====== Methane hydrates ====== Mehane hydrates - a.k.a. methane clathrates - are an important factor in total global methane levels (see [[content:earth_sciences:methane_cycle]]) They are commonly found in permafrost deposits and on (and under) the sea floor, being a frozen, naturally‐occurring, and highly‐concentrated form of methane linked with water molecules. For stability, they require low temperatures (typically < 15 °C) and moderately high pressures. When warmed, the trapped methane is released and ultimately enters the atmosphere - where it is a very potent 'greenhouse' gas. This greenhouse effect leads to higher global temperatures which in turn releases more methane from the hydrates. Thus, they may be a profound factor in the case of positive-feedback 'runaway' global warming. Some climatologists suggest that runaway methane hydrate release was responsible for the 6°C global temperature increase at the end of the Permian period, a rise which is thought to have caused mass extinctions. [ ref. [[https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(03)00093-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0169534703000934%3Fshowall%3Dtrue|Trends in Ecology and Evolution, volume 18, issue 7, pp358-365,]] ] Although the science behind the storage and release mechanisms is well understood, at present the //quantity// of naturally stored methane hydrate worldwide is unknown. //With expert estimates varying by a factor of more than 30 times.// Current //mid-range// estimates put the global quantity at around 2.4 trillion tonnes of CH4 [ Source : [[https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016RG000534|Review of Geophysics]] Volume 55, Issue1 ] Together, these uncertainties make accurate calculations of potential global warming models considerably more problematic. //Note : // As far as //Wikenigma// has been able to determine, none of the widely used computational Climate Models currently take account of methane levels.