For the tenth month in a row, the average temperatures recorded on land and at sea have been beaten. March 2024 continues this worrying series, with an average temperature 1.68°C higher than a normal month of March in the climate of the pre-industrial era (1850-1900), the service announced on Tuesday April 9. Climate Change (C3S) from the European Copernicus Observatory.
If July 2023 became the hottest month ever measured in the world, every month since June has also broken its own record. Continuing this series, the month of March 2024 constitutes a new signal after a year where anthropogenic global warming, accentuated by the El Niño phenomenon, has increased natural disasters, while humanity has not yet reduced its gas emissions. Greenhouse effect.
The last twelve rolling months have thus been the hottest ever recorded in the world, 1.58°C warmer than in the planet's climate in the 19th century, exceeding the limit of 1.5°C set by the Agreement of Paris. This anomaly should however be noted on average over “at least twenty years” to consider that the climate, and not the annual weather, has reached this threshold, recalls the observatory. But “we are extraordinarily close to this limit and we are already on borrowed time,” Samantha Burgess, deputy head of C3S, told Agence France-Presse.
New absolute record in the oceans
It has now been more than a year since the temperature of the oceans, major climate regulators which cover 70% of the Earth, has been warmer than ever. March 2024 even sets a new absolute record, all months combined, with an average of 21.07°C measured on their surface (excluding areas near the poles) by Copernicus.
“It’s incredibly unusual,” says Samantha Burgess. This overheating threatens marine life and brings more moisture into the atmosphere, leading to more unstable weather conditions, such as high winds and torrential rains. It also reduces the absorption of our greenhouse gas emissions into the seas, carbon sinks which store 90% of the excess energy caused by human activity.
“The more the global atmosphere warms, the more extreme events will be numerous, severe, and intense,” recalls the scientist, citing the threat of “heat waves, droughts, floods and forest fires.”
Among recent illustrations, serious water shortages are hitting Vietnam, Catalonia and even southern Africa: after Malawi and Zambia, 2.7 million people are threatened by famine in Zimbabwe, which declared the state of national disaster. Bogota has just rationed drinking water and the fear of shortages hangs over the electoral campaign in Mexico. Conversely, Russia, Brazil and France experienced remarkable flooding.
The influence of climate change on each event remains to be proven by scientific studies. But it is established that global warming, by accentuating evapotranspiration and increasing potential humidity in the air, increases the intensity of certain precipitation episodes.
Since June 2023, global weather has been affected by the natural climatic phenomenon El Niño, synonymous with higher temperatures. This reached its peak in December but must still result in above-normal continental temperatures until May, according to the World Meteorological Organization (WMO). According to her, there is a chance that the opposite phenomenon - La Niña - will develop "later this year" after neutral conditions (neither one nor the other) between April and June.
A risk of new records
Will other records be broken in the coming months? “If we continue to see this much heat at the surface of the ocean (…), it is very likely,” warns Ms. Burgess. Are these records beating predictions? The question is being debated by climatologists after an extraordinary year 2023, the hottest ever measured.
This additional heat, “we can explain a lot of it, but not entirely,” summarizes Ms. Burgess. “2023 is within the range of climate model predictions, but really at the outer limit”, far from the average, she adds, worried.
Air concentrations of carbon dioxide (CO2), methane and nitric oxide – the three main human-caused greenhouse gases – will increase further in 2023, according to US agency estimates. Oceanic and Atmospheric Observation (NOAA), published Friday. The CO2 concentration averages 419.3 parts per million (ppm) in 2023, an increase of 2.8 ppm since 2022.
According to the Carbon Monitor project, however, global CO2 emissions in 2023 increased by only 0.1% compared to 2022, reaching 35.8 gigatons. While these estimates suggest a plateau in human emissions, they nevertheless represent “10% to 66.7% of the remaining carbon budget to limit warming to 1.5°C,” note the authors.
