Extreme heat could make parts of Earth unlivable, scientists warn
New research states if global temperatures were to rise by 1-degree Celsius than the current levels, then billions of people every year would be experiencing extreme heat that's too hot to handle. The study says if the planet's warming rates surpass 1.5-degrees Celsius, it will be 'increasingly devastating for human health.' There's a 66% chance that we will breach that key global warming limit, for the first time ever, between now and 2027, according to estimates.
The body's core temperatures rise at particular levels of heat
Scientists have carried out 462 experiments to understand how much heat, humidity, and physical activity humans can handle before our bodies can't keep a stable core temperature. "As people get warmer, they sweat, and more blood is pumped to their skin so that they can maintain their core temperatures by losing heat to the environment," said Larry Kenny, study's co-author. "At certain levels of heat and humidity, these adjustments are no longer sufficient, and body core temperature begins to rise."
Reevaluating heat and humidity limits
The scientists looked at how people in different areas would be affected if Earth's temperature rose between 1.5-degrees Celsius and 4-degrees Celsius, and said that 3-degrees Celsius would be the most likely increase by 2100 if we don't take action. In 2022, researchers found that we can't handle as much heat and humidity as we once thought. That study claimed the maximum wet bulb temperature is about 31-degrees Celsuis at 100% humidity for young, healthy people.
'Humid heat will be a bigger threat than dry heat'
"Humid heat is going to be a much bigger threat than dry heat. Governments and policymakers need to re-evaluate the effectiveness of heat-mitigation strategies to invest in programs that will address the greatest dangers people will face," said Qinqin Kong, from Purdue University, who was part of the study. Even if temperatures don't reach the danger zone, researchers advise we should still be careful in extreme heat and humidity.
Addressing the future of climate change
To stop temperatures from rising, scientists say we need to cut down on greenhouse gas emissions, especially burning of fossil fuels. If changes aren't made, people in middle-income and low-income countries will be hit the hardest, said the study's lead author. For example, if Earth's temperatures go up by 4-degrees Celsius, Al Hudaydah, Yemen, a port city with over 700,000 people, could have more than 300 days a year with temperatures too hot for humans to handle—making it unlivable.
