It is somewhat deceptive framing, because methane can not accumulate in the atmosphere the way CO2 does. Its levels in the atmosphere will break down relatively quickly if we reduce output, unlike CO2. But the present level of methane in the atmosphere basically captures about 30% as much heat as the present level of CO2. That still leaves CO2 as significantly larger immediate problem and the much larger future problem.
We must do what we can, observing that every little counts - a little, and every lot counts a lot.
Yeah but that CO2 is already part of the ppm that is measured. And water vapor of course, has the ability to cool or heat depending on the position in the atmosphere and amount of particulates for it to condensate on (to form clouds).
