In 2024, the yearly average level of the greenhouse gas carbon dioxide (CO2) rose faster over the prior year than ever in the 67-year-old Keeling Curve record. Reposted 5. December 2025. Update June 7. 2025: Atmospheric carbon dioxide (CO2) concentrations have peaked for the year at 430.5 parts per million (ppm). The 2025 peak is … Continue reading The Keeling Curve and 40 years of blah blah blah.