Daily CO2 readings are updated here automatically with the latest atmospheric CO2 readings available from the Mauna Loa Observatory in Hawaii.
Data sources:
March 1958 to April 1974: Scripps Institution of Oceanography, May 1974 to present day: Dr. Pieter Tans, NOAA/GML
Last update: 2:35:02 AM on Sep. 20, 2024, Hawaii local time (UTC -10)
| Latest | One year ago | Change from previous year | ||
|---|---|---|---|---|
| Date | Reading | Date | Reading | |
| Sep. 19, 2024 | 421.73 ppm | Sep. 20, 2023 | 418.58 ppm | 3.15 ppm increase (0.75 %) |
| Sep. 18, 2024 | 422.03 ppm | Sep. 19, 2023 | 418.86 ppm | 3.17 ppm increase (0.76 %) |
| Sep. 17, 2024 | 421.88 ppm | Sep. 18, 2023 | Unavailable | n/a |
| Sep. 16, 2024 | 421.90 ppm | Sep. 17, 2023 | 418.72 ppm | 3.18 ppm increase (0.76 %) |
| Sep. 15, 2024 | 422.13 ppm | Sep. 16, 2023 | Unavailable | n/a |
| Sep. 14, 2024 | 422.04 ppm | Sep. 15, 2023 | Unavailable | n/a |
| Sep. 13, 2024 | Unavailable | Sep. 14, 2023 | Unavailable | n/a |
| Sep. 12, 2024 | Unavailable | Sep. 13, 2023 | 418.69 ppm | n/a |
| Sep. 11, 2024 | Unavailable | Sep. 12, 2023 | 418.36 ppm | n/a |
| Sep. 10, 2024 | 421.75 ppm | Sep. 11, 2023 | Unavailable | n/a |