Anthropogenic CO2 emission

If the current rate of increase in anthropogenic CO2 emissions continues unabated, the pH of the surfece ocean is predicted to decline by more than 0.4 units by the end... 

The scenaria estimate the CO2 emission absolute volume for the year 2005 to be within the range 45-51 Tg. Table 1 summarises the anthropogenous CO2 emission projection till the year 2010 for the scenario, which assumes significant innovation and restructuring of industrial technologies, resulting in decreased energy demand. 

In terms of global anthropogenic CO2 emission, China with 2373 Mt in 1990 is ranking 2nd in the world already, and no obligation of reduction has been put on the country during the Kyoto summit. It is expected to take the lead by 2010 with more than 5000 Mt/yr of emitted CO2. 

Increasing impacts on the environment with energy-related pollutants such as greenhouse gases urgently require appropriate countermeasures. It is necessary to drastically reduce the consumption of fossil fuels as the main source of anthropogenic CO2 emissions. 

Anthropogenic CO2 emissions guide back into the past wifli respect to CO2 concentration in the atmosphere when the formation of the fossil fuels started. The speed at which the CO2 concentration is currently changed, is roughly estimated to be 180,000 years per year of continued emissions [9]. 

For the purpose of developing the long-term projections in this paper, all fossil fuel resource data used will be that available in 1993 and projections shown in the figures start at 1990. Published data from 1990 to 2001 for anthropogenic CO2 emissions and atmospheric CO2 levels will be used to test the model. The cumulative production of world fossil fuel (oil, gas and coal) and a projection into the future are shown in Fig. 1. The projection was made using the HR Model (Hubbert, 1981) and is based on known, proved reserves only. The total area under the curve in Fig. 1 is47,330 quads (Barabba, 1989 Taylor, 1989 Kilgore, 1993 West, 1993). The curve in Fig. 1 will be used to develop the low estimate of fossil fuel production. 

Studying published anthropogenic CO2 emissions as well as trends in atmospheric CO2 levels allows the development of the FAC Model that can be used to project future atmospheric CO2 levels. Figure 3 shows ice core CO2 data back to 1743 (Keeling et al, 1989) and atmospheric CO2 concentration data from Mauna Loa, Hawaii measured by Keeling and Whorf from 1958 through 2001 (available at http //cdiac.oml.gov). The Mauna Loa data for only January of each year are used to smooth the curve and see the recent increase. 

The published world CO2 emissions from 1860 to 1995 (Houghton, 2002 Marland et al, 2002 Stern and Kaufman, 1998) are summed in Fig. 5. Figure 5 is divided to show that portion of the anthropogenic CO2 emissions which stays in the atmosphere to cause the increase and that portion of the anthropogenic CO2 emissions which have left the atmosphere and gone to various sinks. 

The important point to note is that the atmospheric concentration of CO2 decreases at a significant rate after reaching a peak. Thus, after future anthropogenic CO2 emissions begin to decrease atmospheric CO2 will also decline according to the relationship in Eqs. (3) and (4). 

A second test of the FAC Model can be made by using the published record of anthropogenic CO2 emissions from 1991 through 1999 (Houghton, 2002 Marland etal, 2002 Stern and Kaufman, 1998). The results are shown in Fig. 8. The projection runs parallel to the measured... 

The high estimate of anthropogenic CO2 emissions was deliberately constructed at a high rate of use to create an upper limit for anthropogenic CO2 emissions and future atmospheric CO2 levels. The measured record of atmospheric CO2 levels was expected to be lower. That the test using actual anthropogenic CO2 emissions is a little high indicates that the model needs a little... 

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. 

Measurements by Quay et al. (1992) of the CO2 flux from the atmosphere to the ocean between the years 1970 and 1990 was 2.1 Pg C/yr on average. Another 1.4 0.1 PgC/yrofC02 were removed by the biosphere (Quay et al., 1992). Over the 20-year period in Quay s study the average annual anthropogenic CO2 emissions were 7.0 Pg C/yr of which 3.8 Pg C/yr left the atmosphere. Thus, 55% of the anthropogenic CO2 emissions leaving the atmosphere entered the ocean during the period 1970-1990. 

If the oceanic deposition of carbonate minerals plays a significant role in the removal of anthropogenic CO2 from the atmosphere, then it is unlikely that the process would saturate. Thus, the relations on which the FAC Model are based would continue over the duration that the FAC Model has been applied and longer. If ocean carbonate deposition is a removal mechanism, it would assure that the FAC Model is valid and its projections reasonable if the projections of future anthropogenic CO2 emissions are reasonable. 

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