It sounds like you only care about problems that affect you very directly, which is pretty short-sighted. There are many climate-related problems that are affecting people already in Central America (no rain, can't farm, so they're walking north), the northern US and California (wildfires and wildfire smoke), the Midwest (aquifers depleted, rendering farmland less valuable), Florida (sinkholes from aquifer depletion, flooding in streets, no they can't just build a dike). It's a pretty multi-factorial problem and it's unfortunate that the interpretation here seems to be pretty simplistic.
Your does point out something, though, that really really bugs me from climate activists/politicians. The idea that you have to "believe" in climate change, like you'd believe in religious proclamations. I don't give a sh*t if you believe -- and making this ideological creates tribes where one group is like "I believe climate change isn't happening/is God's will/is natural, so I will run my F150's AC with the windows open and breathe in exhaust proudly because internal combustion and burning oil is what God has ordained as the pinnacle of human achievement". Belief whatever. I'm much more interested in action. Why does it seem good to some people to... just waste resources without much return? Irresponsibly manage our farmlands for short-term profit vs long-term yield? pin success to ownership of fossil fuels in specific places rather than a more flexible and less geopolitically fraught paradigm? There are a lot of visible problems to address, to your point, efitz.
Along these lines, if there's one place where the left and the right in the US have an easy opportunity to cooperate and yet for some reason don't, it's on Chinese emissions.
China's responsible for almost a third of all the CO2 emissions in the world, and they have some of the dirtiest industry on the planet [1]. They got their own relaxed version of the Paris Accords and haven't even been meeting those standards. You don't really see anyone dinging them for any of this though.
Now the left really dislikes emissions and the right simply dislikes China. So you'd think there would be an incentive for them to cooperate on this issue but they don't.
I think it underscores how so much of politics is basically secular religion now and really about identifying with your tribe, like the issue on the left is probably that they don't want to admit a lot of this climate problem is someone else's fault, and the issue on the right is they don't want to admit there's a problem in the first place.
There isn't because geopolitics of US pushing blame based on total instead of per capita emissions (nevermind historical) would make US look retarded - the left doesn't want that taint. Since it's not going to fly internationally, which limits it to domestic politics, and basing domestic politics of changing a geopolitical rivals largely functions as political theatre.
Just to clarify, China is at ~8T per capita [1]. USA is at 14T [2]. Rhodium group [3] says it was 10.1T and 17.6 in 2019 so it seems like the numbers have quite a bit of variability.
I do think that OP has a good point that we do probably need to consider totals since the environment doesn't care about per capita. It's also important to consider that China's energy use is probably dominated by industry supporting manufacturing for the entire world, so that "per capita" number is fairly inflated vs the true number.
The enviroment doesn't care about climate change, earth will go on in some form regardless. Climate change is an anthropocene / (geo)political problem. The only way to coordinate politcal/human problem is via metrics stakeholders think is "fair" to regulate behaviors around. Currently that's per capita, which is already concession of not factoring in historic emissions. OPs point is extra useless because it tries to coordinate geopolitics of climate change via metrics most of the world will never agree to, made even more unfeasible by trying to do so via US domestic politics. It's like suggesting PRC domestic politics should be leveraged to reduce US defense spending, it's fundmentally unworkable.
I think you're splitting hairs. Clearly "environment" in this context isn't the existence of Earth as a planet but life on Earth, the current ecology, and our place within it. That cares very much about how much total carbon output there is, regardless of what we perceive as fair. And again, as I mentioned, China's total energy use is likely artificially inflated than it might otherwise be because the world's manufacturing capacity is centered there - a fairer comparison would likely take carbon emissions used in exports and attribute that back to the home country that is importing the product. I suspect in that context USA & Europe will look remarkably worse per capita.
It may matter on academic considerations, people can discuss it, but it doesn't matter on global regulation layer whereby fairness is determined via collective consensus and for forseeable future, per capita is what everyone can live with. Your last point is signficiant because the rhetoric of total emissions isn't going to fly especially if the numbers make west look worse. In context of OPs post, trying to unilaterally frame climate debate around total emission in US and somehow turn that into geopolitcal leverage is not realistic especially if closer interogation of metric is against most major players interests. I don't think it's splitting hairs rather than acknowleding geopolitical constraints over what's workable and what's not, even if what's workable is suboptimal.
I have a finite amount of attention, resources and energy. I'm fortunate to have more than most. But climate change is not even in my top 10 problems. Preparing for retirement, getting my kid educated, caring for ill family members, supporting my local food bank, keeping my government from going authoritarian - these are where I spend my resources. If I had more I'd probably spend them on things that literally kill millions of people per year like malaria, typhoid, infant mortality, etc.
Your does point out something, though, that really really bugs me from climate activists/politicians. The idea that you have to "believe" in climate change, like you'd believe in religious proclamations. I don't give a sh*t if you believe -- and making this ideological creates tribes where one group is like "I believe climate change isn't happening/is God's will/is natural, so I will run my F150's AC with the windows open and breathe in exhaust proudly because internal combustion and burning oil is what God has ordained as the pinnacle of human achievement". Belief whatever. I'm much more interested in action. Why does it seem good to some people to... just waste resources without much return? Irresponsibly manage our farmlands for short-term profit vs long-term yield? pin success to ownership of fossil fuels in specific places rather than a more flexible and less geopolitically fraught paradigm? There are a lot of visible problems to address, to your point, efitz.