There is no shortage of humans. Arguably too many.

There is a shortage of nature. On top of that, the ecosystems are changing, and once they're gone they're probably not coming back.

We could lose half of the population tomorrow and still, eventually, hit that predicted 10 billion souls -- it would just take a lil longer. If WA and BC turn into chaparral things like Salmon and Snow Crab ain't gonna live there any more, and never live there again.