Distributed costs and concentrated benefits. Each particular emissions reduction plan impacts specific groups that will fight it. General taxation to pay for geo-engineering projects impacts everyone as well, but not in specific ways.
There might be more public support in a moon-shot big engineering project, and fighting the small-government types, than say, reducing emissions for factories and fighting the relevant lobby.
There might be more public support in a moon-shot big engineering project, and fighting the small-government types, than say, reducing emissions for factories and fighting the relevant lobby.