By 2084, if we don't curb global heating, nearly all cities will be too hot to hold the summer games. If a heat wave strikes, they would have to be cancelled, and the risk would be too great.

The only candidates in the Americas will be San Francisco, Vancouver, and Calgary.

But who are we kidding? With that much heating, the world will be in such desperate straits that nobody could even think of holding a world-wide sporting event.