... 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.
There are three specific events that these scientists describe as especially worrisome and potentially imminent, although the time frames are a matter of dispute: widespread coral bleaching that could damage the world's fisheries within three decades; dramatic sea level rise by the end of the century that would take tens of thousands of years to reverse; and, within 200 years, a shutdown of the ocean current that moderates temperatures in northern Europe.
Do we have the political will? That seems to be the question.
Some politicians prefer to live in denial rather than accept the hard choices that must be made NOW!
I am glad WaPo is ringing the alarm bell.
The debate has been intensifying because Earth is warming much faster than some researchers had predicted. James 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.''
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.''
and now the CRIMINAL negligence part ...
Silly me, I thought the government had a responsibility to protect its citizens, not coverup and do nothing in face of imminent catastrophe.
This tipping point debate has stirred controversy within the administration; Hansen said senior political appointees are trying to block him from sharing his views publicly.
When Hansen posted data on the Internet last fall suggesting that 2005 could be the warmest on record, according to a Goddard scientist who did not want to be identified, NASA officials ordered Hansen to withdraw the information because he had not screened it with the administration in advance. 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.''