title: Global methane emission estimates from ultraviolet irradiation of terrestrial plant foliage.
abstract: *Several studies have reported in situ methane (CH(4)) emissions from vegetation foliage, but there remains considerable debate about its significance as a global source. Here, we report a study that evaluates the role of ultraviolet (UV) radiation-driven CH(4) emissions from foliar pectin as a global CH(4) source. *We combine a relationship for spectrally weighted CH(4) production from pectin with a global UV irradiation climatology model, satellite-derived leaf area index (LAI) and air temperature data to estimate the potential global CH(4) emissions from vegetation foliage. *Our results suggest that global foliar CH(4) emissions from UV-irradiated pectin could account for 0.2-1.0 Tg yr(-1), of which 60% is from tropical latitudes, corresponding to < 0.2% of total CH(4) sources. *Our estimate is one to two orders of magnitude lower than previous estimates of global foliar CH(4) emissions. Recent studies have reported that pectin is not the only molecular source of UV-driven CH(4) emissions and that other environmental stresses may also generate CH(4). Consequently, further evaluation of such mechanisms of CH(4) generation is needed to confirm the contribution of foliage to the global CH(4) budget.
authors.affiliation: School of GeoSciences, The University of Edinburgh, Crew Building, West Mains Road, Edinburgh EH9 3JN, UK.
authors.forename: A Anthony
authors.initials: AA
authors.lastname: Bloom
authors.affiliation: National Center for Atmospheric Research (NCAR), Atmospheric Chemistry Division, PO Box 3000, Boulder, CO 80305, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Lee-Taylor
authors.affiliation: National Center for Atmospheric Research (NCAR), Atmospheric Chemistry Division, PO Box 3000, Boulder, CO 80305, USA.
authors.forename: Sasha
authors.initials: S
authors.lastname: Madronich
authors.affiliation: School of GeoSciences, The University of Edinburgh, Crew Building, West Mains Road, Edinburgh EH9 3JN, UK.|Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Daniel Rutherford Building, Mayfield Road, Edinburgh EH9 3JH, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Messenger
authors.affiliation: School of GeoSciences, The University of Edinburgh, Crew Building, West Mains Road, Edinburgh EH9 3JN, UK.
authors.forename: Paul I
authors.initials: PI
authors.lastname: Palmer
authors.affiliation: School of GeoSciences, The University of Edinburgh, Crew Building, West Mains Road, Edinburgh EH9 3JN, UK.
authors.forename: David S
authors.initials: DS
authors.lastname: Reay
authors.affiliation: School of GeoSciences, The University of Edinburgh, Crew Building, West Mains Road, Edinburgh EH9 3JN, UK.
authors.forename: Andy R
authors.initials: AR
authors.lastname: McLeod
mesh_terms: D000332:Aerobiosis / Q000528:radiation effects; D018533:Biomass; D002980:Climate; D038622:Internationality; D008697:Methane / Q000032:analysis*; D018515:Plant Leaves / Q000378:metabolism* / Q000528:radiation effects*; D010944:Plants / Q000378:metabolism* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D008697:Methane
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