But the report warned that just a one-degree centigrade rise in average temperature would reduce this to 500 viable slopes, and that this was likely to happen between 2020-2025.

BBC: Will this become an increasingly rare sight?

Meanwhile, participants for the United Nations Framework Convention on Climate Change prepared for meetings in Bonn, grappling with a convergence of new data from the International Energy Agency suggesting that humanity will be unable to prevent temperatures from exceeding the catastrophic threshold of a 2 degree Centigrade increase across the planet.

FORBES: One Week on Earth