There's no reason to think that will happen though. What happens during times of change is the specialists species die-off and then the generalist species expand into the newly sparsified regions.
There's the degrowth strategy and then there's the innovation(techno-fix) strategy. Innovation is the best strategy regardless of political will, but I'd also argue that realistically degrowth isn't even on the table because the math doesn't work out unless the degrowth is implemented in Africa and Southern and Eastern Asia. Which only the most hardcore environmentalists would have the audacity to suggest that.