This New York Times article says reports of the demise of cap-and-trade systems to price carbon are greatly exaggerated. Problems plaguing carbon trading include profiteering, tax fraud, theft, and dubious emissions cuts, but such schemes could make governments billions, which makes them very attractive.

CITY TECH BLOG
The Impact of the Paris Climate Change Agreement in the United States
The United States, under the Obama administration, joined the Paris Agreement in 2015 and committed to reducing greenhouse gas emissions by 26-28% below 2005 levels by 2025. However, in June 2017, the Trump administration announced its intention to withdraw from the agreement (Shear). In April 2021, President Joe