Greenhouse gas levels in 2025 reached the highest level in recorded history. Currently, the concentration of CO2 in the atmosphere stands at 153% of the pre-industrial level of 1750. This could trigger further warming of the Earth, accompanied by increasingly aggressive weather events.
This was reported by Reuters, citing a report by the UN World Meteorological Organization.
The analysis shows that the global average concentration of CO2 in the atmosphere reached 426.8 parts per million in 2025, which is about 153% of the pre-industrial level of 1750. Compared to 2024, the concentration increased by 2.8 ppm. This is a larger annual increase than the average for the last decade.
Not only carbon
Carbon dioxide is not the only greenhouse gas whose concentration has broken records. Nitrous oxide levels are 26% higher than in the pre-industrial era, and methane levels are a colossal 167% higher. This refers not to annual emissions, but to the volume of gases that has already become part of the atmosphere.
"Every additional part per million matters, because it traps additional heat. In effect, we are overloading the ocean and the atmosphere. This means that heatwaves, tropical cyclones and downpours are intensifying faster than our historical baselines had prepared us for," said WMO Deputy Secretary-General Ko Barrett.
Meteorologists recalled the consequences the world has already faced this year: relentless heatwaves in Europe and devastating floods in Asia.
The El Niño factor
The WMO expects carbon dioxide concentrations to keep rising in 2026. The first factor is the burning of fossil fuels, the second is a super-strong El Niño, which will cause droughts and make carbon absorption more difficult.
"Dark horses"
The organisation is also concerned about sulphur hexafluoride, or SF6, a greenhouse gas widely used in electrical equipment. The growth in its concentration in 2026 was also a record. This compound has a global warming potential 24,000 times higher than CO2. It can remain in the atmosphere for more than 1,000 years.
Hydrogen is not a greenhouse gas, but between 2010 and 2024 alone its concentration increased by 5.3%. This compound is a cause for concern due to its indirect impact on the chemical composition of the atmosphere, which can indirectly contribute to warming.
The WMO stated that both hydrogen leakage and the long-term persistence of SF6 could undermine some of the climate benefits of the global energy transition.
EcoPolitic recently reported that global warming is accelerating the rise in global sea levels. Since 2012, it has been rising by approximately 4.2 mm annually, which has direct consequences for coastal communities and global economies.
