Yesterday, Japan’s prime minister, Naoto Kan, announced that the government was scrapping a planned expansion of nuclear power, which currently provides about a third of Japanese electricity. Instead, the government would redouble efforts to expand its renewable energy portfolio, Kan said. The turnaround followed Kan’s urging last week that a reactor in Hamaoka, near an active seismic zone, be shut down; the company that runs the plant has agreed and is building a seawall to protect the plant from tsunamis when it reopens in 2 years.