After a very mild first month of the year, a second almost spring-like: February 2024 is the hottest February ever recorded on the planet, according to data from the European climate observatory Copernicus obtained by The duty. This is the ninth month in a row where a record has been broken, a sign of an exceptional period, but far from being the last of its kind.
The Earth recorded an average temperature of 13.54°C in February 2024, 0.81°C above the average temperature recorded from 1991 to 2020. This is 0.12°C warmer than the last record for this month, set in 2016. It is also 1.77°C warmer than in the pre-industrial era, which exceeds the threshold of 1.5°C established in the Paris Agreement.
The last 12 months — March 2023 to February 2024 — recorded an average anomaly of 1.56°C, a new record. An average monthly anomaly exceeding the 1.5°C threshold has been observed every month since July 2023.
As a reminder, in 2023, the hottest year on record, the global temperature averaged 1.48°C above those of the pre-industrial era.
And it’s not just the air temperature that continues to increase: that of the ocean surface is also breaking records. The global ocean surface temperature stood at 21.06°C in February, the highest average on record. The previous record, dating from last August, was 20.98°C.
The oceans also broke the daily temperature record. On February 28, the mercury rose to 21.09°C, beating the previous record, set… on the previous February 5 (21.07°C). If we exclude the records broken in February 2024, the previous highest daily temperature (21.02°C) was reached on August 24, 2023.
The oceans, a climate indicator
Philippe Lucas-Picher, professor in the Department of Earth and Atmospheric Sciences at the University of Quebec in Montreal, underlines at Duty the importance of this indicator. “We know that with greenhouse gases, there is additional energy available in the Earth machine, if we want. » In other words, GHGs store energy which is translated into heat. The data, however, shows that the atmosphere only receives a tiny portion of this energy — “about 1-2%,” according to Mr. Lucas-Picher. The overwhelming majority of this thermal energy, more than 80%, is absorbed by the oceans.
Water temperatures have a huge impact on the rest of the global climate: such increases can increase the incidence of extreme climatic phenomena such as floods, heatwaves, forest fires and droughts.
It also explains the abnormally mild winter experienced in the Northern Hemisphere. In Europe, average February temperatures were 3.3°C higher than those observed from 1991 to 2020. In Quebec, the mild temperatures were also accompanied by very little snow. “In Montreal, we see it, it’s exceptional. On the other hand, I have the impression that it will be a classic winter in the years ahead of us, if the trend continues,” adds the researcher.
In addition to global warming caused by human activity, much of the rise in temperatures in recent months is due to the cyclical El Niño phenomenon, which significantly increases the temperature of the waters of the Pacific Ocean.
But the extent of this warming can also be explained by smaller factors, notes Mr. Lucas-Picher. “Some hypotheses show that the explosion of the Hunga Tonga volcano brought a lot of humidity into the air, and water is an important greenhouse gas. » This hypothesis, raised in particular by a group of researchers in an article published in the journal Nature Climate Change, points out that the volcano’s eruption in January 2022 could have accelerated global warming to an extent of around 0.035°C. This study, however, contains significant uncertainty, underlines the professor.
Another hypothesis: maritime transport. New international laws on the emission of sulfate aerosols from ocean liners came into force in 2020, and may therefore have influenced the increase in temperature in the maritime environment. Because although these aerosols are polluting, they also have a cooling effect in the atmosphere. “If boats traveling all over the globe emit fewer aerosols into the atmosphere, this factor is no longer there,” explains the researcher.
Calm by the end of the year?
Even if we see less pronounced atmospheric temperature anomalies at the beginning of March (and a slight downward trend for the oceans), it is difficult to predict what the future has in store for us, argues Philippe Lucas-Picher.
The Copernicus service still forecasts high anomalies for the next three months. These forecasts are based on a multitude of models, notably those of the French, German, Japanese and American meteorological agencies. Beyond this time, however, the forecasts lose precision.
Experts believe that the cyclical El Niño phenomenon is coming to an end. ” The models [climatographiques] tend to show that the water temperature will decrease to the point where we will pass into a La Niña state by the end of the year,” says Mr. Lucas-Picher.
The opposite of El Niño, La Niña is characterized by below-normal ocean temperatures. But given the record-breaking temperatures of the past 12 months, it’s unclear whether this predicted decline will result in a return to pre-2023 trends or whether it will just be a period of calm before even greater warming. “Predicting something on such time scales is very difficult,” concludes the professor.