2024, the hottest year, exceeds the threshold of 1.5°C, confirms the UN

The average global surface temperature has exceeded the average recorded between 1850 and 1900 by 1.55°C (with an uncertainty margin of ±0.13°C), according to the consolidated analysis of the six data sets carried out by WMO. This means we have probably just experienced the first calendar year with a global average temperature more than 1.5°C above the 1850-1900 average, the organization adds. “Today’s assessment by WMO proves once again that global warming is an undeniable fact,” said UN Secretary-General António Guterres, quoted in the press release.

“This means we must redouble our efforts to stay the course,” he said, calling for “cutting-edge climate action in 2025.” “There is still time to avoid the worst climate catastrophe. But leaders must act now,” he stressed.

WMO provides temperature assessment based on multiple data sources to support international climate monitoring and provide authoritative information to the UN climate change negotiation process. Datasets are from the European Center for Medium-Range Weather Forecasts (ECMWF), Japan Meteorological Agency, NASA, US National Oceanic and Atmospheric Administration (NOAA), UK Met Office -United in collaboration with the University of East Anglia Climate Research Unit (HadCRUT) and Berkeley Earth.

“The climate story is unfolding before our eyes. We’ve had not just one or two record years, but an entire ten-year run. This development has been accompanied by extreme and devastating weather conditions, rising sea levels and melting ice, all fueled by record levels of greenhouse gases caused by human activities,” said Celeste Saulo, Secretary General of WMO.

“It is important to emphasize that a single year above 1.5°C does NOT mean we will miss the long-term temperature goals of the Paris Agreement, which are measured over decades rather than over a period of time. individual year. However, it is essential to recognize that every fraction of a degree of warming is important. Whether below or above 1.5°C of warming, each additional increase in global warming increases the impacts on our lives, our economies and our planet,” she added. Note that the publication of the six temperature data sets was coordinated between institutions to highlight the exceptional conditions that prevailed in 2024.

A separate study published in Advances in Atmospheric Sciences found that ocean warming in 2024 played a key role in the record temperatures. According to the study led by Professor Lijing Cheng of the Institute of Atmospheric Physics of the Chinese Academy of Sciences, the ocean is the warmest ever recorded by man, not only at the surface, but also in the 2,000 upper meters.

A team of 54 scientists from seven countries and 31 institutes participated in this study. About 90% of excess heat from global warming is stored in the oceans, making ocean heat content a critical indicator of climate change. From 2023 to 2024, the increase in the heat content of the oceans at 2000 m depth is 16 zettajoules (10 joules to the power of 21), or about 140 times the total electricity production worldwide in 2023, according to the study, which is based on all the data from the Institute of Atmospheric Physics.