I believe they're trying to chemically blocking the sun (using sulfur dioxide) rather than physically blocking it.
It is obvious we're not gonna fix this by changing our habits, so I'm all for a technological solution. It will have unforeseen consequences and we will deal with those, too. Humankind is nothing but adaptable.
I am one of these "assholes". Explain to me why I should care. Don't want kids, don't have much influence in what is gonna happen, just wanna enjoy the time I have on this planet. Don't think this population growth is sustainable in any scenario, and humankind would do better with a few billion fewer.
Fatalism is not gonna change a thing except making your experience on Earth less enjoyable. Turn off the news, live a good life, otherwise you will regret it.
I love how we now have to monitor the content the generation that told us "Don't believe everything you see on the internet." watches like we would for children.