20 Years Later, Andy Revkin Responds to Groundbreaking Global Warming Story

Exactly twenty years ago, on June 23, 1988, James E. Hansen of the NASA Goddard Institute for Space Studies testified to a Senate committee that he could state with "99 percent confidence" that a recent, persistent rise in global temperature was occurring, and had long been expected. That landmark statement, and the dawn of the global warming discussion, was covered by Andy Revkin, then a DISCOVER senior editor and now an environmental reporter for The New York Times. (More discussion of Hansen's testimony can be found on Revkin's blog.) Revkin kindly agreed to take our questions about his piece. Q: How, if at all, were the 1988 predictions wrong? A: Not much was really wrong. The range of warming projected—a doubling of greenhouse gas concentrations from the preindustrial norm—remains similar today. The things that were uncertain in 1988 remain uncertain now, including the mix of warming and cooling influences in clouds. As Steve Schneider, a climate modeler at the National Center for Atmospheric Research in Boulder, Colorado—who is still a frequent source of mine—put it in 1988: