Policies currently in place to limit global warming will expose more than a fifth of humanity to extreme and “potentially fatal” heat by the end of this century, scientists warned in a study published on Monday.

The Earth’s surface temperature is set to rise by 2.7 degrees Celsius by 2100 compared to pre-industrial levels, pushing more than two billion people – 22% of the world’s population that year – out of the climate comfort zone that has allowed humanity to thrive for millennia, according to a study published in in the journal Nature Sustainability.

Countries that will have the most people at risk of ‘death heat’

Under this scenario, India (600 million), Nigeria (300 million) and Indonesia (100 million) would have the largest number of people likely to face “killing heat”.

“This would mean a profound change in the habitable zones on our planet’s surface, and it could lead to a large-scale reorganization of the areas where people live,” said Tim Lenton, a researcher at the University of Exeter in the UK and lead author of the study.

Limiting warming to +1.5 degrees Celsius – the most ambitious goal of the 2015 Paris Agreement – ​​would reduce the number of people at risk to less than half a billion.

Humanity is already facing a warming of almost +1.2 degrees Celsius under the influence of human activity, especially due to the use of fossil fuels (coal, oil, natural gas), with alternating natural cataclysms: heat, drought, forest fires, writes AFP.

• “The costs of climate change are often expressed in financial terms, but our research highlights the phenomenal human cost of failing to address the climate emergency.
• For every +0.1 degree Celsius of warming above the current level, 140 million additional people will be exposed to dangerous heat,” the study coordinator emphasized.

The “dangerous heat threshold” was set in the study at an average annual temperature of 29 degrees Celsius. Historically, human communities were densest in regions with an average temperature of 13 degrees Celsius (in temperate zones) and to a lesser extent in regions with an average temperature of 27 degrees Celsius (in tropical zones).

The risks are heightened in regions located along the Earth’s equator, where the climate can become deadly, with high temperatures that, although lower than in other regions, prevent the human body from sweating because of the humidity.

(Source: Agerpres / Photo: Dreamstime.com)