2025: The hottest year on record confirms the WMO
The World Meteorological Organization (WMO) has confirmed that 2024 is officially the warmest year on record, according to six international datasets. This milestone reinforces a troubling trend: the past ten years are all within the Top Ten warmest years ever recorded.
The global average surface temperature in 2024 was 1.55°C above the 1850-1900 average, with a margin of uncertainty of ± 0.13°C. This makes 2024 likely the first calendar year to surpass the critical threshold of 1.5°C above pre-industrial levels. The WMO’s consolidated analysis includes data from leading organisations such as NASA, NOAA, the UK’s Met Office, the Japan Meteorological Agency, and Berkeley Earth.
A Decade of Extreme Warming
“Climate history is playing out before our eyes,” said WMO Secretary-General Celeste Saulo. “This ten-year series of record-breaking temperatures has been accompanied by extreme weather, rising sea levels, and melting ice, all driven by unprecedented greenhouse gas emissions from human activities.”
While a single year exceeding 1.5°C does not indicate failure to meet the Paris Agreement’s long-term goals—which are measured over decades—every fraction of a degree matters.
“Each increment of global warming heightens impacts on our lives, economies, and ecosystems,” Saulo emphasised.
UN Secretary-General António Guterres said of the development:
“Today’s assessment from the World Meteorological Organization (WMO) proves yet again – global heating is a cold, hard fact.
“Individual years pushing past the 1.5 degree limit do not mean the long-term goal is shot. It means we need to fight even harder to get on track. Blazing temperatures in 2024 require trail-blazing climate action in 2025.
“There’s still time to avoid the worst of climate catastrophe. But leaders must act – now.”
Ocean Warming: A Critical Indicator
A separate study published in Advances in Atmospheric Sciences highlighted the key role of ocean warming in 2024’s record-breaking temperatures. The world’s oceans are now the warmest in recorded history, both at the surface and down to 2,000 metres. According to the study, led by Prof. Lijing Cheng of the Chinese Academy of Sciences, the global upper ocean heat content rose by 16 zettajoules in a single year—equivalent to about 140 times the total electricity generation worldwide in 2023.
The oceans absorb approximately 90% of the excess heat from global warming, making them a vital indicator of climate change. These findings underline the importance of monitoring ocean heat as a metric for understanding long-term trends.
Insights for Policymakers
The WMO’s findings are critical for informing the UN Climate Change negotiations and guiding international climate policy. While natural phenomena like El Niño contribute to short-term temperature spikes, the broader trend of warming remains firmly tied to human-induced emissions.
An international team of experts convened by the WMO estimates long-term global warming in 2024 at about 1.3°C above the 1850-1900 baseline. To track progress against the Paris Agreement’s goal of limiting warming to 1.5°C, sustained and coordinated climate action is imperative.
Looking Ahead: The State of the Global Climate Report
The WMO will publish a comprehensive State of the Global Climate 2024 report in March 2025. This report will delve into key climate indicators such as greenhouse gas concentrations, glacier retreat, sea level rise, and high-impact weather events.
Call to Action
UN Secretary-General António Guterres has called on governments to intensify their efforts by delivering ambitious national climate action plans. Limiting the long-term global temperature rise to 1.5°C remains achievable, but only with immediate, sustained global commitment.
As we move into an increasingly warmer world, it is essential to focus on both mitigating greenhouse gas emissions and adapting to the realities of a changing climate. The data from 2024 underscores the urgency of global cooperation and the need to prioritise climate resilience for the benefit of current and future generations.
More info
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Explore Copernicus data here https://climate.copernicus.eu/
Visit the UKs Met Office here https://www.metoffice.gov.uk
Visit the WMO here https://wmo.int/
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Author: John Constable
(c) HSQE 10/01/25