1. The problem statement, all variables and given/known data On a per-molecule basis, methane is 26 times more effective as an infrared absorber than is CO2. Calculate the corresponding ratio on a per-unit-mass basis, and compare it with the 20-year GWP for methane. What's the reason for any discrepncy you find? (CO2 atmospheric lifetime = 1000 years, GWP relative to CO2 is 1 in 20 years) (Methane atmospheric lifetime = 11 years, global warming potential relative to CO2 in 20 years is 23) 2. Relevant equations 3. The attempt at a solution I am not sure how to start this problem. I think I need to make a ratio between methane and CO2 but am not sure if that is right or how to do so.