The ecological footprint measures human demand on nature, i.e., the quantity of nature it takes to support people or an economy. It tracks this demand through an ecological accounting system. The accounts contrast the biologically productive area people use for their consumption to the biologically productive area available within a region or the world (biocapacity). In short, it is a measure of human impact on Earth's ecosystem and reveals the dependence of the human economy on natural capital.
The ecological footprint is defined as the biologically productive area needed to provide for everything people use: fruits and vegetables, fish, wood, fibers, absorption of carbon dioxide from fossil fuel use, and space for buildings and roads. Biocapacity is the productive area that can regenerate what people demand from nature.
Footprint and biocapacity can be compared at the individual, regional, national or global scale. Both footprint and biocapacity change every year with number of people, per person consumption, efficiency of production, and productivity of ecosystems.At a global scale, footprint assessments show how big humanity's demand is compared to what planet Earth can renew. Global Footprint Network calculates the ecological footprint from UN and other data for the world as a whole and for over 200 nations. They estimate that as of 2013, humanity has been using natural capital 1.6 times as fast as nature can renew it.,
Ecological footprint analysis is widely used around the Earth in support of sustainability assessments. It can be used to measure and manage the use of resources throughout the economy and explore the sustainability of individual lifestyles, goods and services, organizations, industry sectors, neighborhoods, cities, regions and nations. Since 2006, a first set of ecological footprint standards exist that detail both communication and calculation procedures. The latest version are the updated standards from 2009
In 2013, the Global Footprint Network estimated the global ecological footprint as 1.6 planet Earths. This means that, according to their calculations, the planet's ecological services were being used 1.6 times faster than they were being renewed.
Ecological footprints can be calculated at any scale: for an activity, a person, a community, a city, a region, a nation or humanity as a whole. Cities, due to population concentration, have large ecological footprints and have become ground zero for footprint reduction.