User:Andrewjlockley/methane geoengineering2

Geoengineering treatment of methane Methane is a significant GHG, and substantial reservoirs are vulnerable to instability due to AGW. Excursions, from permafrost and clathrates especially, act a positive feedback to AGW. Existing concentrations of well-mixed atmospheric methane substantially exceed pre-industrial levels. Various geoengineering methods are herein proposed for containment of methane, and/or accelerated oxidation to CO2 (a gas with a lower GWP over all timescales). A basic qualitative analysis of each technique is undertaken, to direct further study. Consideration is also given to the potential capacity of each technique to treat the total likely excursions of methane expected as a result of AGW. .Acknowledgements Ideas used in this paper have been worked on by the following: 	Alvia Gaskill 	N. Currier 	Alan Gardain 	Stephen Salter 	David Schware 	Eugene Gordon 	Mike McCracken 	Luxi Zhou 	Dan Wylie-Sears They have not endorsed the whole work.

Background LeLieveld et al (1998) state that: Methane concentrations have increased from about 0.75–1.73 μmol/mol during the past 150 years to date of paper; ~70% of the total source is anthropogenic; methane accounts for 22% of the radiative  forcing by all long-lived greenhouse gases (2.6 W m−2) ; GWP is 21 (kgCH4/kgCO2) over 100yr However, the GWP of methane has probably been underestimated.(Shindell et al, 2009) The paleoclimatic record implies the possibility of dramatic warming in the Arctic in response to AGW http://www.micropress.org/stratigraphy/papers/Stratigraphy_6_4_265-275.pdf Dickens et al (1997) note that “Gas hydrates in oceanic sediments may in fact comprise the Earth's largest fossil-fuel reservoir. But the amount of methane stored in gas-hydrate and free-gas zones is poorly constrained.” Reagan & Moridis (2008) note that “shallow deposits can be very unstable and release significant quantities of methane under the influence of as little as 1°C of seafloor temperature increase” However, Lamarque, predicts. “Using an observed 1% ratio to estimate the amount of methane reaching the atmosphere, our analysis leads to a relatively small methane flux of approximately 5–21 Tg(CH4)/year”. Archer (2007) notes “The hydrate reservoi