Conducting Your First GHG Emissions Inventory

Conducting Your First GHG Emissions Inventory

Conducting a Greenhouse Gas emissions inventory is vital for understanding and addressing an organization’s carbon footprint, including emissions from operations, upstream supply chain and a company’s entire value chain. This detailed guide by North Star Carbon Management outlines the process and key considerations.

What is a GHG Emissions Inventory?

A GHG Inventory is a comprehensive data repository that quantifies the emissions of greenhouse gasses from various sources within a defined boundary. This inventory serves as a critical tool for organizations, local governments, and even entire states to manage their carbon footprint, set reduction targets, and track progress over time.

Infographic highlighting GHG emissions sources and their global distribution. Source: North Star Carbon Management

Developed in alignment with global standards like the Greenhouse Gas Protocol, these inventories include both direct emissions- Scope 1 emissions, which result from sources directly owned or controlled by the organization, and indirect emissions – Scope 2 and Scope 3 emissions, which occur from the organization’s purchased electricity, waste management, and other supply chain activities. By compiling this inventory, organizations gain a clear picture of their net emissions and contribution to climate change, including historical emission trends.

Significance of GHG Emissions Inventory

The significance of a Greenhouse Gas Inventory cannot be overstated in today’s climate-conscious world. Acting as a climate change balance sheet, these are the cornerstone for understanding and managing greenhouse gas emissions at various levels—be it a country, an economic sector, or a local community.

Developed in line with National GHG inventory practices and guidelines such as the IPCC Fourth Assessment Report, an inventory includes estimates of gross emissions of key greenhouse gasses like CO2, methane, and nitrous oxide.

They are instrumental in measuring progress towards local, regional, and even international climate goals, thereby holding entities accountable for their environmental impact. Inventories also inform the development of robust climate action plans and are essential for compliance with regulations and reporting requirements.

In the context of global agreements like the Paris Agreement, GHG inventories play a vital role in setting and updating Nationally Determined Contributions (NDCs), which are voluntary commitments made by countries to reduce their emissions. For instance, India, a significant emitter, relies heavily on its GHG inventory to track its progress towards a 33–35% reduction in emissions intensity of GDP by 2030.

Preparing for Your First GHG Emissions Inventory

Step-by-step GHG management process: from planning inventory to reporting emission reduction progress.

Before embarking on the actual inventory process, it is crucial to gather the necessary information and lay the groundwork for a successful endeavor.

Gathering Necessary Information

To compile a thorough GHG Emissions Inventory, consolidate all pertinent data on your organization’s activities. This includes:

  1. Energy Consumption: Check utility bills for electricity and natural gas usage.
  2. Fuel Usage: Consult with fleet management for data on company vehicles.
  3. Transportation: Use mileage logs or expense reports to track travel emissions.
  4. Waste Management: Record waste generation, disposal methods, and recycling efforts.

Collaborate with key departments like facilities, finance, HR, and sustainability teams to ensure data accuracy and completeness. This multi-departmental approach ensures a comprehensive capture of all emission sources.

Identifying Key Emission Sources

  1. Identifying Sources: Start by conducting a materiality assessment considering factors like emissions intensity and financial impact.
  2. Comprehensive Inventory: Quantify emissions across all operations, focusing on energy use, transportation, waste management, and specific industry-related sources.
  3. Industry-Specific Sources: Understand that emission sources vary by industry. For example, manufacturing may involve production emissions, while service sectors may focus on energy efficiency in offices.
  4. Develop Targeted Strategies: Once key sources are pinpointed, create targeted reduction plans. This could include:
    • Enhancing energy efficiency
    • Adopting renewable energy
    • Optimizing transportation logistics
    • Improving waste management
  5. Measure Progress: By focusing on key areas, organizations can track meaningful progress towards sustainability goals.

Process of Conducting a GHG Emissions Inventory

With the necessary groundwork laid, it’s time to delve into the step-by-step process of conducting your first Greenhouse gas inventory to quantify GHG emissions.

The process involves planning, data collection, emissions calculation, and verification. Use recognized calculation methodologies and consider third-party verification for accuracy.

Infographic detailing a 4-step process for conducting GHG emissions inventory.

Step 1: Planning Your Inventory

Begin by establishing clear goals and objectives for your inventory. Are you aiming to comply with regulatory requirements, meet stakeholder expectations, or simply improve your environmental performance? Defining your goals will guide the entire inventory process.

Next, define the time period within which you wish to assess current inventory. Typically, organizations conduct annual inventories, but you may choose a different timeframe based on your specific needs.

Assign responsibilities to individuals involved in the inventory process, such as sustainability managers, data analysts, and finance personnel. Clear roles and responsibilities will help streamline the inventory process and ensure accountability.

Step 2: Collecting Data

Once you have a plan in place, it is time to collect data on energy consumption, fuel usage, waste management, transportation activities, and other emission sources identified during the preparatory phase.
To ensure data accuracy, employ data collection tools, such as utility bills, fuel consumption records, and invoices. These documents provide concrete evidence of your organization’s resource usage.
It’s important to involve relevant stakeholders in the data collection process. Engage with different departments within your organization to gather comprehensive data.

Step 3: Calculating Emissions

With data in hand, it’s time to calculate your organization’s GHG emissions. This involves converting activity data into emissions using appropriate emission factors and calculation methodologies.
Each emission source requires a specific calculation approach. For example, to calculate emissions from energy consumption, you would multiply the energy usage by the corresponding emission factor for the energy source (e.g., electricity, natural gas). Similarly, emissions from transportation activities can be calculated by multiplying the distance traveled by the emission factor for the specific mode of transportation.

Step 4: Verifying Your Results

Verifying the accuracy and completeness of your inventory and taking steps to correct errors are crucial for instilling confidence in the results. This is endorsed by the IPCC Fourth Assessment Report and the World Resources Institute. Consider engaging a third-party expert or conducting an internal review to validate your emissions data, calculations, and methodologies.

Analyzing Your GHG Emissions Inventory Results

Once the inventory process is complete, it is essential to analyze and interpret the results to gain meaningful insights into your organization’s emissions profile.

Understanding Your Emissions Profile

Analyze your emissions data to pinpoint the primary sources of your organization’s carbon footprint. This deep dive will spotlight areas like:

  1. Manufacturing Processes: A manufacturing company might find that its energy consumption is its largest source of emissions. The company could then implement energy efficiency measures, such as switching to LED lighting and installing more efficient HVAC systems.
  2. Transport & Logistics: A transportation company might find that its fleet of vehicles is its largest source of emissions. The company could then invest in more fuel-efficient vehicles or switch to electric vehicles.
  3. Supply Chain: A food and beverage company might find that its agricultural supply chain is its largest source of emissions. The company could then work with its suppliers to reduce their emissions by implementing sustainable farming practices.

Identifying Opportunities for Reduction

Look for efficiency improvements, process modifications, or technological upgrades that can lower your emissions. Engagement with suppliers and stakeholders can also uncover collaborative opportunities that result in emission reduction.

Maintaining and Updating Your GHG Trackings Inventory

Conducting a GHG discharge inventory is not a one-time event. It requires ongoing monitoring and continuous improvement to ensure the effectiveness of emission reduction efforts.

Regular Monitoring and Reporting

Establish a system for regular monitoring of your emissions to track progress over time. This involves setting up key performance indicators, implementing data collection processes, and conducting periodic reviews.

Continuous Improvement and Updates

As new technologies emerge and emissions tracking methodologies evolve, it is vital to stay up to date with the latest practices and standards. Regularly review and update your inventory process to align with industry best practices and ensure accuracy and reliability of results.


Conducting your first GHG emissions inventory can seem like a daunting task, but by following this step-by-step guide, you can navigate the process with confidence. The journey towards sustainability begins with understanding and quantifying your organization’s carbon footprint. Take that first step today and make a positive impact on our planet’s future.


Curated by Josh Prigge

Josh is a world renowned sustainability consultant with more than a decade of experience in leading sustainability programs and initiatives for large organizations. He is also a sought-after public speaker and a college professor. To learn more about him, read about him here – About North Star Carbon Management.