Emission global uncertainties

Concerns about global climate change have led to extensive research and high-level international debates about the need for targets and timetables to reduce carbon dioxide emissions. Some policymakers believe that current uncertainties in how to approach the issue do notjustify an all-out effort to reduce carbon dioxide emission, while others feel that this is a crisis needing immediate attention. 

Beusen AHW, Bouwman AF, Heuberger PSC, Van Drecht G, Van der Hoek KW (2008) Bottom-up uncertainty estimates of global ammonia emissions from global agricultural production systems. Atmos Environ 42 6067-6077... 

TABLE 12.3. Summary of the Global and Regional Emissions of Fine OAs and BC Expressed as Tg C per Year. Uncertainties, Expressed as Ranges, Are Also Reported for the Globa] Estimative... 

The global natural flux of sulfur compounds to the atmosphere has recently been estimated to be about 2.5 Tmol yr1 (1) which is comparable to the emissions of sulfur dioxide (SO2) from anthropogenic sources (2). A substantial amount of the natural sulfur contribution (0.5-1.2 Tmol yr1) is attributed to the emission of dimethylsulfide (DMS) from the world s oceans to the atmosphere (3.4). One of the major uncertainties in this estimate is due to a scarcity of DMS and other sulfur data from the Southern Hemisphere, particularly the Southern Ocean region between about 40°S and the Antarctic continent, which represents about one fifth of the total world ocean area. 

The above results make it very clear that forecasts of the future oxidation capacity of the atmosphere depend critically on the assumed emissions. The IPCC did not assign probabilities to its emission scenarios but it is apparent that some of these scenarios are highly improbable for oxidant precursor emissions. Integrated assessment models, which couple global economic and technological development models with natural Earth system models provide an alternative approach to the IPCC scenario approach with the added advantage that objective estimates of individual model uncertainties can be combined with Monte Carlo approaches to provide more objective ways of defining means and errors in... 

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