The Hottest Year, By a Hair

Last week, government climatologists hailed 1997 as the warmest year of the century, citing it as another sign that greenhouse warming is real. But it might have been worse. Although last year's upward creep of the thermometer could help make the 1990s the warmest decade on record—warmer than the scorching '80s—computer climate models have called for the rising levels of greenhouse gases to be having a bigger effect on global climate. Reality may catch up with the models, however. By the turn of the century, researchers say, some factors that have slowed global warming so far will dissipate, and it will arrive in earnest.