The corporate carbon footprint is the process of quantitatively determining a company’s direct and indirect greenhouse gas emissions. With the growing adoption of net-zero targets, the implementation of regulations under the European Green Deal, and the introduction of sustainability standards such as the TSRS in Türkiye, carbon accounting has become a priority not only for environmental engineers but also for finance, strategy, and governance departments.

However, the methods used for calculation, the types of emissions covered, and the purpose of reporting vary from one organization to another. This policy brief compares different carbon accounting approaches through real-world examples and provides a comprehensive answer to the question: “Which method should be applied, and when?”

What Is a Carbon Footprint?

A carbon footprint is the calculation of an institution’s direct (e.g., fuel consumption) and indirect (e.g., electricity generation) greenhouse gas (GHG) emissions, expressed in terms of carbon dioxide equivalent (CO₂e).

These emissions are typically classified under three scopes:

Scope	Definition	Examples
Scope 1	Direct emissions from sources controlled by the organization	Company vehicles, gas-powered heating systems, production-related emissions
Scope 2	Indirect emissions from purchased and externally supplied energy	Electricity, steam, cooling, and heating
Scope 3	All other indirect emissions across the value chain	Supplier emissions, business travel, product use phase, waste

Note: Scope 1 and 2 data are relatively accessible, while Scope 3 is the most complex due to data availability, measurement challenges, and the need for assumptions.

Which Calculation Methods Are Used?

• GHG Protocol: The most widely used method globally, fully aligned with sustainability reporting frameworks like TSRS and ESRS. Scope 1 and 2 calculations are mandatory, while Scope 3 is encouraged.
• ISO 14064-1 Standard: A more technical standard, often used in verification and certification processes. It is applied by accredited verifiers in Türkiye.
• Türkiye’s GHG Emissions Regulation: A facility-based mandatory reporting framework for sectors like industry, energy, and chemicals. It focuses on plant-level emissions, not the corporate footprint.

Relation to GRI Standards

GRI 305: Emissions requires disclosure of Scope 1, 2, and, if applicable, Scope 3 emissions.

Organizations familiar with GRI are typically strong in narrative and contextual disclosure of emissions. However, regulation-based frameworks like TSRS and ESRS require this narrative to be supported by quantifiable and comparable data.

For such organizations, adopting the GHG Protocol is an ideal transition to convert qualitative narratives into structured, technical reports.

Implementation Strategy: Which Method and When?

Purpose	Method	Scope	Why
TSRS / ESRS compliance	GHG Protocol	Scope 1–2 required; 3 encouraged	Aligned with international regulations
Carbon certification	ISO 14064-1	Scope 1–2	For accredited audits and formal declarations
CBAM compliance (EU exports)	GHG Protocol / National Regulation	Scope 1	Mandatory for exporting firms
Strategic carbon management	GHG Protocol + Scope 3 module	Scope 1–2–3	For mapping supply chain and logistics-related risks

What To Do About Scope 3?

Though it’s the broadest and most complex area, Scope 3 can yield valuable strategic insights.

Key Scope 3 sources to prioritize:

• Emissions from the supply chain
• Product lifecycle emissions (e.g., appliances, vehicles)
• Waste management processes
• Employee commuting and business travel

Example: Over 85% of a clothing brand’s carbon footprint may stem from fabric production and transportation—both Scope 3 emissions.

Strategy: Instead of trying to collect all Scope 3 data, focus on the top three emission sources identified through a materiality matrix.

How Aligned Should You Be with TSRS?

• Disclosure of Scope 1 and Scope 2 emissions is mandatory under TSRS.
• Scope 3 is not yet required but may be expected to support the “risks and opportunities” narrative.
• The source of data, calculation methodology, and emission factors must be transparently documented.

Conclusion

Carbon footprint assessments are not just environmental tools—they are vital for understanding financial and governance-related risks.

• The right method → in the right context ensures:
  • Legal and regulatory compliance
  • A rational roadmap to net-zero targets
  • Transformed supplier engagement
  • Strengthened corporate reputation

You can’t manage what you don’t measure. Therefore, carbon accounting is not just a technical task—it is a strategic decision.