--- - caption: 'Annual radiative forcing, expressed in watts per square meter for carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). AGGI is the Annual Greenhouse Gas Index, normalized to the year 1990.' chapter_identifier: ~ href: https://data.globalchange.gov/report/indicator-annual-greenhouse-gas-index-2021/table/indicator-annual-greenhouse-gas-index-2021.yaml identifier: indicator-annual-greenhouse-gas-index-2021 ordinal: 1 report_identifier: indicator-annual-greenhouse-gas-index-2021 title: ~ uri: /report/indicator-annual-greenhouse-gas-index-2021/table/indicator-annual-greenhouse-gas-index-2021 url: ~