The successful legal challenge to the approval of the Net Zero Strategy shows how the process of statutory interpretation can result in wide-reaching briefing and reporting requirements being imposed on the Secretary of State and officials. 

Climate Change Act 2008

The Climate Change Act 2008 contains a complex series of measures for meeting the 2050 net zero target. 

Requirements on the Secretary of State include:

  • setting a carbon budget, for successive 5 year periods. 
  • each carbon budget must be set “with a view to meeting” the 2050 target.
  • ensuring that the net UK carbon account for a budgetary period does not exceed the relevant carbon budget.
  • preparing proposals and policies to enable the carbon budget to be met.

Proposals and policies

The legal challenge focused on the proposals and policies in the NZS, and the meaning and application of what seems, at first sight, to be a straightforward provision in the Act:

"such proposals and policies as the Secretary of State considers will enable the carbon budgets that have been set under this Act to be met."

The key point for the judge was that, for the Secretary of State to be satisfied that the proposals and policies in the NZS "will" enable the carbon budgets to be met, he needed to take into account the contribution to reductions in GHG emissions estimated by his officials from individual policies (or groups of interacting policies).

The judge acknowledged that it is reasonable for a minister to rely on briefing material from officials. However, the decision by the minister can be unlawful if the briefing omits something the minister was legally obliged to take into account.

The judge held that the briefing to the Minister did not enable him to appreciate the extent to which individual policies, which might be subject to significant uncertainty in terms of content, timing or effect, were nonetheless assumed to contribute to the 95% cumulative figure.

It was crucial so that he could question whether, for example, the Strategy he was being advised to adopt was overly dependent on particular policies, or whether further work needed to be carried out to address uncertainty, or whether the overall figure of 95% was robust or too high. If it was too high, then that would affect the size of the shortfall and his qualitative judgment as to whether unquantified policies could be relied upon to make up that gap with what he would judge to be an appropriate level of confidence. Information on the numerical contribution made by individual policies was therefore legally essential to enable the Minister to discharge his statutory obligation by considering the all-important issue of risk to delivery.

Report to Parliament

The Act also requires the Secretary of State to:

"lay before Parliament a report setting out proposals a report setting out proposals and policies for meeting the carbon budgets for the current and future budgetary periods up to and including that period"

The judge acknowledged that, depending on the context, "setting out" can mean simply to lay out or display, or to express in detail, describe or enumerate.

The Explanatory Notes to the Act indicated the purpose of this provision is to "ensure that Parliament is clear about how the Government intends to meet its obligations under the Act” (emphasis added).

Accordingly, an explanation must be provided to Parliament as to how the Secretary of State’s policies are intended to meet the statutory targets. The judge accepted the Act does not require the Department's detailed workings or modelling to be provided to Parliament. However, the judge held that the obligations could not properly be discharged without any quantitative explanation being provided to Parliament.

The judge identified several subjects which were not dealt with at all in the NZS, despite being obviously material to the critical issue of risk to the delivery of the statutory targets, and it being plain from the evidence before the court that the information existed at the time.


Judicial review is about legal issues, hence the focus on issues of statutory interpretation. The judge made it clear that the court is not responsible for making political, social or economic choices.

At a basic level, this decision merely requires the Minister to be fully briefed and then provide a more detailed report to Parliament – it continues to be the Minister and Parliament that make the choices, not the judge.

The decision is also a reminder that the significance of issues can make it more important to ensure there is appropriate briefing/ reporting despite the complexities raised by those issues – or, indeed, maybe even because of those complexities.

This case also shows the difficulties of statutory interpretation: how relatively straightforward statutory provisions can require a whole series of considerations to be taken into account, and reported on, despite not being mentioned specifically. It is a reminder of the risks of drafting broad rather than detailed statutory provisions (but remembering detailed provisions are not without risk, eg. something being omitted).


Neil Collar