Chapter IV, Section C:  The Environmental Energy Debits

If solar energy and water are the energy assets of an ecosystem, what are the debits? What are the greatest environmental threats in terms of the energy demands to address them? In short, the main energy debits, broadly, are related to 1) air, water, and soil contamination, 2) acid precipitation and acid mine drainage, 3) eutrophication leading to a “dissolved oxygen crisis” for aquatic biota and 4) reduction in biodiversity, caused by all of the above as well as habitat destruction, particularly, but certainly not exclusively, rainforest destruction. Notably, this list does not include the climate change problem. The energy required to remove greenhouse gases from the environment is a large, but yet unknown, percentage of our total energy consumption, of which 85% is currently tapped from fossil fuels. The greenhouse gasses represent carbon and other compounds at their highest entropy state, thus represent the entropy already accumulated by human history. Though research in carbon sequestration is ongoing, including into carbon sinks such as carbon solids, plant uptake, and increasing ocean uptake, and into storage in subsurface reservoirs, all of the processes require energy to essentially concentrate carbon from a free, liberated gas state. The ultimate carbon sink in the natural carbon cycle, at least the one that spans geologic orders of time, is onto the seafloor by carbonate sedimentation, the carbonate itself produced by biota, which ultimately uses solar energy to make shells. Another notable exception to the energy debit list above is upper atmospheric ozone depletion, though this is broadly a contaminant related issue. What is important to realize is that the boundaries of these energy debit assessments do not correspond necessarily to the media of occurrence of the environmental problem, hence the ability of problems and their solutions to shift energy debits into other systems.

Environmental issues are usually discussed, and even addressed wholly in terms of the media of their occurrence, that is, whether the issue is one of land, air, or water “pollution.” The boundaries between these media are not barriers, and often become a source of feedback when an environmental problem simply exchanges media. The problem with media-specific conceptualization of environmental issues is that often, the proposed solution for one media may lead to an environmental liability in another. The most salient, recent example of this is the addition of MTBE to gasoline to reduce tailpipe emissions, an air pollution problem. Unfortunately in turn, MTBE became a source of persistent ground water contamination associated with very-commonly-occurring fuel tank leaks of petroleum hydrocarbons. These hydrocarbons normally biodegrade relatively quickly, thus limiting the spread of the contamination, but MTBE plumes became relatively extensive. Thus an air pollution problem was exchanged for an increased groundwater pollution problem. Though the following discussion may be in the context of a typical media, particularly when discussing examples, the following classification should be considered media independent, and usually apply to all media.

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