With the new record high temperature set in March, the last 12 months were the warmest ever recorded on earth, 1.58°C above the 19th century global average, before the effects of burning of fossil fuels, deforestation, intensification of agriculture…

Continuing the unbroken streak of ten monthly records, March 2024 rings a new bell, after the year in which man-made global warming, exacerbated by the El Niño phenomenon, multiplied natural disasters, while humanity has yet to reduce as much it is estimated that it is necessary to reduce the emissions of gases that cause the greenhouse effect.

The limit of 1.5° Celsius

July 2023 may have been the hottest month ever recorded in Earth’s history, but all months since June have broken historical records.

March continued its worrying streak, with an average temperature 1.68°C higher than any normal March in the pre-industrial era (1850-1900), the European Observatory’s Copernicus Climate Change Service (C3S) said today.

In the last twelve months, the temperature of the planet was 1.58° Celsius higher compared to the pre-industrial era, in other words it exceeded the limit of 1.5° Celsius set by the Paris agreement.

However, this anomaly would have to last an average of “at least 20 years” for it to be considered that the global climate has changed, that this threshold has been exceeded, and that it is not an annual variation, C3S notes.

But “we are extremely close to that limit and on borrowed time,” Samantha Burgess, the agency’s deputy director, told AFP.

Absolute record in the oceans

It has now been more than a year that the temperature of the oceans, major regulators of the Earth’s climate, as they cover more than 70% of its surface, broke all records. In March 2024, a new absolute record was even recorded, 21.07° Celsius on the surface of the seas (excluding only the zones near the poles), by the Copernicus observatory.

“This is incredibly unusual,” sums up Samantha Burgess. This warming not only threatens marine life, but causes more moisture in the atmosphere, in other words more unstable weather conditions – strong winds, torrential rains…

It also reduces the absorption of greenhouse gases from the oceans, carbon dioxide reservoirs that generally store 90% of the heat caused by human activity.

Droughts and floods

“The more the atmosphere warms worldwide, the more extreme events will be, the more fierce, intense”, according to the scientist, who expects “heat waves, droughts, floods, forest fires”.

Recent indications: water scarcity in Vietnam, Catalonia, sub-Saharan Africa. After Malawi and Zambia, 2.7 million people are threatened by famine in Zimbabwe, where a state of national disaster has been declared. While Bogotá has rationed drinking water, the fear that citizens will face shortages preoccupies the election campaign in Mexico.

The other side of the coin is experienced by Russia, Brazil and France, countries affected by historic floods. Whether any such phenomenon is directly due to climate change remains to be proven by scientists. However, it is established that global warming, by increasing venting and increasing humidity in the atmosphere, worsens the intensity of many such episodes.

End of El Niño, no record (yet).

Since June, the global weather conditions are additionally affected by the natural phenomenon El Niño, synonymous with higher temperatures. It peaked in December, but is yet to translate into above-normal temperatures well into May, according to the World Meteorological Organization (WMO).

According to the same source, there are chances that the reverse phenomenon, La Niña, will occur “later this year”, after neutral conditions (neither one nor the other) in the April-June period.

Should we expect more records in the coming months? “If we continue to see this much heat at the surface of the oceans (…) it is very likely,” Ms Burgess warns.

Acceleration;

Are these records beating predictions? The issue is of intense concern to climatologists after 2023, a year outside the rules, the warmest ever recorded. “We can explain” the rise in temperature “much of it”, but “not all of it”, acknowledges Ms Burgess.

“2023 was within the range of climate model predictions, but really at its limit,” far from average, he adds with concern.

Rising emissions

The atmospheric concentration of carbon dioxide (CO2), methane and nitrogen monoxide – the three main greenhouse gases released by human activity – will increase further in 2023, according to estimates by the US Oceanic Observatory and of the atmosphere (NOAA), which were released on Friday.

The CO2 concentration reached an average of 419.3 parts per million (ppm) in 2023, in other words an increase of 2.8 ppm compared to 2022.

According to the Carbon Monitor program, however, global CO2 emissions in 2023 increased by only 0.1% over 2022, reaching 35.8 gigatons.

While these estimates suggest that anthropogenic emissions may have leveled off, they still constitute “10% of the 66.7% carbon budget remaining to limit (global) warming to 1, 5° Celsius,” the authors pointed out.