Daily Average Mauna Loa CO2:
Week beginning on Jan. 16: 417.62 ppm
Weekly value from 1year ago: 415.26 ppm
Weekly value from 10years ago: 392.90 ppm
Last updated: Jan. 24, 2022
Source: National Oceanic and Atmospheric Administration; Mauna Loa Observatory has been monitoring C02 levels since 1958