Question

which gas has a greenhouse warming potential of 25 and can last in the atmosphere for 12 years?
nitrous oxide
methane
water vapor

Explanation:

To determine the gas with a greenhouse warming potential (GWP) of 25 and an atmospheric lifetime of 12 years, we analyze the options:

• Nitrous oxide (N₂O) has a much longer atmospheric lifetime (over 100 years) and a higher GWP than 25.
• Methane (CH₄) has a GWP of ~25 (over 100 years) and an atmospheric lifetime of about 12 years.
• Water vapor has a very short atmospheric lifetime (hours to days) and is not typically measured with a GWP of 25.

Thus, methane matches the given criteria.

Answer:

B. methane