By comparing the demand of ecological footprint with the carrying capacity of natural ecosystem (also called ecological footprint supply), the ecological footprint index can quantitatively judge the sustainable development of a country or region, thus making scientific plans and suggestions for future human survival and social and economic development.
The calculation of ecological footprint is based on two simple facts:
1. We can keep most of the consumed resources and most of the generated wastes.
2. Most of these resources and wastes can be transformed into bio-productive land with these functions.
The calculation method of ecological footprint clearly points out how much natural resources are used in a country or region, however, these footprints are not a continuous land; Due to international trade, the land and waters used by people are scattered in all corners of the world, which requires a lot of research to determine their location.