CO2 Levels


Composited data from all sites.

Export Data

You can use this tool to export hourly data to files on your computer. You may choose to have the data formatted to XML or CSV. Data timestamps are in Coordinated Universal Time (UTC = PDT+7, PST+8), temperatures are in degrees Celsius, and CO2 concentrations are in particles per million (ppm). Missing values are reported as -999.0. A first-order correction for temperature, pressure, and relative humidity has been applied to convert the CO2 concentrations to dry-air mole fractions. For access to the uncorrected data, please contact Professor Ronald Cohen at


  1. Select your date range
  2. Select your output file format
  3. Select one or more sites (control-click to select more than one site)
  4. Click the "Submit Query" button

Data Summary