Data trimming, nuclear emissions, and climate change.

Ethics requires good science. Many scientists, government leaders, and industry representatives support tripling of global-nuclear-energy capacity on the grounds that nuclear fission is "carbon free" and "releases no greenhouse gases." However, such claims are scientifically questionable (and thus likely to lead to ethically questionable energy choices) for at least 3 reasons. (i) They rely on trimming the data on nuclear greenhouse-gas emissions (GHGE), perhaps in part because flawed Kyoto Protocol conventions require no full nuclear-fuel-cycle assessment of carbon content. (ii) They underestimate nuclear-fuel-cycle releases by erroneously assuming that mostly high-grade uranium ore, with much lower emissions, is used. (iii) They inconsistently compare nuclear-related GHGE only to those from fossil fuels, rather than to those from the best GHG-avoiding energy technologies. Once scientists take account of (i)-(iii), it is possible to show that although the nuclear fuel cycle releases (per kWh) much fewer GHG than coal and oil, nevertheless it releases far more GHG than wind and solar-photovoltaic. Although there may be other, ethical, reasons to support nuclear tripling, reducing or avoiding GHG does not appear to be one of them.