Carbon Accounting
Measure, manage, and reduce greenhouse gas emissions across your organisation. GHG Protocol-aligned methodologies, practical guidance, and free tools to get started.
What Is Carbon Accounting?
Carbon accounting is the process of measuring, quantifying, and tracking greenhouse gas (GHG) emissions produced by an organisation, product, or activity. It provides the data foundation for climate strategy, regulatory compliance, and emissions reduction targets.
Most organisations follow the GHG Protocol, the world's most widely used standard for greenhouse gas accounting. Developed by the World Resources Institute and the World Business Council for Sustainable Development, it ensures consistency and comparability across reports.
Carbon accounting is no longer voluntary for many organisations. The Corporate Sustainability Reporting Directive (CSRD) requires approximately 50,000 EU companies to disclose Scope 1, 2, and 3 emissions. Similar requirements are emerging in the UK, US, and other jurisdictions.
Why Carbon Accounting Matters
Regulatory Compliance
CSRD, SECR, and emerging disclosure rules require verified emissions data. Non-compliance risks fines, reputational damage, and exclusion from public procurement.
Cost Reduction
Identifying emission hotspots reveals energy inefficiencies. Organisations typically find 10–30% cost savings through fuel switching, process optimisation, and waste reduction.
Supply Chain Pressure
Large customers increasingly require supplier emissions data for their own Scope 3 reporting. Carbon accounting capability becomes a competitive requirement.
Investor Expectations
Institutional investors use emissions data to assess climate risk. CDP, TCFD, and ISSB standards all require disclosure of GHG emissions and reduction targets.
The Three Scopes of Emissions
Scope 1: Direct Emissions
Emissions from sources your organisation owns or controls. Includes stationary combustion (boilers, furnaces), mobile combustion (company vehicles), and fugitive emissions (refrigerant leaks).
Scope 1 is typically the easiest to measure because you control the data sources. Fuel receipts, vehicle mileage, and maintenance records provide the activity data needed.
Scope 1 Guide →Scope 2: Energy Indirect
Emissions from the generation of purchased electricity, heat, steam, or cooling consumed by your organisation. These are indirect emissions, but the energy is consumed within your operational boundary.
The GHG Protocol requires two reporting methods: location-based (grid average) and market-based (contract-specific). Renewable energy contracts can significantly reduce market-based Scope 2.
Scope 2 Guide →Scope 3: Value Chain
All other indirect emissions occurring across your value chain. Covers 15 categories including purchased goods, capital goods, transport, waste, business travel, employee commuting, and product use.
Scope 3 typically represents 70–90% of total emissions. It is the most complex scope to measure but also offers the greatest reduction potential through supplier engagement and procurement decisions.
Scope 3 Guide →Regulatory Landscape
Carbon accounting requirements are expanding rapidly across jurisdictions. Understanding which regulations apply to your organisation determines what you must measure, how you must report, and when deadlines fall.
GHG Protocol
The foundation of corporate carbon accounting. The Corporate Standard defines Scope 1 and 2 boundaries. The Scope 3 Standard covers value chain emissions. The Product Standard enables product-level footprinting. Compliance with GHG Protocol is required by CDP, SBTi, and most regulatory frameworks.
CSRD — Corporate Sustainability Reporting Directive
EU directive requiring large companies and listed SMEs to report detailed sustainability information under European Sustainability Reporting Standards (ESRS). ESRS E1 (Climate Change) mandates Scope 1, 2, and 3 disclosure, climate risk assessment, and transition planning. Applies to approximately 50,000 companies.
CSRD Omnibus Guide →ISSB — International Sustainability Standards Board
Developing global baseline sustainability disclosure standards. IFRS S2 covers climate-specific disclosures including GHG emissions across all scopes. Adopted by the UK, Australia, Singapore, Nigeria, and others. Creates convergence with CSRD and TCFD requirements.
SECR — Streamlined Energy and Carbon Reporting
UK legislation requiring quoted companies, large unquoted companies, and large LLPs to report energy use, GHG emissions, and intensity metrics. Simpler than CSRD but still mandates Scope 1 and 2 reporting and energy efficiency action.
How Terrnix Helps
Terrnix provides the tools, guidance, and intelligence organisations need to build credible carbon accounting capabilities — from first calculation to regulatory disclosure.
Free Carbon Calculator
Calculate Scope 1, 2, and 3 emissions using GHG Protocol-aligned methodologies. Export results for CSRD, CDP, or internal reporting.
Readiness Assessment
Evaluate your organisation's carbon accounting maturity across governance, data quality, and reporting readiness. Receive prioritised recommendations.
Implementation Guides
Step-by-step guides for Scope 1, 2, and 3 measurement. Practical methodologies, emission factor selection, and quality assurance.
Regulatory Intelligence
Stay current on CSRD, ISSB, CBAM, and evolving compliance requirements. Understand what applies to your organisation and when.
Related Resources
Scope 1 Emissions Guide
Direct emissions calculation methodology for fuel combustion, fleet, and fugitive sources.
Scope 2 Emissions Guide
Purchased energy emissions using location-based and market-based methods.
Scope 3 Emissions Guide
Value chain emissions across 15 categories. Screening, prioritisation, and calculation.
Carbon Calculator
Free tool to calculate your organisation's carbon footprint across all scopes.
Readiness Assessment
25-question assessment to identify your biggest carbon accounting gaps.
Carbon Accounting FAQ
Answers to common questions about emissions calculation, reporting, and compliance.
Start Measuring Your Emissions
Use our free carbon calculator to measure your Scope 1, 2, and 3 emissions. Export results for CSRD, CDP, or internal reporting. No registration required.