Scientists have just released video showing how, for the first time, they have been able to measure these natural up-wellings to tell whether, if large amounts of this methane ever thawed out from its deep sea beds, it would reach the atmosphere, rather than being absorbed in the water, and thus make the earth even hotter.
The findings of oceanographer Ira Leifer et al, published in a strictly peer-reviewed scientific journal, are that it would do just that.
In other words, all that undersea methane is a potential "positive feedback" of catastrophic proportions.
If warming currents, such as those already detected by scientists at depth, begin to thaw these methane beds, it will make the atmosphere, and consequently the sea currents, even warmer, and melt out more methane.
A number of scientists tell me that would take the Earth up into temperatures humankind has never experienced -- and probably could not survive.
They believe it's happened for natural reasons before -- before, for example, the Jurassic age, when dinosaurs, but no humans, roamed the earth.
That's why they insist we must stop the unnatural burning of fossil fuels -- oil, coal and gas -- which risks giving such a methane mega-burp an artificial kick that could -- hard as this is to take in -- end civilization.
Small doses are the best way to take in such news.
Psychologists tell us that a little denial when facing truly frightening news can, at first, be a good thing. It helps us hold ourselves together in face of the threat, helps keep our "meaning systems" intact.
As long as we keep working back towards reality.
No child wants to think it can harm the basic wellbeing of a protective parent who provides its only world.
They can't even believe they could do such a thing.
Climate scientists are telling us we are doing just that to our own Mother Earth, and we should believe it.