Methane leak more serious than we thought?

If it were more serious than thought, then sensitivity to CO2 must be even less than this lack of warming indicates. How does that translate into to more serious than thought. There was an unaccounted for warming source and CO2 is even less effective as a greenhouse gas than supposed. How stupid and incompetent would scientists have to be to not be able to measure the amount of methane in the atmosphere. That amount is 10 times less than the amount produced by cows. I know alarmists like to pretend that cows didn't exists until the last few decades but even they swamp out that effect. It is less than one part per 10 million. I am sure the effect is less recently with the serious cool down of the northern latitudes. It has been happening for over 10 thousand years and hardly amounts to something worth getting alarmed over AT ALL.