Measured Commitments: Allocating Risk in Public Sector Decarbonisation Clauses

Decarbonisation is no longer a peripheral concern in public contracting. Authorities are expected to use their commercial leverage to reduce emissions across works, goods and services, and suppliers are increasingly asked to commit to carbon reductions as part of the award and delivery of public contracts. The legal risk is not that a contract contains a carbon target. It is that the target is expressed as an aspiration without a defined obligation, a method of measurement or a consequence for failure. A clause requiring a supplier to support the authority’s net zero ambition may read well in a bid narrative, but it is unlikely to withstand scrutiny when performance is disputed.

As authorities review their 2026 contract portfolios, the task is to convert climate policy into contractual obligations that are precise, evidence-based and proportionate. That requires a deliberate allocation of risk rather than an open-ended transfer of climate uncertainty to the supplier.

From aspiration to obligation

The first decision is what the authority is actually buying. A contract may require a specified outcome, such as a reduction in operational emissions by a stated date. It may require a process of continuous improvement, such as producing a credible decarbonisation plan and reporting progress. Or it may require disclosure only, such as annual carbon reporting in a prescribed format. Each is legitimate, but each carries different risk and should be drafted differently.

Outcome obligations should be limited to matters within the supplier’s control. Process obligations should include defined milestones, governance and evidence. Reporting obligations should specify the standard, frequency, data fields and assurance level. Blurring these categories is a common source of dispute, because the supplier may believe it has promised a plan while the authority believes it has promised a result.

Defining the boundary and the baseline

Carbon commitments are meaningless without a defined boundary. The contract should identify whether the obligation covers a single site, a service, a project or the supplier’s whole organisation. It should state whether the target is absolute or intensity-based, and whether it covers Scope 1, Scope 2 and, where relevant, Scope 3 emissions. For construction and infrastructure, the authority may require a project carbon budget using a recognised methodology. For services, the focus may be on fleet, energy use and supply chain data.

The baseline year, baseline figure and any adjustment rules should be recorded in the contract or an agreed schedule. The authority should avoid incorporating a target by reference to a corporate strategy alone, because strategies change and the contractual obligation may become uncertain. If the target is drawn from a policy document, the relevant figure and methodology should be set out expressly.

Measurement, verification and data rights

Measurement is the fault line in most decarbonisation clauses. The contract should specify the methodology, conversion factors, materiality threshold, reporting frequency and verification requirements. It should also address who bears the cost of verification. Proportionate independent verification may be appropriate for large works contracts or performance-based arrangements; for smaller service contracts, a documented self-report with audit rights may be sufficient.

The authority should secure access to the data needed to test performance. That includes rights to request underlying evidence, inspect records and require correction of manifest errors. Data ownership and permitted use should be addressed, particularly where the supplier generates carbon data that the authority needs for grant reporting or statutory returns. Confidentiality provisions should not be allowed to frustrate verification.

Technology, change-in-law and delivery risk

Decarbonisation frequently depends on technology, infrastructure or market conditions that are not fully within the supplier’s control. A contract that guarantees a carbon reduction regardless of grid decarbonisation, fuel prices or planning delays may be uninsurable and may attract a substantial risk premium. The authority should distinguish between ordinary efficiency risk, which the supplier can reasonably manage, and external change that should be shared or retained by the authority.

Change-in-law provisions should identify the relevant regimes, such as carbon pricing, energy performance standards or building regulations, and state how a material change affects price, timetable or specification. Technology risk should be allocated expressly. If the authority specifies a particular technology, it may be fair to retain some performance risk; if the supplier chooses the solution, the supplier should ordinarily bear the risk of its performance. Relief events and price adjustment mechanisms should be clear, time-bound and evidenced.

Grant conditions and funding mismatch

Where a project is funded by a grant, the authority may be required to flow down reporting, audit, record-keeping and clawback obligations. The contract should identify the grant conditions that apply, require supplier cooperation and set out what happens if funding is reduced, delayed or recovered. Back-to-back flow-down is not always possible. A grant funder may require repayment if a carbon target is missed, while the supplier may have no equivalent liability. The authority should decide whether that residual exposure is acceptable, priced or capped.

Flow-down should be limited to the funded scope and to obligations the supplier can realistically perform. The authority should retain control of grant correspondence and decisions, while requiring timely information from the supplier. Indemnities for grant clawback should be treated with caution and should be proportionate to the supplier’s fault.

Remedies that remain enforceable

Remedies should be linked to defined obligations and should be proportionate. Reporting failures may attract service credits, withholding of a performance fee or a requirement for a remediation plan. Persistent failure to meet a process obligation may justify escalation, independent review or termination. Liquidated damages for carbon performance require particular care: they must be a genuine estimate of loss and not a penalty. Specific performance is rarely suitable for carbon outcomes, and injunctions are unlikely to be practical in most service contracts.

The authority should also consider insurance. Contractual carbon penalties may not be insurable, and suppliers may seek caps or exclusions. A clear liability cap, with carve-outs for fraud, wilful default and regulatory breach, is often more defensible than an uncapped obligation that the market cannot price.

Contract management and the evidence trail

Decarbonisation clauses fail in operation when no one owns the data or reviews progress. The contract should name the responsible roles, set reporting dates and provide for regular performance reviews. The authority should keep a decision trail showing how targets were set, how data was verified and how exceptions were handled. That record is valuable not only for dispute resolution but also for audit, grant assurance and future procurement design.

The objective is not to import the whole of climate policy into every contract. It is to use contractual obligations where they can be measured, managed and enforced. A measured commitment, supported by clear evidence and proportionate remedies, is more likely to deliver real decarbonisation than an ambitious clause that neither party can operationalise.