Yeah this is because the USA has offloaded making all its stuff to China. With this in mind the USA CO2 number is even worse than it first appears.

Are you saying that emissions shouldn't be attributed to the country they're generated in? If so, that's certainly an interesting perspective.

The attribution is much more grey with the advent of so much globalization. As humans we like to pin the blame on a singular entity but the real world is far more complicated.

Technically it shdnt. Just imagine you send your oil to another country to produce stuff for you, should the carbon emission for that be counted for country A or B? I think clearly country A. Now what if the oil doesn't come from country A but is bought from the money for the goods from country C. Well, technically you shdnt attribute it to country B. Either A or C.

per capita is the more accurate measure. Yeah I note my mistake in another reply.

Even so, the US historically took the number one spot for both total greenhouse gases and greenhouse gases per capita. If you look at it from a perspective of a longer timespan, the US is basically number one.

It is only in recent times does the US now currently take the number two spots for both categories.

Indeed. Here is an animation of the cumulative emissions starting 1750:

https://www.youtube.com/watch?v=jx85qK1ztAc

The US come in first, my home country Germany takes the fourth spot.