Wetlands emissions

Much of the above work has been directed toward obtaining reliable data-based estimates of wetland emissions for the global CH4 budget. 

Controlling methane release from wetland, rice paddies and gaseous emissions from animals is more problematic. The release from rice paddies and wet lands is slow, intermittent and takes place over a wide geographic area, and thus very difficult to control. Gaseous emissions from agricultural animals contribute to atmospheric accumulation of methane due to fermentative digestion that produces methane in... 

Longer ice-core records show that methane concentrations have varied on a variety of time scales over the past 220 000 years (Fig. 18-15) Qouzel et al, 1993 Brook et al, 1996). Wetlands in tropical (30° S to 30° N) and boreal (50° N to 70° N) regions are the dominant natural methane source. As a result, ice-core records for preanthropogenic times have been interpreted as records of changes in methane emissions from wetlands. Studies of modem wetlands indicate that methane emissions are positively correlated with temperature, precipitation, and net ecosystem productivity (Schlesinger, 1996). 

Denier van der Gon HAC, Neue HU. Influence of organic matter incorporation on the methane emission from a wetland rice field. Global Biogeochem. Cycl. 1995 9 11— 22. 

Whiting GJ, Chanton JP. Primary production control of methane emission from wetlands. Nature. 1993 364 794-795. 

Evaluating Vehicle Emissions Inspection and Maintenance Programs (2001) Compensating for Wetland Losses Under the Clean Water Act (2001)... 

Hooijer, A., Silvius, M., Wosten, H. and Page, S. (2006). Peat C02 Assessment of C02 Emissions From Drained Peatlands in South-East Asia. Delft Hydraulics Report Q3943. www.wetlands.org. 

Table 8.3 Global distributions of CH4 emissions (Tg CH4year ) calculated using inverse modelling. In Scenario A rice contributes 50-80Tg year and in B 15-30Tg year the net contribution of natural wetlands and ricelands is constant...

Little snlfnr is re-emitted from wetlands into the atmosphere. Table 8.7 gives estimates of global emissions of volatile sulfur compounds from different sources. Total emissions are in the range 98 to 120 Tg (S) year 75 % is anthropogenic, mainly from fossil fnel combustion in the northern hemisphere. The main natural sources are the oceans and volcanoes. Wetlands and soils contribnte less than 3 % of the total emission. 

Aselmann 1, Crutzen PJ. 1989. Global distribution of natural fresh-water wetlands and rice paddies their net primary productivity, seasonality and possible methane emissions. Journal of Atmospheric Chemistry 8 307-358. 

Bachelet D, Neue HU. 1993. Methane emissions from wetland rice areas of Asia. Chemosphere 26 219-237. 

Cao MK, Gregson K, Marshall S. 1998. Global methane emission from wetlands and its sensitivity to climate change. Atmospheric Environment 32 3293-3299. 

Conrad R. 1993. Mechanisms controlling methane emission from wetland rice fields. In Oremland R, ed. Biogeochemistry of Global Change. Radiatively Active Gases. New York Chapman HaU, 317-355. 

Janson, R., and C. De Serves, Isoprene Emissions from Boreal Wetlands in Scandinavia, J. Geophys. Res., 103, 25513-25517 (1998). 

Ammonium in aerosols originates from the neutralisation of sulphuric and nitric acid by ammonia. Ammonia is emitted by different sources, most notably animal manure, traffic and application of fertiliser. In general, emissions are for the largest part (80-95%) associated with agricultural activities [19]. Erisman et al. [20] estimated the natural emissions at about 10% of the total emissions in Europe. This percentage includes contributions from wild animals and wetlands. We assume a similar percentage for ammonium in north-western Europe. 

Dichloromethane is a widely used industrial and academic laboratory solvent. New natural sources are recognized subsequent to the previous review, although the amounts are small compared to industrial emissions (Table 3.2). These include estimates of biomass combustion (256, 283, 286), oceanic sources (250, 253, 256, 275, 302), wetlands (275), and volcanoes (216, 217). Macroalgae (Desmarestia... 

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