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GHG Emissions: Everything You Need To Know

What are GHG emissions?

A greenhouse gas (or GHG for short) is any gas in the atmosphere that absorbs heat and thereby keeps the planet’s atmosphere much warmer than it would be. There are five main GHGs in the Earth’s atmosphere; water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone.

Every greenhouse gas has its global warming potential (GWP). GWP is a measurement of how much heat the GHG traps inside the atmosphere. GHGs, such as CO2 and methane, occur naturally and have always been present in the Earth’s atmosphere. So why is GHG bad for the environment? Human activities in the past few hundred years are increasing the levels of GHGs impacting climate change by changing the composition and tilting the balance from the existing status quo towards one with a warmer global climate.

GWP factors were established by the International Panel on Climate Change (IPCC), a United Nations-established scientific organization. We must bear in mind that different greenhouse gases both absorb different amounts of heat and last in the atmosphere for various lengths of time; therefore, the higher the GWP of a GHG, the more significant the global warming impact of that gas.

GHG Emission Chart
                                      GHG Emission Chart

CH4 and N2O emissions depend on many variables such as fuel characteristics, technology type, combustion characteristics, application of pollution control equipment, and ambient environmental conditions. The solution to this issue is to use each GHG’s individual GWP and use it to translate the air emissions into a standard unit that compares and relates all the GHG emissions so they can be reported as a single combined quantity—it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO2).

Why Calculate GHGs?

  1. It helps identify opportunities for energy savings and cost. It is a well-known fact that anthropic greenhouse gas emissions are closely linked to energy use. Thus, by measuring a company’s emissions, we can identify ways to reduce the emission, resulting in lower energy use and cost savings. For example, Unilever aims to decarbonize its business through various methods, such as transferring to renewable grid electricity. They saved upwards of €873 million by investing in energy-saving initiatives. You can read more about their resourcefulness here. Additionally, in 1997 Stonyfield Farm, an organic dairy company, determined their carbon footprint, calculated their emissions & set in motion the incentives that reduced their emissions.
  2. It ensures the company is functioning within regulatory requirements. As government protocols emerge and develop in response to the growing concern for the climate crisis, it becomes increasingly crucial for businesses to be aware of their emissions levels. Accurate measurements based on commonly agreed-upon standards are a necessary first step towards regulatory changes.

How to Calculate Company-wide GHG?

Calculating GHG emissions is a multi-step process. The Greenhouse Gas Protocol (GHG Protocol) is the most widely used international accounting tool for government and business leaders to understand, quantify and manage greenhouse gas emissions. It provides the accounting framework for many GHG standards and programs globally, as well as many individually prepared GHG inventories. GHG Protocol’s toolset enables companies to develop comprehensive and reliable inventories of their GHG emissions. The GHG practitioner gains an early and informed understanding of the project’s impact and potential sources of GHG emissions. This provides an opportunity to influence and even mitigate GHG emissions early in the design process and consider emissions from alternative options.

What Are The Next Steps after Completing a GHG Assessment?

After completing a GHG assessment, a company can lessen the environmental impact of its business’s greenhouse gas emissions in two ways:

  1. Reduce the business’s greenhouse gas emissions by setting up Green initiatives: Most emissions may be costly to a business at first, but implementing policies and procedures to reduce these emissions can minimize long-term costs while still achieving the same operational results. Green initiatives can be as small as replacing existing lighting systems with more energy responsive systems or adding natural lighting and shading and other “green” elements into new buildings as they are built or retrofitted. Home Depot is a good case study that demonstrates how capital investments in more recent, more energy-efficient equipment can reduce emissions and lower operating costs at the same time. A significant reduction in energy consumption leads to a substantial decrease in energy costs. Learn more about what Home Depot, one of the US’s largest home improvement companies, is doing towards the 2050 climate act.
  2. Consider carbon offsets: If you want to tackle your CO2 emissions, every ton of emission reduction results in creating one carbon offset. A variety of offset methods are in use – while tree planting was initially a mainstay of carbon offsetting, renewable energy, energy conservation, and methane capture offsets have become increasingly popular.

Case Study: GHG Emissions calculations

In 2020, our Principal Consultant Mohammed Hidayath led the GHG Emissions calculations of a confidential project in KSA. It was part of the overall LEED for Cities and Communities Plan & Design certification system and aimed to provide validation and estimation on GHG accounting for the project.

Global Protocol for Community-Scale Greenhouse Gas Emission Inventories (GPC) was the tool used to calculate the emissions. The GHG Protocol standard for cities was created in partnership with the World Resources Institute, C40 Cities Climate Leadership Group, and ICLEI – Local Governments for Sustainability (ICLEI).  

The final report found that almost 97% of associated emissions for the project were credited to building consumption, while the last 3% were attributed to transportation. 

GHG emissions are calculated using the protocol at the BASIC reporting level as the other two reporting levels as per the standard: BASIC+ and Territorial also cover Scope 3 emissions to varying degrees. For LEED GHG, emissions are calculated using the protocol at the BASIC reporting level to cover scope one and scope two emissions as per credit requirements:

GHG Inventory Diagram
Source: Global Protocol for Community-Scale Greenhouse Gas Emissions Inventories

Ultimately, GHG calculations can help you identify which aspects of your project are high contributors to the climate and allow you to audit what changes you can make that will reduce costs in the future. 

Are you interested in calculating your GHG emissions? Contact us.