A net zero planner takes a baseline emissions figure and a target year and asks: what does the path between these two points look like? It is a modelling exercise, not a target-setting exercise. The goal is to make the journey concrete — which reductions land in which years, what remains after they've been applied, and whether the residual is a manageable number or a figure that should prompt a conversation about ambition.
Most businesses have a target year and a headline number. Fewer have a model that connects those two things to the decisions they'll need to make in the next three, five, and ten years. That's the gap a good net zero planner fills.
The four inputs that matter
1. Baseline emissions (tCO₂e)
This is the starting point — typically the most recent full year of audited or estimated emissions, covering the scopes relevant to your boundary. For most SMEs doing first-pass planning, this means Scope 1 (direct) and Scope 2 (purchased energy). Scope 3 (supply chain and value chain) matters for completeness but is harder to estimate reliably for an initial model.
2. Target year
The year by which the organisation aims to reach net zero or a defined reduction percentage. Common choices are 2030, 2035, and 2050. Shorter timelines make the annual reduction rate steeper and leave less room for deferred action. A planner makes this tradeoff visible immediately.
3. Annual reduction rate
Either a flat percentage applied year-on-year, or a custom schedule that reflects known investment phases. In practice, reductions are rarely linear — energy efficiency upgrades might deliver a step change in year two, while fleet electrification and supply chain decarbonisation land in later years. The most useful plans model this non-linearity rather than smoothing it away.
4. Residual offset requirement
The emissions that remain in the target year after reductions have been applied. This figure is often surprising — many businesses find their residual is larger than expected once the realistic pace of reduction is modelled honestly. Making the residual visible is one of the primary functions of a net zero planner.
Model your pathway
Use the full tool in The Carbon Workbench to save your pathway, export a PDF report, and pair the model with the project feasibility and credit pricing tools if you're planning to develop your own offset supply.
Use full Net Zero Planner →What a complete model should tell you
Once the inputs are in place, a useful net zero planner should produce at least four outputs:
| Output | Why it matters |
|---|---|
| Emissions in each year of the pathway | Makes the annual pace of change visible and reviewable against operational plans |
| Cumulative emissions to target year | Shows the total climate impact of the pathway — not just the endpoint |
| Residual in target year (tCO₂e) | The gap that offsets or removals would need to fill if the organisation wants to claim net zero |
| Estimated offset cost at target year | Translates the residual into a financial figure using assumed credit prices — useful for budget conversations |
Common mistakes when using a net zero planner
Using an optimistic reduction rate without a delivery plan
It is straightforward to enter a 10% annual reduction rate and watch the pathway reach net zero by 2035. What a model cannot do is confirm whether that rate is achievable. Every percentage point of annual reduction should be linked to a real programme — energy audits, building retrofits, fleet changes, supplier engagement. If the programmes don't exist yet, the rate should probably be more conservative until they do.
Treating the target year residual as the only offset need
Some frameworks ask organisations to offset their cumulative emissions during the transition period, not just the residual at the endpoint. If that requirement applies, the offset budget is substantially larger than a single-year residual calculation would suggest. Check which standard or framework you're working to before sizing your offset strategy.
Ignoring Scope 3
Supply chain emissions are often three to five times larger than Scope 1 and 2 combined for product-based businesses. A pathway that only models Scope 1 and 2 may be technically accurate within its boundary while understating the organisation's full climate impact. It's acceptable to model Scope 1 and 2 first and add Scope 3 progressively, as long as the boundary is clearly stated.
Connecting the planner to credit pricing and project feasibility
If the residual in your model is large enough that purchasing offsets represents a meaningful cost, it's worth stress-testing that number against realistic credit price scenarios. The credit pricing tool lets you model the offset budget at conservative (£8–12/t), base-case (£15–25/t), and optimistic (£30–50/t) price assumptions. The gap between these scenarios is often large enough to affect how an organisation thinks about the pace of operational reduction versus the pace of buying offsets.
Organisations with larger residuals, or those in sectors where offsets will be a long-term part of the strategy, sometimes find it worth exploring whether developing their own offset supply — a carbon project aligned to their operations or supply chain — changes the economics materially. That's where the project feasibility tool connects to the planning work.