IPCC CO2 Emission Factors: What You Need to Know

In the context of global efforts to respond to climate change, quantifying and controlling greenhouse gas emissions has become an urgent task. One of the key tools to support this activity is CO2 emission factor according to IPCC. The following article by GREEN IN will provide a comprehensive view of the concept, role, calculation method as well as practical application of this index, especially in the context of Vietnam.

What is a CO2 emission factor? An in-depth definition from the IPCC

The CO2 emission factor is a specialized index used to measure the amount of CO2 emitted into the environment per unit of energy produced or consumed, for example, tons of CO2/unit of energy. This factor is widely used to estimate the amount of CO2 generated from activities using fossil fuels such as coal, oil, gas, or from industrial production processes.

The CO2 emission factor is not fixed but varies depending on many factors such as energy type, production technology, and fuel quality. Due to this fluctuation, the calculation results based on general data may have certain errors compared to the actual situation.

Therefore, to ensure flexibility and suitability to the data level of countries, the Intergovernmental Panel on Climate Change (IPCC) has proposed three different calculation levels (Tier) as follows:

• Tier 1: Use the global default coefficients provided by the IPCC. This method is simple and suitable for preliminary reports, but is not very accurate because it does not reflect the specific characteristics of each region.
• Tier 2: Uses more specific coefficients, built on national or regional data. This improves accuracy compared to Tier 1.
• Tier 3: This is the most accurate method, using detailed coefficients based on actual measurement data from specific emission facilities. This method is often applied to large and important emission sources.

The core role of CO2 emission factors in greenhouse gas inventories

The CO2 emission factor plays a key role in controlling and managing greenhouse gas emissions:

• Total Emissions Assessment: Countries and businesses use this coefficient to calculate total annual CO2 emissions, thereby providing a basis for developing effective emission reduction policies and measures.
• Control and management: Based on the emission factor, emission reduction strategies are proposed and applied to minimize the negative impacts of economic activities on the environment.
• Climate modeling: Emission factors are an important component of climate change forecasting models, helping scientists develop scenarios about the future of the planet.

Instructions on how to calculate CO2 emissions most accurately

CO2 emissions are calculated based on the following formula:

CO2 emission (ton) = CO2 emission factor (ton CO2/fuel unit) × Fuel consumption

For example, suppose a business in 2024 uses 10.000 m³ of natural gas (NG) and 2.000 tonnes of coke.

1. Calculating emissions from Natural Gas:

• Consumption: 10.000 m³
• Emission factor (estimated): 2,114 t CO2 / 1.000 m³

CO2 emissions = (10.000 / 1.000) × 2,114 = 21,14 tons of CO2

2. Calculation of emissions from Coke:

• Consumption: 2.000 tons
• Emission factor (estimated): 2,77 tonnes CO2 / tonnes coke

CO2 emissions = 2.000 × 2,77 = 5.540 tons of CO2

3. Total CO2 emissions of the enterprise: Total = 21,14 + 5.540 = 5.561,14 tons of CO2

Distinguishing between CO2 and CO2e: Avoiding basic confusion

The two concepts CO2 and CO2e are often confused as one, but they have completely different meanings:

CO2 (carbon dioxide): One of the most common greenhouse gases, produced by burning fossil fuels, industrial production and many other activities.

CO2e (carbon dioxide equivalent): Is a unit of measurement used to convert the impact of all other greenhouse gases (CH4, N2O…) to the same equivalent unit of CO2. This allows us to compare and calculate the total global warming impact of all greenhouse gases.

Formula: CO2e = CO2 + CH4 + N2O + Other emissions

In greenhouse gas inventories, businesses are often required to report a CO2e index to reflect the overall impact of all emissions.

IPCC Guidelines and Practical Application in Vietnam

The IPCC is the authoritative international body that provides guidance on greenhouse gas inventories. CO2 emission factors are often referenced from the “2006 IPCC Guidelines for National Greenhouse Gas Inventories”.

In Vietnam, the Ministry of Natural Resources and Environment (MONRE) issued Decision No. 4432/QD-BTNMT on October 11, 2022, announcing a list of emission factors for greenhouse gas inventories. This decision assigns the Department of Climate Change to preside over the review and update of the list when there are new national characteristic factors or guidance from the IPCC. The list includes emission factors for four main sectors: energy, industrial processes, agriculture - forestry - land use, and waste.

In particular, to specify the inventory work in key economic sectors, the Ministry of Industry and Trade issued Circular No. 38/2023/TT-BCT (dated December 27, 2023) on the set of emission factors and energy norms applied in greenhouse gas inventory. This document plays an extremely important role, providing official CO2 emission factors for many types of fuels and national grid electricity applicable to facilities that must conduct inventory according to Decree 06/2022/ND-CP and are under the management of the Ministry of Industry and Trade.

Enterprises and production facilities should note that, when conducting GHG inventories, specific national emission factors issued by competent authorities (such as the Ministry of Natural Resources and Environment, Ministry of Industry and Trade) will take precedence over the global default factor (Tier 1) of the IPCC. The use of these official factors ensures that enterprises' emission reports are accurate, consistent and in compliance with Vietnamese law.

Below is a summary table of common forms of energy:

Source: Reference data is compiled from Decision 4432/QD-BTNMT of the Ministry of Natural Resources and Environment and Circular No. 38/2023/TT-BCT of the Ministry of Industry and Trade (note: grid power emission coefficient is updated regularly).

The factors in this category generally apply the Tier 1 approach according to the IPCC Guidelines. The use of these factors serves as a basis for many activities:

• National greenhouse gas inventory: Support countries in calculating and reporting emissions to the United Nations.
• Carbon pricing and carbon markets: Help businesses quantify emissions to participate in carbon pricing mechanisms such as carbon taxes or credit markets.
• Emissions reduction planning: Providing critical data for governments and businesses to identify priority areas and develop appropriate emissions reduction strategies.

Challenges and limitations when applying CO2 emission factors

Despite their importance, the use of IPCC CO2 emission factors still faces several challenges:

• Representativeness: The default coefficients (Tier 1) may not accurately reflect the specific characteristics of each country or region, leading to errors in calculation.
• Data: Operational data in some countries may be incomplete or inaccurate, directly affecting inventory results.
• Update: Regular updating is required to reflect changes in production technology and economic activities.

Conclusion

CO2 emission factor according to IPCC is an indispensable tool in the effort to inventory and manage greenhouse gases globally. Understanding and correctly applying these coefficients will help countries and businesses take effective steps in the fight against climate change. This is not only a compliance requirement but also an important part of the sustainable development strategy. GREEN IN is committed to accompanying you on the green transformation path, providing the most comprehensive and in-depth solutions.