Annual Greenhouse Gas Index

Since 2004, researchers in NOAA’s Global Monitoring Division have released the Annual Greenhouse Gas Index to compare the total warming effect of heat-trapping gases each year to their 1990 levels. Using 1990 as a baseline, the index shows the combined warming influence from greenhouse gases—including carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons—and reveals which gases contribute most to the index value each year.

Learn about the index and the calculations used to determine annual results for the AGGI. Annual results are updated each spring.

The Annual Greenhouse Gas Index provides a reliable source of scientific information on the abundance of heat-trapping gases in our atmosphere—a direct connection between the scientists that study these emissions and the society that’s affected by them.