QuarkJets posted:

The cost incurred by the effects of global warming will be many orders of magnitude greater than even the cost of going to a global grid that is 100% powered by nuclear power plants, and even if we tripled the regulatory cost of every new plant going from this point forward, and even if we replaced literally every old nuclear power plant with a new one.

So the problem is that the free market is unable to internalize these massive forthcoming global-scale costs; that's not something that free markets have ever really been able to do, and nobody really expects them to. The return on investment may not be seen for decades and would largely not be reaped by the owner of the nuclear power plants but by society itself benefiting from less fallout caused by global warming. Thus, the task should fall to governments, who in the past have done exactly this kind of thing to significant and great effect, who are able to overcome the limits of the free market, and who typically operate on the much longer time scales that are required to tackle a problem as large and as far-reaching as global warming.