As Earth’s global temperature approaches a critical threshold, scientists have raised alarms about the deadly heatwaves that could affect vast areas of the planet. If global warming reaches two degrees Celsius, dangerous heat levels will spread. They will threaten the survival of millions. This threat is significant even among younger populations.
A new study published in Nature Reviews Earth and Environment shows critical findings. The area exposed to dangerous heat will increase dramatically with a two-degree rise in global temperatures. Heat stress has already caused significant harm. Researchers are warning that its impact will intensify. This situation will worsen in regions like North Africa and South Asia, putting millions at greater risk.
HEATWAVES EXCEEDING HUMAN ENDURANCE
Heatwaves are becoming more frequent and deadly, with some regions experiencing temperatures that exceed human endurance limits. Last year, during the hajj pilgrimage in Saudi Arabia, over 1,300 people tragically died as temperatures reached 51.8°C (125°F), illustrating the deadly consequences of extreme heat.
KEY FINDINGS
The study was led by Tom Matthews. He is a Senior Lecturer in Environmental Geography at King’s College London. The research examined the effects of heat on the human body. It found that, between 1994 and 2023, areas equivalent to about two percent of the planet were exposed to heat levels. These levels were dangerous for people under 60. For older populations, the affected area was much larger, reaching about 20 percent.
The research also warns of the deadly effects of heat stress. The body’s core temperature may rise to 42°C within six hours. This can overwhelm the body’s cooling mechanisms, leading to heatstroke and organ failure.
THE IMPACT OF A 2°C RISE
If global temperatures rise by 2°C, the study’s projections show that the amount of landmass exposed to unsafe conditions for younger adults will triple, affecting about six percent of the Earth’s surface. For those over 60, about a third of the planet’s landmass could become dangerous. These extreme conditions could lead to heatstroke even in the shade, with individuals at risk of death from prolonged exposure.
THE PARIS CLIMATE AGREEMENT AND ITS URGENCY
The Paris Climate Agreement aims to limit global temperature rise to well below 2°C, with an ideal target of 1.5°C. Yet, 2022 marked the first year where the global temperature exceeded the 1.5°C threshold, pushing the planet closer to dangerous and irreversible climate impacts.
THE DANGER OF HUMIDITY AND HEAT STRESS
Heat stress is not just about high temperatures. It’s also about humidity. Humidity prevents the body from cooling off through sweat evaporation. Even lower temperatures can become lethal when combined with high humidity, leading to heatstroke and death.
HEATWAVES: A GROWING THREAT WORLDWIDE
In recent years, heatwaves have claimed tens of thousands of lives. Europe has seen the worst toll. More than 70,000 deaths from heat occurred in 2003. There were 60,000 deaths in 2022 and over 47,000 in 2023. Asia, especially India and Pakistan, has also suffered, with thousands of deaths recorded during heatwaves in 2015.
In Africa, heat deaths are often underreported, though extreme heat in Nigeria in 2024 highlighted the continent’s vulnerability. The World Health Organization (WHO) estimates that heat kills at least half a million people annually. The true number may be much higher. It could be possibly up to 30 times the reported figure.
