That's poppy cock. If everyone emitted the same amount, well you still wouldn't have a case for there being only one solution. Because increasing efficiency of say, gas mileage in cars would have the same effect as removing emitters. Total emissions go down. Or rather than calling them the number of emitters, let's call your solution what it is, population control. If you think it's the only solution, that's pretty foolish.
A real incongruity I've noticed is that the efficacy of any proposed solution never really gets discussed. Unlike other foreign policy issues, where there's lots of different opinions, this topic tends to get distilled down to the same old talking points, every time. If you have some percentage that flat outright believes that human contribution is a lie, obviously they won't be a meaningful part of that discussion at all. As for proposed solutions, there's lots of them. My personal favourite is the
wedge stabilization proposed a number of years ago now.
Because it's not one solution, it's many, so it gives lots of different options. Some countries would be able to do more in some categories than others. Doesn't matter with this concept.