Understanding and Calculating Greenhouse Gas Emissions: A Guide


Is your business more concerned with its environmental impact? Maybe your largest customer is asking for your environmental policies and targets. Many like you are seeking ways to measure and reduce their carbon footprint. Greenhouse Gas (GHG) emissions are a big time contributor to climate change. So – doing good by the environment means you’ll need to calculate and monitor your business’ GHGs. In this guide, I walk you through a detailed, step-by-step process. I hope at the end you understand how to assess your own emissions.

1. Getting Started: Identifying Your Scope

No – it’s not math time yet. Before diving into the calculations, just define the scope of your greenhouse gas emissions impact. That’s called the assessment. The Greenhouse Gas Protocol divides emissions into three scopes:

  • Scope 1: Direct emissions from owned or controlled sources (e.g., fuel combustion in boilers).
  • Scope 2: Indirect emissions from purchased electricity, heat, or steam.
  • Scope 3: Indirect emissions from activities not owned or controlled but related to your organization (e.g., business travel, supply chain).

I say to clients that your scope helps tailor your emission assessment to specific activities. “What do you do?” “What do you drive?” And I almost always start with asking them to send me their electricity, gas, water, waste, fleet, production and other important monthly bills. Getting this makes the process more accurate and manageable.

2. Identifying Emission Sources: Where Do They Come From?

List all the sources contributing to your emissions. For a business, this might include:

  • manufacturing processes
  • transportation
  • energy use

Individuals may consider their electricity consumption, transportation habits, and daily activities. Identifying sources is crucial for accurate data collection.

3. Data Collection: Gathering the Numbers

Gather data on the activities associated with each emission source. For example, if you’re assessing transportation emissions, collect information on the number of kilometers or miles traveled. Get fuel consumption for your fleet (and consider making it greener). Get vehicle types. A cargo van emits differently to a commuter car. Businesses might need to collect data on energy usage, production levels, or other relevant metrics.

4. Emission Factors: The Key to Calculation

Emission factors represent the amount of greenhouse gases emitted per unit of activity. Find relevant emission factors for each of your activities. These factors can be obtained from databases, government publications, or industry standards. They play a crucial role in converting your activity data into emissions.

Make yourself a to-do list like this to capture the steps you need to take to capture GHG emissions for your business

5. Calculating Emissions: Crunching the Numbers

Now it’s time to do math. Multiply the activity level by the corresponding emission factor for each emission source. This simple multiplication gives you the emissions for each greenhouse gas associated with a specific activity. Confused? Lean on software to help. There are MANY great ones out there, like Toronto-based Carbonhound

6. Conversion Factors: Making Units Consistent

Different greenhouse gases have varying global warming potentials. Think potency levels. This step is sometimes missed or rushed. What you have to do: convert all your emissions into a common unit, typically metric tons of carbon dioxide equivalent (tCO2e). This step aims to provide a consistent measurement across different gases and simplifies the comparison process.

7. Quality Control: Checking for Accuracy

Accuracy is crucial in emission calculations. Get it right. get source data. Yes – we mean get your hands on bills and statements. Original data is king. Verify the reliability of your data and check for any inconsistencies or errors in your calculations. Using standardized methodologies, such as those provided by the Greenhouse Gas Protocol, adds credibility to your results.

8. Reporting: Presenting Your Findings

Create a report presenting your emissions data. Microsoft Excel and Word are your friends. Excel for data compiling and calculations, and Microsoft Word for report writing with more details around activities during your baseline year and initiatives to hit new targets. Break down emissions by source and include any relevant contextual information. Clear and transparent reporting is essential, especially if you’re sharing this information with stakeholders, clients, or the public.

9. Setting Baselines and Targets: Planning for Improvement

Establish baseline emissions for future comparisons. Pick a year that you have some good data for. Many of our clients pick last year as their baseline data year. This baseline serves as a reference point for setting reduction targets. “We have XYZ in 2022. So our goal for 2023 is 5% lower.” Goals for emission reduction or mitigation efforts can guide your organization or personal initiatives toward a more sustainable future. BONUS: Outline the actions that you’ll be taking to hit your new reduction targets. For example… “Our sustainability committee is helping 3 office sites reduce their electricity use through reduction of lighting at night, lowering driving, and reducing use of a refrigerant.” 

10. Continuous Improvement: Adapting to Change

Regularly update your greenhouse gas inventory as new data becomes available or as your organization undergoes changes. Many do this annually – at the same time as financial reporting. You already know – continuous improvement makes certain that your emissions calculations remain accurate and relevant over time. Oh – and keep the data backup handy. You never know when you’ll need to pull it when someone asks how you got a certain number. 

11. Verification: Ensuring Credibility

Consider third-party verification to enhance the credibility of your emissions data. This step is especially important for big companies reporting emissions publicly or seeking certification. External verification adds an extra layer of assurance and transparency. There are plenty of verification organizations out there. Do a simple Google search, or contact us at ThisRock for help. 

Conclusion: Taking Small Steps for a Big Impact

I understand. Calculating greenhouse gas emissions may seem complex. Breaking it down into these manageable steps makes the process doable. Whether you’re an individual trying to minimize your carbon footprint or a business aiming for sustainability, understanding and tracking emissions are vital steps toward a greener future.

So – to recap… By consistently monitoring and improving your emissions calculations, you contribute to the global effort to combat climate change. Remember, every small reduction in emissions adds up, making a significant impact collectively. Embrace the process. Strive for accuracy. Let your commitment to sustainability drive positive change. You got this.