Fossil fuel anthropogenic emissions

The principal anthropogenic sources of CO 2 are the burning of fossil fuels and the production of cement. Total CO2 emissions can be estimated based on statistics of fossil fuel use and cement production (Andres et al., 1994). Average 1980 to 1989 fossil fuel combustion emissions have been estimated as 5.5 Gt(C) yr. During 1991, estimated total emissions were 6.2 Gt(C). Cumulative CO2 emissions since the preindustrial era have been estimated as approximately 230 Gt of carbon (Andres et al., 1994), which represents about 30% of the current amount of CO 2 in the atmosphere (Figure 21.11). 

For this base year (1994) the cumulative fossil fuel CO2 emission is 238 10 g CO2—C (Boden 2009) hence, 50 % of the CO2 added to the atmosphere is captured by the world s oceans. The total oceanic dissolved carbonate carbon (Table 2.9) corresponds to 0.028 g as carbon in seawater taking into account the volume of the world s oceans (Table 2.3). The experimentally estimated seawater standard carbonate carbon is 0.0244 g L seawater (Dickson et al. 2007). In the first 200 m of the ocean, the total deposited anthropogenic CO2 (Table 2.82 and assuming that 30% is within this layer) only contributes to 3% to dissolved inorganic carbon (DIC). Hence, it is very difficult to measure trends in the DIC because of manmade changes (see Fig. 2.96). 

B[a]P is the representative of PAHs, generally emitted as a result of incomplete combustion of fossil fuels. Anthropogenic PAH emissions are predominant in Europe so that emissions from natural sources (volcanic eruptions, forest and grassland fires) were neglected [31]. Industrial and non-industrial combustion, public... 

The major anthropogenic sources of VOCs in the U.S. that enter the troposphere and that ultimately form the oxygenates are emissions from the incomplete combustion of fossil fuels vehicular emissions (28.9%) off-highway sources (15.3%) and emissions from solvent use (29.2%). Incomplete fuel combustion by institutional, residential, commercial, and industrial sources each add additional input of the VOC emissions. 

If all parts of the livestock production lifecycle are included, livestock are estimated to account for 18% of global anthropogenic emissions [57]. According to Gill and coworkers [57], apart from enteric fermentation and manure management, the other sources of GHG emission from livestock and related activities are fossil fuels used during feed and fertilizer production and transport of processed animal products. 

Over the last three decades, GHG emissions increased by an average of 1.6% per year, with C02 emissions from fossil-fuel use growing at 1.9% per year. Total GHG emissions in 2004 (Kyoto gases)8 amounted to 49.0 Gt C02-equivalent (C02-eq.), a 70% increase since 1970 and a 24% increase since 1990. Total C02 emissions in 2004 amounted to 26.1 Gt (see Fig. 2.7). Emissions of C02 have grown by approximately 80% since 1970 (28% since 1990) and represented 77% of total anthropogenic emissions in 2004. Total methane (CH4) emissions rose by about 40% from 1970 sectorally there was an 84% increase from combustion and the use of fossil fuels,... 

Polycyclic aromatic hydrocarbons (PAHs, sometimes also called polynuclear aromatics, PNA) are a hazardous class of widespread pollutants. The parent structures of the common PAHs are shown in Fig. 4 and the alkylated homologs are generally minor in combustion emissions. PAHs are produced by all natural combustion processes (e.g., wild fires) and from anthropogenic activity such as fossil fuels combustion, biomass burning, chemical manufacturing, petroleum refining, metallurgical processes, coal utilization, tar production, etc. [6,9,15,18, 20,24,131-139]. 

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