Which countries do you see that are all in? I’m not arguing, just wondering. EU countries I would presume.
I'm not sure any major nation is all in, but some are certainly closer than others.
We, of course, are historically the worst and still the worst per capita, and (afaik) it isn't even close.
China has taken the lead as worst current polluter. I don't know where they stand per capita, but I imagine nations like the UK and Germany are still much worse.
Meanwhile, India is playing catch-up. I don't know when they will pass us, but they surely will. 1.4 billion people and lots of coal plants. I wonder why they aren't investing heavily in nuclear (or are they)?
Of course we are the main reason why the world is much worse of than it could be. We failed to lead. In fact, we actively hindered the efforts of other major nations. Recall our non-participation in Kyoto and Trump's withdrawal from the Paris Accords. But even when we weren't the obvious bad guys, we worked hard behind the scenes to water down (and make voluntary) the progress other nations were trying to make.
Finally, while we are no longer #1, we sort of still are. Much of the reason why China moved ahead of us was because we exported a bunch of energy-intensive manufacturing to China and others. If we're still buying all those cars and phones and TVs, aren't we still responsible for the climate impact?