We scored every UK supermarket on sustainability
We scored every UK supermarket on sustainability. The Co-op leads at 50. ASDA is alone at the bottom at 31. No supermarket scored above 50.
UK supermarkets feed nearly 70 million people. The choices they make about what to stock, where to source it, and what to report shape the country's food system more than any other private sector decision.
We scored 11 UK supermarkets from 0 to 100 using the same formula we apply to every company in the SINK database. Public data. Open methodology. No corporate funding.
Anything above 60 is leading. 40 to 60 is making progress. Below 40 raises concerns.
The scores
The Co-op leads at 50 — five points clear of Sainsbury's. Seven supermarkets are making progress; four raise concerns.
For context, Patagonia scores 50. Ørsted, the Danish energy company, scores 63. UK supermarkets, collectively, are scoring in the same range as outdoor clothing brands — and well below companies built around clean energy.
Why the Co-op leads
Two structural factors help explain the gap.
Ownership. The Co-op is owned by its members, not by shareholders. The cooperative structure may help explain part of the gap — without quarterly pressure from stock market investors, long-term sustainability spending faces fewer obstacles. It is the only mutually owned business in the UK supermarket sector, and it has a long history of ethical positioning that predates the current sustainability era.
Scale. Most of a supermarket's emissions don't come from running its stores — they come from the food, packaging, and supply chain behind what it sells. This is called Scope 3, and it dwarfs everything else. The bigger the supermarket, the bigger that footprint. SINK applies a penalty for total emissions volume because the atmosphere doesn't care about emissions per pound of revenue — only total tonnes. Tesco alone emits roughly 59 million tonnes of CO₂-equivalent a year, more than any other UK retailer by an order of magnitude. The Co-op, with a far smaller estate and turnover, faces a much lighter penalty.
A score of 50 isn't strong on its own. In this sector, it's the highest there is.
The middle of the table
Sainsbury's, M&S, Waitrose, Ocado, Iceland, and Tesco all sit between 42 and 45. Four of the six are tied at exactly 42 — the tightest mid-pack cluster in the data. These supermarkets have substantive sustainability programmes and detailed reporting. They aren't failing. They are being pulled down by the sheer volume of emissions they are responsible for, and in some cases by missed commitments or unresolved supply chain problems.
Sainsbury's, at 45, has more than halved its operational emissions since 2018 and holds a CDP A rating for climate for the tenth consecutive year. Its SBTi-validated targets are absolute. The main blemish is a 2019 Earthsight investigation linking Sainsbury's corned beef to JBS supply chains tied to Amazon deforestation — a governance gap not yet closed.
M&S, at 43, has cut operational emissions by around a third since 2016, but its total footprint is not falling. Its long-term net-zero commitment was removed from the SBTi Business Ambition for 1.5°C list in 2024 for missing a submission deadline. Changing Markets found that 88% of M&S's sustainability claims for clothing would not meet CMA guidelines.
Iceland, at 42, moved up from 38 after renewable electricity procurement — a power purchase agreement plus REGO certificates — lifted its energy score. Iceland reversed its 2018 palm oil ban in 2022, and separately abandoned a pledge to remove own-label plastic by 2023; both commitments remained on its sustainability website after the reversals. Iceland is also the most carbon-intensive UK supermarket — 38.33 tonnes of CO₂-equivalent per million pounds of sales, more than three times Aldi and Lidl.
Tesco, at 42, has cut store and electricity emissions by 65% since 2015, holds SBTi-validated net-zero targets, and is the leading corporate power purchase agreement buyer in Great Britain. The constraint is Scope 3: with 59 million tonnes of CO₂-equivalent in its supply chain footprint, no amount of operational progress closes the volume gap.
The bottom of the table
ASDA is alone at the bottom with a score of 31. ASDA's SBTi targets were removed from the public registry in 2024 following rapid expansion of its convenience format. The company has only self-set commitments in their place — a 50% operational emissions cut by 2025, on track at 48% — but the loss of independent validation matters. In March 2024, the CMA secured binding undertakings from Asda over misleading green claims in its George fashion range. The Environmental Investigation Agency separately criticised Asda for installing HFC refrigerants while competitors were reducing their use.
See the full breakdowns
- Co-op — 50/100
- Sainsbury's — 45/100
- Marks & Spencer — 43/100
- Waitrose — 42/100
- Ocado — 42/100
- Iceland Foods — 42/100
- Tesco — 42/100
- Lidl — 38/100
- Morrisons — 38/100
- Aldi UK — 35/100
- ASDA — 31/100
Think we got a score wrong? Every score is open to challenge. Find the company, pick a question, submit your evidence. That's how SINK stays accurate.
Every score reproducible from public data.