Learning Outcomes

By the end of this lesson, learners should be able to:

  • Explain the purpose of Greenhouse Gas (GHG) Accounting.
  • Describe the GHG Protocol Corporate Standard.
  • Differentiate between Scope 1, Scope 2, and Scope 3 emissions.
  • Explain emission factors and GHG calculation methods.
  • Describe organizational and operational boundaries.
  • Explain carbon offsets, carbon removals, and emissions verification.

Introduction

Greenhouse Gas (GHG) Accounting is the process of measuring, calculating, reporting, and managing greenhouse gas emissions produced by an organization’s activities.

Organizations measure GHG emissions to:

  • Understand their environmental impact.
  • Meet regulatory and reporting requirements.
  • Set emission reduction targets.
  • Monitor progress toward net-zero commitments.
  • Provide transparent climate disclosures to stakeholders.

The most widely used international standard for GHG accounting is the GHG Protocol Corporate Standard, which provides a consistent methodology for measuring and reporting emissions.

1. GHG Protocol Corporate Standard

The GHG Protocol Corporate Accounting and Reporting Standard is the world’s most widely used framework for measuring and reporting greenhouse gas emissions.

It was developed by:

  • World Resources Institute (WRI)
  • World Business Council for Sustainable Development (WBCSD)

Objectives

The GHG Protocol aims to:

  • Standardize GHG accounting.
  • Improve consistency and comparability.
  • Increase transparency.
  • Support climate-related decision-making.
  • Help organizations reduce emissions.

Key Principles of the GHG Protocol

Principle Description
Relevance Reflect the organization’s actual emissions.
Completeness Include all significant emission sources.
Consistency Use consistent methods over time.
Transparency Clearly explain assumptions and methodologies.
Accuracy Minimize uncertainty and errors.

Benefits

  • Supports ESG reporting.
  • Improves climate risk management.
  • Facilitates benchmarking.
  • Meets investor and regulatory expectations.
  • Supports net-zero planning.

2. Scope 1, Scope 2, and Scope 3 Emissions

The GHG Protocol classifies emissions into three scopes.

Scope 1 Emissions (Direct Emissions)

These are emissions from sources owned or controlled by the organization.

Examples

  • Company-owned vehicles.
  • Manufacturing equipment.
  • Industrial boilers.
  • Backup generators.
  • Company-owned factories.

Characteristics

  • Direct emissions.
  • Organization has operational control.
  • Usually easier to measure.

Scope 2 Emissions (Indirect Energy Emissions)

These are emissions resulting from purchased energy consumed by the organization.

Examples

  • Purchased electricity.
  • Purchased steam.
  • Purchased heating.
  • Purchased cooling.

Characteristics

  • Indirect emissions.
  • Depend on the energy supplier.
  • Can often be reduced by switching to renewable energy.

Scope 3 Emissions (Other Indirect Emissions)

Scope 3 includes emissions occurring throughout the organization’s value chain.

These are often the largest and most difficult emissions to measure.

Upstream Examples

  • Purchased goods and services.
  • Business travel.
  • Employee commuting.
  • Waste disposal.
  • Transportation of raw materials.

Downstream Examples

  • Product transportation.
  • Product use.
  • Product disposal.
  • Investments.
  • Franchises.

Characteristics

  • Indirect emissions.
  • Outside direct organizational control.
  • Usually represent the largest share of total emissions.

Comparison of Emission Scopes

Scope Type Examples
Scope 1 Direct Company vehicles, generators, boilers
Scope 2 Indirect (Purchased Energy) Purchased electricity, steam, heating
Scope 3 Other Indirect Suppliers, logistics, travel, product use

3. Emission Factors and Calculation Methods

Organizations estimate greenhouse gas emissions using activity data and emission factors.

Activity Data

Activity data measures the quantity of an activity that generates emissions.

Examples

  • Litres of diesel consumed.
  • Kilowatt-hours (kWh) of electricity used.
  • Kilograms of waste generated.
  • Kilometres travelled.
  • Cubic metres of natural gas consumed.

Emission Factors

An emission factor is a value that converts activity data into greenhouse gas emissions.

Formula:

GHG Emissions = Activity Data × Emission Factor

Example

A company consumes:

  • 8,000 litres of diesel

Emission factor:

  • 2.68 kg COâ‚‚e per litre

Calculation:

8,000 × 2.68 = 21,440 kg CO₂e

Common Sources of Emission Factors

  • National environmental agencies.
  • Intergovernmental Panel on Climate Change (IPCC).
  • GHG Protocol databases.
  • International Energy Agency (IEA).
  • Government emission factor databases.

Common Calculation Methods

Organizations use:

  • Direct measurement.
  • Fuel-based calculations.
  • Energy-based calculations.
  • Spend-based estimation.
  • Supplier-specific data.
  • Engineering estimates.

4. Organizational and Operational Boundaries

Before measuring emissions, organizations must determine which operations are included in the inventory.

This is done by defining organizational and operational boundaries.

Organizational Boundaries

These determine which legal entities or business operations are included.

Two common approaches are:

Equity Share Approach

  • Organization reports emissions according to its ownership percentage.

Example:

  • Owns 40% of a company → Reports 40% of emissions.

Control Approach

Organization reports emissions from operations it controls.

Two control methods:

  • Financial Control
  • Operational Control

Operational Boundaries

Operational boundaries classify emissions into:

  • Scope 1
  • Scope 2
  • Scope 3

This ensures all relevant emission sources are categorized consistently.

Comparison

Organizational Boundaries Operational Boundaries
Determine who is included Determine which emissions are included
Equity share approach Scope 1
Financial control Scope 2
Operational control Scope 3

5. Carbon Offsets and Removals

Even after reducing emissions, organizations may still produce unavoidable greenhouse gases.

These remaining emissions can be addressed through carbon offsets or carbon removals.

Carbon Offsets

Carbon offsets compensate for emissions by funding projects that reduce emissions elsewhere.

Examples

  • Wind farms.
  • Solar energy projects.
  • Methane capture.
  • Energy efficiency programmes.
  • Reforestation projects.

Carbon Removals

Carbon removals physically remove carbon dioxide from the atmosphere.

Examples

  • Tree planting.
  • Afforestation.
  • Carbon Capture and Storage (CCS).
  • Bioenergy with Carbon Capture (BECCS).
  • Direct Air Capture (DAC).

Carbon Offsets vs Carbon Removals

Carbon Offsets Carbon Removals
Avoid or reduce emissions elsewhere Remove COâ‚‚ from the atmosphere
Compensate for emissions Eliminate atmospheric carbon
Often project-based Natural or technological processes

Important Note

Organizations should prioritize reducing emissions first, then use high-quality offsets or removals only for residual emissions that cannot yet be eliminated.

6. Emissions Verification

Emissions verification is the process of checking whether reported greenhouse gas data is accurate, complete, and reliable.

Verification increases stakeholder confidence and improves the credibility of climate disclosures.

Types of Verification

Internal Verification

Conducted by:

  • Internal auditors.
  • Sustainability teams.
  • Internal compliance departments.

External Verification

Conducted by:

  • Independent assurance providers.
  • Accredited verification bodies.
  • External auditors.

Verification Process

  1. Review emission calculations.
  2. Check activity data.
  3. Validate emission factors.
  4. Test calculation methods.
  5. Verify documentation.
  6. Issue assurance statement.

Benefits of Verification

  • Improves reporting accuracy.
  • Enhances credibility.
  • Builds investor confidence.
  • Supports regulatory compliance.
  • Identifies reporting errors.

Summary of GHG Accounting Concepts

Topic Key Focus
GHG Protocol Global standard for measuring and reporting emissions
Scope 1 Direct emissions from owned or controlled sources
Scope 2 Indirect emissions from purchased energy
Scope 3 Other indirect emissions across the value chain
Emission Factors Convert activity data into GHG emissions
Organizational Boundaries Determine which entities are included
Operational Boundaries Determine which emission sources are included
Carbon Offsets Compensate for emissions through external projects
Carbon Removals Remove COâ‚‚ from the atmosphere
Verification Ensures reported emissions are accurate and reliable

Key Takeaways

The GHG Protocol Corporate Standard provides the globally recognized framework for measuring and reporting greenhouse gas emissions. Organizations classify emissions into Scope 1 (direct), Scope 2 (purchased energy), and Scope 3 (value chain emissions), ensuring consistency and transparency in reporting.

Accurate GHG accounting depends on reliable activity data, appropriate emission factors, and clearly defined organizational and operational boundaries. While organizations may use carbon offsets and removals to address residual emissions, priority should always be given to reducing emissions at the source. Finally, emissions verification enhances the credibility of reported data and supports informed decision-making by investors, regulators, and other stakeholders.

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