ALBERT

Description: The extraction of unconventional oil and gas—from shale rocks, tight sand, and coalbed formations—is shifting the geographies of fossil fuel production, with complex consequences. Following Jackson et al.’s ( 1 ) natural science survey of the environmental consequences of hydraulic fracturing, this review examines social science literature on unconventional energy. After an overview of the rise of unconventional energy, the review examines energy economics and geopolitics, community mobilization, and state and private regulatory responses. Unconventional energy requires different frames of analysis than conventional energy because of three characteristics: increased drilling density, low-carbon and “clean” energy narratives of natural gas, and distinct ownership and royalty structures. This review points to the need for an interdisciplinary approach to analyzing the resulting dynamic, multilevel web of relationships that implicates land, water, food, and climate. Furthermore, the review highlights how scholarship on unconventional energy informs the broader energy landscape and contested energy futures.

Description: Unconventional oil and natural gas extraction enabled by horizontal drilling and hydraulic fracturing (fracking) is driving an economic boom, with consequences described from “revolutionary” to “disastrous.” Reality lies somewhere in between. Unconventional energy generates income and, done well, can reduce air pollution and even water use compared with other fossil fuels. Alternatively, it could slow the adoption of renewables and, done poorly, release toxic chemicals into water and air. Primary threats to water resources include surface spills, wastewater disposal, and drinking-water contamination through poor well integrity. An increase in volatile organic compounds and air toxics locally are potential health threats, but the switch from coal to natural gas for electricity generation will reduce sulfur, nitrogen, mercury, and particulate air pollution. Data gaps are particularly evident for human health studies, for the question of whether natural gas will displace coal compared with renewables, and for decadal-scale legacy issues of well leakage and plugging and abandonment practices. Critical topics for future research include data for (a) estimated ultimate recovery (EUR) of unconventional hydrocarbons, (b) the potential for further reductions of water requirements and chemical toxicity, (c) whether unconventional resource development alters the frequency of well integrity failures, (d) potential contamination of surface and ground waters from drilling and spills, (e) factors that could cause wastewater injection to generate large earthquakes, and (f) the consequences of greenhouse gases and air pollution on ecosystems and human health.