Where does this idea that the anti-nuclear movement advocated for fossil fuels come from?
That's never been the case, as anyone who lived at the time of the early protests can tell you (or anyone who's parents did). Even Wikipedia has a whole section on that topic [1].
The members of the anti-nuclear movement didn't intend to advocate for fossil fuels, but in practice that's exactly what they did. When the choice is between a nuclear plant and a coal plant, being anti nuclear is being pro coal. That's why many organizations opposing nuclear power received substantial donations from the fossil fuel industry - because they wanted their opponents to fight amongst themselves.
I don't think anyone thinks the activists are pro fossil fuels, but by stopping the development of nuclear projects they essentially served the fossil fuels industry interests. It's not an accident for example that Friends of the Earth was founded by money from an oil magnate. From the groups wikipedia page:
> stopped more than 150 destructive dams and water projects worldwide
While I empathize with the desire to preserve waterways, you can be sure that for each one of these dams that didn't get built a coal or gas plant didn't shutdown.
Everyone wants the lights and heat to stay on. If that isn't coming from nuclear, it has to come from somewhere, and for the first several decades, it couldn't come from solar and wind.
Coal was the inevitable base load power source given a lack of alternatives. If you focus on limiting nuclear with far greater zeal than coal, this is the result.
It still can't come from solar or wind. Even if we waved a magic wand and had infinite and free energy storage, scaling solar and wind for sustained base load support is still a pipe dream. We are struggling to recycle the minuscule waste stream for solar and wind right now. Heck for wind turbine blades we aren't even really doing anything meaningful - meanwhile they are stacking up.
Without nuclear we are not getting off of fossil fuels - period.