TAMPA, Fla. (WFLA) — For the past week and a half, various parts of the nation have been baking in record heat. Austin, Texas is set to see its hottest June on record with the most 100 degree days, while 1,200 miles north near the Canadian border it hit 101 degrees in Fargo, ND over the weekend.
On Thursday the temperature soared as high as 106 degrees in parts of the Southeast U.S. from Northern Florida into Georgia and Alabama.
While heatwaves are a normal part of summer, there are heaps of scientific evidence that climate change is making them more intense and last longer.
The latest comprehensive 2022 IPCC climate report put out by the UN says that it “unequivocal” that extreme heat is increasing on every continent and that is due to human-caused climate change.
Specifically the report states that a heatwave that would have occurred once in 50 years before pre-industrial times – the time before humans started warming the climate – will now occur about 5 times more and be 2 degrees F warmer. Over the next few decades, if the current pace of warming continues, a 1-in-50-year heatwave will be 14 times more likely and be about 5 degrees F hotter.
Dr. Friederike Otto, one of the lead scientists at World Weather Attribution (WWA), an organization that specializes in determining the extent to which climate change impacts extreme weather says, “Every heatwave in the world is now made stronger and more likely to happen because of human-caused climate change.”
There is perhaps no better example of the the impacts of climate change on extreme heat than last summer’s Pacific NW heatwave, where Lytton Canada hit 121 degrees F and then the next day 80 percent of the town burned to the ground. The heat killed over 1,000 people.
WWA found that climate change made that Pacific NW heatwave 150 times more likely to happen. In a climate before human-caused warming (before 1900), a heatwave of that magnitude would have only occurred once every ~150,000 years. But by the middle of this century a heatwave that extreme may happen once every 10 years.
In the US, research estimates that rare heatwaves are now 3 to 5 degrees F warmer than they were just a few decades ago. A 2017 paper found that global warming increased the severity and probability of a given area experiencing it’s hottest monthly and daily weather events over 80 percent of the globe.
The reason is simple. Small changes in average temperature equals large changes in extremes. It can be most effectively explained using the animation below.
Here in the Tampa Bay area, days with feels like temperatures above 105 degrees used to average ~10 in 1990, by 2030 that’s projected to be about 40, and by 2050 it balloons to nearly 70 sweltering days. And in some parts of the world, the science says heat may make it difficult to live.
To help the public better understand the influence of a warming climate on heat, Climate Central has just released a new tool called the Climate Shift Index. In real-time the tool measures how much climate change has impacted the temperatures on that given day.
On a scale from -5 to 5, the numbers indicate how much more likely an event is today than it was before we started warming the planet. So if a 95 degree day happened once per June on average in 1900 in Tampa, but now it happens 3 times per June on average, then the shift is a 3, meaning it’s 3 times more likely.
The image below shows morning lows on Thursday June 23rd. Some areas in the northern US had no shift due to climate change, while others near the Gulf Coast registered a 5, the highest number. A 5 means that temperatures this warm would be virtually impossible without climate change.
Because of the increasing frequency and intensity of heatwaves, some believe it’s time to start naming them to raise awareness and help protect more people.
Kathy Baughman Mcleod is the Director of Arsht-Rock Resilience Center.
“It’s virtually invisible and silent, it doesn’t have a brand, it doesn’t have a name, so it needs PR,” she said. “We believe that naming and categorizing heat waves is that best way to quickly get people on top of how deadly this is.”
According to the National Weather Service, heat is the leading killer among weather hazards in the US. Triple that of hurricanes.
The Arsht-Rock Resilience Center has put together a Heat Action Platform to help leaders address the increasing danger from heatwaves.
“You have a category 1, a category 2 and a category 3, with actions to take, but category 3 gets a name and then you know this thing has a name and I need to pay attention and I need to act,” Baughman Mcleod said.
The city of Seville in Spain is now testing the platform with a campaign called #NameTheWave. Other cities are considering it and the Arsht-Rock Resilience Center hopes to see more cities jump onboard.