What Are Greenhouse Gas (GHG) Emissions

Greenhouse gas emissions have become central to corporate sustainability, carbon accounting, and climate risk management. If you manage sustainability programs at a mid-size enterprise, you need clear definitions, robust measurement methods, and practical reduction strategies. This guide addresses what are GHG emissions, where they originate, how to measure them, and what helps reduce greenhouse gas emissions all with code snippets, real-world data, and a developer-oriented mindset.

Defining GHG Emissions

What are GHG emissions? In technical terms, GHG emissions are the release of gases that trap infrared radiation in the atmosphere, raising average global temperatures. These gases create a thermal blanket around Earth; too much blanket and the planet overheats. While “carbon emissions” often refers specifically to carbon dioxide (CO₂), GHG emissions include several other compounds, each with different warming potentials.

Main Types of Greenhouse Gases

Understanding what greenhouse gases are is the first step. Here are the principal culprits, their typical sources, and 100-year global warming potentials (GWP):

Gas	Formula	Sources	GWP (100 yrs)
Carbon Dioxide	CO₂	Fossil fuel combustion, cement production, deforestation	1
Methane	CH₄	Agriculture (enteric fermentation), landfills	25
Nitrous Oxide	N₂O	Fertilizer application, industrial processes	298
Hydrofluorocarbons (HFCs)	HFCs	Refrigeration, air-conditioning systems	124–12,500
Perfluorocarbons (PFCs)	PFCs	Aluminum smelting, semiconductor etching	7,390–12,200
Sulfur Hexafluoride	SF₆	Electrical switchgear, magnesium casting	23,500

To compare and sum these gases, emissions are expressed in CO₂-equivalents (CO₂e). Converting units lets you aggregate Scope 1, 2, and 3 emissions into a single metric.

Where Do Greenhouse Gas Emissions Come From?

Quantifying where greenhouse gas emissions come from helps prioritize interventions. According to the IBM reference on greenhouse gas emissions, global emissions break down approximately as:

• Energy (electricity & heat): 25 percent
• Industry: 21 percent
• Agriculture, forestry, land-use: 24 percent
• Transportation: 14 percent
• Buildings: 6 percent
• Other (waste, fugitive emissions): 10 percent

In corporate accounting, the GHG Protocol classifies emissions into three scopes:

1. Scope 1: Direct emissions from owned or controlled sources, such as boilers, furnaces, and company vehicles.
2. Scope 2: Indirect emissions from purchased electricity, steam, or cooling.
3. Scope 3: All other indirect emissions, including purchased goods, business travel, employee commuting, waste disposal, and end-of-life product emissions.

Most enterprises often find that Scope 2 and Scope 3 emissions represent 60–80 percent of their footprint, making data collection across suppliers and partners essential.

How to Measure GHG Emissions

Accurate measurement relies on two components:

1. Activity Data: Quantities of fuel burned, electricity consumed, kilometers driven, materials procured.
2. Emission Factors: Standardized values (e.g., kg CO₂e per kWh) published by regional agencies like the EPA, DEFRA, or IEA.

A simple pseudocode to calculate CO₂e might look like this:

Example: 

Calculating CO2e for electricity consumption

activity_data_kwh = 150000 | kWh per year for Site A

emission_factor = 0.5|  kg CO2e per kWh

co2e_kg = activity_data_kwh * emission_factor

print(f”Total CO2e emissions: {co2e_kg:,} kg”) 

Output: 75,000 kg CO2e

For a comprehensive methodology, review how to calculate carbon footprint here:
https://snowkap.com/how-to-accurately-calculate-your-carbon-footprint/

Many teams integrate such calculations into data pipelines or BI dashboards, using SQL or Python notebooks to automate regular reporting.

What Helps Reduce Greenhouse Gas Emissions

Effective reduction strategies vary by organization size and sector, but common levers include:

• Energy efficiency: Retrofitting lighting, motors, and HVAC systems.
• Fuel switching: Replacing natural gas heating with electric heat pumps.
• Renewable procurement: Power purchase agreements (PPAs) or onsite solar installations.
• Process optimization: Lean manufacturing, waste minimization, logistics routing.
• Supplier engagement: Setting emissions criteria in sourcing contracts.

Integration platforms can simulate “what-if” scenarios. For example, switching 50 percent of purchased electricity to renewables might cut Scope 2 emissions by 30 percent. Visualization dashboards help stakeholders track progress against Science Based Targets.

Understanding what greenhouse emissions are and where greenhouse gas emissions come from empowers mid-size enterprises to transition from manual spreadsheets to automated, scalable carbon management. By applying technical rigor, leveraging platforms like Snowkap, and aligning emissions reduction with core business objectives, sustainability managers can deliver measurable impact and future-proof their organizations against evolving regulatory and market demands.

Frequently Asked Questions

1. What is the difference between carbon emissions and GHG emissions?
Carbon emissions refer to CO₂ only. GHG emissions encompass CO₂, CH₄, N₂O, and fluorinated gases, expressed in CO₂-equivalents (CO₂e) for unified reporting.

2. What is Scope 2 emission?
Scope 2 emissions are indirect GHGs from purchased electricity, steam, heating, or cooling. Learn more in our guide to what is scope 2 emission.

3. How do I track Scope 1, 2, and 3 emissions?
Begin with direct fuel use (Scope 1) and electricity bills (Scope 2), then expand to supply chain and product lifecycle (Scope 3). Our overview of What is scope 1 2 3 emissions offers detailed steps.

4. Where do greenhouse gas emissions come from in a corporate context?
They come from energy generation, industrial processes, transportation, agriculture, land use, and waste. Your organization’s split depends on operations, supplier networks, and facility locations.

5. What helps reduce greenhouse gas emissions most effectively?
Data-driven strategies, automating emissions tracking, prioritizing high-impact interventions, and aligning sustainability with cost savings tend to yield the fastest and most measurable results.