A heat wave in the UK this past July caused so many fires in London that the city’s fire department was busier than at any time since the Nazi attacks in World War II.

According to a preliminary analysis, more than 840 people could have died in England and Wales. Now a quick scientific analysis of the event concludes that without climate change, these conditions would have been “highly unlikely”.

The World Weather Attribution research team that conducted the study studied the weather in the southern half of the country on July 18-19, analyzing both maximum temperatures and two-day averages. An analysis released Thursday found that greenhouse gas pollution made a heat wave at least 10 times more likely and 4 degrees Celsius hotter than it would have been.

Coningsby in Lincolnshire, east England, set a new UK heat record of 40.3°C on 19 July, beating the previous record set in 2019 by 1.6°C. Forty-six UK weather stations recorded a new high.

The heatwave also set a new record for what scientists are calling bewildering high lows, or essentially scorching nighttime temperatures. The new UK night heat record stands at 25.8°C, almost 2°C higher than the maximum set in 1990.

World Weather Attribution scientists used two methods: a statistical approach that examines temperature data, and an analysis that combines historical data with multiple climate models. The team’s methodology is being reviewed. Having a proven approach allows team members to make quick analyzes that are not in themselves subject to immediate peer review.

Heat waves are the simplest type of extreme weather that scientists can study because they can study temperature records without the added complexity of atmospheric and water system dynamics that cause cyclones, droughts and wildfires. The effect of greenhouse gas pollution on temperature in general is so strong that the WWA says they no longer need to study every heat wave to know an effect exists.

“As a result of climate change, previously very rare heat is now just rare,” they write. “While in some cases, events now considered ‘extreme’ temperatures reach the past, which was almost impossible in the past.”

The WWA has become the authority on the connection between global warming and extreme weather events such as droughts and storms. Most of his work deals with intense heat.

A heatwave in June 2021 over the western border of the US and Canada would have been “virtually impossible” without climate change. A heatwave this spring in India and Pakistan was 30 times more likely due to greenhouse gas pollution. A heat wave in Siberia in the first half of 2020 was 600 times more likely.

Source: Bloomberg.