The real measure should be CO2 output per unit of GDP. We still need to make stuff, so if you're going to release CO2, it better be an efficient use of it.
Presumably you'll stop driving, give up home air con and electricity, never fly anywhere, etc. Because those things aren't related to your GDP production.
We're already making a lot more stuff than what is needed (consider half of food is thrown away as food waste). What economies are fighting each other about these days is not so much availability of resources, as being the one who gets to make and sell in order to produce income.
Morally, it matters who makes things. The countries with high GDP who are responsible for the current extra CO2 in the atmosphere could always (you know, in theoretical fantasy-land) help out to make sure others produce as efficiently but reap the benefits. Instead of using the argument you make to pull up the living-standard ladder behind them.
Just because 100 people are dropping candy wrappers at the park doesn't make it okay for you to dump a bag of garbage.