20 feet

Recently, various critics have lamented the cult of catastrophism endemic in certain circles of the environmental movement. Largely, this has revolved around whether or not the 20 ft sea level rise made famous in Al Gore's An Inconvenient Truth is indicative of a propaganda effort designed to elicit mass hysteria amongst the population or an effective didactic tool to mobilize an apathetic population.

While admittedly there are some who seemingly feed off of fear of the ad infinitum trendline ending in annihilation, what's much more troubling about the things that are happening around us are the kinds of subtle shifts that exacerbate climatic variations inherent in the system.

An even darker possibility is that a Western drought caused by climatic variation and a drought caused by global warming could arrive at the same time. Or perhaps they already have. This coming spring, the United Nations’ Intergovernmental Panel on Climate Change will issue a report identifying areas of the world most at risk of droughts and floods as the earth warms. Fresh-water shortages are already a global concern, especially in China, India and Africa. But the I.P.C.C., which along with Al Gore received the 2007 Nobel Peace Prize earlier this month for its work on global-warming issues, will note that many problem zones are located within the United States, including California (where the Sierra Nevada snowpack is threatened) and the Colorado River basin. These assessments follow on the heels of a number of recent studies that analyze mountain snowpack and future Colorado River flows. Almost without exception, recent climate models envision reductions that range from the modest to the catastrophic by the second half of this century. One study in particular, by Martin Hoerling and Jon Eischeid, suggests the region is already “past peak water,” a milestone that means the river’s water supply will now forever trend downward.

This is a quite a pernicious problem since in the years that it takes to figure out what contribution global climate change micht have had on a trend, it becomes ever more late to react to the change either by reducing carbon emissions or by "adapting" to the change. By the time we get around to "adapting" by either piping water from the Pacific Northwest or building massively expensive desalination plants, chances are many thousands of individual decisions will have already made to simply move away. Those decisions will likely affect regional economies to such a degree as to make adaptation unnecessary. The question to our leaders is: do you want to risk exposing families to the risk of having to move away from an area slowly drying out at a time when their modes of income will likely be compromised by such a drought? Moreover, are we willing to risk adapting to droughts in one part of the country and increased rainfall in another? Certainly we can't do anything about natural variations, but we can at least mitigate some of our own contributions.