Published on
updated on
Reading 2 min.
The temptation to interpret these mercury rises as a blatant manifestation of global warming is great. While in fact, the reasoning holds water, be careful not to confuse the concepts of climate and meteorology.
More than thirty degrees across the whole of France and a thermometer above 35 degrees Celsius in the capital. In addition to being the hottest day on the planet, this Monday, August 12, marks the peak of the heatwave that has been hitting France since this weekend. An illustration of global warming? Without a doubt. Except that the term “global warming” is not necessarily the most appropriate. It is in fact more precise to speak of climate change. The Atlantic coast, for example, is experiencing drastic drops in temperature, particularly in Biarritz where the mercury went from 40°C on Sunday to 22°C on Monday, while the majority of the country is facing a rise in temperatures.
This tendency to confuse global warming and climate change remains frequent and is explained by another widespread confusion: that between “weather” and “climate”. While it is true that the former allows us to take the temperature and observe atmospheric changes at a given moment, the latter strictly refers to meteorological trends, observed over several decades, and more precisely over a period of at least thirty years.
In other words, it is wrong to get an idea of the progress of climate change simply by going outside to check the weather. Even during a heatwave, it is a shortcut to say that the earth is warming only because the thermometer climbs dramatically for three days. On the other hand, it is correct to argue that climate change leads to the amplification and increased frequency of heatwaves and heat waves. This cause-and-effect link corresponds to what researchers call “attribution science,” which has been booming since the 2000s.
A question of scale and temporality
Since that time, studies have determined the extent to which temperature increases or the occurrence of extreme climate events (heat waves, floods, earthquakes, forest fires, etc.) are likely to increase due to climate disruption caused by human activity. In January 2024, for example, American researchers from MIT developed a tool to predict the frequency of super-hurricanes. According to their predictions, floods similar to those that occurred during Hurricane Sandy could occur approximately every thirty years by the end of the century.
In short, the major difference between weather and climate is explained by the notions of scale and temporality. Weather is based on daily and ephemeral atmospheric conditions, while climate refers to perennial weather trends over a long period of time. A commonly used metaphor to simply explain this nuance is that of the wardrobe: if the weather lets us know what to wear that day, the climate gives us indications on the type of clothes to invest in when we live in a specific region or if we leave for several weeks to explore another country!
As summarized by energy and climate consultant engineer Jean-Marc Jancovici on his website : “Another big difference between climate and weather is that climate is not determined solely by what happens in the atmosphere (…). In fact, the functioning of the climate machine is conditioned by a huge number of elements.“. Mentioning the elements, the founder of the ecological think tank “The Shift Project” refers to many geological structures and ecosystems that shape the climate such as volcanoes, oceans, polar ice, vegetation, etc.