Net Zero Assessment: independent review

Introduction

On 25^th November 2024, 16 documents relating to a pilot of the Scottish Government’s Net Zero Assessment (NZA) process were provided for independent expert review to Lewis Barlow. Lewis is a Chartered Engineer, a Chartered Environmentalist and a Fellow of the Institution of Civil Engineers, where he is Trustee for Carbon and Climate. A list of the documents provided for review is included as Annex A.

The Net Zero Assessment (NZA) pilot project, conducted by the Scottish Government between March and October 2024, aims to embed quantitative carbon assessment in the early stages of policy development and budgetary decision-making. The goal of the NZA is to support decisions by providing early estimates of carbon emissions - increases or decreases - that may result from policies, allowing mitigation measures to be considered and enhancing opportunities for carbon emissions-reduction efforts.

The NZA pilot involved a proportionate, three-stage process as follows:

• Stage 1 consisted of an initial screening discussion between the lead policy team and a review panel to identify if the policy was likely to have an emissions impact above a ‘de minimis’ threshold.
• Stage 2 involved a ‘light-touch’ assessment of emissions impact, confirming whether the policy was above or below the de minimis threshold and identifying policies requiring full in-depth analysis.
• Stage 3 required a full quantitative emissions assessment for policies exceeding the de minimis threshold.

Of the 16 documents provided for this review, the principal document is “1.2 Net Zero Assessment NZA - Report on Pilot” (herein referred to as the Report), with the other documents comprising supporting information. The Report concluded that the pilot was successful, stating: "The pilot robustly and successfully tested the NZA three-stage methodology across a wide range of policies volunteered by portfolios or drawn from Programme for Government. The pilot clearly demonstrated how policies progress from initial consideration to Stage 1, Stage 2 and Stage 3 assessment" (p12).

The Report highlights the workability and credibility of the methodology, recommending its wider application: "Overall, the pilot proved the methodology is workable and credible and can be recommended for wider roll out across the Scottish Government" (p12).

This document comprises a review of the NZA process based on the documentation provided, including a categorised assessment, conclusions and recommendations.