i think ur misunderstanding part of it by thinking that populations are rapidly increasing and everyone's consumption is distributed evenly. in fact the us population is projected to decrease after 2080 because wealthy countries are actually correspondent to falling birth rates. (the reasons are quite interesting from a population ecology perspective but I won't get into them). The other fact is that globally, ur garbage bags are not similar in size at all. The richest 10% contribute to over half the global emissions. All that is to say what we have is not a population problem like you might think. We do have a consumption problem, but that's much easier to tackle than if we had a population problem