Overview
- The WMO reports the largest single‑year rise in atmospheric CO2 since measurements began in 1957, up 3.5 ppm from 2023 to a global average of about 423.9 ppm in 2024.
- Methane and nitrous oxide also reached record highs, with global averages of roughly 1,942 ppb for CH4 and 338.0 ppb for N2O, according to the bulletin.
- Persistent fossil‑fuel emissions, extensive wildfires—especially in South America—and El Niño combined to boost emissions and reduce natural uptake.
- Forests and oceans absorbed less CO2 in 2024 as heat and drought stressed ecosystems, prompting WMO warnings about destabilizing feedbacks and a scientist’s stark assessment that “the system is breaking down.”
- The year 2024 ranked as the warmest on record at about 1.55°C above preindustrial levels, and the WMO urges rapid, deep emission cuts with Paris targets at growing risk ahead of the COP in Belém next month.