A team of international scientists has said it is “virtually certain” that climate change is increasing the likelihood of the heat wave now affecting Europe.
The data analysis, released on Friday by Climate Central, shows that the risk of a heat wave – defined as three-day periods of excessive heat – has doubled over much of Europe and nearly quadrupled in some of the hottest cities.
The team of climate scientists, who came from universities, research organisations and meteorological services, looked specifically at a few European cities and analysed weather and climate data, weather forecasts and climate models to come up with their predications.
In De Bilt in The Netherlands, for example, they found that a three-day heat wave like the one being experienced now was roughly a 1-in-30 event in the 1990s. It is now likely to happen around 1 in 3 years — four times more likely.
The figures are not better for other central or northern European cities. In Mannheim, Germany, a heat wave was a once-in-a-century event in the 1900s but is now likely to occur every 15 years. And while Zurich, Switzerland is only likely to experience a heat wave like that of the last few days once every 70 years or so, that’s still far more frequent than the 1-in-350 year event in the 1900s.
“There is a strong upward trend in 3-day maximum temperatures over the area affected by this heat wave,” said Geert Jan van Oldenborgh, a climate scientist at the Royal Netherlands Meteorological Institute.
According to Climate Central, European heat waves can be deadly among vulnerable groups such as the elderly in urban areas; around 70,000 additional people died in France and other European countries during a 2003 heat wave.
“Too often, people are still caught unawares by the rising risks,” warns Maarten van Aalst, director of the Red Cross Red Crescent Climate Centre.