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Story supplies meaning and order. Evidence supplies the right to make the claim. Climate, nature and science companies need both, and regulators are now writing the second one into law. The UK government keeps a collection of guidance on making environmental claims about goods and services, and the EU has adopted Directive (EU) 2024/825 on empowering consumers for the green transition, which sets new rules for green claims. A company that already works this way has less to rewrite when the rules reach its market.
Start with the claim before the anecdote
Before writing the story, write down the one sentence you want the audience to believe. "The intervention restored biodiversity." "The product lowers cost." "The technology is ready for commercial deployment." "This project caused the observed change." Then work out what evidence would defend that exact sentence in front of a sceptical reader.
The available evidence often supports a narrower sentence. A pilot can show technical performance and leave commercial economics open. A species detection establishes presence and says little about abundance. A letter of intent shows interest and falls short of revenue. A customer quote records perception and leaves causality untested. Narrowing the claim makes the story durable, because the narrow version survives diligence and the wide one gets quietly withdrawn.
Sort evidence by what it can prove
In our own research we sort evidence into four classes. Direct evidence tests substantially the same claim in the relevant context. Transfer evidence applies a mechanism or finding from an adjacent context. Practice observation describes what happened in a limited number of engagements. Author hypothesis is a synthesis or interpretation that still needs testing.
The classes stop a common slide, where an interesting adjacent finding becomes direct proof somewhere between the lab report and the homepage. A trial on one crop in one climate is transfer evidence for another crop in another climate. Saying so costs a few words and saves a difficult call with an investor's technical adviser. The same logic runs through how to build credible impact stories from evidence.
Put the boundary next to the claim
A qualification in a footnote rarely repairs an overclaim in a headline. If a result comes from a pilot, say pilot scale in the same sentence. If a metric is modelled, label it as modelled. If an outcome followed the work and causality is unproven, write "since the work" and leave out "because of the work".
Sophisticated readers take a stated boundary as a sign the team understands its own evidence. Placement matters as much as wording. We wrote about that in where the evidence sits matters.
Eeden kept its LOI an LOI
Eeden works in textile recycling. Its partnership story connected the company to upcoming regulation, to future demand for recycled textile inputs and to the gap between that demand and available supply. That material sat alongside a Letter of Intent with a partner.
A Letter of Intent is meaningful commercial evidence of interest. It is also a specific kind of evidence, and the honest description is an LOI. Upgrading it into revenue, procurement or a guaranteed rollout would claim more than the document carries, and any investor who reads the LOI would see the gap at once. Described precisely, the LOI makes the case more credible. We tell the story in the Eeden case study.
The ICVCM separates the promise from the test
The carbon market offers a public example of the same structure. The Integrity Council for the Voluntary Carbon Market publishes the Core Carbon Principles, its benchmark for credit integrity. It publishes a separate Assessment Framework, and carbon-crediting programmes and methodologies are assessed against the principles through it.
The principles are the claim. The assessment framework is the evidence standard the claim has to meet. A buyer can read the first in a few minutes and a diligence team can work through the second line by line. Companies can borrow the pattern at their own scale by pairing each headline claim with a short, linked account of how it was tested. For carbon companies specifically, see carbon MRV storytelling.
The Impact story puts evidence in the middle
Evidence needs an order before a reader can use it. The Impact story in our Story System follows five moves.
- Before
- Action
- Observed change
- Evidence
- Meaning
Before is the condition that existed ahead of the intervention. Action is what the company, project or product actually did. Observed change is what changed afterwards. Evidence says how we know, at what confidence and with what limitations. Meaning explains why that change matters to the person making the next decision. The structure keeps the emotional conclusion attached to the evidence underneath it.
The error to avoid is using emotional stakes as permission to loosen causality. Human stakes explain why the evidence matters. They add nothing to what the evidence shows. A founder story, customer anecdote or vivid scene makes an abstract problem tangible and illustrates a pressure or a consequence. Performance claims need data, trials, contracts, measurements or independent verification. Both can sit in the same article, each doing its own job.
Keep an evidence register and match it to the decision
For companies with technical, climate or nature claims, a simple internal register saves a lot of later repair. For each claim, record the following.
- The exact public wording.
- The supporting source, with date and version.
- The evidence class.
- Its limitations.
- The approved public language.
- Every place the claim currently appears.
The register earns its keep when the same fact travels across a website, a pitch deck, a press release and sales material. Without one, claims grow a little each time they are copied, until the homepage says something the lab never measured.
More evidence is sometimes the wrong repair. If a buyer already believes the performance claim and cannot get internal budget, another chart changes nothing. If an investor does not understand the commercial model, a larger technical appendix adds friction. Evidence works when it answers a live doubt held by the person making the next decision. A 90-page appendix can be rigorous and still badly communicated. Put the central claim and its most relevant proof where the reader will find it, and make the methodology, data and limitations one click behind.
How to test your own claims
Take the five claims your company repeats most often. Write each one down, name its evidence class and write its boundary in the same sentence. Any claim that needs a boundary it currently lacks goes on the list for this week. Any claim you cannot trace to a source comes off the website until you can. A precise claim that survives a technical review, an investment committee and a procurement process builds more trust than a dramatic one that lasts a week. Held this way, science and story strengthen each other.
If you want a second pair of eyes on the claims in your deck or website, our pitch and narrative work starts with exactly this audit.
Sources and further reading
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