The concept of the “ecological footprint” (Rees, 1992), in essence, is the size of area that is required to sustain the megacity population, i.e., the land that is required to provide the necessary resources (food, energy, raw materials, etc.) and to process thewaste products. A detailed discussion can be found in Rees (1992)and on the internet.To give an example, the Tokyo metropolitan area extends over 2188 km2 with a total population of 13,189,000 inhabitants amounting to a population density of 6028/km2 (Tokyo Metropolitan Government, 2011). Assuming a biocapacity of the Earth of 1.8 persons per hectare (the global biological capacity available per person, 2008 status; taken from “The Global FootprintNetwork - Glossary” 3) the Tokyo metropolitan area would require 237,402 km2 or roughly two thirds of Japan to sustain itself. Of course, the same area is also a centre of innovation and productivity accounting for a major portion of Japan's economic output.
đang được dịch, vui lòng đợi..
