There can't possibly be a hard cutoff like that, because day-to-day temperature variations far exceed 1.5 degrees. Of course, even an incremental difference ca

There can't possibly be a hard cutoff like that, because day-to-day temperature variations far exceed 1.5 degrees. Of course, even an incremental difference can tip farms over the line from sustainable to unsustainable, especially in subsistence farming regions where people are barely clinging on in the first place. But that has much different implications than a scenario where the world as a whole can't grow enough food.