2023-2024: Global temperatures above 1.5°C

The last two years have exceeded on average the limit of 1.5°C of warming set by the Paris agreement, a sign of a continuous rise in temperatures unprecedented in modern history, the European Copernicus observatory announced on Friday. .

As expected for months, and now confirmed by all temperatures up to December 31, 2024 was indeed the hottest year ever recorded since statistics began in 1850, the Climate Change Service confirmed ( C3S) of Copernicus.

2025 is not expected to be a record year, but the British Meteorological Office has warned that the year should be one of the three hottest recorded on the planet.

In 2025, the year marked by the return to power of Donald Trump in the United States, countries must also announce their new climate roadmaps, updated every five years as part of the Paris agreement. But the reduction of greenhouse gases is stalling in some rich countries: only -0.2% in the United States last year, according to an independent report.

According to Copernicus, the year 2024 alone, but also the average of the two years 2023-2024 exceeded 1.5°C of warming compared to the pre-industrial era, before the massive use of coal, oil and fossil gas does not profoundly modify the climate.

This excess “should alarm us all”, reacted Friday the British minister responsible for carbon neutrality, Ed Miliband, referring to an “existential threat”.

This does not mean, however, that the most ambitious limit of the Paris agreement, observed over at least 20 years, has been crossed, Copernicus recalls. But “it underscores the fact that global temperatures are rising beyond what modern humans have experienced.” Indeed, the current warming of the climate has not been seen for at least 120,000 years, according to scientists.

This is a “serious warning”, judges Johan Rockström, director of the Potsdam Institute for Climate Impact Research (PIK). “We have had a taste of a 1.5°C world, with unprecedented suffering and economic costs for people and the global economy, due to human-enhanced extreme events like droughts, floods, fires and storms,” he told AFP.

Behind these figures is already a series of disasters exacerbated by climate change: 1,300 deaths in June during extreme heat during the pilgrimage to Mecca, historic floods in West and Central Africa, violent hurricanes in the United States and the Caribbean. …

And today the Los Angeles fires, “the most devastating” in California history, in the words of President Joe Biden.

Economically, natural disasters caused $320 billion in losses worldwide last year, according to reinsurer Munich Re.

Containing warming to 1.5°C rather than 2°C (the upper limit of the Paris agreement) would significantly limit its most catastrophic consequences, according to the IPCC, the climate experts mandated by the UN .

“Every year of the last decade has been one of the ten hottest on record,” warns Samantha Burgess, deputy director of C3S at Copernicus.

The oceans, which absorb 90% of the excess heat caused by humanity, also continued to overheat. The annual average of their surface temperatures (excluding polar zones) reached the unprecedented level of 20.87°C, beating the 2023 record.

In addition to the immediate impacts of marine heatwaves on corals or fish, this lasting overheating of the oceans, the main regulator of the earth’s climate, affects marine and atmospheric currents. Warmer seas release more water vapor into the atmosphere, providing additional energy for typhoons, hurricanes or storms.

Copernicus reports that the level of water vapor in the atmosphere has reached a record level in 2024, standing around 5% above the 1991-2020 average.

However, the past year saw the end of the natural El Niño phenomenon, which induces global warming and an increase in certain extreme events, and a transition towards neutral conditions or the opposite phenomenon, La Niña. The World Meteorological Organization already warned in December that the latter would be “short and of low intensity” and insufficient to offset the effects of warming.

“The future is in our hands: rapid and decisive action can always deviate the trajectory of our climate,” underlines the director of the Copernicus climate change department, Carlo Buontempo.

COP29 in Baku, the last major UN climate conference, struggled to come up with a new objective for climate finance in November, but remained almost silent on ambitions to reduce greenhouse gases, and in particular the exit from fossil fuels.