
2025-08-10 00:33:30
Monthly mean carbon dioxide as measured at Mauna Loa Observatory, Hawaii.
July 2025:
427.87. ppm
July 2024:
425.55 ppm
The carbon dioxide data on Mauna Loa constitute the longest record of direct measurements of CO2 in the atmosphere.
https://gml.noaa.gov/ccgg/trends/