Global warming of 2°C will triple the areas with lethal heat

A new study published in the journal Nature Reviews Earth and Environment warns that a 2°C increase in global temperatures will triple the area of land where heat becomes dangerous even for healthy people. The affected areas could be the size of the United States, with the elderly most at risk.

• Extreme heat: a threat to millions

Scientists from the UK and the US combined climate data with studies of mortality caused by extreme temperatures. The results show that a 2°C warming compared to pre-industrial times would triple the area affected by lethal temperatures, where the human body can no longer regulate its temperature and survival becomes impossible after six hours of exposure. For adults aged 18 to 60, more than 6% of the world's land surface will be affected, and for those aged 60 and over, this percentage will increase to 35%. The most exposed areas will be the Indian subcontinent and the Arabian Peninsula, where high temperatures are already a problem.

• Exceeding the limits of the Paris Agreement

Under the 2015 Paris Agreement, countries committed to keeping global warming "well below 2°C". However, current commitments are not enough, and the UN estimates that the world is on track to warm by 2.6-2.8°C by the end of the century.

If these projections materialize, millions of people will be exposed to a climate incompatible with human survival, and the effects on global health and the economy will be devastating.

• Solutions to reduce the impact of global warming

To address this major risk, the study recommends adaptation measures such as creating cool public shelters, using air conditioning and modifying the urban environment to reduce the effects of heat waves. Professor Tom Matthews of King's College London points out that as temperatures rise, access to cooler spaces becomes a vital necessity. In addition, another recent study, published in Nature Medicine, shows that while global warming could reduce the number of deaths caused by cold, this decrease will not compensate for the dramatic increase in mortality due to heat.

Without rapid and effective measures, extreme heat waves will become one of the most serious threats to human health in the coming decades.