Under BAU, 3 Billion People Face Possibility Of Saharan Heat, Across 29% Of The Planet, w/i 50 Years

ONDON, 3 June, 2020 – If humans go on burning ever more fossil fuels to put ever higher concentrations of greenhouse gases into the atmosphere, then one third of the world’s population may face – within 50 years – heat levels that could be all but intolerable. By 2070, 19% of the land area of the planet, home to 3.5 billion people, could be faced with a mean annual temperature of 29°C. That is, although there would be seasons in which temperatures fell well below this average, these would be followed by summers in which the thermometer went much higher.

Right now, only 0.8% of the land surface of the planet experiences such a mean annual temperature, and most of this space is located in the Saharan desert region of North Africa. But population growth – already highest in the poorest and hottest parts of the globe – and the projected increases in planetary average temperatures will expand this danger zone to almost one fifth of the planet’s land area, to embrace a third of the world’s people.

The conclusion – published in the Proceedings of the National Academy of Sciences – sounds like a dramatic advance on repeated warnings that planetary average temperatures could be 3°C above the long-term average for almost all of human history. But it may not be.

One important difference is that climate science forecasts tend to describe the entire planet. But almost three fourths of the planet is ocean, which is warming much more slowly than the land surfaces. Another is that climate forecasts predict average change for a sphere with a circumference of 40,000 kms. And the third factor is that such predictions do not specifically address where humans choose to live.

EDIT

https://climatenewsnetwork.net/3-bn-people-may-face-saharan-heat-levels-by-2070/