Robert T. Watson

About the author: Robert T. Watson is chair of the Intergovernmental Panel on Climate Change, chief scientist at the World Bank, and a former science adviser to the White House.

Scientific data reveals that human activity is largely responsible for the rise in the average global temperature during the past fifty years. Furthermore, global warming is changing the world's climate, as evidenced by rising sea levels, thinning Arctic ice, record numbers of hot days, and heavy rains. Researchers project that the earth's temperature will rise by several degrees Fahrenheit over the next century, resulting in an increased risk of droughts, floods, and other forms of extreme weather. Unless the nations of the world agree to significantly reduce greenhouse-gas emissions, the environment, the economy, and human health will be adversely affected.

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