- A 2 times
- B 12 times
- C 28-36 times
- D 100 times
Correct answer: C. 28-36 times
Explanation: Methane GWP = ~28-34x CO2 over 100 years (IPCC AR5). Over 20 years, GWP is ~84x. Methane is far more potent but shorter-lived (~12 years) than CO2 (~hundreds of years).
Concept context
Ecosystems, food chains, energy flow, nutrient cycles, biodiversity, and conservation.