I don't know where you live, but the Swedish Green party still want to immediately start phasing out nuclear power. More CO2 for the world.
(If the seas do have an ecological crash which makes the remaining eco systems go down, then any surviving Green party members will probably argue the advantage of this, pushing their carts down "The Road".)
I don't see nuclear power as a great solution. The waste contaminates the environment for thousands of years. And the system is not fault-tolerant, failing in ways which render the environment uninhabitable for who knows how long (Chernobyl, Fukushima).
Yeah, it doesn't generate CO2. But at least you can live in a hotter world, can't live with nuclear waste/fallout.
(Also, we don't know that a hotter climate is bad, we've never tried it before)
Are you sure that's an objective assessment of the relative risks, numerically speaking, and not just a common human failing of seeing slow acting, nebulous threats like climate change as being less dangerous than fast and scary threats like nuclear disasters? Nuclear seems the less dangerous bedfellow to me.