I don’t agree with the risk that Earth will become Venus, but it is very possible we could hit the hottest temperatures since ~50 million years ago, which were too hot and humid for humans to live in.

Projecting current emissions into the future, Gingerich found that if emissions continue to rise, we could be facing another PETM-like event in fewer than five generations. The total carbon accumulated in the atmosphere could hit the lowest estimate of carbon accumulated during the PETM – 3,000 gigatons – in the year 2159. It would hit the maximum estimated emissions – 7,126 gigatons – in 2278, based on Gingerich’s calculations. Humans have emitted roughly 1,500 gigatons of carbon as of 2016.