The fearsome heatwaves that seared western North America, southern Europe, and China in July would have been “virtually impossible” without climate change, a new study has found.
Analysis by the World Weather Attribution initiative (WWA) revealed that the furnace-like lethal heat spanning 18 days in parts of the United States and Mexico, 14 days in the lowlands of China, and one week in southern Europe “would have almost no chance of happening in a world without climate change,” reports the Washington Post. “The Chinese heatwave was made about 50 times more likely given global warming, the study found, while the European and North American heatwaves were at least 1,000 times more likely.”
Such lengthy and dangerous heatwaves “are not rare in today’s climate,” WWA co-leader Dr. Friederike Otto, a climate scientist at Imperial College London, told the Post. The level of greenhouse gases now in the Earth’s atmosphere is such that in any given year, North America has a one-in-15 chance of experiencing a severe heatwave. Southern Europe can expect a heatwave once every 10 years and China once every five, the study found.
“Without human-induced climate change, these heat events would however have been extremely rare,” wrote WWA. “In China, it would have been about a one in 250-year event, while maximum heat like in July 2023 would have been virtually impossible to occur in the U.S./Mexico region and Southern Europe if humans had not warmed the planet by burning fossil fuels.”
WWA’s findings have not yet been subject to peer review, “given the rapid timeline under which the study was completed,” the Post notes, “but the group used a set of peer-reviewed methods to detail the fingerprint of climate change in each place.”
Human-caused greenhouse gas emissions also made the heatwave hotter than it would otherwise have been, WWA found, “roughly 2.5°C hotter for the European heatwave, 2°C hotter in North America, and 1°C hotter in China.”
Founded in 2014, the WWA is a coalition of climate scientists from the University of Oxford’s Environmental Change Institute, the Royal Netherlands Meteorological Institute, the Laboratoire des Sciences du Climat et de l’Environnement, the University of Princeton, the U.S. National Center for Atmospheric Research, and the Red Cross Red Crescent Climate Centre.
The WWA has confirmed that dozens of extreme weather events like heatwaves, torrential downpours and floods, hurricanes, droughts, and wildfire were made more likely and/or more intense by global heating.
In light of these findings, experts are warning of the urgent need to accelerate adaptation to heat. Multiple deaths and skyrocketing hospital admissions for heat stress “underscore the need for our systems to adapt much faster, because the risks are rising much faster than we are adapting,” Julie Arrighi, director of the Red Cross Red Crescent Climate Centre, said in a press call.
Some of those immediate solutions include scaling up warning systems, providing cool refuges for the most vulnerable, strengthening grid resilience, securing water supplies, and leaders at all levels embracing “a cultural shift” in their understanding of the perils of extreme heat, Arrighi said.
In Canada, public health experts and advocates are calling for community-based wildfire smoke monitors after the death of a nine-year-old boy from 100 Mile House in British Columbia. Carter Vigh died in late July from an asthma attack, which his parents say was made worse by smoke from nearby fires.
And humanity must hit the brakes on global heating or face even more intense heat, says the Intergovernmental Panel on Climate Change (IPCC). “Relative to present day conditions, changes in the intensity of extremes would be at least double at 2°C, and quadruple at 3°C of global warming, compared to changes at 1.5°C,” the panel wrote in its latest report.
Communities must also resist the impulse to adjust to a “new normal” with a stable climate out of reach until we stop polluting the atmosphere with greenhouse gases, Otto added. “We don’t know what the new normal is until we stop burning fossil fuels,” she said. “We are not in a stable climate.”
Otto added that “this is not what extremes in the future will look like. This could even be a cold year in the summers to come.”