There's lots of debate happening about this topic, of course. Romm sounds convincing but I don't know enough to say whether he's correct. I just listened to a debate about this topic on CBC Radio's Ideas: The Hydrogen Solution (it's a 3-part series, but I've only heard part 3). David Scott argued the pro-hydrogen side and Norm Rubin argued the anti- side. It was interesting but I came away feeling more confused (though still leaning towards anti) because both were pretty good at demolishing their opponent's arguments. Scott did a good job of poking holes in some standard environmentalist lines against hydrogen and nuclear. Rubin sounded at times suspiciously like a climate change denier, so I don't know how credible he is.