The author is an astronomer, science communicator and full professor of science teaching at UQAM.
Needless to say, how hot it was this summer in Quebec and elsewhere in the world: according to the European Union’s Copernicus terrestrial observatory, summer 2023 will have been the hottest since systematic temperature measurements were undertaken, around the middle of the 19th centurye century. For its part, NASA notes that July 2023 was the hottest month on record since 1880. As for the month of August, it is estimated that it was around 1.5 degrees Celsius warmer compared to the average of the period 1850-1900, i.e. at the beginning of the industrial era.
But climate skeptics have found a new target in their fight against the evidence of global warming caused by human activities: the good old thermometer!
Indeed, a well-known European influencer, Robin Menotti, and several Internet users who relay his messages circulated comments this summer on Twitter (now heatwave are several degrees too high. In their communications, these people essentially assert that it is not that hot, and that the temperatures announced are greatly exaggerated.
The basis of their claims is the fact that space agencies, such as the European Space Agency (ESA) and NASA, regularly publish satellite maps of global surface temperatures, which are known to be several degrees higher than the temperature of the air above. According to these climate skeptics (or should we now call them thermosceptics?), it is these surface temperatures that are reported in weather reports, and not the air temperature, all in order to exaggerate the forecasts. heat.
This is of course completely false. There are strict standards set by the World Meteorological Organization, a specialized agency of the United Nations, for measuring temperatures at weather stations across the globe. These must be equipped with calibrated thermometers placed inside a ventilated shelter painted white (a Stevenson shelter, named after its designer, the Scottish engineer Thomas Stevenson, who developed it in 1864). , shelter itself located between 1.25 m and 2 m above the ground.
These are these white boxes, fitted with louvers on all four sides to ensure good ventilation, which house the thermometers and prevent direct sunlight or the heat of the ground from distorting the measurements. These are the same shelters that have been used for more than a century and a half, which allows us to affirm that the temperature measurements are completely comparable over the decades. The rise in temperatures that we have been observing for some time therefore does not come from the instruments themselves, but from global warming, quite simply.
The temperature maps used in weather reports constitute another source of distrust for Menotti and his ilk: meteorologists are accused of using more garish colors to exaggerate the heat forecasts and “scare the world”, so to speak.
But in reality, if there is more orange and red on the maps, it simply reflects the fact that temperatures are higher than we are used to. On the other hand, global warming may force various weather agencies to change the grading and color palette used on their weather maps to account for the higher temperatures we are likely to experience more frequently in the future.
We are definitely living in a rather worrying period in the history of humanity, and it is normal that more and more people feel a more or less acute form of ecoanxiety, which for some translates into a pure and simple rejection of reality. However, climate warming and the associated weather disruptions are less and less a “fantasy”; they now affect large parts of our daily lives. We will therefore have to collectively profoundly change our habits and our way of life if we want to leave our children and our grandchildren with something other than a planet transformed into a parboiler.
There is still time to do it, at least to mitigate the worst effects of climate change. Unfortunately, it is not by peddling false “news” or sowing doubt about the scientific consensus, as climate skeptics do, that we will achieve these objectives. All that remains is to hope that educating citizens will help reverse the trend to ensure a climate transition that will hurt a little less…