Atmospheric CO2 hits record high: UN

The increase in the amount of carbon dioxide in the atmosphere last year was the highest ever recorded, the United Nations said yesterday, calling for urgent action to slash emissions.

Levels of the three main greenhouse gases -- the climate-warming CO2, methane and nitrous oxide -- all increased yet again in 2024, with each setting new record highs, the UN's weather and climate agency said.

In 2024, CO2 concentrations were at 424 parts per million (ppm), methane at 1,942 parts per billion, and nitrous oxide at 338 parts per billion. That marks hikes of 152 percent, 266 percent and 125 percent respectively since pre-industrial levels before 1750.

The 3.5 ppm increase from 2023 to 2024 was "the largest one-year increase since modern measurements began in 1957", the WMO said.