This title offers a definitive account of how we have come to understand the fundamental processes behind global warming. Written by a leading pioneer of modern climate modeling and an atmospheric scientist, it is a compelling firsthand account of how the scientific community came to understand human causes of climate change, and how powerful computer numerical models have been instrumental to these vital discoveries. They show how climate models have been used as virtual laboratories for examining the complex planetary interactions of atmosphere, ocean, and land. These studies are used as the basis for broader discussion of human-induced global warming-and what the future may hold for a warming planet. They explain why increasing atmospheric carbon dioxide has caused temperatures to rise in the troposphere yet fall in the stratosphere, why the surface warming differs by hemisphere, why drought is increasing in arid regions despite global increase in precipitation, and much more.