Categorization of Scope 3 emissions for streamlined enterprise carbon footprinting

Area of Science:

• Environmental Science
• Industrial Ecology
• Sustainability

Background:

• Carbon footprint protocols guide greenhouse gas emission measurement.
• Existing protocols often neglect Scope 3 (supply chain) emissions, which constitute over 75% of industry footprints.
• Better Scope 3 understanding enables broader emissions mitigation across supply chains.

Purpose of the Study:

• To categorize U.S. economic sector Scope 3 footprints.
• To identify significant upstream emission sources using an Economic Input-Output Life Cycle Assessment (EIO-LCA) model.
• To assess the impact of supplier specificity on capturing upstream carbon footprints.

Main Methods:

• Utilized an Economic Input-Output Life Cycle Assessment (EIO-LCA) model.
• Categorized Scope 3 footprints for U.S. economic sectors.
• Estimated upstream footprint capture from top-10 suppliers at economy-wide, industry-specific, and sector-specific levels.

Main Results:

• A large portion of the upstream carbon footprint can be captured by focusing on a few direct suppliers.
• Sector-specific categorization significantly improves Scope 3 footprint capture rates.
• Employee commuting and air travel are more significant for services industries than manufacturing.

Conclusions:

• Organizations can effectively manage their carbon footprint by concentrating on key suppliers and utilizing sector-specific data.
• Protocol organizations should develop more specific Scope 3 guidelines, including sector-specific categorizations.
• Tailored Scope 3 guidance is crucial for effective emissions mitigation across diverse industries.