Large areas of the planet may become too hot to be habitable during extreme heat events.
Researchers say that even healthy young humans would struggle to maintain a safe body temperature if we hit 2 degrees Celsius above preindustrial levels in a new study that examines a ‘worst-case’ scenario.
An international group of scientists has found that an area the size of the United States would become too hot during extreme heat events for even healthy young humans. And for older people who are more vulnerable to heat, the news is even worse.
“So, with just two degrees Celsius warming, what we showed that even for young, healthy adults, an area about the landmass of the U.S. would actually become uninhabitable from a heat stress point of view. But when we extend that to elderly individuals who have a lower thermoregulatory capacity to control their body temperature, that extended to over a third of the landmass with just two degrees Celsius of warming. So, this is some quite alarming data really,” explains Josh Foster, co-author of the study and a lecturer in human environmental physiology at King’s College London.
An estimated 260,000 people have died as a result of heat events since 2000, according to the researchers. But some parts of the world are more vulnerable than others.
“These types of issues aren’t necessarily centered on their own quite specific areas because there are some areas like Bangladesh and Pakistan that are much more vulnerable to high levels of humid heat. But then we also have to focus on drier climates, so the Sahara, some parts of Western Europe which are more prone to extreme levels of dry heating,” says Foster.
Between 1994-2023, only two percent of land reached a point where the combination of temperature and humidity was too high for adults under 60 to physically cope.
The figure rose to more than 20 percent of land for those over 60.
This article and video were provided by The Associated Press.
[Danger sign]
[People taking photos near salt flat and sign reading “Extreme Heat Danger”]
[People cooling off under mist]
[Sign displaying the temperature, 35 degrees Celsius]
[Laborer pulling a heavily loaded handcart]
[NGO worker spraying water on commuters]
[Patients being treated at the emergency ward of Civil Hospital Karachi]
Josh Foster (interview): “So with just two degrees Celsius warming, what we showed that even for young, healthy adults, an area about the landmass of the US would actually become uninhabitable from a heat stress point of view. But when we extend that to elderly individuals who have a lower thermoregulatory capacity to control their body temperature, that extended to over a third of the landmass with just two degrees Celsius of warming. So this is some quite alarming data really.”
[Heatstroke relief camp, officials providing cold water, people drinking water]
[Tub of cold water]
[Man pouring water over his face]
[Man digging for water and dead livestock]
[Dead livestock, birds eating livestock]
Josh Foster (interview): “These types of issues aren’t necessarily centred on their own quite specific areas, because there are there are some areas like Bangladesh and Pakistan that are much more vulnerable to high levels of humid heat. But then we also have to focus on drier climates, so the Sahara, some parts of Western Europe which are more prone to extreme levels of dry heating.”
[Fan]
[82-year-old woman trying to cool down at her home in downtown Veracruz]
Josh Foster (interview): “The cells and the tissues in your body can’t survive being at a core temperature of around 41.5°C. If they’re exposed to those kinds of temperatures, we start to see issues with proteins and enzymes denaturing and we see decreases in just normal cellular function. So we see cell death occurring at those types of temperatures that they’re exposed to, which would then lead to multiple organ failure.”
[People affected by drought]
[Cattle carcasses]
Josh Foster (interview): “I think that if we crossed these boundaries, it would result in very widespread health issues and potentially mass migration as well. What we really don’t know is the level of adaptation that takes place in some of these areas. So as to the lead author on the paper, Tom Matthews, is actually now doing fieldwork in Pakistan to try and understand does the body start to adapt to these levels of heat stress, which we just don’t see in Western regions, or are they making adaptations in the built environment as well?”
[Tourist in Seville using fans]
[Woman drinking water]
[Public thermometer showing temperature at 42 Celsius (107.6 Fahrenheit)]
This script was provided by The Associated Press.