In rich fields of India's Rejasthan state, where the monsoon rains usually sweep in faithfully each summer, the rice crop has been devastated by the first drought in years. Eastward on the Indian subcontinent, great floods have ruined the Bangladesh harvest. Far off in Africa's Sahel region, six years of drought have only recently been interrupted by rain. In the U.S., both the corn and soybean crops will fall far below expectations this year because of a freakish succession of excess spring rains, summer drought and early fall frost.
Is this roster of natural disasters an omen of worse weather to come? The forecasters can only guess. Even the most skilled meteorologists admit that theirs is one of the least exact sciences. But as they ponder the earth's current erratic weather and study their steadily increasing store of knowledge about past climate, more and more scientists are raising storm warnings for the future. At the very least, they foresee troublesome changes in global temperature and rainfall patterns that could seriously jeopardize the earth's ability to feed itself.
Despite such regional woes as America's Dust Bowl of the 1930s, the world's major agricultural areas have enjoyed an unparalleled record of beneficent weather for the past half-century. It has been "the most abnormal period in at least a thousand years," says Reid A. Bryson, director of the University of Wisconsin's Institute for Environmental Studies. Temperatures were surprisingly high, and the warmth fostered plant growth in normally well-watered areas, while some deserts shrank under the influence of regular rainfall.
Now that era may well be ending. From his studies of weather history, British Climatologist Hubert H. Lamb concludes that climate runs in roughly 200-year-long cycles, and that the earth is now entering one of its chilly phases. Perhaps the gloomiest of the weather prophets, Bryson speculates that the earth may be reverting to a frigid interlude comparable to what some scientists call the "little ice age" that cooled Europe from the 16th through 19th centuries. During those years Greenland's once lush fields vanished, England's productive vineyards withered, and agricultural disasters like Ireland's great potato famine came to be accepted as a natural feature of life.