Scientists have warned that if global temperatures rise by 2°C, one-third of the Earth's surface could become uninhabitable for people over 60 years old. A new study highlights that the number of fatal heatwaves is increasing due to climate change. The research suggests that if global temperatures rise by 2°C compared to pre-industrial levels, a land area the size of the U.S. could become dangerously hot, even for younger people.
The study, published in Nature Reviews Earth and Environment, examines the effects of extreme heat on the human body, with the greatest risks identified for people living in North Africa and South Asia.
In 2023, over 1,300 people died when temperatures in Saudi Arabia reached 51.8°C during the Hajj pilgrimage, and experts warn that such deadly heatwaves could become more frequent in the future.
The study found that between 1994 and 2023, about 2% of global land saw temperatures and humidity levels dangerous for individuals under 60, but the figure increases to 20% for older, more vulnerable people. If global temperatures rise by 2°C, the areas affected by extreme heat would triple. For people under 60, the dangerous zones would cover 6% of the Earth's surface, while for those over 60, the affected regions would expand to one-third of the planet.
According to the Paris Climate Agreement, the target is to limit the global temperature rise to 1.5°C, but in 2023, the average temperature increase surpassed 1.5°C for the first time.
The study also notes that the deadly heat thresholds, which have only been exceeded in the hottest regions of the world for short periods, could start affecting even younger populations in the future. At these temperatures, even shade, wind, and adequate water intake may not prevent heatstroke, and prolonged exposure could be fatal.
Experts explain that heat stress can disable the body's natural cooling mechanisms, leading to dizziness, headaches, organ failure, and death. High humidity, in particular, makes it harder for the body to cool itself through sweating, increasing the danger.
Heatwaves have already caused the most deaths in Europe, with more than 70,000 people dying in 2003, 60,000 in 2022, and over 47,000 in 2023. Heatwaves have also caused significant casualties in Asia, with thousands dying in India and Pakistan in 2015 due to extreme heat.
The researchers pointed out that heat-related deaths in Africa are often underreported, but in 2024, deaths were recorded in Nigeria due to extreme heat.
According to the World Health Organization (WHO), extreme heat causes at least 500,000 deaths annually. However, experts estimate the actual number could be 30 times higher. Climate change is expected to make heatwaves more frequent and severe, and experts stress that urgent measures must be taken to control the global temperature rise.
