The UN has just released its report, One Atmosphere: An Independent Expert Review on Solar Radiation Modification Research and Deployment. The report examines scenarios of reducing so-called global warming, through solar engineering methods, seen as the only way of rapidly producing a cooling of the planet, within only a few years. Shutting down fossil fuels and crashing Western civilisation is just not quick enough, so more radical methods are needed. The broad idea is to reflect sunlight away from the Earth, one way being to replicate volcanic emissions and to seed the upper atmosphere with sulphur particles. The UN report does not advocate doing this right now, but sees the prima facie merit of investigating it further. You can be sure that when the magic “10 years” to save the planet passes, it will be done if not opposed.
The problem is, that the assumption is made that global warming is occurring, and occurring at the alarming levels that the UN IPCC say it is. But if they are wrong about either of these assumptions, there could be an alternative problem of global cooling set off, and perhaps cascading effects producing further cooling, which would be far more devastating than any proposed global warming effects. Remember, they accept that the climate system is subject to chaos effects and the rest. And, there are unexpected consequences that could occur, as climate patterns are altered, such as damaging the monsoons, and leading to mass death by starvation in Asia. And, that is going to occur in some nations which have nuclear weapons, and they will not be happy.