Table 1-1: Assumptions made by three different ecological footprint calculation methods

Applies local yields for pasture, arable and forest land

Applies global average yields for pasture, arable and forest land

Applies local yields for pasture, arable and forest land

Does not apply equivalence factors

Applies equivalence factors when aggregating land types

Does not apply equivalence factors

Applies an international energy-to-land ratio obtained from Wackernagel and Rees (1996)

Applies world average CO₂ absorption factor

Applies CO₂ absorption factor for New Zealand Pinus radiata (Hollinger et al, 1993)

Ignores CO₂ absorption by oceans

Assumes oceans absorb 35 percent of CO₂ emissions

Ignores CO₂ absorption by oceans

No allowance for securing biodiversity

Assumes 12 percent of biocapacity is set aside for securing biodiversity (as per WCED, 1987)

No allowance for securing biodiversity

Excludes sea space

Includes sea space, estimated to be 0.1 ha per capita for New Zealand

Excludes sea space

Considers ecological interdependencies between regions as an aggregate (total imports)

Considers ecological interdependencies between regions as an aggregate (total imports)

Makes explicit ecological interdependencies between regions

Based on input-output analysis

Based on work of Wackernagel and Rees (1996)

Based on input-output analysis