Air Emissions and Animal Agriculture

Global Warming Potential

Global warming potential (GWP) is a relative measure of how much heat a greenhouse gas traps in the atmosphere. It compares the amount of heat trapped by a certain mass of the gas in question to the amount heat trapped by a similar mass of carbon dioxide (whose GWP is standardized to 1). CO2 is the most emitted gas and the best studied. Therefore, it was defined as a standard for definition of Global Warming Potential of the greenhouse gases.

Carbon Dioxide Equivalent (CO2e) is a metric measure used to compare emissions from greenhouse gases based on their global warming potential (GWP). It is calculated by multiplying the tons of the gas by its GWP.


The graph above shows the amount of CO2e it takes to produce a food item in a size you would typically consume or buy. For example, even though an apple is 10 oz, it takes much less CO2e to produce that apple than a 6 oz organic beef steak. "USA" indicates food products made on a commercial farm that uses a confinement system.

Last Updated 10/31/2011