One fundamental requirement for sustainability is to demand less from the planet than what the planet’s ecosystems can renew. Ecological Footprint and Biocapacity accounting focuses on this very requirement. It tracks human demand on ecosystems (“Footprint”) in comparison to what ecosystems can renew (“biocapacity”). When demand exceeds renewal, ecological overshoot occurs. It leads to the degradation of natural capital, which eventually leads to a decrease in economic and social welfare.
- Why biocapacity? The focus of Ecological Footprint accounting is biological resources. Ecosystems have a limited ability to renew biomass. This is based on factors such as water availability, climate, soil fertility, solar energy, technology and management practices. This capacity to renew, driven by photosynthesis, is called biocapacity. Rather than non-renewables like oil or minerals, it is the biological resources that are the materially most limiting resources for the human enterprise. For instance, while the amount of fossil fuel still underground is limited, even more limiting is the biosphere’s ability to cope with the CO2 emitted when burning it. This ability is one of the competing uses of the planet’s biocapacity.
- How it is measured. Ecological Footprint accounting tracks how much biologically productive land and water area an individual, population or activity uses to produce all the resources it consumes, to house all its infrastructure, and to absorb its waste given prevailing technology and resource management practices. People obtain resources from forests, cropland, fisheries, and grazing land. They also use these areas for accommodating roads, houses and energy infrastructure. Waste absorption also competes for ecosystem services, for example to assimilate carbon dioxide emissions from fossil fuel burning or cement production. Ecological Footprint accounts add up the areas required for these ecosystems to provide these functions to the extent that they are mutually exclusive. The sum of these areas then represents the total human demand on nature – its Ecological Footprint. In other words, Ecological Footprint accounting builds on “mass flow balance,” where each flow is translated into the ecologically productive areas necessary to support them. This demand then can be compared to the sum total of ecologically productive areas, the biocapacity.
- Overshoot and biocapacity deficits. When a population’s Ecological Footprint exceeds the biocapacity of its territory, it runs a biocapacity deficit. This deficit is balanced either through the use of biocapacity from elsewhere, or local overuse, called ‘ecological overshoot’. At the global level, deficit and overshoot are identical since there is no interplanetary trade allowing for biocapacity use from elsewhere.
- Results from these National Footprint and Biocapacity Accounts show that humanity’s resource demands and carbon dioxide emissions began to exceed the regenerative capacity of the planet to meet these demands in the 1970s. According to Global Footprint Network estimates for 2018, humanity exceeded the planet’s ability to renew biological resources by over 70 percent. The world average biocapacity was 1.6 global hectares per person. In contrast, the world average Ecological Footprint was 2.8 global hectares per person.
- Exaggeration? The National Footprint and Biocapacity accounts are built strictly on UN data sets – using about 15,000 data points per country and year. These accounts may systematically underestimate ecological deficits: On the demand side, UN data sets do not completely document all demands. On the biocapacity side, availability may be exaggerated since some overuses are not factored into the assessment due to lack of consistent data. Such aspects include soil erosion, groundwater depletion, and loss in forest productivity due to increased forest fires and pestilence.
- Scalability. Ecological Footprint accounting can be applied at all scales, from the global down to the product level. Overshoot measured at the global scale is an indicator of humanity’s unsustainability.
For more results:
Global Footprint Network calculates the Ecological Footprint of countries on an annual basis. From 2018 onward, it is producing them in collaboration with York University, Toronto. All results are presented on an open data platform at data.footprintnetwork.org. The 2018 edition of the National Footprint Accounts, based on a full country level data set from the United Nations, stretches from 1961 to 2014. For humanity as a whole (and some individual countries), the results have been “now-casted” until 2018.
 Due to data constraints in UN statistics, the National Footprint Accounts only include carbon dioxide emissions in the waste equation. But in local assessments with more complete data sets, other waste streams have been included such as nitrogen pollution.
 UN data comes with a time lag. Hence the 2018 edition of the National Footprint Accounts only includes data up to 2014. Data points beyond 2014 are estimated through national data, where available, and extrapolations.
 A global hectare is a biologically productive hectare with world average productivity.