I think the real question is the other way around; why isn't the US the world leader in this?
China's answer is fairly straightforward - jobs, exports, energy independence, wind/solar is cheaper, and they have 1.3B people who don't want to live in a big polluted desert.
it kinda is? the us and Europe both have had year-on-year raw and trade-corrected negative ghg production, the us has since the obama administration, inclusive of trump I.
there are a lot of surprises, for example texas being the #1 state for renewable energy production
China's answer is fairly straightforward - jobs, exports, energy independence, wind/solar is cheaper, and they have 1.3B people who don't want to live in a big polluted desert.