Given we've been dimming the Sun, unintentionally, since the onset of the Industrial Revolution anyway, I don't see this as an idea to be summarily written off. Cleaning our atmosphere of particulates helps reduce lung diseases but it also accelerates global warming as more inbound solar radiation gets through to ground level. So why not do this in a way that is controlled, and does not lead to respiratory problems. These geoengineering solutions may be regarded as a last resort, but we may have to face 'last resort' solutions soon given that despite all our efforts to roll out renewables and ditch carbon fuels, CO2 emissions are still rising; our investments in green technologies are simply not sufficient to keep up with the growing worldwide energy demand from a growing global population. It may be simpler and cheaper to do this for a short time rather than solve the intractable politics of global climate within the timeframe required if we are to avoid passing significant irreversible tipping points in global warming. More research needed, as always.
