Some book about the question...

• Unstoppable Global Warming: Every 1500 Years by Dennis T. Avery and S. Fred Singer (Paperback - Oct 28, 2006)
• Global Warming: The Complete Briefing by John Houghton (Paperback - Sep 6, 2004)
• An Inconvenient Truth: The Planetary Emergency of Global Warming and What We Can Do About It by Al Gore (Paperback - May 26, 2006)
• Shattered Consensus: The True State of Global Warming by Patrick J. Michaels (Paperback - Dec 28, 2005)
• Meltdown: The Predictable Distortion of Global Warming by Scientists, Politicians, and the Media by Patrick J. Michaels (Paperback - Oct 25, 2005)
• Global Warming and Other Eco Myths: How the Environmental Movement Uses False Science to Scare Us to Death by Ronald Bailey and Competitive Enterprise Institute (Hardcover - Jun 15, 2002) - Bargain Price
• The Weather Makers : How Man Is Changing the Climate and What It Means for Life on Earth by Tim Flannery (Hardcover - Jan 27, 2006)
• The Politically Incorrect Guide to Global Warming (and Environmentalism) by Christopher C. Horner (Paperback - Feb 12, 2007)
• Global Warming: The Signs and the Science (DVD - Jan 17, 2006)
• Global Warming and Global Politics (Environmental Politics) by Matthew Paterson (Paperback - Sep 5, 1996)

I want only to add one thing: look the date of the last book -- 1996 -- the question is open since that time, 20years old, and there is not made something to resolve it yet...