Earth's recent climate spiral.

[Leonardo17]

It is not westernization.   It is social investment that offsprings can benefit from.   There are two strategies for improving the chances of one’s own genetic line.  

1.  Invest a lot in very few offsprings, so the few you have would likely prosper.    This strategy presupposes there is good social wealth invested in healthcare, security, and equitable opportunity that offspring can benefit from,  so it is not dangerous to invest too much of your own resource in just a few offspring because these few offspring are relatively unlikely to blow your investement by dying from childhood diseases or get murdered for their Apple watches or iPhones.

2.  Invest a little in each of many offsprings, so maybe a few of the many you have might blunder his/her way out of failure.   This strategy assumes each offspring’s chances of biological or social success are slim, because social investment in their health, security and equitable opportunity are slight.   so one would spread one’s own investment  amongst as many offsprings as possible so a few of them might rise from loin cloths to pants.

So the upshot is as  society becomes relatively wealthy, the optimal reproductive strategy changes from having a lot of children to maximize the chance that a few will scrap out a living, to having a few children and give them the best possible education and career opportunities.

So, if our confused, dim witted and deeply malevolent friend really thinks the most important way to control global warming is to reduce birth rate in the developing world, then he should seek to enrich the developing world as quickly as possible. Then the social wealth invested in health care, security, and equitable opportunity in the developing world increases,  \ so the optimal reproductive strategy for the hoi palloi would changes from investing little in each of many children, to investing a lot in just a few children.

But in his gleeful, malevolent and ill informed urge to degrade and harm the majority of mankind, he actually argues for the opposite, to impoverish the developing world so the optimal reproductive strength in the developing world tilt even further to having lots and lots of semi-disposable babies.

I agree. On one hand current third worlders have a small carbon footprint and it is true that their footprint will increase are their society are modernizing. But on the other hand a) fertility rates will decrease and b) It will be like Europe. They will become more intelligent societies who know to control events around them rather than being masses of people who simply react to some outside even without any real social-consciousness.