Florence is a contributing editor at Outside Magazine and a freelance writer for New York Times, New York Times Magazine, The New York Review of Books, Slate, Mother Jones, High Country News, O-Oprah, W., Bicycling and numerous other publications. A fellow at the Center for Humans and Nature and a visiting scholar at George Washington University, her work focuses on the environment, health and science.

Her first book, BREASTS: A Natural and Unnatural History (W.W. Norton 2012) received the Los Angeles Times Book Prize in science and technology and the 2013 Audie in general nonfiction. It was also named a notable book of 2012 by New York Times.