Ecological footprint
Nature can keep up with the demands of human economic activity, but only as long as this activity stays within the regenerative capacity of the biosphere: the living part of the planet. Ecological footprint accounting measures the extent to which the ecological demand of human economies stays within or exceeds the capacity of the biosphere to supply goods and services. These accounts help individuals, organisations, and governments to frame policies, to set targets, and to track progress towards sustainability.
The ecological footprint measures how much land area is required to sustain a given population at present levels of consumption, technological development and resource efficiency, and is expressed in global-average hectares (gha). The largest component elements of Footprint are the land used to grow food, trees and biofuels, areas of ocean used for fishing, and most importantly the land required to support the plant life needed to absorb and sequester CO2 emissions from fossil fuels.
Footprint takes account of the fact that in a global economy people consume resources and ecological services from all over the world. Therefore, a Chiquita plantation in Costa Rica will not count towards Costa Rica’s Footprint, but rather towards the Footprint of those countries where the bananas are consumed. For this reason, a country’s Footprint can be significantly larger than its actual biocapacity. The Footprint of a country is thus best understood as a measure of its consumption, and its worldwide environmental impact.
The same methodology can be used to calculate, in the same units, the Earth’s biocapacity its biologically productive area. Currently, the biocapacity of the Earth is around 11.2 billion hectares or 1.8 global hectares per person in 2001 (assuming that no capacity is set aside for non-human species). In 2001, humanity’s demand on the biosphere its global ecological footprint was 13.7 billion global hectares, or 2.2 global hectares per person. At present, therefore, our Footprint exceeds our biocapacity by 0.4 global hectares per person, or 23 per cent. This means that the planet’s living stocks are being depleted faster than nature can regenerate them.