Parts of Southern Europe experienced an aggressive heat wave last summer, which killed dozens of people across the Mediterranean from Italy to Turkey, and which claimed Europe’s highest-ever recorded temperature of 120 degrees Fahrenheit, in Syracuse, Sicily. For its fiery intensity, the extreme heat event was nicknamed “Lucifer.”
That was just a one-off labeling, rather than part of a structured naming system that scientists have applied to natural disasters like hurricanes. But as extreme heat continues to become a threat (experts say a Lucifer could happen every three years), Seville, Spain, is the first city in the world to name its heat waves, giving them a recognizable identity for people. It’s also categorizing them, but unlike with hurricanes, it’s doing so based on health outcomes rather than on meteorological grounds. This week, Seville’s mayor, Antonio Muñoz, announced the summer pilot, dubbed proMETEO, which if successful, could form a template for other world cities.
Extreme heat is a “silent killer,” says Kathy Baughman McLeod, senior vice president and director of the Adrienne Arsht-Rockefeller Foundation Resilience Center. The foundation has been working to combat extreme heat, which takes the lives of five million people a year globally, including appointing “chief heat officers” around the world, including in Miami, Athens, Greece, and Santiago, Chile. But they needed more awareness around heat. “We believe we need to do something quickly, and something dramatic, to bring the attention to the issue,” Baughman McLeod says.
By categorizing the heat waves, people know what intensity of heat to expect and what they can do to stay safe. Bioclimatologist Larry Kalkstein spent 18 months researching how best to categorize them, based on climatology, meteorology, and health data. He developed a system of three categories that would tell people how to act in each instance, similar to those for hurricanes. Kalkstein, who lives in coastal Florida, says it’s due to the category distinctions that he knows whether to evacuate versus simply to move some furniture indoors.
Hurricane categories are based on pure meteorology —essentially the speed of wind—and that wind speed’s potential to damage property. In the heat case, Kalkstein has developed a method to instead tie the categories to health outcomes. That’s important because the same magnitude of heat wave could have different impacts on people’s health, based on the time of year it happens, or where exactly in a given area it occurs. For that reason, meteorologically identical storms could theoretically be placed into different categories.
Importantly, heat-wave warnings will trigger different resilience responses. Cities like Seville, the hottest city in continental Europe, already have well-established heat interventions, but the idea is to now have those actions vary according to the category. That might be the opening of city swimming pools, water parks, and cooling stations for cooling off; disseminating specific advice based on the category, such as to drink a certain number of glasses of water a day, or to cancel playdates and keep children indoors; plus, mobilizing city health workers to intervene—for example, checking in on the most vulnerable populations, such as the elderly, whose deaths from extreme heat reached 104,000 across the E.U. in 2018.
But categories weren’t enough; they also needed a “PR factor,” Baughman McLeod says, in the form of naming the heat waves. While the categories tell people what to do, the naming is the “big retail branding exercise to convey the severity, and to get you to pay attention,” she says. Names have helped people vividly remember the most notorious storms. “We help people remember how severe they can be by saying Katrina, Maria, Sandy,” she says. Kalkstein lived in Louisiana in 1969 during Hurricane Camille, the second-most-intense hurricane in U.S. history, which destroyed much of the Gulf Coast. “If you said, ‘Oh, that hurricane of 1969,’ I think that’s much less specific than saying, ‘Oh, Hurricane Camille,'” he says.
In Seville’s case, the pilot will start by only naming the heat waves in the most extreme category. Contrary to the hurricanes system, they’ll start at Z and continuing down the alphabet, alternating female and male names, starting with Zoe, Yago, Xenia, Wenceslao, and Vega. The team used a behavioral science company to conduct a focus group to decide on memorable names that were Spanish, but relatively uncommon.
In the fall, Kalkstein’s team will assess the pilot, ensuring that the times they called heat warnings were at times with actual negative health outcomes. “We need a whole summer’s worth of data to make sure,” he says. Already, other cities are in touch with Kalkstein and working on their systems, including Melbourne, Australia, Miami, and Los Angeles. On the same day that proMETEO launched, Athens also rolled out its categorizing system, using Kalkstein’s methodology, though it’s not yet naming the heat waves.
Baughman McLeod intends on publishing a graphic of heat waves to come each summer that are named and categorized, just as the National Weather Service does for hurricanes. This is all in service to educating the public to stay safe. “This is one of the brighter spots of climate work,” she says, “that people do not have to die from heat. This is avoidable.”