Input anthropogenic

The FAC Model was developed using only two sets of data, anthropogenic CO2 emissions data and atmospheric CO2 concentration data. The rate at which CO2 leaves the atmosphere was modeled without any assumptions as to where it went. The projection of future atmospheric CO2 levels is made by inputting anthropogenic CO2 emissions data into the FAC Model. Both real data and projected future CO2 emissions data were used. 

Surface water enrichment is the result of aeolian and fluvial inputs, which are thought to be the most important sources of Th to the ocean. Thorinm-232 has been proposed as a link between the radiogenic thorium isotopes and trace metals and anthropogenic pollutants. " While the pathways are very different for the radiogenic thorium isotopes, Th is delivered to the ocean in a fashion similar to many pollutants and trace metals. For example, Guo et found Th distributions in the Gulf of Mexico and off Cape Hatteras in the North Atlantic Ocean agreed well with the general distribution pattern of aluminum. 

Forests can act as sources of some of the trace gases in the atmosphere, such as hydrocarbons, hydrogen sulfide, NO, and NH3. Forests have been identified as emitters of terpene hydrocarbons. In 1960, Went (10) estimated that hydrocarbon releases to the atmosphere were on the order of 108 tons per year. Later work by Rasmussen (11) suggested that the release of terpenes from forest systems is 2 x 10 tons of reactive materials per year on a global basis. This is several times the anthropogenic input. Yet, it is important to remember that forest emissions are much more widely dispersed and less concentrated than anthropogenic emissions. Table 8-2 shows terpene emissions from different types of forest systems in the United States. 

Biogeochemical cycling in forests includes elemental inputs, exports, and a complex set of physical, chemical and biotic processes which comprise internal nutrient cycles (Fig. 1). Any disturbance, whether anthropogenic (i.e. 

Figure 1. Generalized nutrient balance of ecosystems in the intervals between disturbance events. Natural disturbances such as wildfires, hurricanes, and floods as well as anthropogenic disturbances such as deforestation and biomass burning can dramatically influence nutrient inputs, internal cycles, and ecosystem outputs (losses).

Due to anthropogenic inputs, the mean pH of a lake has decreased from 6.5 to 6.0. Assuming no significant changes in the chemical composition... 

Despite the difficulties, there have been many efforts in recent years to evaluate trace metal concentrations in natural systems and to compare trace metal release and transport rates from natural and anthropogenic sources. There is no single parameter that can summarize such comparisons. Frequently, a comparison is made between the composition of atmospheric particles and that of average crustal material to indicate whether certain elements are enriched in the atmospheric particulates. If so, some explanation is sought for the enrichment. Usually, the contribution of seaspray to the enrichment is estimated, and any enrichment unaccounted for is attributed to other natural inputs (volcanoes, low-temperature volatilization processes, etc.) or anthropogenic sources. 

CFC-12. These manmade chemicals absorb infrared radiation in a part of the spectrum where water vapor and CO2 do not already have strong bands. On the other hand, the manmade increase of CO2 is so large (currently ca. 25% since the mid-1800s - see Chapter 11) that it is the largest anthropogenic input to the greenhouse effect (not counting feedbacks). 

Because the nitrification and denitrification processes both form N2O as a by-product, control of anthropogenic N inputs to the soil in the form of synthetic fertilizers or manure would affect the amount of N2O produced... 

The DPSIR scheme is a reasonable approach also in the case of valuable resources, if we define the impact as (potential) shortage of a resource. This is an input-oriented problem caused by high anthropogenic flows of a scarce nonrenewable resource. 

Figure 9.3. Measured and fitted global annual industrial age Hg mine production and Hg production from world coal industry (after Han et al., 2002a. Reprinted from Naturwissenschaften, 89, Han F.X., Banin A., Su Y., Monts D.L., Plodinec M.J., Kingery W.L., Triplett G.B., Industrial age anthropogenic inputs of heavy metals into the pedosphere, p 500, Copyright (2002), with kind permission of Springer Science and Business Media)...

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