Heatwave - Climate Change Connections In One Simple Analogy

Forbes - Marshall Shepherd

Dr. J. Marshall Shepherd Dr. Marshall Shepherd is a leading international expert in weather and climate. He was the 2013 President of American Meteorological Society (AMS) and is Director of the University of Georgia’s (UGA) Atmospheric Sciences Program. Dr. Shepherd is the Georgia Athletic Association Distinguished Professor and hosts The Weather Channel’s Weather Geeks Podcast, which can be found at all podcast outlets.  Prior to UGA, Dr. Shepherd spent 12 years as a Research Meteorologist at NASA-Goddard Space Flight Center and was Deputy Project Scientist for the Global Precipitation Measurement (GPM) mission

A devastating heatwave is happening in Europe right now. Temperature records are falling and not just by a small margin. The death toll is starting to rise and is prompting memories of the 2003 European heatwave that killed 30,000 to 50,000 people according to most estimates. The World Meteorological Organization tweeted on Friday:

For the first time on record, #France sees a temperature above 45°C. Villevieille measured 45.1°C this afternoon at 1459, topping the previous record of 44.3°C set just an hour previously, per @meteofrance  #heatwave #climatechange

According to meteorologists at Weather.com, a large high pressure system over Europe is the "weather" factor responsible for the heatwave.  Weather is, in part, governed by the space-time patterns of a series of waves in that fluid overhead called the atmosphere. It exhibits natural and day-to-day variability. An atmospheric "road block," if you will, near Greenland responsible for record melting there is also altering the aforementioned global wave pattern and causing extreme heat in Europe. Some voices will roll out the predictable narrative that heatwaves happen naturally. They do. However, an increasing body of scientific literature and simple common sense tells us that something else is going on too.

Oppressive heat is ravaging Europe. European Space Agency

University of Georgia atmospheric sciences professor John Knox offered one of the most compelling and clear analogies to explain why an anthropogenic climate change signal is increasingly associated with events like the European heatwave. Knox wrote:

The old record for the nation was 44.1C (111.4F), from the deadly 2003 heat wave in Europe. So, France just bested its high temperature by 3 degrees Fahrenheit. That's a lot. As with, say, 100-meter dash records in seconds, national temperature records in degrees should be broken in tenths, really hundredths--not integer values.If this were the world of track and field, a new record of this extremity would prompt immediate concerns about doping. The runner is fast, but no way is he or she THAT fast.

By the way, an astute Tweet noted by @robsobs pointed out, "Note that at least 12 other “runners” beat the previous record as well, and all of this happened before the usual peak heat period."

Persistent high pressure aloft is part of the weather pattern explaining the current European heatwave. Tomer Burg's Model Page

Of course, you have the small but very loud crowd that will spew cliche and irrelevant points that actual climate scientists are aware of or have long considered. For example, I saw a person imply that it is not a big deal to have a heatwave in the summer. Professor Knox agrees but points out that summer in France can be hot, but it should not be this hot and certainly not this early. Further, actual climate scientists have assessed how contemporary extreme events are linked to climate change. Previously in Forbes, I summarized the 2016 National Academy of Science report on attribution:

Confidence is greatest for extreme events related to aspects of temperature (e.g. extreme heat and lack of extreme cold events). Attribution science is relatively young but has advanced rapidly. The National Academy panel noted that attribution is most reliable when there are sound physical principles, consistent observational evidence, and the ability for numerical models to replicate the event. These "three legs of the stool" were used as benchmarks to rate the confidence.

The graphic  below conveys that there is very high confidence that the "fingerprint of climate change" is smudged all over the current generation of heatwaves on Earth. Numerous studies affirm that heat waves are increasing (and will continue to) in frequency or intensity as climate changes. A 2018 study in Environmental Research Letters found that across 571 cities:

• heatwave days increase in future climate model scenarios, particularly in southern Europe
• the greatest heatwave temperature increases are in central Europe

Another climate zombie theory (something that keeps coming up though scientists have long disproven it) seen floating around the Internet is that all of the numbers are wrong because the thermometers are in cities or near asphalt. You will typically see some cherry-picked image of a thermometer near a road or building. I always find this one to be amusing because climate scientists are smart enough to know about urban biases. In fact, I wrote an entire article (link) about this misguided attempt to confuse people.
The current heatwave is very dangerous. The combination of record high maximum and minimum temperatures is a double whammy for humans. Warm nighttime temperatures are particularly dangerous for vulnerable populations like the elderly, children, or people without sufficient air conditioning.
As I close, it should be noted that not once did I mention a polar bear or the year 2080. These are "here and now" concerns.

Confidence in extreme weather events and linkages to climate change. National Academy of Science report

Links

• New Temperature Record Set As France Swelters Through June Heatwave
• Is Climate Change Causing Europe’s Intense Heat? A Scientist Weighs In
• Europe Heatwave Sees Temperatures Soar To Record Highs As Wildfires Take Hold In Spain
• Air pollution and irrigation mask extremes of India’s 2019 heatwave
• Heatwave in northern Europe, summer 2018
• Attributing human mortality during extreme heat waves to anthropogenic climate change
• Limiting global warming to 1.5 degrees C could prevent thousands of deaths in the U.S.
• Are we ready for the deadly heat waves of the future?
• The list of extreme weather caused by human-driven climate change grows
• Half a degree stole the climate spotlight in 2018
• Limiting global warming to 1.5 degrees versus 2 has big benefits, the IPCC says
• These weather events turned extreme thanks to human-driven climate change
• South Asia could face deadly heat and humidity by the end of this century
• For three years in a row, Earth breaks heat record
• Global warming amplified death toll during 2003 European heat wave