Overview
- Global CO2 concentrations rose by 3.5 ppm from 2023 to 2024, the biggest year-on-year increase in the observational record.
- Methane and nitrous oxide also reached record levels in 2024, with average concentrations near 1,942 ppb for CH4 and 338 ppb for N2O.
- Oceans and terrestrial ecosystems absorbed a smaller share of emissions as warming reduced ocean solubility and drought and fires weakened land sinks.
- Scientists link the surge primarily to ongoing human emissions, intensified wildfires, and El Niño conditions during the hottest year on record.
- The long-term growth rate has accelerated from about 0.8 ppm per year in the 1960s to roughly 2.4 ppm in 2011–2020, and the WMO stresses rapid emissions cuts to limit worsening extremes.