Before a company can submit a science-based target, it must lock down two foundational elements: a fiercely audited base year and a flawless GHG Protocol-aligned inventory. These dictate the absolute starting line for all future emission reduction math.
Establishing the Base Year (C13)
A base year serves as the historical reference anchor. If a company commits to a 50% reduction, that math is governed entirely by the base year's baseline. Choosing an artificially massive emission year makes future "reductions" look suspiciously easy.
Criterion C13 establishes strict rules:
- Base years absolutely cannot be older than 2015.
- Scope 1 and Scope 2 targets absolutely must share the exact same base year.
The SBTi brutally requires companies to select a representative year. You cannot select an anomalous year where a massive factory was shut down for repairs, and you absolutely should avoid the pandemic distortions of 2020 and 2021.
Think of a base year exactly like the starting weigh-in for a competitive athlete. If the athlete intentionally drinks two gallons of water immediately prior to stepping on the scale, their starting weight is artificially massively inflated. Their subsequent "weight loss" looks incredible on paper, but it is entirely fraudulent. The SBTi brutally audits base years to prevent exactly this kind of inflation.
Inventory and Consolidation
A target is completely worthless without a flawless GHG Protocol-aligned inventory.
- Scope 1: Direct combustion (furnaces, corporate fleets, fugitive methane leaks).
- Scope 2: Purchased energy. Companies must fiercely calculate this using both the dirty location-based grid average and the clean market-based contractual approach.
- Scope 3: The massive sprawling value chain, terrifyingly divided into 15 specific upstream and downstream categories.
The company must aggressively define its organizational boundary using one of three consolidation approaches: Operational Control, Financial Control, or Equity Share. Consistency here is violently enforced. You absolutely cannot switch methodologies mid-decade to favorably adjust the math.
The 5% Recalculation Trigger (C27)
Because massive global corporations constantly acquire, divest, and restructure, the SBTi strictly enforces Criterion C27 to prevent companies from faking reductions by simply selling off dirty subsidiaries.
If a structural change alters the base year inventory by more than 5%, the company absolutely must execute a massive base year recalculation. The company must essentially rebuild its historical math to include the new acquisition as if it had always owned it.
A massive manufacturer hits a base year inventory of 100,000 tCO2e. It then aggressively acquires a new dirty subsidiary adding 6,500 tCO2e. Does this acquisition mandate a brutal C27 base year recalculation?
Key Takeaways
- 1Base years cannot be older than 2015, and Scope 1 and 2 must share the same base year (C13)
- 2Select a representative base year that reflects normal operations - avoid anomaly years like 2020-2021
- 3The GHG inventory must cover all three scopes using both location-based and market-based methods for Scope 2
- 4Organizational boundary must use a consistent consolidation approach (operational control, financial control, or equity share) throughout the target period
- 5Any structural change that shifts the base year inventory by more than 5% triggers mandatory recalculation under C27