How to calculate GHG Emissions?

The GHG Inventory Development Process


Green House Gas Inventory Development Resources

Step 1: Get Started: Scope and Plan Inventory


  • Review GHG accounting standards and methods for organizational reporting
  • Determine organizational and operational boundaries
  • Choose a base year
  • Consider 3rd party verification- (From outside of the company)- can be some other consultancy or independent consultant

Step 2: Collect Data and Quantify GHG Emissions


  • Identify data requirements and preferred methods for data collection
  • Develop data collection procedures, tools, and guidance materials
  • Compile and review facility data (e.g., electricity, natural gas)
  • Estimate missing data to fill gaps
  • Choose emissions factors
  • Calculate emissions

Step 3: Develop a GHG Inventory Management Plan


  • Formalize data collection procedures and document process in Inventory Management Plan

Step 4: Set a GHG Emission Reduction Target and Track and Report Progress


  • Finalize data
  • Complete third-party verification (optional)
  • Report data as needed
  • Prepare to set a publicly reported GHG target and track progress

There are different resources for navigating GHG Protocol tools:


  • Cross-sector tools: Applicable to many industries and businesses regardless of sector.
  • Country-specific tools: Customized for particular developing countries.
  • Sector-specific tools: Principally designed for the specific sector or industry listed, though they may apply to other situations.
  • Tools for countries and cities: These tools help countries and cities track progress toward their climate goals.

Case Study: A Corporate GHG Inventory in the Food Sector-by Clean Metrics 2.0

To test their hybrid technique for creating a corporate greenhouse gas (GHG) inventory, Clean Metrics 2.0 teamed with a US-based maker of organic, plant-based frozen desserts. The goal of this inventory was to create a baseline for annual emissions as well as a foundation for potentially offsetting those emissions.

To rapidly and efficiently compile a GHG inventory using CarbonScope, the hybrid technique combines two types of life-cycle inventory data:


  • The process LCI (PLCI) database, which transforms physical quantities of energy usage into GHG emissions, is used to simulate all emissions in scope 1 (direct fuel burning) and scope 2 (bought electricity).
  • Their ecologically extended input-output LCI (EEIOLCI) database, which translates dollar amounts from purchase records into equivalent GHG emissions based on the industrial sector and distribution channel, is used to model a wide range of emissions in scope 3.

Activity data

Using Clean Metrics’ standard data template for hybrid GHG inventories, the firm contributed activity data for this baseline inventory based on their activities in 2019. Although the actual data is secret, here is an example of what input data for a fictional corporation may look like. The following items are frequently found in activity data:


  • Fuel and electricity used in business activities – measured in kWh, gallons, and other physical quantities.
  • Purchased goods and services (inflows) – in US dollars, without taxes, in 2019.
  • Purchased waste management services – in US dollars, without taxes, in 2019.
  • Purchased freight transportation services – in 2019 US dollars excluding taxes
  • Purchased warehousing and storage services – in US dollars, without taxes, in 2019.
  • The energy utilized in the preparation and usage of sold products– is measured in kWh, liters, and other physical quantities.
  • Employee commute and travel—in passenger miles or kilometers

Separately, the bigger of the two co-packers was able to offer specific activity statistics. Within the company’s acquired products and services, the smaller co-packer was portrayed as a provider supplying frozen dessert production services.

The company receives all of its power from the local utility, which uses renewable sources. The bigger co-packer uses on-site solar to generate around 3.2 percent of its power, with the rest coming from the local grid.

Imported plant-based components are utilized in some of the dessert goods, which are modeled using domestic production as a proxy by assuming that imported commodities have the same input structure and production characteristics as equivalent domestically produced products of equal value.

Although all of the acquired components are organic, the inventory applies emission factors for all industry sectors without discriminating between organic and conventional manufacturing. This can be rationalized by the fact that when systems are in a stable state, organic farming does not necessarily have smaller carbon footprints than conventional farming.

Inventory Results

The company’s operations from all three emission scopes totaled 8387 metric tonnes of CO2e in 2019, according to the results of the GHG inventory study. A thorough breakdown is shown in the table and chart below (units: Carbon in Kg CO2e; Energy in MJ; Water in L).



Natural gas used by the bigger co-packer is by far the greatest contributor to corporate GHG emissions, accounting for 49 percent of total emissions and reported under scope 3.3, according to a sensitivity analysis. Ingredients sourced by the larger co-packer (16.6 percent of total emissions; scope 3.1), manufacturing services provided by the second co-packer (9 percent of total emissions; scope 3.1), truck transport services used to ship finished products (7.6 percent of total emissions; scope 3.9), and cardboard containers used to ship finished products (7.6 percent of total emissions; scope 3.9) are the next four contributors (3.8 percent of total emissions; scope 3.1). Overall, scope 3 emissions account for almost 99 percent of all emissions, with the bigger co-packer accounting for 72 percent of total emissions.

The GHG emissions intensity for a hypothetical corporation with revenue at the midpoint of the revenue range is 0.36 kg CO2e per dollar of revenue. For the ice cream and frozen dessert business in the United States, this intensity is less than half of the industry average.


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