Will major global environmental change take place in the 21st century? How much is known about the change? Can we find out more? Must we take it seriously? Should we do something now, or can we wait a decade or so? This book seeks to answer these questions. Scientists are reaching consensus that rates of change in many of the environmental indicators are already increasing in some cases, and are likely to increase even more rapidly in the 21st century. Although there are still uncertainties, the case is made that the consequences of not taking action are too great to take a chance that the...