WMO Global Climate Report 2025 – Warns of Rapid Climate Acceleration

Feature image: Dried out lake. Credit: Image by Thorsten Frenzel from Pixabay. 

The World Meteorological Organization’s 2025 State of the Global Climate Update for COP30 shows that key climate indicators such as greenhouse gases, ocean heat content, ice loss and extreme weather have all broken records, delivering a more urgent science‐based signal for global action. 

Key Developments 

• Atmospheric concentrations of CO₂, CH₄ and N₂O reached new all-time highs in 2024 and continued climbing into 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%. 

• The past 11 years (2015-2025) are now the warmest on record in the instrumental era. 

• Global mean near-surface temperature from January to August 2025 was measured at 1.42 °C above pre-industrial levels. The year 2025 is on track to be among the three warmest years on record. 

• Sea-ice extent in the Arctic reached record low levels during the 2025 winter freeze; Antarctic sea-ice remained well below average. 

• Extreme weather events (heatwaves, floods, wildfires, storms) increased in frequency and severity, causing major socio-economic impacts.  

• Early-warning systems and climate services have improved globally, but many regions still lack full coverage, leaving key vulnerabilities unaddressed. 

Global Implications 

• Sea-level rise continues steadily, and irreversible ocean warming and acidification mean long-term changes are already locked in. About 900 million people, nearly 11% of the world, live on low-lying coasts and are at direct risk from coastal hazards. 

• Food, water and infrastructure systems are under growing pressure: disrupted rainfall, melting ice, and extreme weather are threatening livelihoods, economies and health worldwide. 

• The narrowing window to stay within the 1.5 °C warming threshold shows that every fraction of a degree of additional warming raises the odds of passing irreversible tipping points. 

Urgent Response Needed 

• Rapid and large-scale reductions in greenhouse gas emissions. 

• Scaling-up of early-warning systems and climate services to cover all vulnerable regions. 

• Strengthening adaptation and resilience. 

• Closing data, research and service gaps in critical areas such as cryosphere monitoring, ocean-atmosphere interaction, and climate extremes. 

This WMO report stands as a firm call to the global community. The window is closing. We must act now to protect lives, economies, and the planet’s stability. 

Read more: Extreme weather events | Health risks | Climate Risks Daily 

Original source: https://wmo.int/publication-series/state-of-climate-update-cop30