Another way to look at it is that fossil fuels don’t have externalities priced in correctly. Nuclear is a safety and regulatory mess.

Global warming is extremely likely to lead to large areas that are well populated today becoming uninhabitable in the next 100 years - either through oceans rising or through extreme heat. This will likely lead to huge migrant crises - not hundreds of thousands, but tens of millions leaving places like Bangladesh. This in turn is very likely to lead to wars and other forms of extreme events. A world at war is very likely to stop growing economically, and we may not be able to require from a nuclear war the way we did after WW2.

Green energy itself is cheap. What makes energy expensive in Germany is that we need to fall back on natural gas energy so often.