It is the greatest environmental challenge of the 21st Century. But what do we truly know about global climate change? And what can we do about it? Most of the world’s top scientists agree that emissions of carbon dioxide and other greenhouse gases from human activities such as industrial processes, fossil fuel combustion, and land-use changes are causing the earth to get warmer. Impacts of this warming may include damage to our coastal areas, accelerated rates of species loss, altered agricultural patterns, and increased incidences of infectious diseases. The effects of climate change - and efforts to mitigate climate change - could also have substantial economic ramifications. The book presents research and analysis from prominent scientists, economists, academics, and policy-makers, including: Tom Wigley and Joel Smith, who, along with other authors of the Science and Impacts chapter, explain the basic science of climate change, the growing evidence that human activities are changing our climate, and the impacts of these changes; Eileen Claussen, John Gummer, Henry Lee, and other authors of the Global Strategies chapter, who describe what nations are or are not doing to address climate change, and the state of international climate talks. Robert Stavins, John Weyant, Ev Ehrlich, and other economists, who explain why economic analyses of climate policy are conducted, why the projected costs of addressing climate change vary so widely among economic models, and how changes driven by today’s economy can influence climate policy; Gov. Jean Shaheen and other authors of the Innovative Solutions chapter, who describe what state and local governments in the United States and multinational companies are doing to monitor and curb greenhouse gas emissions; and Forest Reinhardt, who offers business leaders advice on steering their companies on a path that is healthy for business as well as the global climate.