https://www.youtube.com/watch?v=lnsQ_9EIRTk
The following is a partial transcription of what he said:
Neil: Right at this moment I don't think people know for sure what the announcement will be, but if the secretary of energy is giving the press conference, everyone I think is thinking that we finally can get out more energy than we put in, and that is the key..
(Neil describes fission versus fusion, and (weirdly) magnetic confinement fusion, even though NIF is inertial confinement. It really feels like he doesn't know anything about NIF.)
Host: alright so lets say we've overcome some of those challenges and finally created more energy than we put in to the experiment.
Neil: That's it.. you got it. so now it's up to the engineers. Once we get the physics figured out, which it seems like we have, then the engineers say can I make that smaller, can I make that portable, would it fit in to a car? or is it only the size that might power a city? there are places that don't have access to energy... either oil or sunlight for example... so this would be transformative to civilization, and I see it akin to the transition from horses to automobiles, which happened in a matter of a couple of years, because we got the physics figured out for engines, internal combustion engines, when that happened you couldn't give away a horse, yet we were riding horses for thousands of years, building civilization literally and figuratively on its back. so my analogy to that is, we've been digging fossil fuels out of the ground for 150 years...
Host: How long will it take to heal the planet from any harm that we've done to ourselves?
Neil: Yeah here we are harming a planet that was itself trying to sustain us. by doing that you've sewn the seeds of your own extinction. and so the planet will heal, slowly. a lot of the carbon is taken up in to the oceans, so if you start dropping the carbon in the atmosphere, the oceans will equilibrate with that, so it will take time. but now is better than any time later than now, so oh yeah... I'm giddy.
Host: I can't wait for my fusion engine.
Neil: It's a pivot in civilization.