Carbon Dioxide | Global Temperatures

Atmospheric carbon dioxide CO2 has been monitored at Mauna Loa Observatory since 1958. Many other sites world-wide have been monitoring CO2. They all see the same increasing trend. Click on the graph to examine an interactive version which allows you to zoom in on any section. The blue line is the trend of the data. The varying red line is the monthly plot of values. The red line rises and falls with changes in the growing season primarily in the northern hemisphere. Summer months allow plants to use the CO2 to decrease it as they make O2 using photosynthesis. Winter months produce a rise in CO2 due to decomposition. Close inspection of daily records also shows the CO2 has a cyclical pattern between daytime and nighttime hours. (Not shown on this graph scale.)


How does this compare to the global temperature trend?