# A company carbon footprint

Markdown version of https://bluegreenmaterials.com/en/carbon-footprint. Updated on 2026-11-12.

A company carbon footprint is the total greenhouse gases it emits in a year, directly and indirectly, expressed in tonnes of CO₂ equivalent (CO₂e). It is calculated by multiplying activity data, such as liters of diesel or kWh of electricity, by emission factors, and it is split into three scopes: what you burn in your own facilities and vehicles (scope 1), the electricity you buy (scope 2) and the rest of your value chain (scope 3).

## What a company carbon footprint is

The reference for measuring it is the GHG Protocol Corporate Accounting and Reporting Standard. It covers seven gases: the six of the Kyoto Protocol, which are carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF₆), plus nitrogen trifluoride (NF₃), which the GHG Protocol added in 2013[^huella-ghg-corporate][^huella-ghg-nf3].

Each gas warms the atmosphere with a different strength. To add them up, each one is converted to CO₂ equivalent based on its global warming potential: CO₂e is the common unit for comparing what is emitted, or avoided, across different gases[^huella-ghg-corporate].

This page covers the footprint of an organization, that is, its yearly greenhouse gas inventory, not the footprint of a product.

## Scopes 1, 2 and 3, with examples

Scopes 1 and 2 are defined so that two companies do not count the same emission in the same scope[^huella-ghg-corporate]. Scope 3 gathers everything else that happens in your value chain.

**The three scopes under the GHG Protocol[^alcance3-ghg-standard]**

| Scope | What it includes | Examples at a plant in Mexico |
| --- | --- | --- |
| Scope 1: direct emissions | What the sources your company owns or controls emit | Natural gas or LPG burned in boilers and furnaces, diesel in your trucks and forklifts, emissions from chemical processes in your equipment |
| Scope 2: purchased energy | What was emitted generating the electricity, steam, heating or cooling you buy and consume | The electricity your plant draws from the grid |
| Scope 3: other indirect emissions | Everything else in your value chain, upstream and downstream, in 15 categories | Making the steel and inputs you buy, the freight you hire, business travel, the waste you send for treatment or recycling, the use of what you sell |

The Corporate Standard requires scopes 1 and 2 to be accounted for and reported separately at a minimum; there, scope 3 is an optional category[^huella-ghg-corporate]. The 2011 Scope 3 Standard goes further: companies following it must account for all their scope 3 emissions and disclose and justify any exclusion[^alcance3-ghg-standard]. The 15 categories and how waste is treated are in [scope 3, waste and recycling](https://bluegreenmaterials.com/en/scope-3-waste-and-recycling).

## How to calculate your company carbon footprint

The GHG Protocol organizes the calculation in five steps: identify the sources, select a calculation approach, collect activity data and choose emission factors, apply calculation tools and roll the data up to the corporate level[^huella-ghg-corporate]. For a company in Mexico it looks like this:

1. **Decide what you count**: Choose whether you consolidate by control (operational or financial) or by equity share. That tells you which plants, warehouses and vehicles are in your inventory[^huella-ghg-corporate].
2. **List your sources**: Per plant: boilers, furnaces, vehicles, processes and electricity purchases. If you will measure scope 3, also purchases, freight, travel and waste.
3. **Collect activity data**: Fuel invoices in liters or cubic meters, electricity bills in kWh, fleet logs and tonnes of waste by type and destination. Keep the document behind each number: it is your evidence.
4. **Choose emission factors with a source**: For grid electricity, SEMARNAT asked companies to use the 2024 National Electricity System factor during the 2026 reporting period of the Cédula de Operación Anual: 0.444 t CO₂e per MWh, because the 2025 factor was still being estimated[^huella-semarnat-fe2026].
5. **Calculate**: Emissions = activity data × emission factor, gas by gas, converted to CO₂e. For example, 1,200 MWh of electricity × 0.444 t CO₂e per MWh = 532.8 t CO₂e of scope 2.
6. **Set a base year**: Choose and report a base year for comparison, and define when you recalculate it, for example if you buy or sell a plant[^huella-ghg-corporate].
7. **Report with an audit trail**: Report each scope separately and disclose assumptions, methods and data sources, so a third party can review it[^huella-ghg-corporate].

- **0.444 t**: CO₂e per MWh: the national grid factor for the 2026 Cédula de Operación Anual[^huella-semarnat-fe2026]
- **25,000 t**: CO₂e per year or more: from there, direct and indirect emissions are reported to the RENE[^huella-semarnat-rene]
- **15**: scope 3 categories in the GHG Protocol[^alcance3-ghg-standard]
- **7**: gases in the Corporate Standard: the six of Kyoto plus NF₃[^huella-ghg-nf3]

> **If your company emits 25,000 t CO₂e or more** SEMARNAT requires the energy, industry, transport, agriculture, waste, and commerce and services sectors to report their direct and indirect emissions to the National Emissions Registry (RENE) when they reach 25,000 t CO₂e or more[^huella-semarnat-rene]. The report is filed through the Cédula de Operación Anual[^huella-semarnat-fe2026]. We explain it in [the RENE](https://bluegreenmaterials.com/en/mexico-national-emissions-registry-rene).

## The five principles of a sound inventory

The GHG Protocol requires accounting and reporting to be based on five principles[^huella-ghg-corporate]. ISO 14064 uses the same ones for quantification; we explain it in [ISO 14064](https://bluegreenmaterials.com/en/iso-14064).

- **Relevance**: The inventory reflects the company emissions and serves decision making, inside and outside the company.
- **Completeness**: It includes every source within the chosen boundary. Anything excluded is disclosed and justified.
- **Consistency**: The same methods from year to year, so results can be compared. Every change in data, boundary or method is documented.
- **Transparency**: Every number has an audit trail: assumptions, methods and data sources in plain view.
- **Accuracy**: Neither above nor below actual emissions, as far as can be judged, with uncertainty as low as practicable.

## Common mistakes when calculating a footprint

- **Subtracting recycling from the inventory.** Emissions avoided by recycling are not included in or deducted from scope 3: they are reported separately[^ghg-scope3]. See [avoided emissions](https://bluegreenmaterials.com/en/avoided-emissions).
- **Excluding categories without saying so.** Minor activities can be left out, as long as the exclusion is disclosed and justified[^alcance3-ghg-standard].
- **Using the electricity factor from another year.** SEMARNAT publishes a notice with the grid factor for each reporting year[^huella-semarnat-rene]. Use the one for the period you report.
- **Mixing estimates with real data without saying so.** An average consumption works to get started, but it is documented as an assumption and replaced with the real figure once you have it.
- **Adding up the scope 3 of several companies.** The same emission can be scope 3 for several companies at once, which is why scope 3 is not added across companies to get a regional total[^alcance3-ghg-standard].
- **Putting biomass CO₂ in scope 1.** Direct CO₂ from burning biomass is reported separately, not inside scope 1[^huella-ghg-corporate].

## Where recycling fits in your footprint

What you send for recycling, such as the scrap from your plant, is waste from your operations: it goes in scope 3 category 5, waste generated in operations[^ghg-scope3].

The GHG Protocol recommends the recycled content method: the emissions of the recycling process belong to whoever uses the recycled material, who reports them in their category 1. You only count the emissions of recovering the material, if they are not already in the factor of the recycled material[^ghg-scope3].

What is saved when that steel replaces steel made from ore is not subtracted from your footprint. If you report it, it goes separately, as avoided emissions, with data showing the material was collected, recycled and used[^ghg-scope3]. We go into detail in [scope 3, waste and recycling](https://bluegreenmaterials.com/en/scope-3-waste-and-recycling) and [avoided emissions](https://bluegreenmaterials.com/en/avoided-emissions).

## How to use the Bluegreen certificate if you sell scrap

When you sell scrap through Bluegreen, each lot gets a certificate with a folio that anyone can verify online, without an account. Its CO₂e figure is **net**: what recycling avoids, counted only on the weight that reached the mill (the lower of the origin and destination net weights, so material lost on the way does not count), minus what each haul emitted.

- Transport is calculated as kilometers from the Carta Porte × tonnes carried × 100 g CO₂e per tonne-kilometer, the GLEC Framework v3.0 value for road freight in North America, well to wheel[^metodologia-glec]. That is how ISO 14083 quantifies transport.
- Yard operations (cutting, baling, cranes) are not measured per lot yet and are not subtracted. The certificate says so.
- The current factor set is preliminary, and certificates with preliminary factors are not presented as verified.
- Bluegreen follows the GHG Protocol and the quantification principles of ISO 14064, and holds no ISO certification.

In your footprint, the certificate works as evidence of the tonnes you sent for recycling (the activity data for your category 5) and, separately, as support for avoided emissions. Do not subtract it from your scopes. See [the full methodology](https://bluegreenmaterials.com/en/impact-methodology) and [what each report includes](https://bluegreenmaterials.com/en/reports).

## Frequently asked questions

### What is a company carbon footprint?

The total greenhouse gases a company emits in a year, directly and indirectly, expressed in tonnes of CO₂ equivalent and split into scopes 1, 2 and 3[^huella-ghg-corporate].

### What are scopes 1, 2 and 3?

Scope 1: emissions from sources your company owns or controls, such as boilers, furnaces and vehicles. Scope 2: emissions from generating the electricity, steam, heating or cooling you buy. Scope 3: all other indirect emissions in your value chain, in 15 categories[^alcance3-ghg-standard].

### How do you calculate a carbon footprint?

You multiply each piece of activity data (liters of fuel, kWh, tonnes of waste) by its emission factor, convert each gas to CO₂e and add up by scope. The GHG Protocol organizes it in five steps, from identifying sources to rolling data up to the corporate level[^huella-ghg-corporate].

### Which electricity emission factor do I use in Mexico?

The National Electricity System factor published by SEMARNAT. For the 2026 reporting period of the Cédula de Operación Anual it asked companies to use the 2024 factor: 0.444 t CO₂e per MWh[^huella-semarnat-fe2026].

### Is my company required to report its emissions?

Facilities in the sectors SEMARNAT lists report to the RENE when their direct and indirect emissions reach 25,000 t CO₂e or more[^huella-semarnat-rene]. Below that threshold, the RENE does not require you to report.

### Does recycling reduce my carbon footprint?

Sending waste to recycling instead of landfill changes your category 5 emissions. What is saved by replacing virgin material is reported separately, as avoided emissions, and is not deducted from scope 3[^ghg-scope3].

### Is a carbon footprint the same as scope 3?

No. Scope 3 is one part of the footprint: the indirect emissions in your value chain that do not come from purchased energy. The full footprint adds up all three scopes[^alcance3-ghg-standard].

## Sources

[^huella-ghg-corporate]: GHG Protocol (WRI and WBCSD), «A Corporate Accounting and Reporting Standard, revised edition (capítulos 1, 3, 4, 5 y 6)» (2004). https://ghgprotocol.org/sites/default/files/standards/ghg-protocol-revised.pdf
[^huella-ghg-nf3]: GHG Protocol (WRI and WBCSD), «Nitrogen Trifluoride Now Required in GHG Protocol Greenhouse Gas Emissions Inventories» (2013). https://ghgprotocol.org/blog/nitrogen-trifluoride-now-required-ghg-protocol-greenhouse-gas-emissions-inventories
[^alcance3-ghg-standard]: GHG Protocol (WRI and WBCSD), «Corporate Value Chain (Scope 3) Accounting and Reporting Standard (tablas 5.1, 5.3 y 5.4, recuadro 5.6, capítulo 6 y sección 9.5)» (2011). https://ghgprotocol.org/sites/default/files/standards/Corporate-Value-Chain-Accounting-Reporing-Standard_041613_2.pdf
[^huella-semarnat-fe2026]: Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT), «Aviso a los establecimientos sujetos a reporte en el RENE: factor de emisión del Sistema Eléctrico Nacional para la COA 2026 (29 de mayo de 2026)» (2026). https://www.gob.mx/cms/uploads/attachment/file/1081506/aviso_factor_de_emision_electrico_coa_2026.pdf
[^huella-semarnat-rene]: Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT), «Registro Nacional de Emisiones (RENE)» (2026). https://www.gob.mx/semarnat/acciones-y-programas/registro-nacional-de-emisiones-rene
[^ghg-scope3]: GHG Protocol (WRI and WBCSD), «Technical Guidance for Calculating Scope 3 Emissions, version 1.0, category 5» (2013). https://ghgprotocol.org/sites/default/files/2023-03/Scope3_Calculation_Guidance_0%5B1%5D.pdf
[^metodologia-glec]: Smart Freight Centre (GLEC), «Global Logistics Emissions Council Framework v3.0, tabla 6: North American road emission intensity values» (2023). https://knowledgeplatform.ecta.com/wp-content/uploads/2023/09/2023_GLEC_FRAMEWORK_v3.0_September.pdf