TAMPA, Fla. (WFLA) — Western Europe just experienced a disastrous heatwave with nearly 2,000 people dead, and that number is rising.
London had it hottest temperature on record, by far, at 104.4 degrees Fahrenheit. This is a feat that has no prior precedent, considering London is further north than Seattle and Montreal.
As a result, the London Fire Brigade had its busiest day since World War II.
So what is behind this historic heat? The answer is extreme weather spiked by climate change. Simply put, the seemingly impossible, is now being made probable by a rapidly warming climate.
Here’s a look at the weather pattern that caused the extreme heat wave. A very amplified jet stream pumping heat north from southern Europe and Africa.
This propelled temperatures into uncharted territory, 30 degrees above the normal summer temperatures and more than 4 degrees above the London all-time record. It was so far into the right “tail” of the temperature distribution that statistics dictates it was virtually impossible in a pre-global warming climate.
But we live in a new, warmer world. Global temperatures have risen 2 degrees Fahrenheit, and even more over land in Europe. And that has shifted what is considered a normal temperature curve in the 1900s, into extreme territory, allowing these history-breaking records to be more easily reached.
Coincidentally, a peer-reviewed paper came out a few weeks ago raising the alarm about European heatwaves. The authors found that Europe is a heatwave hotspot, that heatwaves are warming three to four times faster here than on average in the mid-latitudes, and that double jet streams are playing a role.
Double jet streams, or split flow as meteorologists like to call it, happen naturally. But the authors have found that they are increasing and can explain a large portion of the faster acceleration in heat intensity over Europe.
So it seems that climate change is not just making heatwaves more intense through background warming, climate change may also be manipulating the steering flow, causing heat domes to become more prominent in parts of the world.
This is not the first paper to find that a warmer world may be weirding the jet stream, but the extent to which is hotly debated among climate scientists.
Below are two figures from the paper. The top shows the heatwave hotspot over Europe, which since 1979 has seen its heatwave intensity rise by almost 4 degrees per decade. The bottom shows another hotspot over the Southwest US and Texas. The white boxes with text on top of the images were added by WFLA Climate Specialist Jeff Berardelli.
These figures illustrate that the climate is not warming uniformly and some areas are more likely to suffer heat extremes. Research has in fact found that concurrent heatwaves – heatwaves occurring simultaneously around the globe at the same time – have increased in frequency by six times.
The bottom line is that human-caused climate change is causing previously unprecedented extremes to become much more likely. And as humanity continues to emit greenhouse gases, in just decades extremes like this will become routine; instead of happening once every 1000 years, they will likely occur once every decade or more.