Photo of heavy rains in New Orleans

Indicators are based on observed data that can be used to track and communicate climate-related conditions, trends, and impacts. 

Indicators—which may be physical, ecological, health or societal—can be used to assess risks and vulnerabilities and help inform resiliency and adaptation planning in a changing climate.

Go beyond the data and explore climate indicators with an interactive Story Map developed by the USDA Forest Service with support from the Environmental Protection Agency. Explore the climate story through observations including human consequences of climate change, adaptation, and resilience. Examine observed evidence of changes in greenhouse gases, weather and climate, oceans, snow and ice and how these changes can impact health and society.

View the eighteen USGCRP indicators below, or use the filters to search by topic or USGCRP agency

The Annual Greenhouse Gas Index (AGGI) is a measure of the capacity of Earth’s atmosphere to trap heat as a result of the presence of long-lived greenhouse gases. The AGGI provides standardized information about how human activity has affected the climate system through greenhouse gas emissions.
Carbon Cycle Energy International Mitigation Physical Climate
Eight routinely-measured glaciers located north of the Arctic Circle show the cumulative change in mass balance, or the net gain or loss of snow and ice (accumulation vs. melting and sublimation), since 1945.
Arctic Cryosphere Physical Climate
Sea ice extent is a measure of the surface area of the ocean covered by sea ice. Increases in air and ocean temperatures decrease sea ice extent; in turn, the resulting darker ocean surface absorbs more solar radiation and increases Arctic warming.
Adaptation Arctic Coasts International Oceans Physical Climate Cryosphere Ecosystems & Biodiversity
The global average concentration of carbon dioxide (CO₂) in the atmosphere is tracked and updated monthly, capturing both seasonal and interannual trends. Data are drawn from paired, weekly samples collected at 40 sites in the remote marine boundary layer around the globe.
Carbon Cycle Energy International Mitigation Physical Climate
This indicator shows, by year, the number of weather and climate disasters causing more than one billion U.S. dollars in direct losses.
Societal Impacts Extreme Events Adaptation Vulnerability
The number of frost-free days in a year reflects the overall warming trend in the climate system.
Adaptation Agriculture & Food Ecosystems & Biodiversity Physical Climate Seasonality
This indicator describes trends in multi-day extreme heat events in cities across the United States.
Extreme Events Human Health Societal Impacts Cities & Infrastructure Vulnerability Physical Climate
Degree days are defined as the number of degrees by which the average daily temperature is higher than 65°F (cooling degree days) or lower than 65°F (heating degree days). Degree days reflect changes in climate and are used as a proxy for the energy demand for heating or cooling buildings.
Adaptation Cities & Infrastructure Energy Human Health Mitigation Physical Climate