Overview

• Global CO2 climbed by 3.5 ppm from 2023 to 2024 to roughly 424 ppm, the largest one-year increase since measurements began in 1957, according to the WMO.
• Methane and nitrous oxide concentrations also reached record levels in 2024, with carbon dioxide now about 52% above pre‑industrial levels.
• WMO scientists link the surge to continued fossil fuel use, exceptional wildfire emissions, a strong El Niño, and a reduced ability of land and oceans to absorb CO2.
• With 2024 the warmest year on record and warming at about 1.3–1.4°C, the UK Climate Change Committee urged planning for at least 2°C by 2050, warning the country is ill‑prepared for escalating extremes.
• Scientific assessments indicate current national pledges could yield roughly 2.6°C of warming this century with many more hot days, sharpening the stakes ahead of next month’s COP30 in Belém, Brazil.