06/23/2010 05:12 am ET Updated May 25, 2011

Lisa Jackson Jokes With David Letterman (VIDEO)

EPA Administrator Lisa Jackson got some prime-time airtime with a two-part interview with David Letterman on Earth Day. Letterman joked about Jackson's former job as head of environmental protection of New Jersey, "monitoring the environment of New Jersey, or the United States, which is a bigger job?" Jackson replied, "Well, you don't want to send a rookie in to do heart surgery."

Jackson also cautioned Letterman against hopelessness and cynicism, saying she thought clean energy could be a game changer.