Both would kill us, so it doesn’t matter which passes the finish line first. This is what the article warns about - massive engineering projects that affect the climate, whether for the purpose of geo-engineering or not.
Nothing wrong with solar IF we can pump the heat out of the atmosphere, or dodge it in some other way. Which we can’t, yet, and a solution to this is not waiting around the corner.
There could be more to it than that - like take up ballet.