Sustainability is full of confident claims, and plenty of them do not survive contact with the evidence. If you spend an hour on one of our courses, you should be able to trust what you read without taking our word for it. This page sets out the standards every lesson has to meet, what sponsorship can and cannot buy, and what to do when you find something that falls short.
How a course is made
Our writers use AI to support their writing process. After the writing process, every course is checked by our team of editors against the standards on this page before it is published. Nothing goes live unreviewed.
Check any claim yourself
Claims that rest on evidence carry a numbered marker like [1]. Each marker matches an entry in the References list at the end of that lesson, and most entries link straight to the original document, so you can read the study, the regulation, or the dataset for yourself.
If a load-bearing claim has no reference behind it, that is a mistake on our side, not a style choice. Please tell us.
What has to be cited
We cite the claim, not just the number. A statistic is easy to source; the sentence that tells you what that statistic means is the one doing the teaching, so that is the sentence that has to carry a reference. A lesson needs a source whenever it states:
- a mechanism or a scientific finding;
- an interpretive claim about how a system works;
- anything phrased as "studies show" or "research finds";
- a regulatory or industry fact;
- a comparison such as "X is three times more...";
- a statistic that is not common knowledge.
Equally, we do not decorate ordinary sentences with references. General framing, common knowledge, and clearly signalled opinion stay uncited, because a wall of citations attached to nothing in particular makes a page look rigorous instead of being rigorous.
Contested evidence is presented as contested
Some of the most-discussed topics in sustainability genuinely do not have a settled answer: carbon offset additionality, household recycling effectiveness, fair-trade premium pass-through, organic versus conventional yields, electric-vehicle lifecycle emissions, plant-based versus animal-source nutrition. On claims like these, one supportive study is not enough to write them up as fact.
Instead we either cite a systematic review or meta-analysis that acknowledges the disagreement, or cite each side and say plainly in the text that the evidence is mixed. If you see "the evidence on this is mixed" in a lesson, that is the policy working, not the author hedging.
Every course argues against itself
Each course is required to examine the limits, failures, or counter-evidence of its own central claim. You will meet these as sections titled something like Where this falls short, When the model breaks, or The strongest criticisms.
Two rules govern them. They sit next to the claim they qualify rather than being tucked away at the end, and they have to name the strongest specific criticism with a source. Vague gestures such as "some critics disagree" do not satisfy this. Sustainability content that omits well-documented criticism is advocacy, not education.
Extra scrutiny where greenwashing lives
Certain claims tend to originate with the organisations that benefit from them: offset quality, recyclability rates, "biodegradable" and "compostable" labels, corporate sustainability reporting. For those we prefer independent and academic sources over industry ones. Where an industry source is genuinely the only one available, the lesson says so in the text so you can weigh it accordingly.
What you will not find in a lesson
- Product placement. Lessons do not push a brand, a shop, or one product as the answer.
- Doom or moralising. We do not inflate a risk for effect, and we do not imply that household choices alone fix systemic problems. Where an action is small, we say it is small.
- Marketing language in disguise. Claims are written to be checkable. If a sentence cannot be supported, we rewrite or remove it rather than soften it into something vague enough to be unfalsifiable.
Courses supported by a Knowledge Partner
Some courses are sponsored by an organisation we call a Knowledge Partner. You will always know when you are on one: the partnership is stated on the course overview with the partner's name and logo, and again in the footer of every lesson. Any material a partner contributes is labelled as theirs.
Sponsorship buys attribution and, on some tiers, a clearly marked contribution. Here is what it does not buy:
- Control over the lessons. We choose the topic, the argument, and the wording. Contributed material meets the same citation and counter-evidence standards as everything else, and partner links in references get the same review as any other source.
- A place in the quiz. Partners are never named in the quiz briefing, the questions, the answers, or your result screen, and they have no influence over any of them. An automated check in our build blocks partner branding from reaching those screens.
- Your reward. Partners do not fund payouts and cannot change what you earn. Rewards on a sponsored course are set by us under the same rules as any other course.
- A sales channel. No calls to action for the partner, no lead capture forms, no funnels pointed at their sales team.
- A veto. A partner may check the factual accuracy of the module they contributed and how their own organisation is described. Nothing beyond that is theirs to approve. If a claim does not survive fact-checking, it does not ship, whoever is paying.
When we get it wrong
We publish a lot of material, sources get updated, and some claims age badly. Typos and reference fixes are made as soon as we spot them. A substantive correction is reviewed like new content, and if a claim turns out to be unsupportable we rewrite or pull it.
One limit worth stating plainly: our courses are general education. They are not personal medical, legal, or financial advice, and they are not a substitute for guidance specific to your situation.
Tell us if something looks off
If a claim looks unsupported, a source does not say what we say it says, or a sponsored course reads like an advert, we want to hear about it. While logged in, use the Feedback button and pick the Content category, which sends us the page you were on. Otherwise, contact us and mention the course and lesson.