Fossil Fuels and Climate Change

Out of necessity, modern societies are finally beginning to rethink the issue of energy use. No scientific challenge today is greater than reversing the climatic effects of our increasing dependence on the combustion of fossil fuels—coal, petroleum, and natural gas. Because these fuels form so much more slowly than we consume them, they are nonrenewable. In contrast, wood and other fuels derived from plant and animal matter are renewable. 

CHAPTER 6 Thermochemistry Energy Flow and Chemical Change 

International conferences, such as the 1997 Conference on Climate Change in Kyoto, Japan, provided a forum for politicians, business interests, and scientists to seek ways to cut greenhouse emissions. But the largest producer of CO2, the United States, refused to ratify the Kyoto Protocol and, as a result, many expect global warming and its associated effects on Earth s climate to increase. 

Standard states are chosen conditions for substances. When 1 moi of a compound forms from its eiements with aii substances in their standard states, the enthalpy change is A/-/ . Hess s iaw aiiows us to picture a reaction as the decomposition of reactants to their eiements, foliowed by the formation of products from their elements. We use tabulated A/-/° values to find AH°xn or use known A/-/°xn and AH° values to find an unknown A/-/°. As a result of increased fossil-fuel combustion, the amount of atmospheric CO2 is climbing, which is seriously affecting Earth s climate. 

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Formation Equatfons Determining AH from AHf Fossil Fuels and Climate Change... 

Standard Enthalpies of Reaction (AH xn) 205 Formation Equations and Their Standard Enthalpy Changes 205 Determining AN°r from Values for Reactants and Products 206 Fossil Fuels and Climate Change 207... 

EXAMPLE 6.13 Fossil Fuels and Climate Change One way to evaluate fuels with respect to global warming is to determine how much heat they release during combustion relative to how much CO2 they produce. The greater the heat relative to the amount of CO2, the better the fuel. Use the combustion reactions of carbon, natural gas, and octane, in combination with the enthalpy of combustion for each reaction (aU given earher), to calculate the heat (in kJ) released by each fuel per 1.00 kg of CO2 produced. ... 

The plant concept for co-production of hydrogen and electricity is applicable to a very broad range of fossil fuels and also biomass without paying tributes to climate change. At the same time energy supply security is improved, as a result of the diversification of (fossil) feedstock options. 

After normalization of the results (Figure 18.9), three impact categories turned out to be very important for both techniques fossil fuels, respiratory inorganic, and climate change. According to the normalization graph, the environmental load of SPE is slightly lower than that of LLE. 

The use of fossil fuels to meet variable electrical demands may be limited in the future because of concerns about the price of natural gas and climate change. With any deep reduction in greenhouse gas emissions, carbon dioxide emissions will likely be limited to transportation, consumer products and other mobile applications - not stationary applications such as peak power production. While carbon dioxide from fossil power plants may be sequestered underground, such fossil power plants are likely to be uneconomic for the production of intermediate and peak electricity because of their high capital costs (MIT, 2007) and the difficulties in operating such plants with variable output. 

Some of the processes that add carbon to the atmosphere or remove it, such as the combustion of fossil fuels and the estabhshment of tree plantations, are under direct human control. Others, such as the accumulation of carbon in the oceans or on land as a result of changes in global climate (i.e., feedbacks between the global carbon cycle and climate), are not under direct human control except through controlhng rates of... 

Which really poses the greater environmental threat—the burning of fossil fuels and its contribution to the greenhouse effect and climatic change, or the use of nuclear power and the related radiation and disposal problems ... 

Between 1850 and 1998 atmospheric carbon dioxide levels have risen from 285 to 366 ppm, mainly because of the combustion of fossil fuels and changes in land use from forestry to agriculture. This unbalanced release of stored carbon is now generally accepted as setting us on a global climate change journey with an unknown but likely to be unpleasant destination. Combustion of fossil fuels alone contributed 6.3 Gt (gigatonnes or 10 tonnes) of carbon dioxide emissions annually between 1989 and 1998. 

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