When could we reach 4°?

We’ve already reached 1.5°. I think it’s safe to assume no serious emissions reductions, and the possibility of increases, for the the next four years. We’ll likely see a 2° warmer world in the next 20 years. While many estimates put 4° out at 2100, some studies estimate we’ll reach it in the next 40 years. Given the challenge of thinking exponentially and our political reality, I’m inclined to believe the earlier estimates of 4° by 2060.