Warm thoughts on a cold day

Updated Global warming may seem like an odd topic to be considering just three days after being blasted with 38 inches of snow (that's just short of a meter to my international friends). But Left End of the Dial had a link to a CNN piece for Monday that brought it back to mind.

Global warming is approaching the critical point of no return, after which widespread drought, crop failure and rising sea-levels would be irreversible, an international climate change task force warned Monday. ...

"An ecological time-bomb is ticking away," said Stephen Byers, who co-chaired the task force with U.S. Republican Senator Olympia Snowe, and is a close confidant of British Prime Minister Tony Blair. "World leaders need to recognize that climate change is the single most important long term issue that the planet faces."

The report, called "Meeting the Climate Challenge" and available in .pdf format through this link, addresses one of the big fears among climate scientists: the possibility of a "runaway greenhouse effect" where in addition to environmental factors (particularly human activity) acting as "forcings" on the climate, the warming itself becomes a forcing, generating a feedback loop that would dramatically and drastically escalate both the severity and rapidity of climate change and would react sluggishly (i.e., over perhaps centuries) - if at all - to efforts to mitigate it. The report suggests we are on the verge of just that point of no return, beyond which our efforts would be futile.

Just how rapidly can severe changes occur? One of the "tipping points" the report lists would be the shutting down of the Gulf Stream, which would have an large impact, including making parts of the world much colder. I gave a brief explanation of how global warming can make some areas colder here, but the root idea is that it can result in the disruption of the flow of warm tropical water toward the poles.

Yes, but how rapidly, how severe? In his new book Boiling Point, Ross Gelbspan reports on an ice core study which indicates just that sort of breakdown of the warm currents took place about 11,000 years ago, giving what's now the UK a climate much like that of Greenland.

The entire change took four years. That's how rapid, that's how severe.

But so what? After all, actually doing anything about it could hurt the profits of the oil industry, the coal industry, the natural gas industry. Admittedly, it would also help industries dealing in renewable energy and help people live longer and healthier lives - but they don't pour big bucks into campaign coffers. There are priorities, y'know!

Updated to include the link to the report; that same sentence was also edited for the sake of proper grammar.