We told you on Monday about an open letter penned by James Hansen and three other prominent climate scientists calling on the world to ramp up development and deployment of “safer” nuclear power. The scientists argue that renewable energy isn’t enough to spare the world from the wrath of global warming, and that the power of the atom needs to be better tapped to help get us off fossil fuels. Publication of the letter coincided with the buildup to this evening’s screening by CNN of the controversial pro-nuclear documentary Pandora’s Promise. The issue of nuclear power bitterly divides environmentalists, so plenty of people were not pleased to hear Hansen, a darling of climate-activism circles, leading a call for more nuke power. Many of the environmentalists and scientists who have written rebuttals in recent days have focused on safety concerns and the flailing economics of nuclear power. Here are excerpts from a few of those rebuttals.