Not sure if I'm interpreting the data correctly, but it looks like the 1,000 times more heat trapping property of HFC's relative to CO2 fades to irrelevance when compared to the 5,000,000 times higher concentration of CO2 currently found in the troposphere.

So McKenna's bending the curve comment addresses something like 0.0002% of the problem, multiplied by 1/15th to adjust for atmospheric life span differences.

Does that sound like an appropriate drama deflator?