Well, that would certainly (maybe) stop all the naysayers predictions of doom and gloom, and just leave us with the "I told you so" brigade.Or we could phase out fossil fuel use as rapidly as possible (the root cause of the problem), since that can be done much faster than changing the global profile of population growth.
So, who is going to be first and to what degree? Driving a Tesla is, and going solar is only a token. What about refusing to fly, ditching the mobile phone, riding a push bike instead of driving (everywhere), eating whole raw food and definitely no packaged or processed foods, living in a home (shelter) that has zero impact on carbon emissions and made of materials which had no carbon emissions in their formation.
Who determines the degree? The individual, the state, a world body? Who enforces the in-actions? Or do we just do what we as individuals justify to ourselves that we are doing enough and our fair share.