_THERE IS NOW a broad consensus in this country, and indeed in the world, that global warming is happening, that it is a serious problem, and that humans are causing it. The recent report by the Intergovernmental Panel on Climate Change concluded there is a greater than 90 percent chance that greenhouse gases released by human activities like burning oil in cars and coal in power plants are causing most of the observed global warming. This report puts the final nail in denial's coffin about the problem of global warming . . . .