It is a major unexplored / controversial avenue for tackling climate change: https://en.wikipedia.org/wiki/Stratospheric_aerosol_injection https://en.wikipedia.

It is a major unexplored / controversial avenue for tackling climate change: https://en.wikipedia.org/wiki/Stratospheric_aerosol_injection https://en.wikipedia.org/wiki/Stratospheric_aerosol_injectio... It appears that it is within our economic means to inject aerosols (likely sulphur-based) into the atmosphere to cool it, mimicking the cooling occurring after major volcanic eruptions - and to do it at sufficient scale that we can "undo global warming". We could cool the Earth quite nicely. The downsides are non-trivial however: - Sulphides lead to acid rain which is destructive to the environment in its own ways - This relies on continued aerosol injections; the sulphides subside rather quickly. So if we stop doing it, the Earth will return on its warming trajectory - We will end up injecting a lot of foreign material into the atmosphere. It will eventually land somewhere and do something - and it's unclear what exactly. - This doesn't eliminate other issues with climate change, such as ocean acidification - It is hard to predict what other consequences this will lead to. One fear is that it might strangle food production, by lowering solar irradiation. Plus, the Earth will be cooler, but what climate precisely will this lead to is unknown. Personally I suspect we will end up doing it anyway, simply because we can, and because we're not so good at CO2 reductions. We umm and arr about it, but then a very hot and dry summer will come and we'll just do it - for better or worse.