Climate change made Europe's heatwave at least five times more likely

Change in ° F = 9/5 * change in ° C = 1.8 * change in ° C

So when you see a reference to a change in ° C, the change in ° F is almost twice as big.

https://www.newscientist.com/article/2208331-climate-change-made-europes-heatwave-at-least-five-times-more-likely/

July 2, 2019
By Adam Vaughan

Climate change made last week’s deadly heatwave in Europe at least five times more likely, according to a rapid analysis.

The team of European researchers who conducted the work also found humanity’s warming of the planet made the heatwave about 4°C [7.2°F] hotter than it would otherwise have been. The findings came as new data showed that the average European temperature last month was the hottest ever for June.

The intense heatwave affected large areas of Europe, setting temperature records in Germany, Austria, Spain, the Czech Republic, Switzerland and the Netherlands. France saw the hottest temperatures, including an all-time high of 45.9°C [114.6F] near the city of Nîmes, a level more typical of Death Valley, California. Manure self-ignited in Spain, causing a wildfire.

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While the researchers were very confident in the heatwave being made at least five times more likely, they said the real world temperature data shows the probability could have been increased by as much as 100 times.

Geert Jan van Oldenborgh of the Royal Netherlands Meteorological Institute says although five times is the minimum, the true figure “could be much higher.” Up to 100 times is a possibility but should not be taken too seriously, the team says, because of the difficult of modelling clouds, the interaction between atmosphere and soil, and reproducing such extreme, record-breaking temperatures in models.

Compared to a heatwave in June in 1901, last week’s one was about 4°C hotter. “This is a strong reminder again, that climate change is happening here and now,” said Friederike Otto of the University of Oxford.