The question of whether methane (CH4) in the atmosphere is a threat to life is extraordinarily complex and generally not well understood. But, yes it is a serious threat, very serious and horribly real.
Okay, but don’t scientists understand this, and why aren’t they speaking out?
They are speaking out but only a very few.
Here’s the “speaking out” problem: Leading climate scientists are not willing to honestly expose their greatest fears, as discovered by Amy Goodman of Democracy Now! whilst at COP21 in Paris this past December, interviewing one of the world’s leading climate scientists, Kevin Anderson (University of Manchester) of Tyndall Center for Climate Change Research who said: “So far we simply have not been prepared to accept the revolutionary implications of our own findings, and even when we do we are reluctant to voice such thoughts openly… many are ultimately choosing to censor their own research.”