A recent paper by Nisbet et al. notes that methane (CH4) in the atmosphere isn’t just increasing, it’s accelerating; the increase has gotten faster recently.
There was a time — from about 1999 until 2007 — when atmospheric methane wasn’t increasing at all. It had been, before 2000, but it remained steady for that 8-year period. But in 2007 it started rising again, as is plain to see in the following graph. What is not plain to see is that around 2014 it started rising even faster; the years 2014 through 2018 saw very rapid increase in CH4 levels.