I think a more interesting question is...
Is it easier/cheaper to mitigate the effects than to fix the source of the problem.
Unfortunately that depends very much on what others do. If you are a small nation then the answer is clear - no point going alone in cutting CO2, better off putting your effort into getting your country to cope with the effects.
It’s a global problem and will need a global solution.
Unless we get the majority to cut emissions then it’s a waste of effort.
However that should stop some of the important, but not so large, countries taking a lead and cutting emissions. The net effect of their cuts might be small, but showing they are willing is important.
But we need USA and China to be onboard or it’s going to be a futile effort.