MLO data from the most recent month is preliminary
Mauna Loa carbon dioxide data from the most recent month is preliminary and subject to subsequence updates to account for retrospective calibration and quality control. See scrippsco2.ucsd.edu for data that has passed these routine quality checks and updates. The datasets are archived once a month on the scrippsco2.ucsd.edu website and the Scripps CO2 Program library archive database at UCSD.
Scripps CO2 program grants unrestricted usage of the figures on this website provided credit is given to the Scripps Institution of Oceanography. For figures showing data before 1958, permission may also be required from those providing these earlier data (see links below). The figures referred to here are the plots displayed on the front page and located at PDF Downloads.
CO2 data after 1958 are from the Scripps CO2 program
Citation: C. D. Keeling, S. C. Piper, R. B. Bacastow, M. Wahlen, T. P. Whorf, M. Heimann, and H. A. Meijer, Exchanges of atmospheric CO2 and 13CO2 with the terrestrial biosphere and oceans from 1978 to 2000. I. Global aspects, SIO Reference Series, No. 01-06, Scripps Institution of Oceanography, San Diego, 88 pages, 2001. http://escholarship.org/uc/item/09v319r9
CO2 data before 1958 going back 2000 years
Citation: MacFarling Meure, C., D. Etheridge, C. Trudinger, P. Steele, R. Langenfelds, T. van Ommen, A. Smith, and J. Elkins. 2006. The Law Dome CO2, CH4 and N2O Ice Core Records Extended to 2000 years BP. Geophysical Research Letters, Vol. 33, No. 14, L14810 10.1029/2006GL026152.
CO2 data before 1958 going back 800,000 years
Citation: Lüthi, D., M. Le Floch, B. Bereiter, T. Blunier, J.-M. Barnola, U. Siegenthaler, D. Raynaud, J. Jouzel, H. Fischer, K. Kawamura, and T.F. Stocker. 2008. High-resolution carbon dioxide concentration record 650,000-800,000 years before present. Nature, Vol. 453, pp. 379-382, 15 May 2008.