I have no idea if Chinese use 10% or 90% hydro for bitcoin. Or anything inbetween. I do know China has really bad air quality issues. I do know politicians all over the world like to find scapegoats.
So what better then to tell your people that bitcoin is making the air bad. Follow my logic most people don't use BTC so if China bans btc claiming it is bad for the air, most Chinese people would say okay since most Chinese people don't use or own BTC.
This is why being on the leading edge of Green is important for BTC. BTW any country could make the claim that BTC is causing bad air and use it to ban BTC.
No country can truly "ban" bitcoin for any reason really. They can impose fines and criminal penalties if you get caught using, mining, or supporting bitcoin, but the great thing about bitcoin is that it really cannot be stopped. I dont think anyone here is talking about anyone banning anything based on its air pollution. This is more a discussion of we should care that our beloved bitcoin needs a more Eco-friendly mining community.