Unintended consequences is an important one, as shown by this thread.
Well, sure - but there's no solution to that, other than no change, which is untenable.
I’m an advocate of appropriate constraint/direction of markets, but it must take a holistic view to avoid merely swapping one problem for another - and leaving the consumer carrying the can.
But realistically, who can carry the can, other than the consumer? In the absence of malfeasance, there's no liability - no liability, no recourse.
The US is another matter entirely. And again, whether they can actually wean themselves from carbon, may not matter. They may simply choose not to.
Non-renewables are going to become increasingly expensive as renewables become cheaper, so I have an abstract faith in the US's ability to adapt.
WRT the Paris Accords - Trump won't be president forever, it's entirely possible that the US never abandons it. The targets are self-regulating in any case.