Earlier quoted context omitted.
Apparently I need help understanding why this matters more than simply prioritizing countries who emit the most. Do you want to reduce total emissions or do you want reduce it equitably across countries? The greenhouse effect doesn’t care how equitable the reductions are.
I think the best way to understand the problem is to imagine China taking your concerns seriously and satisfying them by drawing a line down the middle and declaring themselves to now be two countries. They’re both so far down the list now!
That’s an interesting hypothetical. In the same vein of “assume the cow is spherical”, I also have a degenerate example! Suppose the Vatican City has horrific per capita emissions. Maybe the pope has a gastrointestinal disorder involving frequent methane emissions. The pope is otherwise healthy and will remain in office for decades. China and India point at them “but per capita emissions!” and refuse to do anything.