One of the more heartening developments in this election has been the outspokenness of scientists who strongly disagree with the Bush Administration’s policies, such as Scientists and Engineers for Change. But few have more earned the right to speak out than has James Hansen, who has been a leader in the climate change community for two decades. Tonight he’s speaking at the University of Iowa, and he’s naming names, claiming that NASA Administrator Sean O’Keefe warned him against talking about dangerous anthropogenic interference in the climate system. (O’Keefe denies it, but Hansen’s version is backed up by another attendee at their meeting.)

Presidential science advisor John Marburger continues his series of lame responses, claiming that Bush “has put forward a series of policy initiatives including a commitment to reduce the greenhouse gas intensity of our economy.” Marburger certainly knows better–greenhouse gas emissions, which is what Nature pays attention to, will rise even if greenhouse gas intensity (emissions per unit of economic output) falls. Besides, greenhouse gas intensity has been falling for decades as companies and individuals naturally strive for greater efficiency, so there’s no particular accomplishment there.