In its 2001 report on global climate, the Intergovernmental Panel on Climate Change of the United Nations prominently featured the "Hockey Stick", a chart showing global temperature data over the past 1,000 years. The Hockey Stick demonstrated that temperature had risen with the increase in industrialization and use of fossil fuels. The inescapable conclusion was that worldwide human activity since the industrial age had raised CO2 levels, trapping greenhouse gases in the atmosphere and warming the planet.

The Hockey Stick became a central icon in the "climate wars", and well-funded science deniers immediately attacked the chart and the scientists responsible for it. Yet the controversy has had little to do with the depicted temperature rise and much more with the perceived threat the graph posed to those who oppose governmental regulation and other restraints to protect our environment and planet. Michael E. Mann, lead author of the original paper in which the Hockey Stick first appeared, shares the real story of the science and politics behind this controversy. He introduces key figures in the oil and energy industries, and the media front groups who do their bidding in sometimes slick, bare-knuckled ways to cast doubt on the science.

Mann concludes with an account of the "Climategate" scandal, the 2009 hacking of climate scientists' emails. Throughout, Mann reveals the role of science deniers, abetted by an uninformed media, in once again diverting attention away from one of the central scientific and policy issues of our time.