Tweaking Mother Nature

By Sora Song

If Ross Hoffman has his way, weather will someday submit to the whim of man instead of the other way around. Hoffman, a principal scientist at the technology research firm Atmospheric & Environmental Research, in Lexington, Mass., forecasts a sunny future in which, say, stampeding typhoons could be safely corralled and driven back out to sea. The key to weather control, says Hoffman, is understanding that even the fiercest tempest is a delicate creature. And by exploiting the sensitivity of weather to tiny changes in the environment, Hoffman has successfully tamed two hurricanes, thus saving dozens of lives and billions of dollars in property--at least on a computer.

The idea struck in 1977 when, as a graduate student at M.I.T., Hoffman was introduced to chaos theory. A chaotic system like weather appears to behave randomly but is actually governed by rules. It is also influenced by seemingly trivial tweaks to the system--hence the old romantic notion that a flap of a butterfly's wings in the rain forest of Brazil might give rise to a storm off the coast of Iceland. Perhaps, thought Hoffman, chaos and sensitivity, which make weather so difficult to predict, could be harnessed to purposely change it.

In the laboratory, the hypothesis holds true. By introducing small changes to wind speeds and temperature in a computer simulation, Hoffman nudged the course of Hurricane Iniki, which leveled swaths of Kauai, Hawaii, in 1992. Shifts of up to 5 m.p.h. in wind speeds sent the eye of the storm on a track veering 60 miles to the west of the island, and 1??F fluctuations in temperature quelled its destructive winds. They sound easy enough, but in the real world those kinds of modifications "would require a huge amount of energy," says Hoffman, "not in the realm of what we're capable of these days." Scientists may never find a way to alter wind speeds, but Hoffman speculates that in 10 years, orbiting satellites that generate solar power in space may be used to beam down enough heat to change temperature. "But these things take time, money and effort," says Hoffman. Whether his theories will ever become reality is, well, up in the air. --By Sora Song