Question to the HM Treasury:

To ask the Chancellor of the Exchequer, with reference to the his Department's policy paper entitled Net Zero Review Final Report, published on 19 October 2021, what recent progress his Department has made on developing the green book in line with environmental evidence.

As outlined in the Net Zero Review final report, HM Treasury is building its governance, capabilities and processes to support our transition to Net Zero. The Green Book mandates the consideration of climate and environmental impacts in appraisal and provides detailed guidance on how to do so. There have been a range of recent updates to the Green Book and particularly on environmental appraisal to support best practice. This includes both net zero and appraising wider impacts on the environment.

In January 2023, supplementary guidance to the Green Book on the appraisal and evaluation of energy use and greenhouse gas (GHG) emissions was revised to improve its use for policymaking when applied to climate and environment.

The Treasury requires all departments to adhere to the Green Book guidance when providing a business case for a policy, programme or project.