The Ecological Footprint measures humanity’s demand on the biosphere in terms of the area of biologically productive land and water required to provide the resources we use and to absorb our carbon dioxide emissions. This area is reported in global hectares (gha) – hectares with world average productivity. The Footprint of a country includes all the cropland, grazing land, forest and fishing grounds required to produce the food, fibre and timber it consumes, the carbon uptake land needed to absorb the carbon dioxide emitted in generating the energy it uses, and the builtup land required to provide space for its infrastructure—regardless of where these areas are located on the planet. National footprint accounts are derived from internally recognized sources, such as the UN-FAO, and go back to 1961.
To see if ecological limits are being exceeded, the Ecological Footprint can be compared with biocapacity, the amount of biologically productive area that is available to provide resources and absorb waste. In the mid-1980s, humanity’s global Footprint began to overshoot global biocapacity, and by 2006 this excess was approximately 44 percent.
Global Footprint Network releases updated National Footprint Accounts each year, and biennially publishes summary results in WWF’s Living Planet Reports. Descriptions of the methodology and additional data are available at www.footprintnetwork.org.