Environmental Engineering Reference
In-Depth Information
Fields that may lie in temperate zones within several hundred feet of the surface have
understandably been the first to be exploited. This leaves oil beneath oceans, in remote Arctic
regions, tightly associated with sands, and/or laden with impurities as an increasing
component of that that remains to be exploited. Technological advances have greatly
increased the amount of petroleum that can be extracted from the earth, once discovered, but
often at high operational and environmental cost Political factors also contribute to petroleum
accessibility. While the United States was once the world's greatest petroleum producer, it
and many other developed countries are now net importers: the United States now imports
approximately 56 percent of its demand, or ~1 1.2 million barrels per day [7, 8]. The United
States is not only the greatest consumer of world petroleum resources-demanding ~25
percent of the global total production [4]-but notable to foreign suppliers, the United States is
also the greatest importer, with nearly double the net imports of second-ranked Japan [9]. Of
the 1.7 trillion barrels of oil in the world's proven reserves, over half of those are located in
the Middle East. Petroleum suppliers are therefore becoming increasingly concentrated in
regions of the world, particularly the Middle East, that have historically been politically
unstable and/or unfriendly to western interests [6].
Finally, petroleum is far from environmentally benign. Petroleum combustion releases
carbonaceous gases, principally carbon dioxide (CO2), carbon monoxide (CO), and methane
(CH4), as well as sulfurous gases such as sulfur dioxide (SO2). Decades of climate and
atmospheric composition data are now confirming the link between increasing concentrations
of greenhouse gases such as those emitted by combustion of fossil fuels and increasing global
temperatures [10]. In addition, concerns are growing about the volume of discarded wastes
that the United States and other countries produce. Global consumption of petroleum-based
thermoplastics, the greatest component, now exceeds 100 million tons per year, of which
approximately half is discarded within two years of production. Much of the other half, used
to generate products with longer lifetimes, is just beginning to enter the waste stream, with
the result that plastic waste generation is expected soon to exceed the growth in consumption
[11]. This, in turn, is expected to create a considerable demand on landfill space [12].
An accompanying problem is that wealthy countries can export such wastes to poorer
countries. Although these practices have been addressed through measures such as the Basel
Ban, diminishing waste volumes is the most straightforward solution to exploitation of
vulnerable peoples and natural areas [13]. As a result, the impetus for transition from fossil
fuels to renewable energy sources and materials feedstocks is resulting as much from
environmental considerations as it is from concerns about future conflict over petroleum
resources.
2. Benefits of Petroleum Replacement
Numerous technologies are under development for the replacement of petroleum as the
primary energy source and materials feedstock in developed countries. Wind, solar,
hydroelectric, geothermal, and biomass-derived power will each be called upon to contribute
to the post-petroleum economy, and conservation measures are also expected to receive
greatly increased attention. Materials derived from biological molecules are also gaining
diversity and availability.
