I won't say "full retard" because he's done the whole nuclear power graph joke about how logarithmic scales are for wimps or whatever.
And that's one of my sticking points on MMGW, if they REALLY believed it, any scientist who can do MATH would know nuclear is the only energy source that could power our civilization at it's current level, with growth factored in. And have the side benefit of doing a whole host of things "cleanly" that open up to us when you've got energy to spare to throw at most any problem.
Besides, not counting the ability with cheap energy to synthesize any hydrocarbon we wish from raw feedstocks like CO2, biomass and garbage in RDP process etc. we kind of need oil and petrochemicals for things other than simply burning, plastics, lubrication, pharmaceuticals, fertilizers...
So even if I think they're probably wrong, I don't have a problem with any MMGW'er who wants to go full-retard on fission.