Methodology

v1.3

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 scores are independent assessments based on publicly available information. They represent our editorial judgment applied consistently across all companies — they are not statements of verified fact. All scores are 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. Oil & Gas scores 20 because the core business is extracting fossil fuels — no amount of solar panels on headquarters changes that. SaaS scores 70 because software has a fundamentally lower environmental footprint. This is a ceiling, not a floor — it caps how high a company in that sector can score.

Performance (70% weight)

Ten questions, each scored 0–10, based on publicly available evidence. This is where effort counts. A company that discloses fully, sets science-based targets, transitions to renewable energy, and maintains clean governance will score high regardless of their industry.

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. Each is scored 0–10 based on the thresholds below. Performance = sum of all ten scores.

Scores between anchors (0, 3, 6, 10) reflect how closely a company meets the next threshold. The anchors define the range. The evidence determines where within it a company falls.

Q1Scope 1 & 2 Reporting
0
No emissions disclosure
3
Partial or unverified data
6
Full Scope 1 & 2, GHG Protocol aligned
10
Third-party verified, multi-year, granular breakdown
Q2Scope 3 Reporting
0
No Scope 3 data
3
1–2 categories only
6
Majority of material categories
10
Full value chain with methodology, verified
Q3Emissions Trajectory
0
Rising or no data
3
Flat or marginal decline
6
Consistent year-on-year reduction
10
On track for 1.5°C pathway across all scopes
Q4Science-Based Targets
0
No targets
3
Internal targets, not SBTi
6
SBTi committed or validated
10
SBTi validated with near and long-term, net zero pathway
Q5Offset Credibility
0
Heavy reliance on cheap offsets
3
Mix of offsets and reduction
6
Reduction-first, limited high-quality removals
10
No offsets or exclusively verified CDR, reduction-first
Q6Energy Transition
0
No renewable energy strategy
3
Under 25% renewable
6
50–90% renewable with clear plan
10
100% renewable (owned operations), supplier transition underway
Q7Governance & Accountability
0
No sustainability governance
3
CSR page exists, no board oversight
6
Dedicated officer, TCFD disclosure, board oversight
10
Exec compensation linked to climate, shareholder vote, mission-locked structure
Q8Lobbying Alignment
0
Active lobbying against climate policy
3
Mixed trade association memberships
6
Neutral, no misaligned lobbying
10
Active climate advocacy, published lobbying audit, distanced from misaligned groups
Q9Circular Economy & Supply Chain
0
Linear model, no supply chain engagement
3
Basic recycling or take-back
6
Measurable circular targets, supplier requirements
10
Closed-loop systems, full supply chain transparency, industry-leading practices
Q10Controversies & Red Flags
0
Major ongoing investigations, documented regulatory violations
3
Multiple credible complaints or fines
6
Minor issues, addressed transparently
10
Clean record, proactive disclosure, industry awards

Base Impact by Industry

Each industry gets a base score reflecting the environmental ceiling 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

v1.3March 2026

Published rationale for every base impact score.

SaaS / Digital Services base score revised from 75 to 70 — reflects growing energy intensity from AI and data centre expansion.

Electronics / Hardware base score revised from 45 to 40 — better reflects full lifecycle footprint including mining, fabrication, and e-waste.

Apparel (Durable) base score revised from 25 to 30 — previous score understated the gap between durable and fast fashion models.

Added interpolation note for rubric scoring between anchors.

Added verification requirement: community verifications must include a source or justification.

v1.1Initial public release

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

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