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 of heat trapped by a similar mass of carbon dioxide. Thus, considering GWP for CO, to be 1, methane has a GWP of 25 and sulfur hexafluoride has a GWP of 22,800 for a time horizon of about 100 years.