Current Methods for Calculating National Ecological Footprint Accounts

The Ecological Footprint is a resource accounting tool that measures how much bioproductive land and sea is available on Earth, and how much of this area is appropriated for human use. The Ecological Footprint, human demand, and biocapacity, ecosystem supply, are both measured in units of global hectares, a hectare normalized to the average productivity of all bioproductive hectares on Earth. As of 2003, there are approximately 11.2 billion global hectares of area available. In that same year, humanity demanded products and services from the equivalent of 14.1 billion global hectares. This overshoot, if it continues, will put global ecosystems at serious risk of degradation or collapse. Humanity's Ecological Footprint is spread across six land use categories: cropland, grazing land, fishing grounds, forest, built-up area, and land for carbon absorption. Of these six, land for carbon absorption is the most significant globally, representing nearly one half of humanity's total Footprint. A concerted international effort to shrink human demand to within the limits set by nature will be an important component of any effort to create a sustainable future for all people.