Climate change and its consequences

Are humans changing the climate? In its latest assessment, scientists on the Intergovernmental Panel on Climate Change say we probably are, and the consequences could be serious. But uncertainties about risks and response costs make it difficult to formulate a specific long-term action plan. The potential risks the panel identifies, however, are sufficient to warrant additional actions beyond those now under way in the United States and other countries. Topics included are as follows: human impacts on climate: state of the science; potential natural impacts; socio-economic consequences; effectiveness and cost of response options; final comments.