The Tour De France is an iconic bicycle race held annually. Cyclists make their way through mostly France and some grueling terrain. At the time of writing, the race was heading into the final stages. The headline of an article at Bicycling.com says it all, "Tour de France Stage 18: The First, and Hardest, Day in the Alps." If the geologic and topographic challenges of the Earth are not challenging enough, the cyclists are facing record-breaking heat. These circumstances provide an opportunity for a teachable moment about the climate change.
I can hear it now. A contrarian perspective or Tweet arguing that "it is just summer and its supposed to be hot." In another corner of social media, there is a someone saying "climate changes naturally and extreme heat is a part of the cycle." While a true statement, it doesn't refute the anthropogenic climate change is happening. The World Meteorological Organization (WMO) tweeted on July 25, "New national temperature record of 40.5 degrees C (104.9 degrees F) set yesterday in #Germany in Geilenkirchen but it may be broken today." The day prior to that tweet the same organization posted:
#France set new temperature records on Tuesday as temperatures topped 40°C. Many more heat records are expected in the next 2 days in countries including France, Germany, Belgium, NL, and possibly UK, during Europe's 2nd intense #heatwave of the year.
#ClimateChange
While writing this article, the WMO literally added the following alert, "Paris just set a new heat record of 40.6 degrees C or 105 degrees F (at 1336) and the temperature is still rising, says @meteofrance, which has issued a maximum-level #RedAlert for the #heatwave."
Inevitably with extreme weather events, the question arises about the connection to climate change, and it should. There is a new branch of climate science called attribution. NOAA's outstanding climate.gov website uses a movie analogy to describe the process of attribution:
Attribution is the process of giving credit for something, like crediting all the people who were involved in making a movie. Like a movie, any extreme event has lots of contributors; extreme event attribution is the science of deciding whether manmade global warming was one of them. Extreme event attribution tells us how much of the credit or risk for an event (or type of events) should go to global warming and how much should go to natural weather patterns or random climate variability.
As one of the co-authors of the National Academy of Science report on attribution, there are a couple of points that I want to "signal boost." Analogies and other types of examples are useful in science communication to broader audiences so I will use the Tour De France. The first lesson is about doping or the use of performance or body-enhancing drugs, which has been an issue with the Tour De France. The cyclists can obviously naturally ride the course, but the drugs give them a boost or change their natural performance. There is a strong consensus that climate change is giving naturally-occurring heat waves a "boost" too. The National Academy report and most of the scientific literature agree that there is climate change "DNA" in most heatwaves today. The figure above from NOAA illustrates that heatwave frequency and length are increasing in the United States. Even a headline I found today in The Economist, an outlet that is not considered a bastion of climate alarmism, reads, "Greenhouse-gas emissions are increasing the frequency of heatwaves."
Another lesson relates to how a cyclist is affected by the race. While each cyclist in the Tour De France race is equally exposed to the grueling stress of the race, mountains, and heat, there will be some cyclists more likely to succumb to the conditions. Others will be more resilient and press on. This analogy is applicable to heat. A German-born colleague posted in social media that the her elderly parents would likely struggle with the extreme temperatures and no air-conditioning. Petra Klein, a professor at the University of Oklahoma, also told me:
AC units are not common in residential buildings in Central Europe, if they do become more widespread it will only drive up CO2 emissions so no easy solution. Even doctors' offices and hospitals are not equipped for dealing with heat which is why we surely see an increase in death rates like after the 2003 heat wave.
The map below shows surface temperatures (in Celsius degrees). The map shows temperatures derived from long wave radiation (heat) emitted to a sensor aboard a satellite. For reference, a paved road or black rooftop is typically much warmer than air temperatures, which is why your automobile or bank sign temperature readings are often inaccurate. Likewise, colder regions over Poland are probably cloud tops. This graphic illustrates just how hot the surfaces are in Europe right now (if not obscured by clouds). When Copernicus Emergency Management Services tweeted this graphic they said:
Day 2 Land Surface Temperature over the affected areas in Europe, as measured yesterday 24 July by the #Copernicus #Sentinel3 (satellite).Let’s take particular care of the sick & elderly, remain hydrated & beware of the extreme danger
