(NewsNation) — Climate change has been blamed for the worsening of natural disasters around the world, and now, a new study shows that as the Earth gets warmer, certain places could get harder to live in.
Researchers in a study published in "Proceedings of the National Academy of Sciences" say as heat waves become more "frequent, intense and longer-lasting due to climate change, the question of breaching thermal limits becomes pressing."
Past research, according to The Washington Post, has found that at some level of heat and humidity, the human body can no longer cool itself, causing people's internal temperature to rise uncontrollably.
A wet-bulb temperature of 35 degrees Celsius has been seen as the threshold for people being able to regulate their body temperature, although a study from January 2022 found this to be closer to 31 degrees Celsius. If one is exposed to this heat for hours, the Post writes, it could trigger illness or death if they can't find shade, air conditioning, drink water or cool down another way.
(The National Weather Service defines a "WetBulb Globe Temperature" as a way to measure heat stress in direct sunlight that takes into account temperature, humidity, wind speed, sun angle and cloud cover.)
Some places have already passed this threshold for brief periods, but Daniel Vecellio, a postdoctoral researcher at George Mason University’s Virginia Climate Center and the study’s lead author, says this doesn't mean these places are already "unlivable."
But in an interview with The Washington Post, he said they soon could be if their climates continue to change.
“It’s when you see these accumulations of weeks or months of this at a time that things become ‘too hot for humans,’” Vecellio said in the newspaper, though he added that the planet can stave off some of the "worst impacts" by limiting global warming.
These are the countries and cities researchers in the study said would go above the heat threshold for hours at a time in the future:
United States
New York City could see 23.1 hours at 4 degrees Celsius above the heat threshold.
Chicago could see 31.9 hours at 4 degrees Celsius above the heat threshold.
Nigeria
Lagos could see 108.8 hours at 4 degrees Celsius above the heat threshold.
Kano could see 175.5 hours at 4 degrees Celsius above the heat threshold.
Sudan
Khartoum could see 103.5 hours at 4 degrees Celsius above the heat threshold.
Niger
Niamey could see 254.9 hours at 4 degrees Celsius above the heat threshold.
Iraq
Basra could see 117 hours at 4 degrees Celsius above the heat threshold.
Iran
Ahvaz could see 173.5 hours at 4 degrees Celsius above the heat threshold.
Bandar Abbas could see 958.6 hours at 4 degrees Celsius above the heat threshold.
Yemen
Aden could see 1,770.2 hours at 4 degrees Celsius above the heat threshold.
Al Hudaydah could see 2,407.1 hours at 4 degrees Celsius above the heat threshold.
United Arab Emirates
Dubai could see 783.9 hours at 4 degrees Celsius above the heat threshold.
Saudi Arabia
Jeddah could see 540.6 hours at 4 degrees Celsius above the heat threshold.
Mecca could see 142.5 hours at 4 degrees Celsius above the heat threshold.
Dammam could see 804.7 hours at 4 degrees Celsius above the heat threshold.
Thailand
Bangkok could see 101.3 hours at 4 degrees Celsius above the heat threshold.
Vietnam
Ha Noi could see 602.1 hours at 4 degrees Celsius above the heat threshold.
Hai Phong could see 492.7 hours at 4 degrees Celsius above the heat threshold.
Japan
Tokyo could see 36.9 hours at 4 degrees Celsius above the heat threshold.
Osaka could see 39.9 hours at 4 degrees Celsius above the heat threshold.
South Korea
Seoul could see 95.7 hours at 4 degrees Celsius above the heat threshold.
Busan could see 93.2 hours at 4 degrees Celsius above the heat threshold.
China
Shanghai could see 327.6 hours at 4 degrees Celsius above the heat threshold.
Beijing could see 127.9 hours at 4 degrees Celsius above the heat threshold.
Guangzhou could see 274.3 hours at 4 degrees Celsius above the heat threshold.
Shenzen could see 115.3 hours at 4 degrees Celsius above the heat threshold.
Bangladesh
Dhaka could see 346.1 hours at 4 degrees Celsius above the heat threshold.
Pakistan
Lahore could see 1,013.5 hours at 4 degrees Celsius above the heat threshold.
Karachi could see 452 hours at 4 degrees Celsius above the heat threshold.
India
Delhi could see 556.9 hours at 4 degrees Celsius above the heat threshold.
Mumbai could see 55.4 hours at 4 degrees Celsius above the heat threshold.
Kolkata could see 548.5 hours at 4 degrees Celsius above the heat threshold.
Chennai could see 94.2 hours at 4 degrees Celsius above the heat threshold.