During a year of extremes, carbon dioxide levels surge faster than ever

Atmospheric carbon dioxide measured at NOAA’s Mauna Loa Atmospheric Baseline Observatory peaked in May 2024 at a monthly average of 426.9 parts per million, establishing another high mark in the 66-year record of observations on the Hawaiian volcano. Credit: NOAA
June 6, 2024 — Carbon dioxide is accumulating in the atmosphere faster than ever — accelerating on a steep rise to levels far above any experienced during human existence, scientists from NOAA and the Scripps Institution of Oceanographyoffsite link at the University of California San Diego announced today.
Levels of carbon dioxide (CO2) measured at NOAA’s Mauna Loa Atmospheric Baseline Observatory by NOAA’s Global Monitoring Laboratory surged to a seasonal peak of just under 427 parts per million (426.90 ppm) in May, when CO2 reaches its highest level in the Northern Hemisphere. That’s an increase of 2.9 ppm over May 2023 and the 5th-largest annual growth in NOAA’s 50-year record. When combined with 2023’s increase of 3.0 ppm, the period from 2022 to 2024 has seen the largest two-year jump in the May peak in the NOAA record