Emissions of greenhouse gases continue to rise, and emission reduction efforts are increasingly seen as inadequate to stay below the 2°C threshold agreed internationally, but countries shy away from shouldering the burden of emissions abatement. Therefore, in the next decades an increase in meteorological extreme events is increasingly likely to trigger public pressure to find quick solutions to halt climate change. Climate engineering (CE), especially Solar Radiation Management (SRM) proposals, will be attractive in this context.

But SRM could turn into a Pandora's Box if not managed carefully. A sudden political demand for implementing CE could end in disaster if pressure leads to premature deployment. It is vital to establish a solid understanding of CE with all its indirect effects as well as significant acceptance and thus legitimacy. Since for many CE options, the risks seem negatively correlated to costs, a global research coordination effort is needed that is fully transparent and avoids biases introduced by interest groups. The IPCC would be the right forum to harness this research. Research should go hand in hand with the development of new norms and international approaches in monitoring, similar to the case of nuclear weapons or terrorism.

It is time for climate engineering to enter the discourse on climate change mitigation - in a research-led, transparent and conscientiously governed manner.