We show CO₂ emissions by country of production, not country of consumption. The CO₂ emitted in China for things US uses counts as China's.

But China chooses how to make goods, and if we forced less efficient production via regs, it would hike prices, harming low/middle inc folks

Economic systems are complex organic structures, wherein manipulation for single-level outcomes often yields N-depth unintended consequences

You're making the well-understood concept of negative externalities sound much more complicated than it is.

We should price negative externalities appropriately, and have appropriate low-distortion redistribution policies.

But consider how many variables and unknowns an economic system contains, and that we can't reliably model systems that are far less complex