For the first time, Germany’s Green Party will control one of the country’s state governments, just in time to decide the fate of several nuclear plants temporarily idled in response to the Japanese nuclear mess—the same mess that catapulted the Greens to unfamiliar success in state elections two weeks ago.

Were they to surrender to their inner Al Gore, their answer to the resulting electricity shortage would be for consumers to make do with much higher prices. But Green Party leader Winfried Kretschmann is unlikely to seek immediate return to the political wilderness. Forget the fantasy talk of wind and solar. The choice then is nuclear or coal.

Countries all over the world are making similar choices in light of Japan’s disaster, whose severity the government now puts on a par with Chernobyl (even if the radiation releases haven’t been remotely comparable). Thanks to Fukushima, officials everywhere will have to reacquaint themselves with one of the great noise-to-signal puzzles of modern science: How much harm does low-level radiation exposure do?

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