The debate over whether humans should explore ways to manipulate the climate has taken on increased urgency over the past year, as efforts to curb greenhouse gas emissions linked to global warming have encountered political roadblocks in the United States and elsewhere.

The measure adopted under the Convention on Biological Diversity, which recently concluded in Nagoya, Japan, states “that no climate-related geo-engineering activities that may affect biodiversity take place, until there is an adequate scientific basis on which to justify such activities and appropriate consideration of the associated risks for the environment and biodiversity and associated social, economic and cultural impacts, with the exception of small-scale scientific research studies” under controlled circumstances.

While some scientists and environmentalists have called for geoengineering research as a precautionary measure against catastrophic global warming, activists hailed the moratorium as a way to keep individual actors from altering the climate. The prohibition does not apply to the United States, which has yet to ratify the convention.