Global Stations CO2 Concentration Trends Graphic | Scripps CO2 Program

Global Stations CO2 Concentration Trends


Black Dots: Monthly average atmospheric carbon dioxide concentration versus time at stations in the Northern and Southern Hemispheres where CO2 concentration is in parts per million in the mole fraction (p.p.m.).

Black Curves: The sum of 4 seasonal harmonics and a spline function to the stations CO2 concentration data. The seasonal harmonics include a linear gain factor, to represent increasing amplitude with time.

Station code names are as follows: PTB = Point Barrow, LJO = La Jolla, MLO = Mauna Loa Observatory, CHR = Christmas Island, SAM = Samoa, and SPO = South Pole.

Data from Scripps CO2 Program.

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 (