Last year, a private company proposed “fertilizing” parts of the ocean with iron, in hopes of encouraging carbon-absorbing blooms of plankton. Meanwhile, researchers elsewhere are talking about injecting chemicals into the atmosphere, launching sun-reflecting mirrors into stationary orbit above the earth or taking other steps to reset the thermostat of a warming planet.

This technology might be useful, even life-saving. But it would inevitably produce environmental effects impossible to predict and impossible to undo. So a growing number of experts say it is time for broad discussion of how and by whom it should be used, or if it should be tried at all.

Similar questions are being raised about nanotechnology, robotics and other powerful emerging technologies. There are even those who suggest humanity should collectively decide to turn away from some new technologies as inherently dangerous. . . . “There is no one to say ‘thou shalt not,’ ” said Jane Lubchenco, an environmental scientist at Oregon State University and a former president of the American Association for the Advancement of Science.

Nor will there be, given that the international system can’t even keep Russia out of Georgia. I’m surprised that the story mentions both the Asilomar guidelines for recombinant DNA research and nanotechnology without also mentioning the Foresight Guidelines for responsible nanotechnology research. Some related thoughts here. I’ll just add that these discussions continue to assume that it will be mostly Western scientists and engineers engaging in this kind of activity, when trends are otherwise.