1. Ecological Footprint

2. Definition of Ecological Footprint “area of land in the same vicinity as the population that would be required to: –1) provide all the population’s resources and –2) assimilate all of its wastes” (IB) Area required to sustainably support a population Model which gives a quantitative estimate of human carrying capacity Wackernagel & Reese (1995)

3. –Today the earth has 10.8 billion hectares of biologically productive space –Less than one quarter of the earth’s surface Includes 2.3 billion hectares of productive ocean and 8.5 billion hectares of productive land –This means that there are 1.7 biologically productive hectares per person –This number will decrease with increasing population size

4. Calculating Footprints It is possible to approximate the footprint of a population by adding the per capita land requirement for food and the per capita land requirement for CO2 waste absorption Food production = Food consumption (in kg/year) / Food production per hectare of local arable land (in kg/ha/year) CO2 absorption = CO2 emissions (in kg C/year) / net carbon fixation per hectare of local vegetation (kg C/ha/year) Add these values together and multiply by the total population

5. This is a very rough approximation! Neglects resources from aquatic and atmospheric sources Neglects assimilation of any wastes other than CO2 Neglects energy and materials imported to increase yield of arable land Neglects loss of productive land through urbanization Etc.

6. Ecological Footprint Calculators Estimate of ecological footprint of individuals based on country of residence, food eaten, goods and services consumed, transportation used, housing, energy use and waste generation http://www.earthday.net/footprint/index.asp http://www.bestfootforward.com/footprintlife.htm http://www.mec.ca/Apps/ecoCalc/ecoCalc.jsp

7. Footprints in Developed versus Developing populations Correlation between average income and ecological footprint Usually developing countries have lower ecological footprints but they may also have lower capacities Food - meat-rich diet versus grain diet Energy - fossil fuel dependence and CO2 emissions Biome - amount of CO2 fixation depends on climate and vegetation type

8. What about other species? It may require 30-70% of biosphere to maintain biodiversity Currently 3% of biosphere is protected (parks & reserves) How much of the earth’s biologically productive area should be set aside for other species?