An Inconvenient Truth, by Al Gore.
The Omnivore's Dilemma, by Michael Pollan.
Global Warning: The Last Chance for Change by Paul Brown.
A Sand County Almanac, by Aldo Leopold. (Everyone should read this book sometime in their life).
The Rough Guide to Climate Change, by Robert Henson.
The Condor's Shadow: The Loss and Recovery of Wildlife in America by David Wilcove.