+nad That article was incidental to ozone, and had nothing at all to do with CH4. If you'd like to understand methane better, I'd read and understand:
[Short-lived climate pollution](https://goo.gl/mG3AGl)
[Short-lived climate pollution (supplement)](https://goo.gl/YY2QFc)
[Disentangling the effects of CO2 and short-lived climate forcer mitigation](http://goo.gl/dJnCnp)
[Much ado about methane](http://goo.gl/5NMdNv)
If someone feels they need a climate background to understand the science in these, I often recommend Ray Pierrehumbert's textbook, _Principles_ _of_ _Planetary_ _Climate_ or David Archer's _Global_ _Warming_: _Understanding_ _the_ _Forecast_, which is also accompanied by an [online course](http://forecast.uchicago.edu/), with lectures.