Atmospheric CO2 Data

Ice-Core Merged Products

Atmospheric CO2 record based on ice core data before 1958, (Ethridge et. al., 1996; MacFarling Meure et al., 2006) and yearly averages of direct observations from Mauna Loa and the South Pole after and including 1958 (from Scripps CO2 Program).

Measurement Frequency Data File Dates
CO2 yearly merged_ice_core_yearly.csv 13.3 C.E. - present
CO2 yearly spline spline_merged_ice_core_yearly.csv 13.3 C.E. - present

MLO and SPO Averaged Products

Measurement Frequency Data File Dates
CO2 monthly mlo_spo_monthly_mean.csv 1958 - present
CO2 yearly mlo_spo_annual_mean.csv 1959 - present

Usage Restrictions

Scripps CO2 program data and graphics on are licensed under a CC BY license, Creative Commons Attribution 4.0 International License (, which clarifies appropriate uses and requirements, including that credit be given to the Scripps Institution of Oceanography at UC San Diego. Some products from this site incorporate data from sources external to the Scripps CO2 program, as indicated. Additional credit must be given for these products, as appropriate for that source.

Ethical usage may also require disclosing intentions at early stages to avoid duplicating ongoing studies at Scripps or elsewhere. For applications supporting peer-reviewed scientific publications, coauthorship may sometimes be appropriate. An example would be if an important result or conclusion depends on this product, such as the first account of a previously unreported phenomenon.

Please direct queries to Ralph Keeling (