Heat records in Europe are dropping like flies

Paris. Germany. The Netherlands. Belgium. 

The second potent heat wave to hit Europe in the span of a month is currently toppling all-time temperature records in a region that keeps many of the oldest weather records in the world. A number of national records broke on Wednesday, but Thursday, July 25, is shaping up to be even hotter.

Every heat wave has both weather and climate influences. The foundational idea is that weather patterns carry in masses of hot summer air, but the added heat produced by human-caused climate change amplifies modern heat waves. That’s why a cluster of heat records are now falling. 

“The global rise in background temperatures due to climate change means the risk that an extreme heat wave will occur has increased,” said Len Shaffrey, a climate scientist at the University of Reading in the UK. “For example, the probability of a heatwave such as that experienced in Europe in June 2019 was estimated to have become at least five time more likely due to climate change.”

“It’s just warmer than it would have been 50 years ago — this is quite logical,” added Mika Rantanen, a meteorologist and Ph.D student at the Institute for Atmospheric and Earth System Research in Finland.

Let’s take a look:

• Paris hit 108.6 degrees Fahrenheit (42.6 C) on Thursday, trouncing the previous record (40.4 C) set over 70 years ago. In Paris, records go back to 1658, when Louis the Great reigned over the nation.

• After the Netherlands broke its national temperature record on Wednesday, the nation swiftly and easily broke it again on Thursday, with temperatures reaching 107 F (41.7 C).

• The UK toppled its all-time July temperature record on Thursday, hitting 100.5 F (38.1 C). Though, the UK Met Office noted that the nation’s all-time record of 38.5 C may still be broken Thursday. 

• After Germany broke its highest temperature in recorded history on Wednesday, the nation set a new record of 106.7 F (41.5 C) on Thursday.

• Belgium’s national heat record fell on Wednesday, as temperatures reached 103.8 F (39.9 C).

The weather system that brought heat to Europe is broadly known as a “blocking pattern,” wherein a large zone of either high or low pressure is locked or “blocked” in by other weather systems. Heat waves typically arise when a high pressure system — which invites clear skies and sunshine — settles over a region, like Europe. It’s happening now, explained Shaffrey.

“Blocking weather patterns are quite persistent and typically last for a few days to a week,” he noted. “Exceptionally persistent blocking patterns have been known to last for up to a month.”

What’s more, there’s evidence that heat wave-producing blocking patterns are becoming more common in Europe, though there’s still much research to be done. Powerful, high atmospheric wind patterns, including the jet stream, have grown weaker and “wavier” during the summer, which means more stagnant atmospheric weather. This allows heat waves to persist over a region, like Europe, and lock in days of scorching weather. 

Amplified warming in the Arctic — one of the most conspicuous consequences of climate change — may cause these persistent weather patterns, explained Rantanen. As the Arctic warms, there is less of a temperature difference between the high-latitudes and mid-latitudes, which could result in weaker, wavier atmospheric patterns. “If the temperature difference is decreasing, then the jet stream may become weaker and more wavy,” said Rantanen.

The temperature difference is indeed decreasing. The Arctic is the fastest warming region on Earth, and has heated up twice as much as the rest of the planet. 

Though nearly the entire planet — not just certain regions — is now experiencing warming climes and the often extreme consequences of this heating. “The latest numbers are just another reminder that the impacts of human-caused warming are no longer subtle,” climate scientist Michael Mann, the director of the Earth System Science Center at Penn State University, recently told Mashable after June 2019 turned out to be the warmest June on record. 

After roasting the UK and Netherlands, the heat wave is expected to settle over Scandanavia, potentially bringing temperatures up to around 95 F (35 C) in Finland, where Rantanen lives. 

Most Finland housing doesn’t have air conditioning, he noted. That’s because heat waves were once unusual in the cooler, high-latitude nation. For the residents of Finland, purchasing or installing AC systems was once deemed unnecessary. 

“They didn’t have a need for them,” Rantanen said.

UPDATE: July 25, 2019, 1:52 p.m. EDT: This story has been updated to include the latest temperature records in Paris. Paris set a heat record earlier in the day, and then proceeded to break its record again.