This report reviews greenhouse gas (GHG) emissions and climate change mitigation data and models used in Aotearoa New Zealand. We make some recommendations on modelling capacity, data availability and accessibility and oversight/synthesis of the different types of models used.
It is important to gather climate change data so the government can monitor and assess the impacts of climate change mitigation initiatives. Economic-environmental modelling plays an important role in decision making to achieve climate emissions reduction targets.
Climate change mitigation data in Aotearoa is hosted by a range of organisations and collected using different frameworks and methodologies. Main collated data sources are the GHG emissions account and the GHG emissions inventory. Sector specific data are available through relevant government agencies.
A stock-take of New Zealand’s modelling capacity identified 84 climate change or climate change mitigation models: 13 multi-sector models, 23 land use and agricultural models, 25 energy models, and 23 transport models. The stock-take identified at least one model for each sector of the first Emissions Reduction Plan for Aotearoa - except for Building and Construction. Modelling capacity varied between sectors. The more developed sectors demonstrate greater interdependency between models. Almost all modelling takes a production-based approach. Capacity for a consumption-based approach was much more limited.
Collaboration on modelling between different government agencies allows for greater coordination (for example of key assumptions), facilitates interdependencies between models through sharing of data and information, and avoids duplication. A collaborative approach helps build capacity within the modelling community through learning opportunities and peer review. We identified two examples of formal collaboration. We found no formal international collaboration (outside of international reporting requirements).
Fyfe, Caroline, Phoebe Taptiklis, Dominic White, Niven Winchester. 2023. “Review of emissions data and modelling systems (Phase 1) Report". Motu Working Paper 23-06. Motu Economic and Public Policy Research. Wellington, New Zealand.