Poor countries have no incentive to pay carbon fees. Then have rich countries pay their carbon fees? So then tax payers of developed nations take the hit and have their own economic output lowered while countries ignoring carbon fees move ahead. It's a death spiral.

Have a look at Steven Koonin's "Unsettled". He was an Obama DOE appointee and Provost of Caltech (he's a physicist). He makes convincing arguments that the climate change models are highly unreliable. It's not Fox News garbage, he's legit.

The US and EU are making very large policy moves based on models that are not necessarily accurate.