Currency is critical on the environmental battlefront; nothing ages more quickly than last week's fish kill or last month's political debate. Some of the best-run sites, like Econet, EnviroLink, Greenpeace and the Sierra Club, keep activists up-to-date with full-time environmental news services (plutonium found in children's teeth in u.k.) and regular "action alerts" (public comments needed on diamondback timber sale). The combination can be quite effective, as when Quebec's Cree Indians used the Internet to mobilize support against Canada's Great Whale Hydroelectric Project a few years ago.

But the green movement on the Net is not as grass roots as it might seem--or as the technology would allow. On Usenet, the Internet's popular bulletin-board system, discussion groups devoted to environmental causes (like alt.politics.green, sci.environment, alt.save.the.earth), draw primarily from the same handful of participants and are nowhere near as active as alt.conspiracy or rec.arts.tv.soaps. On some sites the only people posting seem to be employees of foundation-funded organizations.

The next step for the Web, suggests Michael Schrage, an M.I.T. research associate and computer columnist for the Los Angeles Times, is to wire up the ecosystem itself. "It would require only a little ingenuity--and very little money--to devise, say, groundwater sensors that could be linked to the Net," he observes. Similarly, researchers could connect cheap video cameras to the Web to monitor wetlands and smokestacks. Urban activists could plant sensors on city streets to determine which are the most polluted. Thinking even more globally, environmental groups could track how waste is being disposed of in Russia or France or Malaysia or Brazil. "We haven't a clue to what happens if we begin to network the ecosphere and make the results accessible to anyone who wants them," Schrage confesses. But if plugging the planet directly into the Net makes its inhabitants more environmentally conscious, even the most technophobic back-to-nature types would have to applaud.