GWP compares a refrigerant's impact on the environment to which molecule baseline?

GWP compares a refrigerant's impact on the environment to which molecule baseline?

• A. nitrogen
• B. water vapor
• C. ozone
• D. carbon dioxide

Answer: (D)

GWP measures how much heat a given mass of a greenhouse gas traps in the atmosphere over a set time, compared to the same mass of carbon dioxide. Carbon dioxide is used as the baseline with a GWP of 1, so all other gases are scored relative to CO2. This baseline is chosen because CO2 is the most well-understood reference gas, has a long atmospheric lifetime, and provides a stable standard for comparing different gases. Water vapor and ozone are important greenhouse gases, but their levels fluctuate a lot and involve complex climate feedbacks, so they aren’t used as the baseline. Nitrogen is not a greenhouse gas in this context.

GWP measures how much heat a given mass of a greenhouse gas traps in the atmosphere over a set time, compared to the same mass of carbon dioxide. Carbon dioxide is used as the baseline with a GWP of 1, so all other gases are scored relative to CO2. This baseline is chosen because CO2 is the most well-understood reference gas, has a long atmospheric lifetime, and provides a stable standard for comparing different gases. Water vapor and ozone are important greenhouse gases, but their levels fluctuate a lot and involve complex climate feedbacks, so they aren’t used as the baseline. Nitrogen is not a greenhouse gas in this context.