Edit: sorry, I assumed you're new here. Apologies.
To start with, I don't agree that land shortage is not one of the worst threats to endangered species. Your reasoning is mostly suited to megafauna, but won't exactly fit colonial birds, rainforest dwellers, lots of plants, etc. (Your argument doesn't actually rely on AGW being the worst problem, so you can jettisone the beginning.)
Am I right that you consider the first obstacle to solving AGW to be the lack of coordination between nations? In this case, what direction should the solvers choose?
I argue that agw is the worst because it is the only one that hits at very deep-seated human assumptions that may well be genetic/inherent.
The first obstacle to agw is, even before coordination, is anchoring - we assume that everything must get better only, and nothing ever gets worse. Further, a lot of systems are built up on the assumption that there will always be a continuously expanding material economy. This is like the case where becoming slightly more rational from a point of relatively complete irrationality is likely to make one less effective :...
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