Which description best defines Global Warming Potential (GWP)?

Which description best defines Global Warming Potential (GWP)?

• A. A direct measure of ozone depletion potential.
• B. A ratio of the heat trapped by a kilogram of gas to that trapped by CO2 over a defined time period.
• C. The rate at which the gas degrades in the atmosphere.
• D. The total emissions of the gas over its lifetime.

Answer: (B)

Global Warming Potential describes how much heat a given mass of a greenhouse gas traps in the atmosphere compared with the same mass of CO2, over a defined time horizon. It combines how strongly the gas absorbs infrared radiation (radiative efficiency) with how long it stays in the atmosphere (lifetime), producing a dimensionless ratio. Because CO2 is used as the reference gas, the GWP value tells you how potent that gas is relative to CO2 for warming over the chosen time period, which is why emissions are often expressed as CO2e. The standard horizon is typically 100 years, though other timeframes (like 20 or 500 years) are also used, and the GWP can differ with the horizon due to differing lifetimes and radiative effects. This is why the correct description is a ratio of the heat trapped by a kilogram of the gas to that trapped by CO2 over a defined time period. The other descriptions refer to unrelated concepts: ozone depletion potential, atmospheric degradation rate, and total lifetime emissions, none of which define GWP.

Global Warming Potential describes how much heat a given mass of a greenhouse gas traps in the atmosphere compared with the same mass of CO2, over a defined time horizon. It combines how strongly the gas absorbs infrared radiation (radiative efficiency) with how long it stays in the atmosphere (lifetime), producing a dimensionless ratio. Because CO2 is used as the reference gas, the GWP value tells you how potent that gas is relative to CO2 for warming over the chosen time period, which is why emissions are often expressed as CO2e. The standard horizon is typically 100 years, though other timeframes (like 20 or 500 years) are also used, and the GWP can differ with the horizon due to differing lifetimes and radiative effects. This is why the correct description is a ratio of the heat trapped by a kilogram of the gas to that trapped by CO2 over a defined time period. The other descriptions refer to unrelated concepts: ozone depletion potential, atmospheric degradation rate, and total lifetime emissions, none of which define GWP.