Earlier quoted context omitted.
Ecologically speaking, the US is an absolute monster of a nightmare. The American carbon footprint is incredible.
Not intending to make this political, but it's a relevant point to consider: we should also take into account the carbon footprint of all the bombs that were dropped by America and its proxies into the equation as well. The environmental impact from these would be immense, I'd imagine.
A Time-Lapse Map of Every Nuclear Explosion Since 1945 - by Isao Hashimoto https://www.youtube.com/watch?v=LLCF7vPanrY
1 second = 1 month