Future forecast: Hazardous heat to hit three times more often
A new study predicts that if climate change worsens, much of the world will likely experience what is officially referred to as "hazardous heat" at least three times more frequently.
According to a study published on Monday in the journal Communications Earth & Environment, soaring temperatures and humidity that feel like 39.4 degrees Celsius or higher in many of Earth's wealthy mid-latitudes should occur 20 to 50 times annually by the middle of the next century. Currently an occasional summer shock.
As per the study's lead author, in regions like the U.S. Southeast, that oppressive heat index may last for the majority of the summer by 2100.
Furthermore, the sticky tropics are far worse. According to the study, by the end of the century, a tropical belt that encompasses India will likely be hit one to four weeks each year by heat waves that are currently regarded "very dangerous," or when the feels-like heat index exceeds 51 degrees Celsius.
“So that’s kind of the scary thing about this,” said study author Lucas Zeppetello, a Harvard climate scientist. “That’s something where potentially billions of people are going to be exposed to extremely dangerous levels of heat very regularly. So something that's gone from virtually never happening before will go to something that is happening every year.”
Zeppetello and colleagues examined the likelihood of two distinct heat index thresholds—103 degrees (39.4 Celsius) and above 124 degrees (51 Celsius), which the U.S. National Weather Service classifies as dangerous and extremely dangerous—using more than 1,000 computer simulations. They made calculations for the years 2050 and 2100 and compared those to the number of times that heat occurred annually worldwide between 1979 and 1998.
Even in the improbable best-case scenario of global warming confined to only 3.6 degrees (2 degrees Celsius) since pre-industrial times — the less rigorous of two international targets — the study revealed a three- to ten-fold rise in 103-degree heat in the mid-latitudes.
According to the analysis, there is just a 5% possibility that warming will be that minimal and infrequent. The report predicts that by 2100, the tropics will be steaming at 103 degrees Fahrenheit "during most days of each normal year."
From 1979 through 1998, Chicago had that 103 degree heat index just four times. By the end of the century, though, the study's most likely scenario predicts that Chicago will experience that hot and sticky threshold 11 times a year.
According to Zeppetello, who conducted a large portion of the research at the University of Washington State during the warming-driven 2021 heat wave, heat waves are one of the new four horsemen of the apocalyptic climate change. The others are sea level rise, water scarcity, and changes in the overall ecosystem.
In contrast to other climate research that examines what happens at varying amounts of carbon pollution, this study is based on mathematical probability. Michael Mann, a climate scientist at the University of Pennsylvania, is now more dubious of this study as a result. He added that it disregards recent Australian initiatives as well as historic climate legislation approved by President Joe Biden of the United States earlier this month.