The year 2025 is on track to be the second or third warmest on record, according to the World Meteorological Organization (WMO).
The planet’s relentless warming trend has shown no sign of slowing, according to the State of the Global Climate Update 2025 released by the WMO on November 6, 2025.
The report has been prepared to inform discussions at the 30th Conference of the Parties (COP30) to the United Nations Framework Convention on Climate Change in Belem (Brazil) with authoritative, up-to-date information on the state of global climate.
The report reveals that the past 11 years (2015-2025) are set to be the warmest on record, with each year surpassing previous temperature highs.
UN Secretary-General Antonio Guterres called for urgent action to drive down global temperatures and keep the 1.5 degrees Celsius goal within reach.
The trend of extreme warming continues, driven by record concentrations of greenhouse gases (GHGs).
According to the report, concentrations of the three key GHGs in the atmosphere – carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) – reached record-high observed levels in 2024.
Real-time data indicate that they continue to rise in 2025.
The atmospheric concentration of CO2 has increased from around 278 parts per million (ppm) in 1750 to 423.9 ppm in 2024, an increase of 53 per cent. The average CO2 growth rate during the past decade was 2.57 ppm per year.
Emissions from fossil fuels have been the largest source of human emissions since the 1950s.
Global average methane (CH4) concentrations increased from 729 parts per billion (ppb) in 1750 to 1942 ppb in 2024, which represents an increase of 166 per cent.
Nitrous oxide (N2O) concentrations increased from 270 ppb in 1750 to 338.0 ppb in 2024, which represents a 25 per cent increase.
At present, 2025 will likely be the second or third warmest year on record, and cooler than 2024.
The report highlights ocean heat content continued to rise in 2025. More than 90 per cent of the excess energy generated by the greenhouse effect is absorbed by the oceans. This intensifies storms, accelerates polar melting, and contributes to sea level rise. Between 2016 and 2025, the average rate of sea level rise doubled, reaching 4.1 mm per year.
Throughout 2025, extreme events caused massive economic and social upheaval and loss of life. These included flooding in many countries in Africa and Asia, as well as wildfires in Europe and North America, extreme heat throughout the world, and deadly tropical cyclones.
The report highlights numerous weather and climate-related extreme events during the first eight months of 2025, from devastating flooding to brutal heat and wildfires, with cascading impacts on lives, livelihoods and food systems. In this context, the WMO hailed significant advances in early warning systems.
Since 2015, the number of countries reporting multi-hazard early warning systems has more than doubled, from 56 in 2015 to 119 in 2024, the report said. However, 40 per cent of countries still lack such systems.
Urgent action is needed to close these remaining gaps, says the report.