Comparing Product, Process, and Corporate GHG Accounting

Product, process, and corporate greenhouse gas accounting serve different purposes and use different methodologies, though they are often interrelated and can inform each other.

Corporate AccountingOrganization-wide emissionsProcess AccountingUnit operation emissionsProduct AccountingIndividual product emissions

Key Characteristics Comparison

Aspect	Product Accounting	Process Accounting	Corporate Accounting
Primary Focus	Individual products or services	Specific operations or activities	Organization-wide emissions
System Boundary	Life cycle stages	Process units	Organizational and operational control
Time Frame	Life cycle perspective	Operational time frame	Annual accounting period
Key Standards	GHG Protocol Product Standard, PAS 2050	Process-specific standards	GHG Protocol Corporate Standard
Reporting Unit	Per functional unit	Per process output	Total organizational emissions

Product Accounting

Product accounting focuses on the emissions associated with a specific product throughout its life cycle. Key characteristics include:

Tracks emissions from cradle-to-grave or cradle-to-gate
Uses functional unit as reference
Includes upstream and downstream emissions
Requires allocation for multi-output processes
Supports product carbon footprint labeling

Example: Office Chair

Product accounting would include:

Raw material extraction and processing
Manufacturing processes
Distribution and retail
Use phase (if relevant)
End-of-life disposal or recycling

Functional unit: "One office chair with a 10-year service life"

Process Accounting

Process accounting focuses on emissions from specific operations or activities. Key characteristics include:

Focuses on unit operations
Measures direct emissions from processes
Supports process optimization
Used for regulatory compliance
Helps identify efficiency improvements

Example: Paint Production Line

Process accounting would track:

Mixing vessel emissions
Heating system emissions
Ventilation system losses
Process-specific fugitive emissions
Utility system emissions

Reporting unit: "kg CO₂e per batch" or "kg CO₂e per operating hour"

Corporate Accounting

Corporate accounting focuses on total organizational emissions. Key characteristics include:

Covers all operations within defined boundaries
Categorizes emissions into scopes
Supports corporate reporting
Enables target setting
Facilitates emissions trading

Example: Manufacturing Company

Corporate accounting would include:

Scope 1: Direct emissions from owned facilities
Scope 2: Purchased electricity and steam
Scope 3: Supply chain and product use emissions

Reporting unit: "tonnes CO₂e per year"

Relationships Between Approaches

Integration Points

Process data feeds into both product and corporate accounting
Product accounting can inform Scope 3 emissions in corporate inventories
Corporate boundaries influence process and product assessments

Data Sharing

Emission factors often used across all approaches
Activity data can support multiple accounting types
Quality control systems can be shared

Choosing the Right Approach

Consider:

Purpose of the assessment
Intended audience
Available resources
Data availability
Reporting requirements

Best Practices

Maintain consistency in approaches over time
Document methodologies and assumptions
Ensure data quality across all levels
Consider relationships between different accounting types
Align boundaries where possible
Update calculations regularly