He’s been talking about it for months, but looks like he’s going to actually introduce it. An embedded-emissions tariff like this was proposed during early draft outlines of Build Back Better, but didn’t survive negotiation.
I’ll note that his idea of ‘more methane gas instead of coal’ is something which might have been a reasonable intermediate step 30 years ago. It’s not now, in a world where wind and solar are the cheap option.
The US is at 0.21t/$1000 in GDP. Globally it is 0.26t/$1000 of GDP. China is about as bad as it gets without being aa fossil fuel exporter. However such a law would help most African and Latin American countries quite a bit, as they often are relativly clean already. In Latin americas case even with a decent quality of life. I doubt the US does that and natural gas is not making that any better.