A Global Warming Potential (GWP) is the Index used to translate the level of emissions of various gases into a common measure in order to compare the relative radiative forcing of different gases without directly calculating the changes in atmospheric concentrations.
GWPs are calculated as the ratio of the radiative forcing that would result from the emissions of one kilogram of a greenhouse gas to that from emission of one kilogram of carbon dioxide over a period of time (usually 100 years).
GWP is a measure of how much a greenhouse gas contributes to global warming, relative to the effect of carbon dioxide (CO2). The GWP of a gas is expressed as a factor of CO2, with CO2 having a GWP of 1. Here are some examples of how GWP is used in the environmental context:
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Assessing the impact of greenhouse gases: GWP is used to compare the impact of different greenhouse gases on the environment. For example, methane has a GWP of 28-36, meaning it has a much stronger warming effect than CO2 over a 100-year period.
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Setting emissions reduction targets: Governments and organizations use GWP to set emissions reduction targets for different greenhouse gases. For example, the Paris Agreement aims to limit global warming to below 2°C above pre-industrial levels, and countries have committed to reducing their emissions based on the GWP of different gases.
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Carbon offset projects: Carbon offset projects use GWP to calculate the amount of greenhouse gas emissions that they have reduced or removed. This information is used to issue carbon credits, which can be sold to companies or individuals to offset their emissions.
GWP is an important tool for understanding the impact of greenhouse gases on the environment and for setting emissions reduction targets. By reducing emissions of gases with high GWP, we can work toward mitigating the impacts of climate change.