Wade Allison, emeritus professor of physics at Oxford, has a more realistic idea for fighting global warming than any being promoted at this week’s climate summit in Paris: Increase by 1,000-fold the allowable limits for radiation exposure to the public and workers from nuclear power plants.

Politicians in Paris might notice their host country ranks 20th in per capita income but 50th in greenhouse emissions. You know why: France gets 75% of its electricity from nuclear. France has waded forward even while, for reasons having...