Carbon Footprint Calculation & Emissions Inventory

At corporate level, carbon footprint calculation and GHG inventory are two names for the same job. A structured record of how much greenhouse gas a company emitted in a given year, from which sources, of which gases and within which boundaries, is called a "greenhouse gas inventory" or "carbon inventory" by practitioners and a "corporate carbon footprint" in sales and communications. Whether you are a multinational subsidiary reporting into a group inventory, a Turkish supplier answering an EU customer's questionnaire or an exporter preparing for CBAM, you need the same deliverable. Alalëa builds it in line with the GHG Protocol Corporate Standard and ISO 14064-1:2018, ready for verification.

Carbon footprint or GHG inventory: one service

The difference is vocabulary, not method. The GHG Protocol's corporate standard is called the "Corporate Accounting and Reporting Standard", and its output is an inventory; ISO 14064-1:2018 covers the quantification and reporting of GHG emissions and removals at organisation level. A company that asks us to "calculate our carbon footprint" and one that asks for "ISO 14064 consulting" usually expect the same deliverable: an inventory of Scope 1, 2 and 3 emissions with a documented method that can be compared year on year.

The two frameworks differ mainly in presentation:

The most robust approach is to calculate on GHG Protocol logic, map the results to ISO 14064-1 categories and verify under ISO 14064-3, so one inventory serves SBTi, CDP and the verifier at once. The two frameworks are converging: on 9 September 2025 the GHG Protocol and ISO announced a strategic partnership to develop their standards together. Under the GHG Protocol's July 2026 plan, public consultation on the unified corporate standard is expected in the second quarter of 2027 and publication in the last quarter of 2028. Until then, inventories continue to be prepared under the 2004 Corporate Standard and the 2015 Scope 2 Guidance. For more detail, see GHG Protocol or ISO 14064?

A product carbon footprint is a separate exercise

A corporate inventory answers "how much did our company emit in a year?" and is expressed in tCO2e per year. A product carbon footprint (PCF) answers "how much does one unit of this product emit over its life cycle?" and is expressed in kg CO2e per unit. A PCF is calculated under ISO 14067:2018 or the GHG Protocol Product Life Cycle Standard. We provide this too; see what to do when a customer requests a PCF and PCF or LCA?. A well-built corporate inventory is the data foundation for product work.

Why companies in Türkiye are building inventories now

A carbon inventory used to be a voluntary communication tool. Today the requests come from several directions at once.

The current rules behind these items:

• CBAM: According to the European Commission, the definitive regime has applied since 1 January 2026. The first annual declaration and certificate surrender for 2026 imports are due by 30 September 2027. The obligation sits with the EU importer, but the data comes from the Turkish producer. See CBAM readiness and CBAM preparation from the supplier's perspective.
• TR ETS: Under the Turkish Emissions Trading System Regulation published in Official Gazette No. 33353 of 27 August 2026, operators carrying out Annex 1 activities report the previous year's emissions, verified, by 30 April each year. According to the Carbon Market Board decisions, the pilot period covers 2026 and 2027 emissions; category B and C installations in electricity generation, cement, iron and steel, aluminium and fertilisers take part, and the 2026 system year carries a reporting obligation only. See ETS readiness.
• TSRS: By the Public Oversight Authority (KGK) decision published on 16 January 2026, the thresholds were reset at TRY 1 billion in total assets, TRY 2 billion in net sales revenue and 500 employees. Entities exceeding at least two of the three in two consecutive reporting periods are in scope. The amendments to TSRS 2 greenhouse gas disclosures made in July 2026 are mandatory for periods beginning on or after 1 January 2027.
• SBTi: The Net-Zero Standard V2.0, published in June 2026, requires Category A companies to obtain independent assurance of at least limited level for the base year inventory and introduces a 5 percent threshold for base year recalculation. See SBTi target setting.

Even outside these rules, customer questionnaires and bank requests make an inventory necessary in practice. For a foreign-owned group, the Turkish entity's figures usually feed the parent's consolidated inventory, so boundary and factor choices need to match the group's approach.

Our method, step by step

The hard part is not the arithmetic but deciding what goes into the calculation and taking data from the right place. We work in this order.

1. Purpose and use case

We first clarify which decisions the inventory will support: a TSRS report, an SBTi submission, a CDP response, a customer questionnaire, group reporting or internal management. The purpose sets the depth of Scope 3, the expected data quality and the need for verification.

2. Organisational and operational boundaries

Which legal entities and sites are included, and in what share? The GHG Protocol recognises the equity share approach and the control approaches (financial or operational control) and requires the chosen approach to be applied consistently across the company. Leased buildings, joint ventures, contract manufacturing and franchises are decided here and recorded in a boundary note.

3. Source list and Scope 3 screening

Fuels, processes, vehicles, refrigeration systems and purchased energy are listed site by site. We first screen the 15 Scope 3 categories for size and data availability, then concentrate detailed calculation on the large ones. See Scope 3 categories 1 to 15 and where to start with Scope 3.

4. Data request list

We turn the source list into a tailored data request: which document, unit, period and owner. Evidence copies are kept, because verification starts from these documents, not from the calculation file.

5. Emission factor selection

We select factors from the most specific to the most general: first site or supplier-specific values, then official Turkish values such as the electricity factors of the Ministry of Energy and Natural Resources (ETKB) and national inventory values, and only then IPCC 2006 defaults and annual international datasets. The source, year and version of every factor go into the factor library. The latest ETKB form used for Scope 2, for example, covers the 2023 calculation period and was published on 26.12.2025. For a comparison of factor sets, see IPCC, DEFRA or EPA?

6. Calculation

The core formula is the same for every source:

Emissions (tCO2e) = Activity data × Emission factor

Gases are converted to CO2 equivalent using global warming potentials (GWP). The Corporate Standard covers CO2, CH4, N2O, HFCs, PFCs and SF6; the GHG Protocol later added NF3. We calculate Scope 2 using both the location-based and the market-based method, as the dual reporting requirement of the Scope 2 Guidance demands; with YEK-G (Türkiye's renewable energy guarantees of origin) and I-REC certificates available in Türkiye, the requirement applies directly. For the location-based figure we use the ETKB national electricity generation factor (0.434 tCO2e/MWh for the 2023 calculation period) and account for grid losses separately in Scope 3. See market-based and location-based Scope 2.

7. Quality control (QA/QC)

Following the GHG Protocol's inventory quality management approach, we check unit conversions and formulas, sample input data for transcription errors, repeat calculations roughly by hand, investigate large year-on-year changes and have a second person review the work. The errors we catch most often are billing periods mixed up with the calendar year, the gross versus net calorific value of natural gas and the wrong electricity factor.

8. Uncertainty assessment

We assess the uncertainty of activity data and factors for each item. The GHG Protocol acknowledges that such estimates often carry a subjective component; their real value is showing where better data is worth the effort. The output is therefore next year's data quality plan, not just a number.

9. Base year and recalculation policy

We choose a base year with verifiable data and document the rationale and the recalculation threshold. Acquisitions, divestments, methodology changes and significant errors trigger recalculation; organic growth does not. If an SBTi target is planned, the threshold is set in line with the 5 percent in V2.0.

10. Report and verification readiness

The inventory report sets out the organisational boundary and consolidation approach, operational boundary, reporting period, separate Scope 1 and 2 totals, biogenic CO2 reported separately, methods, exclusions and the base year. If verification under ISO 14064-3:2019 is planned, we prepare the documents the verifier will ask for and answer verifier questions together with you. As a general rule of thumb in the GHG Protocol, an error above 5 percent of the total inventory is considered material, and we prepare to that standard. See the top 10 things checked in emissions verification.

Data your company will need to provide

Every data request list is company-specific, but most inventories need the following:

The data does not need to be perfect, but every number must be traceable to its source.

Sector considerations

The centre of gravity of the inventory differs by sector:

• Cement and iron and steel: Process emissions and consistency with TR ETS and CBAM data are decisive. The installation report and corporate inventory must share the same records. See cement and iron and steel.
• Textiles and apparel: Dyehouse energy and purchased yarn and fabric stand out; the boundary for contract manufacturing needs care. See textile and apparel.
• Food and beverage: Refrigerants and agricultural raw materials are decisive. If land-related emissions are significant, a separate study is needed: FLAG emissions. See food and beverage.
• Automotive suppliers: Purchased steel, aluminium and plastics are often the largest item. See automotive suppliers.
• Logistics and retail: Fleet fuel and subcontracted carriers; store electricity, refrigerants and products sold. See logistics and retail.
• Finance: The main topic is the emissions of the loan and investment portfolio (Scope 3, Category 15). The July 2026 TSRS 2 amendments can focus this disclosure on financed emissions. See finance and insurance.

What determines the scope and timeline of the work

Data, not calculation, drives the timeline. The main factors:

• Number of sites and legal entities: Each new location means a new data owner and a new source list.
• Depth of Scope 3: A spend-based screening and a calculation built on supplier-specific data are very different exercises.
• How data is organised: Invoices and fuel records kept in one place by calendar year speed things up; scattered records slow data collection.
• Process emissions: Cement, lime, glass and chemicals need additional analysis and laboratory data.
• Verification target: If ISO 14064-3 verification is planned, the evidence folder has to be built to that level from the start.

The first year is the longest because the data map and data owners are set up then; later years are updates on the same infrastructure.

Why Alalëa

• An SBTi Certified Expert founder: Alalëa's founder, Göker Avcı, is an SBTi Certified Expert. We build the inventory around the questions SBTi asks at target-setting stage, so the base year, boundary and Scope 3 coverage need not be reopened.
• Methodological rigour: Every factor, assumption and data point is documented, so a third party given the same data reaches the same result.
• Türkiye-specific knowledge: ETKB electricity factors, national inventory values and the TR ETS, TSRS and CBAM rules sit in one data infrastructure that reconciles easily with a foreign parent's reporting.
• Open knowledge: Our GHG Protocol sector boundary guide and articles let you read our approach before we start.

After the inventory: targets and a roadmap

The inventory shows which few sources account for most emissions; the next step is a target and an action plan:

1. Target: Our SBTi target setting service uses the same inventory. See also current points in the SBTi process.
2. Roadmap: A decarbonization strategy ranks reduction measures by impact and feasibility.
3. Disclosure: The inventory and targets are the quantitative basis of CDP reporting and TSRS disclosures.
4. Carbon pricing: To bring carbon into investment decisions, see internal carbon pricing.

To build your inventory, prepare an existing inventory for verification or discuss how to respond to a customer request, get in touch with us.