What it is
NOAA's Climate.gov interactive tool for visualizing greenhouse gas concentrations (CO2, CH4, N2O, ozone, CFCs) from over 200 sampling sites worldwide. Users can compare time series between locations, overlay multiple gases, and download raw data for analysis.
Why we picked this
This is the primary source data for atmospheric greenhouse gas concentrations. When you see a CO2 graph in any publication, the measurements likely came from NOAA's monitoring network. Direct access to the instruments, no intermediary.
Key takeaways
- NOAA's Mauna Loa observatory has measured atmospheric CO2 continuously since 1958, creating the Keeling Curve, the most iconic dataset in climate science.
- The tool covers five major greenhouse gases across 200+ sites, enabling spatial and temporal analysis of atmospheric composition.
- All data is freely downloadable, making it the foundation for academic research, journalism, and public education about atmospheric change.