John and All- Mr. Lockley makes a great point. If methane release tends to be limited to vents or so-called "hotspots", and the number of vents is a reasonable amount, the use of Lair or LN2 to freeze and seal these vents becomes MUCH more feasible than trying to cool/refreeze large permafrost regions.
Are we able to determine the number of these vents using satellites, aircraft etc? If so is this information currently available? This would be the primary consideration for feasibility- if it's something like 10,000 or more vents, at some number it just becomes unreasonable. However, on the order of 1,000-3,000 vents would seem feasibly and on the order of hundreds would be very feasible. Another consideration would be liquefaction capacity- whether existing liquefaction plants are close enough to support this activity, or if it would make more sense to build new plants (maybe 2-4) near existing high-latitude airports (these plants are quick/easy to build). Ideally it would be great to power them using captured methane (!) or by harnessing the strong/steady winds of the tundra. Secondly, as warming and drying continues in permafrost regions, this will create imminent danger of tundra wildfires, which can cause enormous CO2 and methane release. Already in July 2009 intense fires burned large permafrost regions in Russia, Canada and Alaska (see http://climatechangehealth.com/arctic/smoke-from-tundra-fires-in-russia-and-alaska ). However, I believe future wildfires could be more-effectively controlled using liquid nitrogen (LN2), by releasing a wide stream of LN2 on or just upwind of the fire lines via aircraft. The LN2 would then expand over 800 times into a cold/heavy gaseous nitrogen, and be pushed by the wind to form a "GN2 blanket" covering long portions of the fire line. By diluting oxygen levels from 21% to below 15%, combustion should be eliminated and the cooling provided would help prevent re-ignition. This method could provide greatly-improved capability for extinguishing large wildfires compared to current firefighting methods using water and/or fire retardants. If this method was shown to work in the tundra, it could create confidence for using it at lower latitudes, where wildfires are already becoming more intense from severe droughts and record high temperatures. Thirdly, the liquefaction process for creating Lair or LN2 might also capture a significant amount of methane in the process. Since liquid methane boils at a warmer temperature than Lair or LN2, cooling methane-rich air would form liquid methane first, allowing it to be distilled from the cold air and stored in highly-insulated dewars. Note: methane boils at -161 °C (-258 °F), while air and LN2 boil at -196 °C (-320 °F). To summarize, by creating the capability for delivering Lair/LN2 at high latitudes, this might provide a three-fold benefit of mitigating methane release, controlling large wildfires, and distilling liquid methane out of ambient air. John please help with the number of methane vents. I would appreciate any and all comments!! Thank you- Mark On May 9, 12:37 am, Andrew Lockley <[email protected]> wrote: > Using liquid air to seal methane vents may well work. Using it for general > cooling of the sea or land surface will not. > > Oxides of nitrogen are critical in the formation of hydroxyl radicals. They > therefore play a key role in the breakdown of methane. Although greenhouse > gases in their own right, it's vital to accurately judge the effect of > manipulations. An increase may paradoxically treat warming very > effectively. > > There's no credible technology of which I'm aware which could capture > methane from air > > A > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
