A recent Met Office study found that the concentration of atmospheric carbon dioxide, the most significant planet-warming gas, rose at its fastest annual rate last year. The measured increase of 3.58 parts per million (ppm) exceeded predictions. Satellite measurements showed a global rise due to record high emissions from fossil fuels, weakened natural carbon sinks, and exceptional wildfires. To limit global warming to 1.5°C, the build-up of CO2 in the air needs to slow to 1.8 ppm per year, but the forecasted rise between 2024 and 2025 is expected to be less extreme due to a shift from El Niño to La Niña conditions, which will partially re-strengthen carbon sinks. However, even this slower rise will still be too fast to track IPCC scenarios that limit global warming to 1.5°C. Professor Richard Betts emphasized the need for urgent international action for rapid emissions cuts to limit global warming below 1.5°C. He noted that the long-term warming trend will continue due to ongoing CO2 buildup in the atmosphere.
In 2024, the rate of increase in atmospheric CO2 levels reached an unprecedented peak.
