The world’s oceans are warming at an increasing rate, global sea levels have reached new records, and a powerful El Niño is adding to already exceptional temperatures. Together, these developments are shaping another unusually warm year and raising concerns about climate-related risks extending into 2027.
According to a new assessment by the World Meteorological Organization (WMO), released on 9 November at the opening of the COP31 climate conference in Antalya, Türkiye, 2026 is expected to rank among the four warmest years since global temperature records began.
The global average temperature between January and September was 1.47 °C above the 1850–1900 pre-industrial average, with an uncertainty of ±0.13 °C. This places the year close to the levels recorded in 2023 and 2025, although below the annual record of 1.55 °C set in 2024.
The assessment remains provisional, and a single year above 1.5 °C would not, by itself, mean that the Paris Agreement’s long-term warming threshold has been crossed.
A transition from La Niña conditions early in 2026 to a particularly strong El Niño has contributed to rising temperatures. El Niño involves warming in the tropical Pacific that redistributes heat and alters atmospheric circulation, typically increasing global average temperatures by around 0.1–0.2 °C.
WMO expects the event to persist into early 2027, potentially influencing rainfall, drought and extreme weather patterns across several regions.
This natural climate variability is occurring against a longer-term warming trend driven by greenhouse gas emissions. Atmospheric carbon dioxide concentrations reached 426.8 parts per million in 2025, approximately 53% above their pre-industrial level, while methane and nitrous oxide also reached record concentrations.
Ocean warming and sea level rise reach new records
Beyond surface temperatures, the State of the Climate Update for COP31 documents how excess heat continues to accumulate throughout the Earth system.
More than 90% of that additional energy enters the oceans, where heat content reached a record in 2025 and continued increasing during the first seven months of 2026, according to preliminary measurements. Ocean warming affects marine ecosystems, contributes to stronger tropical storms and drives sea level rise through thermal expansion.
Global mean sea level reached its highest recorded values during June, July and August 2026. The average rate of sea level rise has increased from 2.4 millimetres annually during 1993–2002 to 3.9 millimetres during 2017–2026, reflecting both warming seawater and the loss of land-based ice.
Glaciers worldwide lost approximately 408 billion tonnes of ice in 2025, equivalent to about one millimetre of global sea level rise. It was the fourth consecutive year in which all 19 glacierized regions experienced net ice loss.
The consequences extend beyond environmental measurements. Across Europe, repeated heatwaves, drought and wildfires coincided with more than 30,000 excess deaths during the summer of 2026, according to provisional estimates. Elsewhere, floods, droughts and tropical cyclones disrupted agriculture, infrastructure and livelihoods.
In India, an estimated 146.5 million people were exposed to extreme heat conditions during April, illustrating the scale of populations facing dangerous temperatures.
The report also documents progress in preparedness. The number of countries reporting multi-hazard early warning systems increased from 56 in 2015 to 136 in 2025, although substantial gaps remain, particularly in countries with limited resources.
These systems depend on continuous observations, international data sharing and reliable forecasts, allowing authorities to anticipate dangerous conditions and reduce potential losses.
As governments meet at COP31, the assessment shows that rising temperatures are only one part of a changing climate. Continued ocean warming, shrinking glaciers and higher sea levels reflect changes that extend far beyond individual weather events, while stronger monitoring and early warning systems remain essential for helping communities respond to the risks ahead.
Report:
World Meteorological Organization (WMO), ‘State of the Climate Update for COP31’ (2026), November 2026. WMO/2026/15
Article Source:
Press Release/Material by World Meteorological Organization (WMO)
Featured image credit: Gaël Handschin | WMO 2027 Calendar Competition | CC BY-NC-ND
