Methodology

v2.0

Every SINK score is produced by the same formula, using the same rubric, applied to publicly available data. No exceptions. No special treatment. This page explains exactly how it works so you can verify any score yourself.

SINK is a physics-first environmental impact score. We measure what the planet physically experiences — absolute emissions, ecosystem damage, resource depletion, water impact — not reporting maturity or corporate process. Scores are independent assessments open to challenge and correction by anyone with evidence.

The Formula

SINK = (0.3 × Base + 0.7 × Performance) × Scale

Base Impact (30% weight)

A fixed score representing the sustainability ceiling of an industry based on its physical impact on the planet. Oil & Gas scores 20 because the core business is extracting fossil fuels. SaaS scores 70 because software has a fundamentally lower environmental footprint. Financial Services scores 50 because the planet experiences what banks finance, not just their office emissions.

Performance (70% weight)

Ten questions, each scored 0–10, measuring real environmental impact across carbon, energy, nature, water, resources, and accountability. A company with low physical impact and basic evidence will score higher than one with polished reporting but a massive footprint. Operational evidence (energy bills, supplier records) is accepted alongside formal sustainability reporting.

Scale Penalty (multiplier)

Total emissions volume determines a multiplier between 0.60x and 1.00x. A company emitting 50 million tonnes of CO₂e per year has its score reduced by 40% — because scale matters. Physics doesn't care about percentages. The planet experiences absolute tonnes, not relative improvement.

The 10-Question Rubric

Every company is assessed against these ten questions. The first seven measure physical impact — what the planet actually experiences. The last three measure whether the company is improving and can be held accountable. Performance = sum of all ten scores.

Scores between anchors (0, 3, 6, 10) reflect how closely a company meets the next threshold. Operational evidence (energy bills, supplier records, water bills) is accepted at all levels — formal sustainability reporting is not required to score well.

Q1Carbon Footprint — Operations
0
No data of any kind
3
Energy bills or fuel records, no formal calculation
6
Full Scope 1 & 2, GHG Protocol or equivalent
10
Verified, granular, publicly disclosed, declining trend
Q2Carbon Footprint — Supply Chain
0
No knowledge of supply chain emissions
3
Can name key suppliers and their locations
6
Majority of material Scope 3 categories quantified
10
Full Scope 3, verified, with active supplier engagement
Q3Emissions Trajectory
0
No data, or emissions rising
3
Stable or falling but limited evidence
6
Evidenced year-on-year absolute reduction
10
On track for 1.5°C pathway across all scopes
Q4Energy Source
0
No renewable energy, no efficiency strategy
3
Efficiency improvements but standard grid tariff
6
50–90% renewable with clear plan, or on-site generation
10
100% renewable (owned operations), supplier transition underway
Q5Nature & Biodiversity Impact
0
No awareness of nature impact
3
Avoids worst practices (e.g. no palm oil, FSC timber)
6
Quantified nature footprint, deforestation-free, TNFD-aligned
10
Net positive nature impact with measurable outcomes
Q6Resource Use & Waste
0
Linear model, no waste strategy
3
Basic recycling, some waste awareness
6
Measurable circular targets, supplier requirements
10
Closed-loop systems, full supply chain transparency
Q7Water Impact
0
No water data, or significant pollution with no management
3
Knows water consumption, no significant pollution risk
6
Quantified water footprint with reduction targets, verified
10
Water positive or neutral with measurable ecosystem benefit
Q8Targets & Commitments
0
No targets, heavy reliance on cheap offsets
3
Informal goals, or offsets with unclear quality
6
SBTi committed or science-aligned, reduction-first
10
SBTi validated near and long-term, net zero pathway
Q9Transparency & Accountability
0
No sustainability information published
3
Owner-driven sustainability, no formal structure
6
Dedicated role, TCFD/CSRD disclosure, board oversight
10
Mission-locked structure (B Corp), everything publicly verifiable
Q10Controversies & Red Flags
0
Major investigations, environmental damage, anti-climate lobbying
3
Multiple complaints or fines, misaligned trade associations
6
Minor issues addressed transparently, no misaligned lobbying
10
Clean record, proactive disclosure, active climate advocacy

Base Impact by Industry

Each industry gets a base score reflecting the physical environmental impact of its core business activity. Click any row to see the rationale. All scores are open to challenge.

IndustryBase Score

New sectors added as companies are scored. Base scores set by editorial review and open to challenge with evidence.

Scale Penalty

Total EmissionsMultiplierEffect
Under 100K tonnes1.00xNo penalty
100K – 1M tonnes0.95x
1M – 10M tonnes0.82x
10M – 50M tonnes0.70x
50M+ tonnes0.60xMaximum penalty

Scoring Bands

86+
Near the frontier

Theoretical near-maximum. Requires exceptional performance across all dimensions at scale.

75–85
Exceptional

Best-in-class. Only a handful of companies in our database have reached this level.

60–74
Leading practice

Genuine sustainability leadership backed by verified data and science-based targets.

46–59
Making progress

Meaningful effort with room for improvement.

31–45
Below expectations

Some action but significant gaps remain.

16–30
Significant gaps

Major disclosure or performance deficiencies.

0–15
Critical concern

Minimal effort or actively harmful practices.

We don't grade on a curve. We grade against the planet. Scores above 75 are exceptionally rare — reflecting how demanding the rubric is. The majority of companies score between 30 and 60. A score of 60+ represents genuine sustainability leadership, the kind backed by verified data, science-based targets, and transparent governance.

Net Positive Badge

Net PositiveDisplayed alongside the SINK score

A separate designation for companies whose core business demonstrably removes more greenhouse gas than it creates. The badge is displayed alongside the SINK score — it does not change the score itself.

Eligibility requires all three:

1.Core business purpose is environmental restoration or carbon removal (not an offset programme bolted on)
2.Verified net negative emissions across all scopes, third-party verified
3.Credible removal methodology (DAC, verified reforestation with permanence, measurable ecosystem restoration)

Companies cannot pay to receive this designation.

Verification Tiers

◌ Pending Review

Scored using publicly available data. Awaiting community verification.

◉ Community Reviewed

At least 5 community verifications across the 10 questions, with fewer than 3 open challenges. Each verification must include a source URL or brief justification.

✓ Verified

At least 20 community verifications, fewer than 2 unresolved challenges, and score stable for 30+ days.

How to Challenge a Score

Every question on every score has a “Challenge” button. Click it, select the tier you think is correct, provide your evidence — a source URL is required — and submit.

Challenges are published publicly. When community evidence supports a more accurate assessment, the score is updated, the challenger is credited, and the change is logged permanently in the score history. No score is final.

We'd rather be corrected than wrong. That's the point.

Changelog

v2.0April 2026

Major rubric overhaul: physics-first methodology. Questions now measure what the planet physically experiences, not reporting maturity.

Rubric restructured from 10 reporting-focused questions to 10 impact-focused questions: 7 measuring physical impact (carbon, energy, nature, resources, water) and 3 measuring accountability.

New questions added: Nature & Biodiversity Impact (Q5) and Water Impact (Q7).

Offsets folded into Targets & Commitments (Q8). Governance folded into Transparency & Accountability (Q9). Lobbying folded into Controversies & Red Flags (Q10).

SME-accessible scoring: operational evidence (energy bills, supplier records, water bills) now accepted at all levels. Companies are scored on physical impact, not reporting sophistication.

Base impact revisions: Financial Services 65→50 (financed emissions), Healthcare 55→45 (chemical manufacturing, water pollution), Construction 40→35 (concrete, embodied carbon), Meat/Dairy 35→30 (methane, deforestation), Fast Fashion 20→15 (water pollution, microplastics, waste).

New industry categories added: Renewable Energy (75), Consulting / Professional Services (65), Energy Supply / Utilities (55), Hospitality / Hotels (45), Food Service / Restaurants (45), E-commerce / Online Retail (40), Ride-hailing / Mobility Platforms (30).

All existing companies rescored under v2.0 rubric.

v1.3March 2026

Published rationale for every base impact score. SaaS revised 75→70, Electronics 45→40, Apparel (Durable) 25→30. Added interpolation note and verification source requirements.

v1.1Initial public release

Formula, 10-question rubric, base impact table, scale penalties, scoring bands, verification tiers, and challenge process.

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