Ecological Footprint

1
Ecological Footprint

• area of land in the same vicinity as the
  population that would be required to 1)
  provide all the populations 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)

2

• Today the earth has 10.8 billion hectares of
  biologically productive space
• Less than one quarter of the earths 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

3
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

4
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.

5
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

6
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

7
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 earths biologically productive
  area should be set aside for other species?