The Washington Post called Lester Brown "one of the world's most influential thinkers." In 1986, the Library of Congress requested his personal papers noting that his writings "have already strongly affected thinking about problems of world population and resources."

In 2003 he published the book, Plan B: Rescuing a Planet Under Stress and a Civilization in Trouble. In January 2005 he published a further study emphasizing the central points stressed in this keynote address. See: Outgrowing the Earth: The Food Security Challenge in an Age of Falling Water Tables and Rising Temperatures. It is this study which was the basis of his lecture at Harvard on Monday, 28 February 2005.