As usual, because methane breaks down within a few years, the main impact is about rate of release, rather than total volume released. So this isn’t good, but it’s also not currently at anything like the scale which would make a major difference.
The researchers, on board the ship Sarmiento de Gamboa, have observed columns of methane in the ocean up to 700 meters long and 70 meters wide . . .
. . . “We have estimated that in this area there are some 24 gigatons of carbon accumulated in methane hydrates, an amount equivalent to what all of humanity emits in two years,” warns Urgeles.
Potentially (ok - not currently), “24 gigatons of carbon accumulated in methane hydrates” is a serious amount. Note that as methane increases in the atmosphere, it’s lifetime increases as oxidising capacity is used up, a positive feedback. Methane may also help explain the rapid at the ends of ice ages (when sea-level rose ±100m). If there’s any really bad runaway warming scenario, it has to do with methane.
and we’re pulling the trigger on that gun… hooray…