Saturday, September 17, 2005

Global warming: point of no return?

The bottom line: we're screwed.

Global warming 'past the point of no return'
A record loss of sea ice in the Arctic this summer has convinced scientists that the northern hemisphere may have crossed a critical threshold beyond which the climate may never recover. Scientists fear that the Arctic has now entered an irreversible phase of warming which will accelerate the loss of the polar sea ice that has helped to keep the climate stable for thousands of years.

They believe global warming is melting Arctic ice so rapidly that the region is beginning to absorb more heat from the sun, causing the ice to melt still further and so reinforcing a vicious cycle of melting and heating.

The greatest fear is that the Arctic has reached a "tipping point" beyond which nothing can reverse the continual loss of sea ice and with it the massive land glaciers of Greenland, which will raise sea levels dramatically.
Some people still think this is alarmist nonsense. However, the scientific consensus continues to grow more one-sided: global warming is real. And the evidence is coming from many directions. For instance, this:

Vegetation Growth May Quickly Raise Arctic Temperatures
Warming in the Arctic is stimulating the growth of vegetation and could affect the delicate energy balance there, causing an additional climate warming of several degrees over the next few decades. A new study indicates that as the number of dark-colored shrubs in the otherwise stark Arctic tundra rises, the amount of solar energy absorbed could increase winter heating by up to 70 percent.

Yet some people still think that the warming probably isn't even real, and many more think the effects won't be as serious as projected even if warming is real. The latter sort of remind us of the people in New Orleans who decided not to evacuate before the hurricane (either because they had no easy means to, or they simply thought they could "ride it out"). Well guess what. In that case, the effects were much worse than most feared.

And there are reports that political leaders who have previously supported efforts to reduce greenhouse gas emissions, like the UK's Tony Blair, may be changing their minds. Considering the source, don't take that as a sure thing. But it is possible that the problem is now recognized as so serious that reducing emissions, even more drastically than foreseen by the Kyoto treaty, won't avert something really bad. What's the alternative? This last reference suggests:
So what will happen instead? Blair answered: "What countries will do is work together to develop the science and technology….There is no way that we are going to tackle this problem unless we develop the science and technology to do it."
However, if warming is real, unavoidable, and likely to have more serious effects -- and possibley sooner -- than generally supposed, then perhaps science and technology won't be able to let us avoid a really bad outcome. Maybe the best we can hope for is making it a little less bad.

Pursuing the Katrina analogy, it may be it's much too late to flee the hurricane bearing down on us or to prevent the breaching of the levees. At best we can employ science and technology in a crash program to build better pumps to clean up a little bit faster after the diaster that "no one could have foreseen" actually occurs. It may or may not be possible to significantly mitigate global warming over the next century. But part of our preparation should certainly be a large investment in science and technology for coping with the possible effects we can foresee.

Maybe that's a pessimistic scenario. But isn't disaster planning largely about planning how to handle the "worst" case?

People will be tempted to think that with just a little preparation we can "ride out" the coming global warming storm without much inconvenience. But if New Orleans is any indication, that might not be such a good idea.

And what about New Orleans itself? Rebuilding it might be the "right" thing to do. But we darn well better plan for higher sea levels and more frequent and powerful hurricanes.


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