Climate change may affect humanity more severely, more broadly, and sooner than previously thought. This is the conclusion of a study*, according to which around a billion of the Earth's inhabitants could be forced to relocate or be displaced due to unbearable heat.

The worst-case scenario, as the study shows, could affect about 1/3 of the planet's population, who would have to face heat similar to that which has been typical in the hottest parts of the Sahara over the last 50 years. Meanwhile, the most optimistic variant would still affect about 1.2 billion people, who would "fall out" of the temperature comfort zone to which they have been accustomed for the last 6,000 years.

* Future of the human climate niche, Chi Xu, Timothy A. Kohler, Timothy M. Lenton, Jens-Christian Svenning, and Marten Scheffer; https://www.pnas.org/content/117/21/11350