> US citizens still emit over 50% more CO2 each
The problem the US has per-capita is lower population density. The majority of the US population lives in suburban or rural areas without mass transit and changing that on the relevant timescale is not feasible. It also has major population centers in areas that experience winter and thereby have higher energy costs for heating, exacerbated by the lower population density (more square feet of indoor space to heat per capita), with the same infeasible timescale for changing that.
As a result, the only way to fix it is to switch to other forms of energy rather than having any real hope of significantly reducing consumption in terms of GWh. Use more electric cars and hybrids, generate electricity using solar, wind and nuclear, switch from fossil fuels to electric heat pumps for heating, etc. But that's largely what's happening. The percentage of hybrid vehicles goes up, despite Trump's posturing nobody actually wants coal, ~100% of net new generation capacity in recent years is solar and wind and even when new natural gas plants are built, they're displacing old coal fired ones, which results in a net reduction in CO2. It would be nice if this would happen faster, but at least the number is going in the right direction.
The problem China has is that they've been building brand new coal fired power plants at scale. WTF.
You listed out a whole lot of excuses for America, suburbia this, heating that, etc etc, etc...
Now an assignment - you are Chinese and you have 1.5bn people in your country, lets hear it? You think you can't reasonably list 100x "excuses" for their "issues" and "reasons" for CO2 consumption?
They are working a lot harder than pretty much all other countries combined to usher in renewables and many other things while we elect people who don't know what wind is/does and stare at the Sun during the eclipse.
Assume the avg. home will last 50 years. Limit construction on new suburban developments, problem solved in 50+ years. It would be unpopular, but you claimed it wouldn't be possible, very different. The latter is denying agency in the situation.