Climate

Last summer, as much of the United States endured stifling heat waves and severe drought, climatologists warned that the hot weather could be a harbinger of worse to come. Because of the atmospheric "greenhouse effect," they said, Planet Earth is slowly becoming warmer. Their specific predictions vary: In a "greenhouse world," some regions may benefit, others may suffer. The outlook has changed; only a decade ago, several respected scientists feared the onset of a new Ice Age. Here, Diana Morgan assesses the recent evolution of climatology-the study of climate and its impact. She describes past efforts to determine how changes in climate have influenced human history. Today, Steven Lagerfeld's survey of the research indicates, most climatologists think that the "greenhouse effect" is here to stay. They believe that mankind can learn to live with a slight "global warming," and may be able to avert more radical shifts in temperature and rainfall.