Greenhouse gas emissions are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Without GHGs, earth couldn’t maintain a liveable temperature. However, rapid industrialization has released large volumes of man-made GHGs, causing abnormal warming.

When GHGs accumulate and temperatures rise, the climate system and weather patterns shift significantly. This shift threatens economic and social structures and human health. Therefore, corporate and public bodies must limit their GHG production.

The first step is measuring GHGs from all operational activities. By understanding a company’s GHG emissions, stakeholders can make effective changes.

In this article, we would discuss some types of greenhouse gas emissions and the basic steps for calculating GHG emissions. 

Types of Greenhouse Gas Emissions

The greenhouse gas emissions inventory covers the seven direct greenhouse gases under the Kyoto Protocol:

• Carbon dioxide (CO2)
• Methane (CH4)
• Nitrous oxide (N2O)
• Hydrofluorocarbons (HFCs)
• Perfluorocarbons (PFCs)
• Sulphur hexafluoride (SF6)
• Nitrogen trifluoride (NF3)

These gases contribute directly to climate change owing to their positive radiative forcing effect. HFCs, PFCs, SF6 and NF3 are collectively known as the ‘F-gases’.

In general terms, the largest contributor to global warming is carbon dioxide which makes it the focus of many climate change initiatives. Methane and nitrous oxide contribute to a smaller proportion, typically <20%, and the contribution of F–gases is even smaller (in spite of their high Global Warming Potentials) at <5% of the total.

1. Carbon dioxide

Carbon dioxide (CO2) is the primary GHG responsible for climate change. It is the most abundant GHG, not the most potent. CO2 is emitted from a number of different sources including: the extraction and burning of fossil fuels (such as coal, oil, and natural gas), from wildfires, and natural processes like volcanic eruptions. Sequestration can remove carbon, where soils and trees absorb CO2 naturally.

2. Methane

Methane (CH4) comes from livestock farms, natural gas systems, and landfills. Although it has a shorter atmospheric lifespan than CO2, it traps radiation more efficiently. Methane’s global warming potential is 25 times greater than CO2 over 100 years. Industrial plants and waste management sites use methane capture technologies to reduce emissions.

3. Nitrous oxide

Nitrous oxide activities, especially in agriculture, produce 40% of global nitrous oxide (N2O) emissions. One pound of N2O has 300 times the impact of CO2. Once released, N2O can last over 100 years in the atmosphere.

4. Fluorinated gases (F-gases)

Fluorinated gases are man-made and have a higher warming effect than CO2. However, they don’t harm the ozone layer. The Kyoto basket includes hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). Since 1990, hydrofluorocarbon emissions have increased by 284%. This spike is due to their use as substitutes for ozone-depleting substances.

Despite the variety of GHGs, measuring GHGs converts all emissions to CO2 equivalents (CO2e). Each greenhouse gas emissions are measured, multiplied by its global warming potential, and aggregated to total GHG emissions in CO2 equivalents.

How Greenhouse Gas Emissions Affect to Environment

The IPCC (Intergovernmental Panel on Climate Change) has assessed how higher GHG concentrations impact the environment. Their reports warn of more frequent extreme weather events, including intense heat waves and heavy rainfall. These events lead to increasing droughts, wildfires, and floods, causing infrastructure destruction.

Moreover, changing weather patterns pose risks to economic activity, especially in agriculture. For example, unseasonably warm temperatures and drought conditions threaten worker safety and crop performance. 

Seriously, if global temperatures rise over one degree, some communities may be displaced entirely.

The Importance of Measuring Greenhouse Gas Emissions

Measuring GHG emissions is crucial for meaningful climate action. Without accurate measurements, companies won’t know where to implement changes. 

Comprehensive data is essential for any significant financial or strategic decision, including environmental ones. The reporting process provides the necessary information, removing guesswork and assumptions.

A common misconception is that energy use is the primary driver of corporate emissions. However, energy generally accounts for less than half of a company’s GHG emissions. For many, energy consumption is only 20 percent of their total GHG output. 

Other significant emissions sources include employee commuting, business travel, paper use, and external web hosting.

Reporting GHG emissions not only helps reduce emissions but also offers secondary benefits. It helps companies identify hidden inefficiencies, which can be both financial and environmental burdens. For example, some facilities might use more energy than others, leading to higher costs.

Additionally, companies can gain a competitive edge by reporting their emissions. Increased sustainability awareness has impacted markets and consumer behavior. Along with more legislation, there is a growing desire among consumers and investors to support environmentally responsible companies.

Methods of Measuring Greenhouse Gas Emissions

Greenhouse gas emissions are divided into three categories, or scopes, for measurement. These scopes were developed through the Greenhouse Gas Protocol to standardize corporate reporting globally. The distinction between scopes relates to direct and indirect emissions. They are: 

Scope 1 

Scope 1 emissions are direct emissions from the reporting company’s owned facilities and other operations. For example, emissions from consuming combustible fuels for a fleet of vehicles.

Scope 2 

This grouping captures indirect emissions. This means emissions from the use of energy which typically comes from a utility provider outside of the reporting company’s ownership structure. Standard Scope 2 emissions include heating and cooling buildings.

Scope 3 

The final category for emissions measurement covers all the remaining activities beyond the range of the first two Scopes. This includes all the indirect emissions not contained in Scope 2. Such as employee travel, waste generation and purchased goods and services.

Basic steps for Measuring Greenhouse Gas Emissions

1. Determine the Scope of GHG Reporting

First, stakeholders must define the activities and operations included in their GHG inventory. The Greenhouse Gas Protocol offers two approaches: equity share and control approach.

• Equity Share Approach: Companies account for emissions based on their ownership stake. For example, if a company owns 15% of a building, it reports 15% of the building’s emissions.
• Control Approach: This common approach accounts for all emissions from operations under the company’s operational or financial control.

2. Collect Activity Data

After selecting an approach, the organization collects GHG emissions data.

• Scope 1 and Scope 2 Emissions: Identify applicable sources for each scope. Consider whether employees use company cars or if assets run on natural gas or electricity. Utility bills and financial statements provide consumption details.
• Scope 3 Emissions: Though not compulsory, companies may distribute surveys to gather data on commuting habits, business travel, work-from-home schedules, and additional purchased goods and services.

3. Calculate Greenhouse Gas Emissions

After data collection, perform a quality assurance check to verify accuracy. Use the approved data to calculate emissions.

Emissions Factors: Apply the raw data to corresponding emissions factors, which illustrate the amount of GHG emissions per unit of activity. For example, a car driving one kilometer produces 0.16 kg of CO2. Multiply the kilometers driven by the relevant emissions factor to determine total emissions for that activity.

4. Compliant Reporting

Adhere to mandatory sustainability reporting legislation, which varies by company size and location.

• UK: Companies with over 500 employees must comply with TCFD requirements from FY23/24.
• US: Listed companies will need to comply with US SEC requirements.
• EU: Companies must comply with EU CSRD.

These requirements are based on ISSB guidelines, ensuring consistency. And, companies can also voluntarily report to the CDP, which grades submissions.

See more: Trade And FDI: Channels Of Low-Carbon Technology Transfer