the one problem i see with the calcualtion on the release of methane from siberia, is that it assumes all of it will be in methane. the only way that can happen is if it says wet 24 7 until the gass is release. if it dries out, the methane oixdies into co2. even with things as they are now. a large part of it is dry most of the year. only the lakes are staying wet and those will drain off as soon as the peat on the bottom decays enough to stop blocking the water. if it does not decay, there is no problem. if it does the water will drain, again, after a time, no problem.
another problems is that the higher the methane levels in the atmosphere, the more oxidation occurs there. lightning does not set off much, since there is so little. but let the concetration get up, and the storms will be come real boomers.
