Since the earth has been cooling off for ten years now, maybe a little more global warming is more important now than ever before.
Cmon, the guy is a comitted vegetarian, according to his religion. He has every right to try to promote this and hope others will join his faith. But it ain’t about the weather.
Just wait half a century now when hydrogen powered cars start emitting water vapor into the atmosphere as exhaust. Talk about a “global warming greenhouse effect”- water is 95% of the greenhouse effect and far more powerful at retaining Earth’s heat than carbon dioxide.