This is why the US should not just be "about equal". We can afford to improve the situation, not just maintain the status quo. Instead, we often find ourselves sitting in judgement of developing countries doing the same things we did to develop.
Do you want a pony, too?
Look, we're not talking about straight up charity. You can talk people into charity; despite the standard narrative, the United States is quite generous in that regard. What you're asking for is for us to reduce our standard of living explicitly so other people can pollute. That's going to be a hard sell.
Every gain we make needs to unambiguously be a gain otherwise some will choose to ignore the self restriction for their own personal gain and with CO2 we all lose when that happens.