21 July 2017 (Phys.org)
The idea behind injecting aerosols into the atmosphere, as Niemeier and Tilmes point out, is to mimic the cooling that occurs when volcanoes erupt. Along with smoke, volcanoes also emit a lot of sulfur, which is why scientists suggest we do the same artificially. But that might be easier said than done, Niemeier and Tilmes note, because it would involve replicating an eruption the size of Mount Pinatubo every day for approximately the next century and a half.
And there are problems with cloud seeding, too, which might be done to disperse cirrus clouds, preventing them from trapping heat—the main problem is lack of precision; doing it wrong could lead to more warming, for example.
For these reasons and many more, Pasztor, Scharf and Schmidt suggest taking a very serious look at how to prevent one country, group or even a wealthy individual from striking out on their own with such approaches. Adding a governing body to the equation, they suggest, could prevent these scenarios.