I would suggest you consider that issue may be more complicated than a single variable. While it make for great back and forth on an HN thread and wonderful, cathartic gotcha moments, (perhaps I also feel this urge), it really is a complicated issue, and pretty much all signs point to climate change as being a very disruptive, likely cataclysmic change to the entire planet. Ecosystems don't respond to rapid, catastrophic changes well. Loss of biodiversity--losing a link in the food chain--tends produce shockwaves through the entire system, which can lead to collapse.

E.g. https://phys.org/news/2015-06-tide-pools-rapid-die-off-sea.h...