Climate change made spring’s heat wave 35 times more likely — and hotter, study shows

washington – Caused by man of Climate Change turned up the thermostat and increased the chances of this month’s deadly heat that is roasting the southwestern United States, Mexico and Central America, a flash new study finds.

The scorching daytime temperatures that triggered cases of heatstroke in parts of the United States were 35 times more likely and 2.5 degrees hotter due to warming caused by the burning of coal, oil and natural gas, World Weather Attribution, a collection of scientists which rapidly analyzes and non-peer-reviewed climate attribution studies calculated Thursday.

“This is an oven; you can’t stay here,” said Magarita Salazar Pérez, 82, of Veracruz, Mexico, in her non-air-conditioned home. Last week, the Sonoran Desert reached 125 degrees, the hottest day in Mexican history, according to study co-author Shel Winkley, a meteorologist at Climate Central.

And it was even worse at night, which is what made this heatwave so deadly, said Friederike Otto, a climate scientist at Imperial College London who coordinates the attribution study team. Climate change has made nighttime temperatures 2.9 degrees warmer and unusual nighttime heat 200 times more likely, she said.

There simply isn’t the fresh air at night like people are used to, Salazar Pérez said. Doctors say cooler nighttime temperatures are essential to surviving a heat wave.

At least 125 people have died so far, according to the World Weather Attribution team.

“This is clearly related to climate change, the level of intensity that we are seeing, these risks,” said study co-author Karina Izquierdo, an urban advisor at the Red Cross and Red Crescent Climate Center based in Mexico City. .

The alarming part of this heat wave, which is technically still baking the North American continent, is that it’s no longer so out of the ordinary, Otto said. Previous studies by the group analyzed heat so extreme that they considered it impossible without climate change, but this heat wave not so much.

“From a climate perspective, in that sense, it wasn’t rare, but the impacts were really, really bad,” Otto told The Associated Press in an interview.

“The changes we have seen in the last 20 years, which seem like yesterday, are very strong,” said Otto. His study found that this heat wave is now four times more likely to happen than in the year 2000, when it was almost a degree colder than now. “It feels kind of distant and like a different world.”

Although other groups of international scientists – and the global target for reducing carbon emissions adopted by countries in the 2015 Paris climate agreement – refer to warming since pre-industrial times in the mid-1800s, Otto said comparing what is happening now with the year 2000 is more impressive.

“We are looking at a changing baseline — what was once extreme but rare is becoming increasingly common,” said Carly Kenkel, chair of marine studies at the University of Southern California, who was not part of the study. of the assignment team. She said the analysis is “the logical conclusion based on the data.”

The study looked at a large swath of the continent, including Southern California, Arizona, New Mexico, Texas, Oklahoma, Mexico, Guatemala, El Salvador, Belize and Honduras and the five hottest consecutive days and five hottest consecutive nights. For most of the area, those five days were June 3-7 and the five nights were June 5-9, but in some places the heat peak started on May 26, Otto said.

For example, San Angelo, Texas, reached a record high of 111 degrees on June 4th. Between June 2 and 6, the nighttime temperature never dropped below 80 degrees at the Corpus Christi airport, a nightly record, with two days where the thermometer never dropped below 85, according to the National Weather Service.

Between June 1 and 15, more than 1,200 daytime high temperature records were tied or broken in the United States and nearly 1,800 nighttime high temperature records were achieved, according to the National Center for Environmental Information.

The assignment team used current and past temperature measurements, contrasting what is happening with what occurred in previous heat waves. They then used the scientifically accepted technique of comparing simulations of a fictional world without human-caused climate change with current reality to find out how much global warming factored into the 2024 heat wave.

The immediate meteorological cause was a high pressure system parked over central Mexico that blocked thunderstorms and cooling clouds, then moved into the southwestern U.S. and is now bringing heat to the eastern U.S., Winkley said. Tropical Storm Alberto formed on Wednesday and headed toward northern Mexico and southern Texas with some rain, which could cause flooding.

Mexico and other places have faced months of drought, water shortages and brutal heat. Monkeys are falling from the trees in Mexico because of the heat.

This heat wave “exacerbates existing inequalities” between rich and poor in the Americas, Izquierdo said, and Kenkel agreed. It’s in the nighttime heat that inequalities really become apparent, because the cooling ability with central air conditioning depends on how comfortable they are financially, Kenkel said.

And that means that during this heat wave, Salazar Pérez has been quite uncomfortable.