When London broiled at record temperatures last month, it was a rare occurance easily labeled “extreme weather.” But the heat surge that rippled airport runways and led to major health alarms in a place that typically gets by without air conditioning can’t be considered entirely random bad luck.
Human-derived climate change dramatically upped the odds of record-shattering heat, a new study concludes. In fact, the study from a growing body of scientists comprising an organization called World Weather Attribution, says these record temperatures were 10 times more likely to have happened in modern times versus the pre-industrial era, largely because humans burn fossil fuels CL00, +0.75% for heating, driving, cooking, medical care and more.
When fossil fuels are burned, they release large amounts of carbon dioxide, a greenhouse gas, into the air. Greenhouse gases trap heat in our atmosphere, causing global warming. Weather extremes have always occured, but it’s their frequency and severity that’s grown more alarming.
London’s heat wave, which peaked on July 18 and 19, set a record for the hottest temperature in the history of the U.K., at 104.54°F (40.3°C). On July 19, a total of 34 weather stations broke the previous all-time national temperature record, according to the U.K. Met Office, the official weather bureau. And the scorching readings hit as parts of western Europe sweltered under their own streak of extreme highs.
Two years ago, with meteorologists quickening the rate at which they try to warn the world of the perils of unchecked climate change, the Met Office posted an alarming, red-splashed temperature map. It was meant as a teaching tool. In fact, the Met Office is increasingly leaning on the findings from World Weather Attribution and others. The Met Office imagined, as a strict hypothetical, what July 23, 2050 might feel like for this far-northern, populous island nation and its Irish neighbors. July 2022’s record and the real map shown across television and social media was nearly identical to the 2050 hypothetical — 28 years early.
Read more: U.K. weather officials drew a scary heatwave map for 2050 — this week it came true, 28 years early
Heat extremes and precipitation extremes are far more likely and intense now, World Weather Attribution studies have shown. In some cases, extreme heat events, including those in 2021 in the typically temperate U.S. Pacific Northwest, have been found to be virtually impossible to occur without human-caused warming, the group says.
With the U.K. heat wave, and that suffered this summer for Spain and Portugal, as well as the extreme temps for Portland and Seattle last year in mind, some climate scientists have been asking whether their computer models have been underestimating the dangers of once unthinkable extreme events.
Read: How to prepare for severe heat, as New York and Washington take their turn at record temperatures
“In Europe and other parts of the world we are seeing more and more record-breaking heatwaves causing extreme temperatures that have become hotter faster than in most climate models,” said Friederike Otto, a researcher at Imperial College London who co-directs the World Weather Attribution group, in a statement.
“It’s a worrying finding that suggests that if carbon emissions are not rapidly cut, the consequences of climate change on extreme heat in Europe, which already is extremely deadly, could be even worse than we previously thought,” Otto added.
And as for the U.S., since the 1980s, there have been three daily record high temperatures for every two record lows, according to the National Weather Service.
Read: Americans want EV tax incentives. But are they ready to lose gas cars forever?
A heat wave is defined by the National Weather Service as a period of abnormally and uncomfortably hot and unusually humid weather that typically lasts two or more days. The World Health Organization defines it in human-health terms: prolonged periods of excessive heat that results in dehydration, heat stroke, heart and kidney failure and a host of heat-related illnesses that can lead to mortality.
For certain, vulnerable populations, like children, athletes, low-income households that may be without AC or great ventilation, outdoor workers, first responders and people with chronic illnesses, are most at risk to extreme heat.
Extreme or relentless summer heat can also exacerbate poor air quality by trapping harmful pollutants close to the Earth’s surface and creating ground-level ozone. These pollutants can trigger respiratory issues in people with asthma and other lung diseases.