After a summer packed full of record temperature highs, experts say more days with more extreme heat could become the new normal across Europe at rates faster than previous models forecasted.
According to a new study published in Geophysical Research Letters, summer temperature extreme highs have tripled since 1950 with an average increase of 2.3°C (4.14°F) over the last seven decades. On the other hand, winter has lost as many as half its number of extremely cold days in that same timeframe.
“Even at this regional scale over Europe, we can see that these trends are much larger than what we would expect from natural variability. That’s really a signal from climate change,” said study author Ruth Lorenz in a statement.
Observational data from 4,000 stations in Europe between 1950 and October of last year was collected by climate scientists in order to determine if climate models used for regional projections would reproduce observed trends – previous studies have only modeled the long-term effects of extreme temperature changes rather than looked collectively at past trends. To do so, they analyzed the top 1 percent of temperature and humidity extremes, as well as the top 1 percent of coldest days to see how these changed over time.
Though the trends vary by region, 90 percent of weather stations in the study indicate a warming climate – too high to be explained by natural variability. On average, extremely hot days have increased by 2.3°C (4.14°F) and cold days have warmed by 3°C (5.4°F). Central Europe warmed by almost 1°C (1.8°F) more than the average over the whole study period.
“In the Netherlands, Belgium, France, the model trends are about two times lower than the observed trends,” said Geert Jan van Oldenborgh, a climate analysist not involved in the study. “We’re reaching new records faster than you’d expect.”
A study earlier this year found that the climate is warming faster and more consistently than it has in the last 2,000 years, and with it comes potential health risks that may impact cities and their most vulnerable populations. Dangerous heat can lead to heat exhaustion or stroke, particularly in the elderly and very young, those who spend a lot of time outdoors, and those who have chronic ailments.
“Lots of people don’t have air conditioning for instance and it makes this really important,” Lorenz said. “We expected results based on modeling studies but it’s the first time we see it in what we’ve observed so far.”
The study authors are quick to note that these results “need to be interpreted with caution because not all underlying station data are complete or have been homogenized,” adding that this can result in “spurious trends” at individual stations and subregions.