Regional ecological footprint

Methods - how we monitor

• Where and how we collect the data

  Footprint calculations are based on region-wide population, economic and energy statistics and models.

  Monitoring frequency

  This benchmark ecological footprint calculated for the Waikato region was calculated for the 1997-98 year. This update is for the 2003/04 year.  This indicator is intended to updated every five years.

  Monitoring history

  This indicator is based on data collected between 2002 and 2005 with calculations applying to the 2003-2004 year.

  Measurement technique

  The regional ecological footprint is largely based on region-wide economic data and models based on data supplied by Statistics New Zealand⁵and includes:

  • Population statistics based on sub-national estimates produced by Statistics New Zealand (2004)⁶, with a population estimate of 381,900 used for the Waikato region.
  • Estimates of embodied land, energy and material flows through the economic transactions between the region's economic sectors. These are derived from input/output tables compiled by Statistics New Zealand.
  • Estimates of land use data by economic sector based on data gathered from Quotable New Zealand (2004)⁷, Ministry of Agriculture and Forestry (2004)⁸, Agriquality New Zealand (2004) )⁹ and Works Consultancy Services Limited (1996)¹⁰ . The latter is the source of the National Traffic database used to estimate the road component of 'built land'.
  • Energy related carbon dioxide emissions by economic sector obtained from the Energy Efficiency Conservation Authority (2004)¹¹. The conversion of carbon dioxide emissions into energy land is based on Hollinger et al. (1993)¹².
• How the indicator is compiled

  The Waikato Regional Ecological Footprint includes three elements - land use required from:

  • within the Waikato region (intra-regional)
  • other regions (inter-regional)
  • other countries (international).

  Three databases are required to calculate the Waikato Regional Ecological Footprint:

  • 'Generation of Regional Input-Output Tables' (GRIT), which measure the use of resources and the generation of wastes and emissions through the region’s economy, including interactions between industry sectors. These tables use internationally standardised GRIT methodology (a non-survey modelling technique).
  • Land inputs (land area used by each economic sector).
  • Energy data - carbon dioxide outputs/emissions by sector. This data is converted into ‘area of land used’ by applying a ‘pinus radiata’ (pine forest)carbon uptake rate.

  The intra-regional calculation measures the amount of land from within the Waikato region required to meet current levels of ‘final demand’ (that is, final consumption of goods and services produced in the Waikato region). This is then adjusted to account for land appropriated through imports and exports (inter-regional and international trade).

  Adding all the sectors gives the regional total land area. Dividing by the regional population generates ‘per person’ ecological footprint figures.

  To compare the Waikato region’s ecological footprint (McDonald and Smith, 2006) with:

  • the average New Zealand ecological footprint (Hails 2006)
  • ecological footprints of other countries (Hails 2006)
  • the global ecological footprint (the average world-wide ‘per capita’ footprint, or ‘Earthshare’) (Hails 2006).

  the following steps were taken:

  • 'Per person' ('per capita') ecological footprint figures for the Waikato region (3.68 - including fishing grounds) calculated by McDonald and Smith (2006) were adjusted to match global estimates generated by Hails (2006).
  • Modifications included:
    
    • the use of global average biological productivity yields, such as kilogram of milk per hectare of land (instead of local New Zealand yields)
    • the use of equivalence factors (to take into account any variations in biological productivities) for the various land types
    • applying a global average carbon dioxide sequestration factor, and including sea space and carbon dioxide absorption by oceans.

  This resulted in an adjusted ecological footprint for the Waikato region of 5.8 ha per person.
• Limitations

  There are a number of limitations in calculating this indicator:

  • The focus on ‘productive land’ in the context of the Waikato Regional Ecological Footprint excludes conservation land, and other non-productive land uses. The use of alternative units (for example, energy) may be a better measure from an ecological perspective.
  • The assumptions made for deriving energy land.
  • The use of local yields (New Zealand, rather than global averages) was used whenever possible. However, for some aspects there was a lack of data.
  • Static assumptions where dynamic modelling would be preferable.
  • Generally has limited policy relevance, although there is the potential to break ecological footprints down into components that can be used for target setting (for example, transport, energy, consumption).
  • GRIT versus survey-based input-output tables - the latter would be more accurate, however they still need a more detailed breakdown of economic sectors (for example, agriculture can be broken down into sheep/beef, dairy, horticulture and other categories).
  • Energy land conversion numbers.
• Quality control procedures

  Data analysis and quality assurance procedures set out by McDonald and Patterson (2001) were used in the calculation of the Waikato Regional Ecological Footprint.