They war-gamed dimming the Sun. It went even worse than you think.

A simulation of solar geoengineering, which involves dimming the Sun to counter climate change, has revealed that the approach can backfire when geopolitics takes over. The simulation, led by researchers at the University of California, Berkeley, and the University of Oxford, tested the effects of a global effort to inject aerosols into the stratosphere to reflect sunlight and cool the planet. The study found that the approach can be hijacked by nations with different interests, leading to unintended consequences and even global conflict. The simulation showed that as the global effort to cool the planet succeeded, some nations began to use the geoengineering system to their own advantage, injecting more aerosols to further cool their own regions, but not others. This led to a 'self-reinforcing feedback loop' where nations began to inject more aerosols to counter the effects of other nations' injections, causing the global temperature to drop even further. The study's authors warn that this kind of scenario is a 'worst-case scenario' and highlights the need for more research and international cooperation to address the risks and benefits of solar geoengineering.