Wednesday, September 12, 2007

The Flip Side

Yesterday's New York Times examined an aspect of global warming that doesn't get much attention: adaptation. Planning for adaptation is taboo in some circles, because it implies that it might be better to learn to live with climate change than to take steps to avert it. Mr. Tierney's article about the views of the controversial Danish environmental economist Bjorn Lomborg raises some interesting points for consideration, while contributing to the sense of futility attached to much of the adaptation discussion. That's a pity, because I view adaptation as an essential component of a rational global strategy to deal with climate change.

Consider Dr. Lomborg's ideas about rising sea level and coastal development. Citing the example of the minimal impact of past sea-level increases on rich countries like the US, he suggests we would do better to increase global wealth and limit coastal development, rather than investing heavily to reduce greenhouse gas emissions, in order to slow the rise in sea level from global warming. While there's some merit to this argument, I don't see it in the same either/or terms he does.

If an increase of a foot or two in sea level were the worst potential outcome of climate change, then it probably wouldn't be worth expending enormous efforts preventing it, instead of planning to adapt to a world with a bit less shoreline. But that presumes we can predict those results accurately, instead of facing enormous uncertainties, due to intricate feedback mechanisms involving ice, water and cloud cover. Sea level could go up by inches or meters, along with a wide range of other global warming impacts affecting agriculture, biodiversity, and human health.

However, if we took some of Dr. Lomborg's ideas as being additive, rather than alternative to the measures necessary to mitigate climate change, then we might have something useful. Reducing our emissions sufficiently to avert the worst consequences of global warming will be quite challenging. We are likely to see further warming and some adverse consequences, despite our best efforts. In that case, taking reasonable steps to prepare for a world that includes some of those outcomes--such as higher sea levels--looks smart, rather than defeatist.

So let's imagine that the Congress passed strong measures to reduce US emissions along the lines currently being debated, and that the President signed them into law. That would suggest not only a scientific consensus on climate change, but a political consensus that it represents a high-priority problem for us and the world. Might it then also make sense to begin a frank conversation about how prudent it is for millions of Americans to migrate to a state with a mean elevation above present sea level of only 100 feet? Census estimates show the population of Florida growing from 18 million today to 29 million by 2030. Even if you dismiss the computer animations that show Florida going underwater within a century or so, putting that many extra people, their homes and other property at future risk from climate change doesn't make much sense, particularly if the US government ends up as the insurer of last resort for most of these folks. The alternative might require seawalls on an unimaginable scale.

The politics of this look terrible, of course. Florida has been a key state in the last couple presidential elections, and both parties see it as pivotal to their future chances. Which candidate would be first in line to suggest that Florida shouldn't grow so rapidly? Perhaps adaptation isn't the easy way out, after all. But easy or not, this is only one example of how we cannot argue that climate change is an enormous problem demanding urgent action, while simultaneously promoting actions that will compound the impact of its foreseeable consequences. In that sense, mitigation and adaptation are two sides of the same coin.

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