A renowned climatologist-and political conservative-assesses current scientific understanding of climate change and sounds a call to action.

The vast majority of scientists agree that human activity has significantly increased greenhouse gases in the atmosphere-most dramatically since the 1970s. Yet global warming skeptics and ill-informed elected officials continue to dismiss this broad scientific consensus.

In this new edition of his authoritative book, MIT atmospheric scientist Kerry Emanuel-a political conservative-outlines the basic science of global warming and how the current consensus has emerged. He also covers two major developments that have occurred since the first edition: the most recent round of updated projections from the Intergovernmental Panel on Climate Change climate simulations, and the so-called "climategate" incident that heralded the subsequent collapse of popular and political support in the United States for dealing with climate change.