...destruction.
It is the product of the release of nutrients from the Amazon basin now being destroyed and carbon dioxide.
I agree that the world population is unsustainable, but I note that birth rates are higher in poor countries than in rich countries, one reason being high infant mortality.
I considered this some time back on another website: Current Energy Demand; Ethical Energy Demand; Depleted Uranium and the Centuries to Come
Repeatedly, I have argued in my writings and comments around the internet, by frequent appeal to the fine and widely read paper on the environmental and human effects of nuclear energy by the climate scientists Kharecha and Hansen,[35] that the fact that nuclear energy saves lives lies at the crux of the argument that the use of nuclear energy must be expanded as a moral imperative. At the same time as I am arguing for saving lives, I am arguing that the population must be reduced for decent human life to remain or in too many cases to become sustainable. It would seem that these ethical arguments are at cross purposes. However, with some exceptions, it is now understood by observation that those places where the fertility rate is at or below replacement level are most often the same places where people are secure in their homes, the places where they are well provided for, where they are educated and safe. Maybe, just maybe, the key to yet saving what might be saved of the planetary environment would be involved with honoring in practice, rather than broach, the 25th article of the Universal Declaration of Human Rights of 1948.[36]