Greenhouse gases table

Let us use as an example one recent environmental case history relevant to petrochemicals production. Nitrous oxide (N2O) is implicated as a contributor to stratospheric ozone damage, and is also a potent greenhouse gas (Table 2.7). Recent work indicated that about 10% of the nitrous oxide contributions to the atmosphere was from the world s adipic acid plants, slightly more than the fraction contributed by biomass burning [31, 32]. It has been estimated that about 1 mol of N2O is produced per mole of adipic acid, or about 0.3 kg of N2O per kg of adipic acid. 

Concerns over atmospheric methane as a greenhouse gas and the large contribution of biomethanogenesis as a source of this gas make it important to determine the relative significance of various components of this activity. A recent paper (8) summarized estimates (28-30) of source fluxes of atmospheric methane based on several carbon isotopic studies and presented new data on natural sources and biomass burning. These data (Table III) show that of a total flux of 594 million tons (Tg) per year, 83% is produced via biomethanogenesis from a combination of natural (42%) and anthropogenic (41%) sources. 

Table 2 Estimated percentage of greenhouse gas emissions per capita (unit tons of CO2 equivalent/capita)...

In Vietnam, total greenhouse gas emissions in 2000 were 150.9 million tons C02 equivalent thereafter, average per capita was 1.5 million tons. Vietnam s level of CO2 emissions per capita was rather low compared to world average (Table 2). 

Carbon dioxide is not the only greenhouse gas that humans have been changing. Methane is another important greenhouse gas. It has increased in the atmosphere by almost 100% since 1800 but has been stable or even seen a slight decrease since 1990. See Table 2-2. 

Biofuels offer a number of technical and enviromnental benefits over conventional fossil fuels, which make them attractive as alternatives for the transport sector. The benefits include greenhouse gas reductions including reduced carbon dioxide emissions, which will contribute to domestic and international targets, the diversification of the fuel sector, biodegradability, sustainability, and an additional market for agricultural products. Biofuels help to protect and create jobs. Table 3.1 shows the major benefits of biofuels. 

Certain issues are clear-cut. Figure 2 shows the increase in C02 content in the earth s atmosphere [5]. The increase since 1950 is particularly noticeable, and we need to be concerned about the effect this will have on the earth s climate. Although it is important, carbon dioxide is not the only greenhouse gas of concern. Table 2 shows the other pertinent pollutants in the atmosphere, their 1985 concentrations, and their projected annual growth rate [5],... 

Table 6.3. Life-cycle impacts from production by fermentation of agricultural waste, as yet poorly quantified. Transportation impacts include greenhouse gas warming, air pollution and traffic accidents, assuming current vehicles such as diesel trucks. See caption to Table 6.1 (with use of Sorensen, 2004c).

The results show the extraordinary contribution that the new technology may bring to reducing greenhouse gas and particulate emissions. The main factors arc the new amount of biomass available for power production, the higher efTiciencies in conversion and, to a lesser extent, the avoided emissions as a result of less sugar cane burning. The final results are shown in Table 4. 

After water vapor and C02, methane (CH4) is the third most important greenhouse gas. Each additional molecule of CH4 added to the atmosphere absorbs about 20 times as much long-wave infrared radiation as does a molecule of carbon dioxide. This occurs in part because some of the absorption spectrum of methane lies in windows in the carbon dioxide absorption spectrum (see Fig. 4-42) therefore, methane absorbs wavelengths that are not already being highly attenuated by carbon dioxide. Currently, the global concentration of methane in the atmosphere is approximately 1.7 ppm and is increasing at an annual rate of approximately 0.01 ppm per year (Table 4-14). The seasonal fluctuations shown in Fig. 4-44 may correspond to seasonal... 

Table 4.1 Greenhouse gas emission trends (Mt (. (he), the Kyoto target and different projections in the context of Germany... 

Table 11.1 Greenhouse gas emissions from 1990 to 2004 excluding bunkers in the Czech Republic (Gt C02e)... 

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