Research Reveals Human-Caused Climate Change Contributing to Extreme Heat Waves
Extreme temperatures recorded in the Southwestern United States, southern Europe, and northern Mexico earlier this month would have been “virtually impossible” without the influence of human-caused climate change, according to research made public on Tuesday. The study, conducted by World Weather Attribution, an international group of scientists, focused on the worst heatwaves during the northern hemisphere summer.
During the first half of July, millions of people in North America, Europe, and Asia sweltered under intense heatwaves. The researchers found that a heatwave in China was made 50 times more likely by climate change. In the United States, Phoenix experienced temperatures of 110 degrees Fahrenheit (43 degrees Celsius) or higher for more than 20 consecutive days. Similarly, many places in southern Europe saw record-breaking, triple-digit temperatures. In China, a remote township in Xinjiang reached a scorching 126 degrees, breaking the national record.
Friederike Otto, a senior lecturer in climate science at Imperial College London and co-founder of World Weather Attribution, stated, “Without climate change, we wouldn’t see this at all. Or it would be so rare that it basically would not be happening.” However, in the current climate changed by fossil fuel emissions, heatwaves of this magnitude are no longer rare events.
According to the researchers’ statistical analysis, heatwaves of this intensity were virtually impossible before the industrial revolution. Before human activities contributed to climate change, China’s heatwave would have occurred only once every 250 years, and North American and European heatwaves were virtually non-existent.
The study also revealed the future likelihood of extreme heatwaves if greenhouse gas emissions continue at current levels. The United States and Mexico could expect heatwaves like the one experienced this July once every 15 years. In southern Europe, there would be a 1 in 10 chance each year, and in China, a 1 in 5 chance annually.
Julie Arrighi, director of the Red Cross and Red Crescent Climate Centre and one of the researchers with World Weather Attribution, underlined the rising risks from heat and the urgency to adapt cities and critical infrastructure to extreme temperatures while also reducing greenhouse gas emissions.
Despite the implementation of heat action plans in many governments, such programs remain imperfect, and the human cost of extreme temperatures remains high. The death toll from this month’s heatwaves is yet to be determined, but already, more than 100 people have died in Mexico due to heat-related causes. Last summer, approximately 61,000 people died across Europe because of heatwaves.
The study conducted by World Weather Attribution, though not peer-reviewed, utilized standardized methods published in 2020 and compared observed temperatures with modeled projections of a planet without human-caused climate change. Andrew Pershing, vice president for science at nonprofit group Climate Central, praised the methodology, stating that it is standard in the field.
The analysis by the European Union’s Copernicus Climate Change Service confirmed that the first two weeks of July were probably the hottest on record. The National Oceanic and Atmospheric Administration forecasts more unusually hot temperatures across most of the United States in August. As the planet continues to experience extreme heat, the need for urgent action to address climate change becomes even more apparent.