Over the last few years, intentionally manipulating Earth’s climate on a planetary scale has gone from a fringe idea to a possibility debated by mainstream scientists. That’s worried a lot of people, and last week the practice was informally placed off-limits by 193 nations.
The moratorium, enacted under authority of the international Convention on Biological Diversity treaty won’t be legally binding for at least several more years. If it goes into effect, the United States — which has signed but not ratified the treaty — won’t be bound to it. It would also allow small-scale, highly controlled research.
But even informally, the moratorium has teeth. It would make anyone who wants to try geo-engineering — feeding CO2-gobbling oceanic plankton with iron, pumping sunlight-blocking aerosols into the atmosphere, storing CO2 in underground rock deposits — an international pariah. And while research is technically possible, it would have to pass a regulatory gauntlet so challenging that it might as well be banned.