Most of the world's plastic pollution coming out of 10 Asian and African rivers for example.
This is why arguments from educated, intelligent and responsible Westerners that they themselves shouldn't have children in order to reduce the impact on the planet are flawed.
If not for their children with the same skills and views, who else will reign in the Asians and Africans who are busy destroying their environments?
The first thing that the world needs is for all countries to reach a stable population level. This means hugely reducing fertility in some developing countries, mostly by making sure contraception is widely available and that women are educated enough to know how to use it.