Impacts of circular approaches on emissions, jobs, and other factors

Material flow and Sankey diagram findings

The research involved collection and analysis of data on the mass of materials used in the economy, and associated energy and carbon emissions metrics. Sankey diagrams were used to show the flows of materials and emissions within New Zealand’s economy.  

Some of the findings, distinctive to New Zealand are:

• New Zealand’s predominance of biomass resource, which, through both imports and domestic extraction of biomass grown here, makes up 64% of total mass of material flow.
• An estimated 8.5% of the material flowing into the economy ends up as waste in landfill, with less than 1% of materials recovered, indicating a low level of recovery through recycling or composting.
• Concrete and aggregates dominate the material flows into New Zealand’s built environment, comprising 87% of the total 11,095 kt mass flows. Timber comprises only 3.5% of the material flows into the built environment.  

Opportunities for New Zealand

A wide range of opportunities were identified for circular economy approaches to contribute to emissions reduction and wider impact in New Zealand. The report presents these in detail, assessing their likely benefits and limitations.  

The best areas of opportunity were identified as:

• Resource efficient buildings and infrastructure, for example switching to more renewable, bio-based, and recycled materials.
• Innovations in sustainable agriculture, such as the use of more local and organic alternatives to imported fertiliser.
• Critical materials, for example through improving product durability and domestic recycling of critical materials, such as plasterboard and those found in electronic devices.

Emissions savings potential

Estimated emissions savings of 1.5 – 1.9 Mt CO2e per annum (non-cumulative) were identified from quantifiable opportunities, equivalent to approximately 3% reduction on 2021 net emissions.

Additional emissions savings could be realised in the longer term through sustained action. By 2050, savings of 13 – 19 Mt CO2e (total not per annum), could be achieved through vehicle sharing models (that reduce materials used in vehicle manufacture), and the reuse of vehicle components such as batteries. A further saving of 1.5 Mt CO2e per annum was estimated to be achievable in 50 years’ time if we start designing residential buildings to last 100 years, rather than 50 years. There are other circular economy approaches that could reduce emissions further that cannot easily be quantified.

Conclusions

This research was the first of its type for New Zealand and should be viewed as a starting point for this type of analysis due to current data gaps. Greater availability and quality of data would strengthen future analysis.

The findings indicate that circular approaches have the potential to support significant emission savings over time, but that achieving this will take deliberate and sustained action. Other impacts of circular approaches reviewed in the research included greater productivity through more efficient use of physical resource inputs, new and changed jobs, and opportunities to mitigate supply chain risks.

Read more about this research in the report, downloadable here:

The research was carried out by thinkstep-anz, supported by Aurecon and the Sustainable Business Network.