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 one thousand 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 wel.