Every time I've look into it seems like this isn't the case. Nuclear plants are simply too expensive, have too many production bottlenecks, and take too long to construct (too name but a few issues). No serious analysis I've seen of how we meet emissions goals has ever placed a big emphasis on nuclear power. Probably one of the biggest parts of meeting the goals will be increased energy efficiency, but a lot of nuclear advocates I've seen seem to be under the mistaken impression that it's all about 100% carbon free electricity generation (something that's not going to happen either way).
I think only having power sources cheaper than carbon will fix it. Which could potentially include sources cheaper because a carbon tax forces carbon prices to include their externalities.
Studies show that efficiency initiatives can reduce emissions[1][2]. It's not going to solve everything, but as I said, it's going to be a major component, as will alternative energy sources like wind and solar (you won't be able to get 100% wind and solar, but you don't have to). Any serious analysis of ways to fight global warming looks at a variety of different actions. They don't pretend that there's a single component ("Have all electricity generation done by [X Type Power Plant]") that solves everything.
This is one of the things I've noticed about a lot of nuclear advocacy. Though there's often appeals to science and reason, the main driver appears to be an emotional one. There's the claim that the real interest is in combating global warming, but many advocates have shown no interest in learning about the best ways to combat global warming. Their interest seems to start and stop with advocacy for their preferred solution, whether or not it's even a good solution to the problem.
Global emissions are up, despite efficiency improvements. The proper level to look at the system is the whole earth. Those reports look at local instances.
Don't get me wrong. I think efficiency is good. I'm just not sure it actually can reduce emissions globally.
