The common reporting unit: National Footprint Accounts

The National Footprint Accounts (Redefining Progress, 2002), published as part of WWF's Living Planet Report (Loh, 2002), are a series of ecological footprint calculations for over 250 countries, prepared by Wackernagel in collaboration with WWF-International, UNEP World Conservation Monitoring Centre and his teams at Redefining Progress and the Centre for Sustainability Studies (Mexico).

The National Footprint Accounts use an ecological footprint methodology known as the 'compound' or 'top-down' approach. The compound approach captures all resource use, including trade, within a geographical boundary, and is measured at a national level.

To calculate the per person ecological footprint of a nation, using the compound methodology, the following national data is used:

  • Production, import and export of materials, such as crops, animals, fish and wood.
  • Energy consumption, including the net balance of embodied energy through traded products including minerals.
  • National land use.

International bodies, such as the United Nations Food and Agriculture Organisation (see FAO, 2002) and the International Energy Agency (see IEA, 2003), regularly publish this type of data. Data for the South West was not represented in any of these publications, and not being a nation, it is not included in the National Footprint Accounts.

To enable comparisons between regions with different bioproductive capabilities, the ecological footprint is presented in global hectares (gha).

One global hectare is equivalent to one hectare of biologically productive space with world average productivity.

To convert different areas with different productivities into standardised global hectares, two conversion stages are required:

  • For each area type, the local area is converted to a 'global average' equivalent area using yield factors – so if one hectare of land is twice as productive as the global average, it becomes two 'global average hectares' of that area type. The National Footprint Accounts give 'yield factors' for each nation to enable this conversion. These results are presented in specific area types, for example 'global average arable area' or 'global average forest area'. However 'global average hectares' for different area types represent different amounts of bioproductivity.
  • 'Global average' areas for each area type (arable, pasture, forest, built land) are converted into standardised units of area by applying equivalence factors. The equivalence factors, from the National Footprint Accounts, are subject to change due to both data availability and variability in the bioproductivity of the planet over time. This international, standardised unit of area is the global hectare (gha).

The results of the National Footprint Accounts are reported in ecological footprint per person for each country, as totals and split between the different area types. Table 1 shows the results* for the UK, from the Living Planet Report 2002 (Loh, 2002), based on 1999 data.

* The Living Planet Report 2004 (Loh & Wackernagel, 2004) was published in the final stages of the Stepping Forward study, too late for the updated figures to be incorporated into the calculations for this report.

Table 1
The National Footprint Account for the UK, using 1999 data
Area type Per person ecological footprint (gha) Per person biocapacity (gha)
Total ecological footprint 5.35 1.64
Crop area 0.68 0.52
Forest AWS* 0.32 0.13
Wood fuel 3 x 10-4 -
Forest NAWS** - 0.001
Permanent pasture 0.33 0.41
Fishing grounds 0.47 0.36
Built land 0.21 0.21
Hydro area 0.001 0.001
Energy 3.33 0
* Available wood supply.
** No available wood supply.
Source: Redefining Progress, 2002

While the National Footprint Accounts represent the global ecological footprint 'gold standard', the results are not immediately relevant to national or regional policy-makers or individuals, as they do not relate to policy areas or activities such as waste or transport. It is possible, using a 'component' methodology, to provide a policy-relevant disaggregation of the National Footprint Accounts. Components relate to key activity and policy areas, such as the production and consumption of food, domestic energy, personal transport and the materials, products and services traded and consumed.

Geographical and responsibility accounting principles

Before a regional ecological footprint, such as Stepping Forward , can be calculated, a fundamental boundary decision needs to be made - should it calculate the South West's footprint (geographical principle) or consumption associated with the South West's residents (responsibility principle)?

These two approaches can give very different results. Taking airports as an example, it is possible to include all the airport activities as part of the South West's footprint (geographical principle), or to estimate the impact attributable to South West residents using airports anywhere (responsibility principle).

This study calculated the South West residents' ecological footprint using the responsibility principle, as this is most compatible with other global, regional and city studies. Sustainability assessments using the average earthshare are only valid when using the responsibility principle. See Lewan & Simmons (2001) for further discussion on the responsibility versus geographical principle.