The Global Warming Potential (GWP) | Meaning and Application

|  October 13, 2023

🕓 Reading time 7 minutes

Table of contents

1. Greenhouse gases and their impact on climate change

2. The unit of measurement Global Warming Potential (GWP)

3. Who collects the GWP values?

4. How is the Global Warming Potential (GWP) used in greenhouse gas calculations?

1. Greenhouse gases and their impact on climate change

Climate impact of greenhouse gases

The “Global Warming Potential” (GWP) is a key figure used to estimate the AImpact of greenhouse gases on climate change Climate change is the result of the release of several greenhouse gases into the atmosphere, each of which has a different effects on the climate has.

Relevant greenhouse gases under the Kyoto Protocol

The Kyoto Protocol identifies some Main cause of these emissions, including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and various fluorinated greenhouse gases (F-gases). These F-gases include hydrogen fluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Since 2015, nitrogen trifluoride (NF3) has been added to the list. Depending on the activity, several of these greenhouse gases can be released simultaneously during different processes.

2. The unit of measurement Global Warming Potential (GWP)

Unit of measurement for comparison to CO2

What is that Global Warming Potential (GWP)? The Global Warming Potential (GWP) is a measure used to assess the impact of greenhouse gases on climate change. It is a relative unit of measurement, which indicates how much heat-absorbing effect a greenhouse gas has in Comparison to carbon dioxide (CO2) over a certain period of time.

CO2 serves as Reference gas with a GWP of 1.

The GWP is a measure that indicates how much a particular greenhouse gas contributes to global warming compared to carbon dioxide (CO2) over a certain period of time.

Greenhouse gases, such as methane (CH4), nitrous oxide (N2O), and hydrofluorocarbons (HFCs), have different GWP values based on their ability to capture infrared radiation and store heat in the atmosphere. higher GWP value means that the gas has a greater climate impact per unit quantity has.

Period of Global Warming Potential

The most common time periods over which GWP values are calculated are 20, 100, and 500 years. This means that the GWP of a gas indicates how much heat-absorbing effect it has compared to CO2 over that period. For example, nitrous oxide has a GWP of about 265 over 100 years, meaning it contributes about 265 times more to warming than CO2 in the first 100 years after its release. 

Normally, a period of 100 years is used to calculate GWP values. This is also required by the ESRS E1 for reporting after the Corporate Sustainability Reporting Directive (CSRD).

3. Who collects the GWP values?

Intergovernmental Panel on Climate Change (IPCC)

The GWP values (Global Warming Potential) are determined by international scientific bodies and organizations One of the most prominent institutions involved in calculating and updating GWP values is the Intergovernmental Panel on Climate Change (IPCC)The Intergovernmental Panel on Climate Change (IPCC) is a globally recognized scientific organization that analyzes climate change and its impacts on behalf of the United Nations.

The IPCC has published reports and guidelines that specify GWP values for different time periods (such as GWP-20, GWP-100, and GWP-500), as well as the methods for calculating and updating these values. The GWP values are based on scientific studies and models that assess the climate impacts of various greenhouse gases. The GWP values are regularly updated to reflect current scientific knowledge.

4. How is the Global Warming Potential (GWP) used in greenhouse gas calculations?

Conversion to CO2 equivalents (CO2e)

Each greenhouse gas has its own GWP, which indicates how much heat-absorbing effect it has compared to CO2 over a given period of time. Overall climate impact of an activity or product To calculate the emissions of the various greenhouse gases in CO2 equivalents (CO2e) This allows all emissions to be converted to a uniform basis to ask.

To calculate total emissions in CO2e, the amount of the respective gas is multiplied by its GWP value. This yields the equivalent amount of CO2 that has the same climate impact as the emissions of the gas in question.

The conversion formula is:

Emissions (in tonnes of gas) x GWP = emissions in CO2e.

Converting to CO2e allows different emissions to be compared and aggregated on a common basis. This is crucial for understanding the overall impact on climate change and planning measures to reduce emissions. It also allows for the identification of major polluters and "super-gases" that have particularly strong climate impacts.