Global Warming Potential (GWP) is a crucial metric used within the context of a Life Cycle Analysis (LCA) to measure the potential impact a substance has on global warming.
GWP is vital in a LCA because it provides a standardized method to evaluate and compare the climate change impacts of products, processes, or services.
- Definition of GWP: GWP is a relative measure that compares the amount of heat trapped by a certain mass of a greenhouse gas (GHG) to the amount of heat trapped by a similar mass of carbon dioxide (CO2). Essentially, it is a way of quantifying how much a given GHG contributes to global warming compared to CO2.
- Time Horizon: GWP values are typically calculated over specific time horizons, such as 20, 100, or 500 years. This is because different gases remain in the atmosphere for different lengths of time and have varying short- and long-term effects on temperature.
- Use in LCA: In an LCA, the GWP is used to assess the potential climate change impact of different emissions across a product’s lifecycle. It enables the comparison of the impacts of different GHGs in a common unit. For instance, if a product’s lifecycle releases methane and CO2, the GWP allows these emissions to be converted into a CO2 equivalent (CO2e) value based on their respective GWPs, facilitating a more straightforward comparison and aggregation of climate impacts.
- Importance: GWP is vital in LCA because it provides a standardized method to evaluate and compare the climate change impacts of products, processes, or services. This helps in identifying areas with significant GHG emissions and opportunities for reducing environmental impacts.
- Data and Standards: GWP values for various greenhouse gases are provided by scientific bodies like the Intergovernmental Panel on Climate Change (IPCC) and are used in accordance with international standards like ISO 14040 and ISO 14044 for LCAs.
How We Use GWP
We use GWP as a measurement of a product’s environmental footprint. This allows us to compare the impact of different products and how variations within a product – like using plastic vs glass in bottles – affect its environmental impact.
Products with a higher GWP have a bigger environmental impact. Generally we are evaluating and comparing products to find the ones with the lowest GWP, so we can make more informed purchasing decisions and lower our own environmental footprint.