakers cut global carbon dioxide emissions in half over the next 50 years or risk the triggering of changes that would be irreversible.
The debate has been intensifying because Earth is warming much faster than some researchers had predicted. James E. Hansen, who directs NASA's Goddard Institute of Space Studies, last week confirmed that 2005 was the warmest year on record, surpassing 1998. Earth's average temperature has risen nearly 1 degree Fahrenheit over the past 30 years, he noted, and another increase of about 4 degrees over the next century would "imply changes that constitute practically a different planet."
"It's not something you can adapt to," Hansen said in an interview. "We can't let it go on another 10 years like this. We've got to do something."
Princeton University geosciences and international affairs professor Michael Oppenheimer, who also advises the advocacy group Environmental Defense, said one of the greatest dangers lies in the disintegration of the Greenland or West Antarctic ice sheets, which together hold about 20 percent of the fresh water on the planet. If either of the two sheets disintegrates, sea level could rise nearly 20 feet in the course of a couple of centuries, swamping the southern third of Florida and Manhattan up to the middle of Greenwich Village.
While both the Greenland and the Antarctic ice sheets as a whole are gaining some mass in their cold interiors because of increasing snowfall, they are losing ice along their peripheries. That indicates that scientists may have underestimated the rate of disintegration they face in the future, Oppenheimer said. Greenland's current net ice loss is equivalent to an annual 0.008 inch sea level rise.
The effects of the collapse of either ice sheet would be "huge," Oppenheimer said. "Once you lost one of these ice sheets, there's really no putting it back for thousands of years, if ever."
When Hansen posted data on the Internet in the fall suggesting that 2005 could be the warmest year on record, NASA officials ordered Hansen to withdraw the information because he had not had it screened by the administration in advance, according to a Goddard scientist who spoke on the condition of anonymity. More recently, NASA officials tried to discourage a reporter from interviewing Hansen for this article and later insisted he could speak on the record only if an agency spokeswoman listened in on the conversation.
"They're trying to control what's getting out to the public," Hansen said, adding that many of his colleagues are afraid to talk about the issue. "They're not willing to say much, because they've been pressured and they're afraid they'll get into trouble."
GOI: Nothing like good old fashioned censorcism and intimidation from "handlers" to prevent evidence from coming to light.
John R. Christy, director of the Earth Science System Center at the University of Alabama in Huntsville, said it is possible increased warming will be offset by other factors, such as increased cloudiness that would reflect more sunlight. "Whatever happens, we will adapt to it," Christy said.
GOI: Oh yeah!! Let's just adapt to things after they've gone beyond the tipping point! Smart thinking there.
Scientists who read the history of Earth's climate in ancient sediments, ice cores and fossils find clear signs that it has shifted abruptly in the past on a scale that could prove disastrous for modern society. Peter B. deMenocal, an associate professor at the Lamont-Doherty Earth Observatory of Columbia University, said that about 8,200 years ago, a very sudden cooling shut down the Atlantic conveyor belt. As a result, the land temperature in Greenland dropped more than 9 degrees Fahrenheit within a decade or two.
"It's not this abstract notion that happens over millions of years," deMenocal said. "The magnitude of what we're talking about greatly, greatly exceeds anything we've withstood in human history."
David Warrilow, who heads science policy on climate change for Britain's Department of Environment, Food and Rural Affairs, said that while the science remains unsettled, his government has decided to take a precautionary approach. He compared consuming massive amounts of fossil fuels to the strategy of the Titanic's crew, who were unable to avoid an iceberg because they were speeding across the Atlantic in hopes of breaking a record.
"We know there are icebergs out there, but at the moment we're accelerating toward the tipping point," Warrilow said in an interview. "This is silly. We should be doing the opposite, slowing down whilst we build up our knowledge base."
GOI: So let's just take the chance that this won't happen (or isn't happening) like the opponents of global warming want us to do. Yeah, that's a great gamble. On one hand we on conservative with the environment and take the pre-cautions on the other hand we take a "wait and see" approach.
So for the proponents of the last option I want to ask, "Then what happens if global warming IS true like most of the science data shows and we pass the 'tipping point'?" I guess then all we say is, "Oops sorry about that one???" I think the possible destruction of our Earth's atmosphere is a big enough issue to be pro-active so that we don't have to take such a drastict and deadly gamble.
What's the worst that could happen if we reduce green house gas emissions? Oh, we spent some more for a better planet?? Oh how terrible. Yeah, I think taking some actions to help our planet is a good thing. Just in case. "God" forbid we do something to take a pre-emptive stance on our environment. It's apparently "o.k." with invading outher countries but not o.k. to protect the planet on which we all live on?? It's time to pull our heads out of the asses of the oil, gas and other destructive industries.
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