Efforts to reduce carbon dioxide emissions worldwide aren’t working, so some researchers think we may need to resort to spraying reflective aerosols into the upper atmosphere to shade the earth and cool it off a little. The problem is we don’t know much about what that might do to the ozone layer or precipitation, among other things. And we don’t have laws to regulate geoengineering research to make sure someone doesn’t do something stupid, like doing a large scale test before we understand the impact of the aerosols, at least on a small scale, on atmospheric chemistry..
An article in Science says that we need to establish a form of governance on geoengineering research that will establish a moratorium on large scale project, but allow scientists to go forward with small scale research to better understand what geoengineering might do. Crucially, the article says we need to admit that something as controversial as geoengineering is going to need international laws.