Greenhouse gas emissions and infrastructure investment decisions

This report was commissioned to help the Scottish Government assess and report on the alignment between its investment in infrastructure and Scotland’s climate goals. Scotland has committed to achieving net-zero greenhouse gas (GHG) emissions by 2045 and appropriate investment in infrastructure will play a significant part in reaching this goal: it is estimated that just over half of annual GHG emissions are associated with infrastructure.

Government infrastructure investment priorities are set out in Scotland’s Infrastructure Investment Plan. This report informed the latest draft plan for consultation.

We identify four different types of assessment approach:

1. Absolute emissions methods: ‘How much of Scotland’s remaining carbon budget is ‘used up’ by a particular infrastructure asset?’ and ‘How much value per unit of carbon budget does this infrastructure asset create?’
2. Baseline-and-intervention methods: ‘What is the total change in emissions caused by the decision to build this infrastructure asset?’
3. Gap analysis: ‘What is the gap between current infrastructure plans/spend and what is needed to meet the emission reduction targets?’
4. Taxonomies: give a simple categorisation of different types of infrastructure, e.g. as ‘low carbon’ or ‘high carbon’, usually for broadly indicating whether an asset is likely to be consistent with reduction targets.

 Conclusions and suggestions

1. A phased approach is needed.
2. A taxonomy approach could be applied over the short term.
3. Applying a gap analysis approach would help build an understanding of the investment required to reach the GHG reduction targets.
4. A suite of assessment methods could be applied to provide a holistic understanding of the impact of the Infrastructure Investment Plan.
5. Assessment approaches can be applied to quantify emissions associated with Scotland’s infrastructure projects that occur beyond Scotland.