Home › Pathways › Measure & Report › 1.1 GHG Accounting
Measure & Report  ·  1.1.1

GHG Emissions Inventory

The GHG emissions inventory is the quantitative foundation of any decarbonization program — establishing what is emitted, from which sources, and how much. A credible inventory covers all three scopes, follows GHG Protocol methodology, and is reproducible year-over-year to track progress. The maturity pathway progresses from manual, spend-based estimates to automated, activity-based data collection with third-party assurance.

← Back to Pathways

Self-Assessment

Select where your organization currently operates and where you want to get to. There is no obligation to reach "Leading Org." — choose the target that is right for your business context and investment capacity.

📍 Current Level
🎯 Target Level
Select your current and target levels above to map your assessment on this initiative.
Fundamental
Market Standard
Above Average
Leading Org.

Technology

  • Spreadsheet-based GHG inventory using spend-based emission factors (EEIO) for Scope 3
  • Utility bill data and fuel receipts as primary Scope 1 and 2 data sources
  • EPA emissions factors (eGRID, AP-42) applied to activity data for stationary and mobile combustion

Process

  • Defining organizational and operational boundaries (control approach vs. equity share)
  • Identifying all Scope 1 sources: stationary combustion, mobile combustion, process emissions, refrigerants
  • Calculating location-based and market-based Scope 2 emissions for all metered facilities

Financing

  • Internal sustainability team staff time as primary cost; no dedicated software investment
  • GHG Protocol Corporate Standard and free EPA tools used as no-cost methodology resources

Technology

  • Fundamental Technologies +
  • Dedicated carbon accounting platform (e.g., Watershed, Persefoni, Salesforce Net Zero Cloud)
  • Activity-based data collection replacing spend-based estimates for material Scope 3 categories
  • Automated utility data ingestion via utility API or energy data management system

Process

  • Completing all 15 Scope 3 categories with materiality assessment documented per GHG Protocol
  • Establishing a consistent inventory management calendar: data collection, review, and sign-off cycle
  • Reconciling year-over-year inventory with documented explanations for material changes

Financing

  • Carbon accounting SaaS platform ($50K–300K/year depending on scale) budgeted as sustainability opex
  • Engaging a sustainability consultant for first full-scope inventory build and methodology documentation

Technology

  • Market Standard Technologies +
  • Primary supplier emissions data integrated directly into inventory via API or supplier portal
  • Real-time or near-real-time Scope 1 and 2 data feeds from smart meters, IoT sensors, and BMS
  • Automated emission factor updates applied dynamically as eGRID and supplier data refreshes

Process

  • Achieving activity-based methodology across all material Scope 3 categories (Cat. 1, 3, 4, 11, 15)
  • Conducting annual inventory peer review against prior year and industry benchmarks
  • Publishing full inventory with category-level Scope 3 breakdown in CDP response and sustainability report

Financing

  • Platform and data integration costs justified by regulatory compliance readiness and investor disclosure quality
  • Internal audit function engaged to review inventory data controls and methodology documentation

Technology

  • Above Average Technologies +
  • Fully automated, integrated GHG inventory updated continuously across all scopes and emission sources
  • Digital product-level carbon footprint tracking enabling SKU-level Scope 3 Category 11 attribution
  • AI-driven anomaly detection flagging data quality issues and unusual emissions patterns in real time

Process

  • Publishing inventory with reasonable assurance from accredited third-party verifier across all three scopes
  • Inventory methodology and assumptions disclosed in full, enabling external replication and scrutiny
  • Contributing inventory data and methodology to industry working groups advancing GHG accounting standards

Financing

  • Inventory infrastructure treated as core enterprise data asset with board-level governance and dedicated budget
  • Assurance costs ($100K–500K depending on scope) embedded in annual sustainability program budget

Related Pathways

← All Pathways 5.1.2 Scope 3 Value Chain Mapping 5.1.3 Internal Carbon Pricing 5.2.1 Voluntary Frameworks