Appendix D - Spend-based emission factors

0.1 Spend-based emission factors

In 2023, Auckland Council has published emission factors using a spend-based emissions accounting approach. Using data from Stats NZ Tatauranga Aotearoa, emission intensities are calculated for 199 commodity types. These can be linked to an entity’s expenditure on goods and services. It is assumed that goods and services purchased from outside of New Zealand generate the same quantities of emissions per dollar of expenditure as equivalent goods and services produced in New Zealand.

In terms of consumption, spend-based emissions accounting focuses on calculating the emissions ‘embodied’ in the goods and services people consume. In other words, all emissions released directly and indirectly throughout the industrial supply chain that generated each good or service.

Entities completing a GHG inventory may find this dataset useful for estimating Scope 3 emissions, which may be difficult to do in the absence of activity or supplier specific data. The generated emission intensities and datasets have potential applications beyond GHG inventory management, such as assessing entities’ consumption patterns to identify potential opportunities to reduce GHG emissions, or analysing the impact of different development trajectories.

Note these emission factors will only give you an estimation of your supply chain emissions. We recommend using these factors only if better quality activity data isn’t available. These emissions factors do not relate to specific products and to ensure an accurate measure of emissions and reflect choices between different products supplier specific data is required.

Access the Auckland Council Consumption Emissions Modelling report here: https://www.knowledgeauckland.org.nz/publications/consumption-emissions-modelling/.