A practical guide to setting science-based targets

A science-based target is often described as an ambition. In practice it is a calculation with a governance process around it, and most of the difficulty sits in the data rather than the ambition.

1. Fix the boundary before you fix the number

Which legal entities, which operations, which financial-control or operational-control basis? A target set on a boundary that later changes is a target that has to be recalculated, and restatements are expensive in credibility.

For groups with subsidiaries, joint ventures or contracted operations, this step is where most of the first month goes.

2. Build the inventory, then check it

Scope 1 and 2 are usually tractable. The problems appear in the details: refrigerant leakage, generator fuel, purchased steam, and the choice between location-based and market-based electricity accounting.

Scope 3 is where Zimbabwean and regional companies are most exposed. For a miner, purchased goods and services and downstream processing dominate. For an agricultural processor, land-use change and upstream inputs do.

A screening exercise — spend-based where activity data is missing — is a legitimate starting point, provided the result is labelled as an estimate rather than presented as measurement.

3. Choose the pathway

Near-term targets generally require absolute reductions in the order of 4.2% per year for a 1.5°C-aligned pathway, with scope 3 covered where it is material. Net-zero targets require deeper long-term reduction and a limited role for neutralisation.

Offsets do not count towards target delivery. This is the single most common boardroom misunderstanding, and it is worth stating plainly at the start.

4. Test the pathway against capital plans

A target that assumes decarbonisation projects the company has not funded is a press release. The credible version maps abatement measures to capital cycles, with marginal abatement cost curves showing what each tonne costs and when it is available.

5. Submit, and expect questions

Validation asks for evidence: inventory methodology, base-year recalculation policy, target ambition relative to the sector pathway, and how scope 3 coverage was determined.

What makes it work

Three things separate targets that get used from targets that get filed:

• Ownership at board level, with the target wired into capital allocation.
• A data owner per scope, not a single overworked sustainability lead.
• A reforecast cycle, so the pathway is reviewed when the business changes rather than at the next submission window.

Set the boundary, measure honestly, cost the abatement, then commit. In that order, a science-based target becomes a management tool rather than a disclosure exercise.