According to an alarming new report, at least two billion people are at risk from the heat, a risk that will progressively increase by 2100. To date, 60 million people around the world are already exposed to dangerous heat, with average temperatures of 29 degrees or more.
According to the researchers' calculations, the situation could accelerate if the global average temperature increases by 1.2 degrees from pre-industrial levels: for every 0.1 degrees of further increase, about 140 million people will be forced to live in precarious conditions due to excessive heat.
More than a fifth of humanity will be exposed to potentially dangerous heat by the end of the century: with a temperature increase of 2.7 degrees compared to pre-industrial levels, in fact, well two billion people will be forced to live outside the 'climate niche' in which the human species has thrived for millennia.
This is indicated by the study published in the journal Nature Sustainability by the international group of experts led by the University of Exeter in the United Kingdom and by the University of Nanjing in China.
Two million people at risk from heat by 2100
Tim Lenton, director of the Global Systems Institute at the University of Exeter said: "The costs of global warming are often expressed in financial terms, but our study highlights the tremendous human cost of failing to address the climate emergency." Considering that the world population could reach 9.5 billion individuals by the end of the century, India would be the country with the highest number of people exposed, over 600 million, followed by Nigeria, over 300 million people.
In countries like Burkina Faso and Mali, nearly 100% of the land could become dangerously warm for people. The country with the largest extension of territory exposed to the threat of heat would be Brazil, while a dizzying increase in the areas affected would be recorded in Australia and India.
Conversely, if global warming could be contained within 1.5 degrees, only 5% of the world's population would remain exposed to the threat of heat, thus saving a sixth of humanity.