evidence: 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 Oceanography offsite 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. [...] "Not only is CO2 now at the highest level in millions of years, it is also rising faster than ever," said Keeling. "Each year achieves a higher maximum due to fossil-fuel burning, which releases pollution in the form of carbon dioxide into the atmosphere. Fossil fuel pollution just keeps building up, much like trash in a landfill."