WMO’s State of the Global Climate 2025 Report

Context: On March 23, 2026 (World Meteorological Day), the World Meteorological Organisation (WMO) released its flagship State of the Global Climate 2025 report.

Key Takeaways from WMO’s State of the Global Climate 2025 Report

Atmospheric Concentrations:

Greenhouse gas (GHG) levels have reached concentrations not seen in human history.

Carbon Dioxide: Now roughly 50% higher than pre-industrial levels; concentrations are at their highest in 2 million years.
Methane & Nitrous Oxide: Both have reached their highest levels in at least 800,000 years.
The Energy Gap: Despite renewables surpassing coal in electricity generation in 2025, total global emissions reached record highs because clean energy cannot yet keep pace with rising global energy demand.

Earth’s Energy Imbalance (EEI)

For the first time, the World Meteorological Organisation (WMO) has included EEI as a core climate indicator.

Heat Surplus: The gap between incoming solar radiation and outgoing heat reached a 65-year high in 2025.
About 91% of this excess heat is absorbed by the oceans, 5% by land, 3% by melting ice, and only 1% by the atmosphere.
- Because so much heat is stored in the oceans, the planet will continue to warm for decades even if all emissions were to stop today.

Ocean Warming and Acidification

The oceans are bearing the brunt of the energy surplus, leading to irreversible changes.

Record Heat Content: 2025 set a new record for ocean heat (0–2000m depth), with the rate of warming doubling in the last 20 years (2005–2025) compared to the previous 45 years.
Acidification: Oceans have absorbed nearly 29% of human-generated $CO_2$ since 2015, causing surface pH to drop to levels likely unprecedented in 26,000 years.
Marine Heatwaves: Despite La Niña, nearly 90% of the global ocean surface experienced at least one marine heatwave in 2025.

Cryosphere Retreat

The “white shields” of the planet are failing, creating a dangerous feedback loop.

Glacier Loss: Glaciers suffered their most severe mass loss on record over the 2022–2025 period.
Sea Ice: Arctic sea ice remained at near-record lows, while Antarctic sea ice recorded its third-lowest extent ever, following the record lows of 2023 and 2024.

Socio-Economic and Health Impacts

The climate crisis is no longer just an environmental issue; it is a humanitarian emergency.

Heat Stress: Over 1.2 billion people (one-third of the global workforce) now face occupational heat risks annually, particularly in agriculture and construction.
Food Insecurity: Climate-driven disasters are triggering “cascading impacts” on social stability, migration, and biosecurity (pests and animal diseases).
Disease: Warmer temperatures have accelerated the spread of mosquito-borne diseases like Dengue, which now puts half the global population at risk.