Planning Too Far Ahead
"There are engineering questions about the massive storage repository proposed for the Nevada desert. Certainty about its ability to keep groundwater supplies safe falls off after about 10,000 years—while the facility needs to function as planned for several hundred thousands of years."
The quote is from an interesting article on global warming and ways of dealing with it in the latest issue of Harvard Magazine. The context is a discussion of problems in storing nuclear waste as one limit to increases in the role of nuclear power.
To me, at least, the idea of worrying about effects more than ten thousand years out is so absurd as to be marginally sane. Nobody alive knows whether our species will still exist in ten thousand years, if it exists if most humans will still live on earth, or if we still live on earth what sort of society, economy and technology we will have. If things do continue more or less along current lines—not, in my view, very likely—ten thousand years of economic growth would give us a society for which a little radioactivity in Nevada groundwater would be a trivial problem. If we assume a 1% annual rate of growth in per capita real income, it takes only about 2300 years to bring the income of the average individual up to the current income of the world.
Worrying about problems ten thousand years out is particularly odd given that nuclear power is being discussed as a way of limiting global warming. Elsewhere in the article, in the context of a time horizon of 100 to 500 years, another source suggests the possibility of sea level rises of over 200 feet. I am reluctant to trust extrapolations that far out as well—but compared to 10,000 years, a hundred years is practically as close as next Thursday. And drowning areas containing a considerable fraction of the population of the globe would be a slightly more serious problem than contamination of the Nevada water table.