Levels of carbon dioxide in the atmosphere have been routinely monitored as various sites around the World since the late 1950s. Data for earlier times has been obtained from ice cores, such as the one from Siple Station in Antarctica.
We consider data from three atmospheric monitoring sites.
The data used to draw the figures found later in this activity were adapted from that given on the Web at http://cdiac.esd.ornl.gov/trends/co2/contents.htm
Online Trends - A Compendium of Data on Global Change
Trends: A Compendium of Data on Global Change is part of the Carbon Dioxide Information Analysis Center's (CDIAC's) continued effort to distribute, in an accessible format, scientific data critical to global-change issues. Trends is intended for researchers, policy makers, educators, and others interested in the observational data underlying the issues related to our changing global environment.
For presentational purposes missing data have been replaced by data from the
Full details of the sampling methodology and methods of analysis can be found on the Web. Selected information is available locally.