ACCA P1考试：Integrated Reporting and Sustainability
1.3.2 Measuring EF
EF may be summarised by the equivalent area of land needed to assimilate the impact. The normalised measure of land is called "global hectares" (gha).
The EF therefore measures the extent to which nature's resources are being used, and can be used to calculate how much faster resources are used than they can regenerate.
EF is not a complete sustainability measure.
*Although EF reflects an ecological outcome it does not, for example, include any measure of social well-being. Comparing the footprint of a particular measurement segment against that segment's bioproductive capacity allows determination of whether the group is a net user or provider of resources.
Illustration 2 Environmental Footprint
Carbon dioxide emissions in the United Arab Emirates account for almost 8 of the 9.5 gha per person the country uses. (A sustainable "earthshare" is estimated to be 1.7 gha.)
A country's EF is determined by:*
the amount consumed by its average resident; and
the resource intensity used in providing the goods and services consumed.
For organisations, categories of operational impact include:
energy usage (e.g. electricity and gas);
transportation (e.g. commuter travel, fleet operations (diesel), air travel);
*The World Wildlife Fund (WWF) has developed an Ecological Footprint (see http://footprint.wwf.org.uk/) which, through a series of questions, allows individuals to broadly calculate their own ecological and carbon footprints. The 2012 WWF Living Planet report estimated that the Ecological Footprint (the amount of biologically productive land and water required to meet the demand for food, timber and shelter and absorb pollution from economic activity) was 50% more than the actual bio-capacity available in the world (compared with 30% excess estimated in 2008). Further footprint calculators can be found online (e.g. carbon footprint questionnaire at www.carbonfootprint.com).