Imagine if every developed economy invested in nuclear at the same level of France even if you still need to rely on fossil fuel peaker plants - that's a good start no? France, even with fossil-fuel backup has far lower emissions than most other countries (3x lower emissions than the darling of renewable energy, Germany ... which by the way relies on France's nuclear power too)
Here's something to get depressed at: Imagine if every developed economy invested in nuclear at the same level as France but in the 70s. Think of the trillions and trillions of tons of CO2 that would not have been emitted into the atmosphere. It would have bought us decades to get global warming under control.
When history passes judgment, it won't be the climate-denialists that will take the brunt of criticism, but anti-nuke environmentalists who fucked things up (and continue to do so) for our species.
A lot of countries have more than that in renewables: https://en.wikipedia.org/wiki/List_of_countries_by_renewable...