WMO says 2024 CO2 rise on record, fueling warming and extremes

The United Nations weather agency reported Wednesday that atmospheric carbon dioxide concentrations surged by the largest single-year amount on record in 2024, topping 423.9 parts per million and marking the biggest one-year increase since systematic measurements began in 1957. The World Meteorological Organization said the rise, driven by ongoing fossil fuel combustion, more widespread wildfires and a reduced capacity of land and oceans to absorb carbon, is accelerating global warming and will contribute to more extreme weather.

The WMO’s annual Greenhouse Gas Bulletin said CO2 concentrations rose by 3.5 parts per million from 2023 to 2024. Methane and nitrous oxide likewise reached new highs, at 1,942 parts per billion and 338 parts per billion respectively. Together, the three gases are at levels far above preindustrial measurements, with increases since before 1750 of roughly 152 percent for carbon dioxide, 266 percent for methane and 125 percent for nitrous oxide. Carbon dioxide accounts for about two thirds of the long-term warming effect from these long-lived greenhouse gases.

WMO Deputy Secretary General Ko Barrett said the extra heat trapped by these gases is...