This has only been measured for a few decades, but a detectable increase in the rate of increase in atmospheric methane made me think of tipping points. Could the much-to-be-feared feedback loops in permafrost and methane hydrates thawing be underway right now?

This article doesn’t mention either permafrost or hydrates. It does say that the increases are not a result of leaking natural gas wells or any other fossil fuel industry site. They narrow the cause down to “sources such as wetlands, waste, and agriculture”. I supposed some frozen wetlands could be thawing out, but it seems like the article would have mentioned that. I am skeptical that there has been any drastic worldwide change in landfill operations. A big change in agricultural practices – this could be plausible, I don’t know enough to say it is not.