Perhaps the environmental movement in America is stalled because the vast majority of scientists who support the idea that global warming is a result of human activity are social scientists ("Green movement's blues," Dec. 29).

Hard science points in the other direction. It recognizes that the warming comes first, caused by irregularities in the sun's energy reaching earth, followed by an increase in atmospheric carbon dioxide released from sea water.

True science trumps computer models any day.

William Vail, Glen Burnie