According to scientists, the heatwave that burned Britain this week was made at least ten times more likely by climate change.
On July 19, temperatures at Heathrow Airport surpassed 40 degrees Celsius (104 degrees Fahrenheit), and records were broken at 46 local monitoring stations across the country. Ambulance dispatches increased, and grass fires erupted throughout London. more info
Such an event would have been exceedingly implausible without human-caused climate change, which has warmed the Earth by 1.2 degrees Celsius over pre-industrial levels, according to scientists.
“We are living in a world where temperatures are rising very fast,” said Friederike Otto, an Imperial College London climate expert. “In 1.3C or 1.4C, this type of event will already be much less rare.”
According to the World Weather Attribution (WWA), an international research cooperation that investigates the effect of climate change in extreme events, climate change is increasing the frequency and severity of heatwaves.
To establish how climate change affects the likelihood of this specific heatwave in Britain, 21 WWA climate experts, including Otto, conducted a fast analysis of the event, comparing today’s climate with the past using weather data and computer simulations.
They discovered that before the industrial revolution and the rise of greenhouse-gas emissions, the heatwave would have been significantly less likely and 4 degrees Celsius milder.
The scientists, however, added that their estimations were conservative because extreme temperatures in Western Europe have risen faster than their climate models predicted.
“The climate models have a systematic bias in that they underestimate the trend in extreme temperatures in summers in western Europe because of climate change,” Otto explained.
In May, the WWA determined that climate change had rendered the South Asia heatwave of March and April this year 30 times more likely, while last year’s heatwave in the Pacific Northwest would have been “virtually impossible” without it. more info
Scientists were unable to make such a firm prediction for Britain’s heatwave.
Nonetheless, climate experts have raised concern about how rapidly previous warnings have come to fruition.
“Two years ago, scientists at the UK Met Office found the chance of seeing 40 degrees in the UK was now 1 in 100 in any given year, up from 1 in 1000 in the natural climate,” said Fraser Lott, a climate scientist at the UK Met Office Hadley Centre, in a statement. “It’s been sobering to see such an event happen so soon after that study.”