Overview

• Global average CO2 reached about 423.9–424 ppm in 2024, roughly 52% above pre‑industrial levels, after a record 3.5 ppm year‑over‑year rise.
• Methane and nitrous oxide also hit new highs, with atmospheric concentrations reported around 1,942 ppb and 338 ppb respectively.
• WMO links the spike to continued fossil fuel burning, exceptional wildfire emissions and reduced absorption by land and oceans during the warmest year on record.
• Scientists warn that carbon sinks appear to be weakening, raising concerns about reinforcing feedbacks that could accelerate warming.
• Separately, the UK Climate Change Committee urged planning for at least 2°C of warming by 2050 with stronger, accountable adaptation targets for health, infrastructure, and flood, heat and drought risks.