I think it is a complex issue that involves overpopulation, over consumption, immigration and migration. Marxists will point out that we can use technology and policy in order to preserve finite resources (food, clean water, forests) and introduce polices meant to preserve fragile ecosystems and species diversification. I think there is some truth to that. I don't think you can overlook overpopulation though. It is more of matter of combining overpopulation with the demographic and social changes that have more of the third world population moving to urban centres and consuming more meat and buying social goods, all of which leads to more expensive food and pollution. Could we mitigate those problems with technology and policy? Yes, but that rests on the premise that we will find effective technologies and policies to do so. I think it is terribly hard to muster the international political will to solve problems like these. Overpopulation is still a problematic factor that we have to address.