Is it better to look at per capita or per unit of economic growth? One of my central complaints of the Left is that they tend to find the later unimportant whereas for me it's the former that doesn't matter. Per country is not even on the table I think.
> Is it better to look at per capita or per unit of economic growth?
Per capita IMO. Not all economic growth (assuming you're talking about GDP) is created equal, and not all of it is desirable. You can grow the economy both by drilling oil and by installing solar panels, but one of them helps the problem and the other hurts it. If we start pricing carbon externalities into both activities, the panels would make more sense financially.
Economic growth exists to serve people and make lives better - it's not an end in itself. And emissions per capita is an indicator of how carbon-efficient the economy is in providing whatever lifestyle it provides to its participants.
Per country means nothing. We could just subdivide the world in to hundreds more countries and all celebrate how none of us has more than 1% of the global emissions.
That's an enormous amount, especially since the US is about 5% of the world population.