Mercury emissions from global biomass burning: spatialand temporal distribution

摘要: This chapter represents a new addition to the UNEP global mercury budget: emissions from biomass burning, here defined as wildfires and prescribed burns, excluding contributions bio-fuel consumption charcoal production use. The results cover 1997-2006 timeframe. average annual emission estimate burning for is 675 ± 240 Mg yr-1. accounts 8% of all current anthropogenic natural emissions. largest Hg are tropical boreal Asia, followed by Africa South America. They do not coincide with carbon emissions, which originate Africa. Our methodology budget estimation based on satellite-constrained bottom-up fire database (GFED version 2), divides globe into regions similar ecosystems burn behaviour. To model output paired regional factors Hg, EF(Hg). There large uncertainties in associated burned area, fuel mass, combustion completeness. discrepancy between traditional ground assessments (e.g. FRA, 2000) unacceptably at this time. Of great urgency development validation cycling forests, accounting biogeochemistry each region. would provide an understanding source/sink relationship thus accumulation or loss ecosystems. Limiting forests have two beneficial effects: reducing source releases atmosphere maintaining sink atmospheric mercury. Restricting release reduce vegetation/soil pools, potential case fire.