Frankly, we probably ought to hit net negative for some while to actually unwind the mess rather than settling for merely stopping accelerating the worsening but I agree with your assessment of the odds.
Agree, and yet (assuming we reach that happy place) what happens next? Who decides how high to wind the global thermostat? Would countries who have benefited from increased temperatures (Russia perhaps) all fall in line and happily agree to go back to (say) pre-industrial revolution levels of CO2?
Even once (if) we get to negative co2 it will take centuries for the temperatures to drop back to pre-industrial levels. We’re still taking “only” slowing down temperature increase for well beyond the lifetime of anyone alive today.
Every country that extracts fossil fuels is deciding to turn up the global thermostat, but rather than calling it out as a decision, we treat it as a default or an irrelevant consequence.
I'm not sure we need to worry about that until we are magically able to sustain negative or net zero emissions globally. On the present horizon at least it looks like we will be settling for somewhere around two degrees above from pre-industrial temperatures.
According to Jean-Marc Jancovici (https://www.youtube.com/watch?v=IaQ-U-dP_7M, in french though), this is right on the money: CO2 being extremly stable and given the quantity we already have transfered in the atmosphere, a 1.5°C global rise in temperature is inevitable already. We'd have to in the negative indeed to have a impact, and with the system inertia and the cascading effects, it's not even sure it would reverse the trend completly.
