Atmospheric CO₂ tracker (Mauna Loa)

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Interpretation

Daily means are averages of the hourly measurements that pass NOAA's quality checks; days without enough valid hours are missing and are shown as gaps, not filled in. Monthly means use months with at least 10 valid days; the trend is a centered 12-month running mean of those. Annual growth compares each month with the same month a year earlier and averages the differences, using NOAA's Mauna Loa monthly means (from 1958, so growth starts in 1959). The decadal rate compares the average of the 10 years up to each month with the average of the 10 years before, from the same monthly means (so it starts in 1978). Recent values are preliminary and may be revised. Data: NOAA Global Monitoring Laboratory, Mauna Loa daily mean CO₂ (gml.noaa.gov/ccgg/trends). Dr. Xin Lan, NOAA/GML, and Dr. Ralph Keeling, Scripps Institution of Oceanography.