This is an excellent question. It is a very popular idea that there is some "tipping point", plus positive feedback loops, that are definitely going to make thi

This is an excellent question. It is a very popular idea that there is some "tipping point", plus positive feedback loops, that are definitely going to make this problem worse, someday. That they are popularly imagined by non-scientists, and that the effects are always promised for the future rather than identified in the past, are cause for skepticism. Judging by the fact that for the billion years after life has dominated, Earth climate has always stayed decidedly non-Martian and non-Venusian, the evidence is strong that negative feedback loops are more powerful than the positive ones that people may publicize. I would like to see more substantiation behind such assertions.