Billions Could Struggle to Survive Deadly Heat in Coming Decades
Billions of people around the world, especially those living in major cities like Delhi and Shanghai, could face a life-threatening struggle to survive as temperatures rise and deadly, humid heat becomes more common, according to a new study. The research, published in the journal Proceedings of the National Academy of Sciences, warns that even areas like the U.S. Midwest could be affected by lethal combinations of heat and humidity if global warming continues at its current pace.
The Growing Threat of Deadly Heat
Co-author Matthew Huber of Purdue University expressed deep concern about the study’s findings, stating that the implications are “very disturbing” and could result in a surge of people needing emergency medical care. The study builds on Huber’s previous research on the point at which heat and humidity combine to push the human body beyond its limits. It reveals that if temperatures rise 2 degrees Celsius above preindustrial levels, around 750 million people could experience one week per year of potentially deadly humid heat. At 3 degrees Celsius of warming, this number would increase to over 1.5 billion people.
Global Warming Projections
According to the United Nations Emissions Gap report, under current policies, the world is on track for a 2.8-degree Celsius increase in temperature by the year 2100. This would have dire consequences for regions like India, Pakistan, and the Gulf, which have already experienced dangerous humid heat. However, the study also highlights the rising risk in other areas, including South America and Australia.
Understanding Wet-Bulb Temperature
Scientists use a measurement called “wet-bulb” temperature to track moist heat. This measurement is taken by covering a thermometer with a water-soaked cloth, simulating the body’s cooling process through sweat evaporation. The study argues that a wet-bulb temperature of 35 degrees Celsius persisting for six or more hours could be the limit for the human body. However, recent research suggests that the threshold may be lower, between 30 and 31 degrees Celsius.
A Growing Concern
This study adds to the growing body of evidence expressing concern about the increasing occurrence of dangerous humid heat. Another recent study published in Science Advances reached a similar conclusion, indicating that the geographic range and frequency of such conditions will rapidly expand under even moderate global warming.
It is crucial to address the urgent need for climate action to prevent the devastating consequences of deadly heat. The findings of this study serve as a wake-up call to governments, policymakers, and individuals worldwide to prioritize sustainable solutions and reduce greenhouse gas emissions. By taking immediate and collective action, we can work towards creating a safer and more livable planet for future generations.
