Bill McKibben is the author of "The End of Nature" (1989), the first book for a general audience about global warming. Recent books include "Eaarth: Making a Life on a Tough New Planet" (2010), "Deep Economy" (2006), "Enough" (2004), which critiques human genetic engineering and other rapidly advancing technologies; "Wandering Home" (2005), which catalogs his foot-travels across the Vermont landscape; and "Age of Missing Information" (2006), in which he compares his experience watching 1700 hours of videotaped TV to that of contemplating nature in the Adirondacks. In 2007, with six Middlebury College students, McKibben set up Step It Up 2007, which organized more than 1400 climate change demonstrations across the United States. He now leads a similar campaign on a global basis with the group 350.org, and in 2011 he led the fight to stop the Keystone Pipeline project.