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Factors influencing the creation of high-impact oil and gas geophysical seismic cutlines in an ecologically-sensitive landscape in northeastern British Columbia, Canada
Abstract
Oil and gas (OG) resource extraction has adverse impacts on landscapes despite the socio-economic benefits that trickle down to society. Whereas many recent studies have focused on direct landscape change from OG activities, this study focuses on factors associated with the creation of high-impact OG seismic cutlines, geophysical survey paths that have widths of more than 5.5 m. Using geographic information systems and a spatially-explicit logistic regression framework, we model the relationship between high-impact seismic cutlines and associated explanatory variables (e.g., seismic cutline type, land ownership type, etc.) by drawing on political ecology perspectives. The study finds that mechanically-cut seismic cutlines are 514.34 times significantly more likely to be high-impact seismic cutlines as compared to hand-cut seismic cutlines. We find that seismic cutlines found on private land are 0.05 times significantly less likely to be high-impact type as compared to those found on crown (public) land. These findings suggest that societal land use decisions and preferences are likely to influence the creation of spaces for different levels of OG land user–environment interactions. Thus, land use managers are presented with unique land use challenges that require environmental management strategies for dealing with the impacts of OG activities on the environment.
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Seismic lines are linear features created by the oil and gas industry for energy exploration. Though individually narrow, collectively seismic lines are a pervasive management challenge, resulting in changes to biogeochemical cycles, plant and animal abundance and behaviour, predator–prey relationships, and forest successional trajectories. These impacts arise from historical construction methods that used bulldozers to remove vegetation and substrate leaving lines as persistent openings in a state of arrested succession. In the mid-1990s, “low-impact seismic” (LIS) line construction began, using mulchers to remove vegetation aboveground to minimize impacts and hasten reforestation. Here, we evaluated the effectiveness of LIS in retention, recruitment, and growth of seedlings in forested peatlands in northeast British Columbia. Retained and recruited trees on LIS lines were found at 69% and 64% of sites, had mean densities of 3400 and 6000 stems/ha, and mean heights of 42 and 11 cm, respectively. These LIS lines appeared to recover along expected trajectories toward tree cover, thereby mitigating challenges typical of older seismic exploration. Our results suggest it is feasible to further fast-forward line recovery by ensuring mulcher drums are kept as high as possible to increase the number and height of trees through the mulching process.
Integrated optimization of well placement and hydraulic fracture parameters in naturally fractured shale gas reservoirs is of significance to enhance unconventional hydrocarbon energy resources in the oil and gas industry. However, the optimization task usually presents intensive computation-cost due to numerous high-fidelity model simulations, particularly for field-scale application. We present an efficient multi-objective optimization framework supported by a novel hierarchical surrogate-assisted evolutionary algorithm and multi-fidelity modeling technology. In the proposed framework, both the net present value (NPV) and cumulative gas production (CGP) are regarded as the bi-objective functions that need to be optimized. The hierarchical surrogate-assisted evolutionary algorithm employs a novel multi-fidelity particle-swarm optimization of a global–local hybridization searching strategy where the low-fidelity surrogate model is capable of exploring the populations globally, while the high-fidelity models update the current populations and thus generate the next generations locally. The multi-layer perception is chosen as a surrogate model in this study. The performance of our proposed hierarchical surrogate-assisted global optimization approach is verified to optimize the well placement and hydraulic fracture parameters on a hydraulically fractured shale gas reservoir. The proposed surrogate model can obtain both the NPV and CPG with satisfactory accuracy with only 500 training samples. The surrogate model significantly contributes to the convergent performance of multi-objective optimization algorithm.
While there is scholarship focused on the nexus between resource extraction and development, further examination is needed of how the harms and benefits of extraction are differentiated among different stakeholders based on factors such as their access to power, authority over decision-making, social status,and gender. This article combines theoretical insights from assemblage thinking and political ecology to unpack the intertwined range of actors, networks, and structures of power that inform the differentiated benefits and harms of hydrocarbon extraction in Ghana. The study shows that power serves as a crucial ingredient in understanding relations among social groups, including purported beneficiaries of extractive activities, and other actors that constitute the networked hydrocarbon industry. The different levels (i.e. global, national, sub-national,local) at which the socio-ecological 'goods' and 'bads' of hydrocarbon extraction become manifest are relational. The article contributes to ongoing scholarly and policy discussions around extractivism by showing how a multi-scalar analysis reveals a more complex picture of the distributional politics, power asymmetries, and injustices that underpin resource extraction.
Abstract Slope aspect plays a critical role in influencing vegetation pattern in semiarid area. The dry valleys of the Hengduan Mountains Region, southwestern China, are striking geographical landscape, suffering from severe ecological degradation. Here, we comprehensively investigated how slope aspect affects vegetation attributes in one of these valleys- the dry valley in the upper reaches of Min River. Three sites were selected along the valley and we quantitively examined the vegetation difference between slope aspects at the whole valley scale and each site level. We found significant vegetation differences between slope aspects in species composition, vegetative structure, and biodiversity pattern, which were in accordance with the observed significant difference in soil nutrient. Generally, north-facing slopes are associated with higher biomass, coverage and height, and species diversity than south-facing slopes. We also found between-aspect differences varied among the study sites, resulting in increased biomass, height, and β diversity differences, decreased density and coverage differences, and opposite trend observed in α diversity at relatively wet site. In conclusion, slope aspect had significant effect on vegetation attributes, which was significantly influenced by local climate (aridity) in terms of both strength and direction depending on the specific attributes investigated.
This paper intends to develop quantitative indicators for comparative sustainability assessment of petroleum oil pathways in the province of Alberta, Canada. Eighteen pathways of oil production were developed in this study, and the sustainability indicators were assigned for each pathway to cover greenhouse gas (GHG) emissions, water demand, and land use in addition to the cost of supply. The developed sustainability indicators were aligned per functional unit and covered the full life cycle of petroleum oil production. The developed GHG emissions, cost of supply, and land use indicators are found in the range 17.50–226.20 kg of CO2 eq./bbl, 12.28–53.53 USD/bbl, and 0.06–0.178 m2/bbl, respectively. Four scenarios were comparatively conducted and assessed against the business-as-usual scenario within the period horizon 2009–2030. The cost-effective scenario was optimized with the objective function to minimize the cost of supply based on the constraints derived from the business-as-usual scenario. Sustainable scenarios were conducted with the lowest possible impacts on natural resources, GHG emissions, and the cost of supply accompanied by specific assumptions for petroleum oil production from different pathways in Alberta. The average annual savings on water demand and land area were found to be 67 and 30%, respectively, due to the shifting of upgrader feedstock from surface mining to the in-situ steam-assisted gravity drainage (SAGD) pathway. The corresponding increases due to this shifting in upgrader feedstock were found to be 40 and 3% in GHG emissions and cost of supply, respectively.
Recently, several seminal works have been drawing attention to the revolution of shale gas production technology of the USA, the impact of shale gas on energy sectors, as well as the influences of shale gas on macroeconomic variables of employment, economic growth, etc. Nevertheless, one may claim that two gaps appear in literature. The first gap is the absence of an econometric study estimating the effect of shale oil/gas on national economies. The more considerable second gap is the absence of econometric analyses revealing the impulses of shale gas on local economies. Therefore, this paper observes the possible causalities between the shale gas and local gross domestic product (GDP) employing quarterly data covering the period 2007–2016 for 12 states in the US. After performing the tests of cross-sectional dependence, heterogeneity, stationarity, and cointegration, the paper conducts the panel Granger causality analyses. The empirical findings depict that (i) there is available unidirectional relationship from local shale gas production to local GDP in Colorado, Ohio, and West Virginia; (ii) there occurs an impulse from GDP to local shale gas production for Louisiana, North Dakota, and Oklahoma; (iii) a bidirectional causality coexists between local shale gas production and GDP in Arkansas, California, and Texas; and (iv) there exists no association between local GDP and local shale gas extraction in Montana, New Mexico, and Wyoming.
Information about forest change patterns from oil and gas (OG) activities could improve our understanding of the land use–land cover change nexus, aid in predicting future forest changes, and prompt the need for more mitigation measures in reducing impacts from the activities. However, little is known about forest change patterns from OG infrastructure development in northeastern British Columbia (BC). In this study, we assess forest change from the impacts of OG infrastructure development using a geospatial approach. The study finds that forest cover was reduced by 0.234% between 1975 and 2017. However, we show that forest cover change (− 0.182%) from OG infrastructure development between 1995 and 2017 was faster compared to that of the two decades before 1995. The faster change, however, coincides with the period of the OG boom in BC. Between time points and locations, we measured a larger amount of forest fragmentation in the land cover for the year and location with larger quantities of human-induced land classes. The differences in the quantity of human-induced land cover types between time points and locations could account for the differences in the amount of fragmentation. Our findings suggest that forest fragmentation is likely to reduce if land managers would make relentless effort to reduce the quantity of anthropogenic-induced land cover classes and increase forest recovery programs in the forest areas.
New technologies and increasing energy demand have contributed to rapid expansion of unconventional oil and gas development in the U.S. in the past two decades. Quantifying the effects of energy infrastructure on land cover and wildlife habitat is essential for informing land-use policy, developing wildlife conservation strategies, and projecting impacts of future development. The greater sage-grouse (Centrocercus urophasianus; GrSG) is a species of concern in sagebrush ecosystems of the western U.S. and Canada and the focus of widespread conservation and management efforts. Increasing energy development within GrSG range has prompted the need to quantify and predict impacts of energy infrastructure on their habitat and populations. We mapped the annual distribution, surface type, and activity level of energy and non-energy infrastructure in the Parachute-Piceance-Roan (PPR), a small, peripheral greater sage-grouse population in Colorado with expanding oil and gas development, from 2005 to 2015. During that time, the footprint of energy infrastructure more than doubled to 3,275 ha (+108.6%), including 195 new well pads, 930 ha of new pipelines, and 230 km of new roads. In contrast, non-energy infrastructure decreased to 532 ha (-8.3%). The majority of energy infrastructure present each year (77-84%) was supporting infrastructure (i.e. facilities, roads, pipelines) rather than well pads, with an average of 2.24 ± 0.52 SE ha of supporting infrastructure per ha of well pad. Pipelines comprised 74-80% of reclaimed surface and roads comprised 54-69% of disturbed surface across years. By 2015, anthropogenic infrastructure covered 2.70% of occupied range and 2.93% of GrSG habitat, and energy infrastructure covered 2.50% and 10.79% of two priority habitat management area zones in the PPR. Three land cover classes most affected by energy infrastructure were also those strongly selected by GrSG. Topographic constraints appear to concentrate energy infrastructure in areas with gentler topography that also have the highest GrSG use. Together, these patterns suggest that future energy development will cause substantial additional loss and modification of GrSG habitat in the PPR. Our findings are valuable for assessing surface disturbance caps for land-use management and projections of energy infrastructure effects on wildlife habitat in this and other expanding oil and gas fields.
Given a history in political ecology of challenging hegemonic “scientific” narratives concerning environmental problems, the current political moment presents a potent conundrum: how to (continue to) critically engage with narratives of environmental change while confronting the “populist” promotion of “alternative facts.” We ask how political ecologists might situate themselves vis-à-vis the presently growing power of contemporary authoritarian forms, highlighting how the latter operates through sociopolitical domains and beyond-human natures. We argue for a clear and conscious strategy of speaking power to post-truth, to enable two things. The first is to come to terms with an internal paradox of addressing those seeking to obfuscate or deny environmental degradation and social injustice, while retaining political ecology’s own historical critique of the privileged role of Western science and expert knowledge in determining dominant forms of environmental governance. This involves understanding post-truth, and its twin pillars of alternative facts and fake news, as operating politically by those regimes looking to shore up power, rather than as embodying a coherent mode of ontological reasoning regarding the nature of reality. Second, we differentiate post-truth from analyses affirming diversity in both knowledge and reality (i.e., epistemology and ontology, respectively) regarding the drivers of environmental change. This enables a critical confrontation of contemporary authoritarianism and still allows for a relevant and accessible political ecology that engages with marginalized populations likely to suffer most from the proliferation of post-truth politics.
A simple integrated assessment framework that gives rules for the optimal carbon price, transition to the carbon-free era and stranded carbon assets is presented, which highlights the ethical, economic, geophysical and political drivers of optimal climate policy. For the ethics we discuss the role of intergenerational inequality aversion and the discount rate, where we show the importance of lower discount rates for appraisal of longer run benefit and of policy makers using lower discount rates than private agents. The economics depends on the costs and rates of technical progress in production of fossil fuel, its substitute renewable energies and sequestration. The geophysics depends on the permanent and transient components of atmospheric carbon and the relatively fast temperature response, and we allow for positive feedbacks. The politics stems from international free-rider problems in absence of a global climate deal. We show how results change if different assumptions are made about each of the drivers of climate policy. Our main objective is to offer an easy back-on-the-envelope analysis, which can be used for teaching and communication with policy makers.
This study presents a novel approach for evaluating land-use changes caused by energy development and other anthropogenic activities. We illustrate this technique by assessing the landscape footprint of energy development in the Eagle Ford Shale Play and Permian Basin of Texas, which saw rapid expansion in drilling during 2008–2012. We compare changes in land-use from oil and gas infrastructure construction during this time period with that of wind energy development in West Texas, urbanization in Central Texas, and extensive agricultural areas. Previous studies often use land-use proxies when comparing the footprint of energy infrastructure (e.g., 1 km2 gridded well density or proposed wind project footprints) with other anthropogenic land-change. This study presents an improved technique because it compares high-resolution datasets of agricultural activity and urbanization with mapped—not surrogate—land-change from oil and gas and wind power infrastructure using high-resolution (1 m) aerial imagery. We found that changes in land-use caused by anthropogenic factors affected 1.06% (3456 km2) of the ~ 324,000 km2 study area. Oil and gas development (well pads and pipelines) was ~ 48% of total changes in land-use (but did not account for access roads), changes in agriculture caused ~ 26%, and urbanization was ~ 24%. Construction of wind turbine pads and high voltage power transmission lines was less important (~ 1%). We illustrate this approach for a single species (i.e., Spot-tailed Earless Lizard, Holbrookia lacerata) in Texas. This study is part of an ongoing, multi-year research program generating science to inform the federal Endangered Species Act listing decision for H. lacerata. Additionally, this technique can facilitate effective management of a variety of biotic resources in other rapidly developing environments globally by identifying what anthropogenic activities are most important and where land-change is most intense so that on-the-ground conservation strategies can be implemented where they are needed most.
The oil and gas industry has grown significantly throughout the boreal and arctic ecosystems of North America. A major feature of the ecological footprint of oil and gas exploration is seismic lines—narrow corridors used to transport and deploy geophysical survey equipment. These lines, which traverse forests, tundra, uplands, and peatlands, were historically up to 10 m wide. Over the past decade, seismic lines have decreased in width (in some cases down to 1.75–3 m); however, their density has increased drastically and their construction is expected to continue in regions of Canada and the United States that are rich in oil and gas resources. We examine the literature related to the environmental impacts of, and restoration and reclamation efforts associated with, seismic lines in the boreal and arctic ecosystems of North America. With respect to conventional seismic lines, numerous studies report significant and persistent environmental changes along these lines and slow recovery of vegetation that translates into a lasting fragmentation of the landscape. This fragmentation has many ramifications for biodiversity and ecosystem processes, including significant implications for threatened woodland caribou herds. While modern, low-impact seismic lines have comparatively lower ecological effects at the site-level, their high density and associated potential edge effects suggest that their actual environmental impact may be underestimated. Seismic line restoration is a critical aspect of future integrated landscape management in hydrocarbon-rich regions of the boreal-arctic, and if widely applied, has the potential to benefit a wide range of species and maintain or re-establish key ecosystem services such as carbon sequestration and biodiversity.
Power and politics have been central topics from the early days of Political Ecology. There are different and sometimes conflicting conceptualizations of power in this field that portray power alternatively as a resource, personal attribute or relation. The aim of this article is to contribute to theorizations of power by probing contesting views regarding its role in societal change and by presenting a specific conceptualization of power, one which draws on both political ecology and sociotechnical approaches in science and technology studies. We review how power has been conceptualized in the political ecology field and identify three trends that shaped the current discussion. We then develop our conceptual discussion and explicitly ask where power emerges in processes of resource governance projects. We identify four locations that we illustrate empirically through an example of rural electrification in Tanzania that aimed at catalyzing social and economic development by providing renewable energy-based electricity services to people. Our analysis supports the argument that power is relational and productive, and it draws on science and technology studies to bring to the fore the critical role of non-human elements in co-constitution of society-technology-nature. This leads us to see power exercise as having contradictory and ambiguous effects. We conclude that by exploring the tension between human agency and constitutive power, we keep the politics alive throughout the analysis and are able to show why intentional choices and actions really matter for how resource governance projects play out in everyday life.
Environmental DNA (eDNA) detection is increasingly being used to assess the potential presence of aquatic species. Setting defensible thresholds for qPCR assays are necessary to differentiate “detection” from “non-detection”, but threshold rationales are rarely reported in eDNA studies. Detection thresholds for data inclusion and exclusion have implications for downstream data analysis; uncritical acceptance could result in false positive results (Type I error), whereas overly conservative thresholds could result in high false negative interpretation (Type II error). We assessed the use of the receiver operator characteristics (ROC) framework to identify a detection threshold for balancing sensitivity and specificity of eDNA data. The ROC framework was tested using empirical eDNA data from redside dace (Clinostomus elongatus), an endangered freshwater fish in southwestern Ontario. Based on negative controls, positive controls, and quality assurance guidelines, a minimum concentration of 1 copy reaction⁻¹ was identified as the most appropriate threshold for this study. Although optimal thresholds will likely vary between studies and labs based on empirical data, the ROC framework provides a statistical method for establishing defensible thresholds for data acceptance or rejection as well as tradeoffs between the sensitivity and specificity of eDNA data.
The American West has seen a resurgence of capital investment in extractive mineral development on federal
lands, emanating from the recent global financial crisis. For these extractive projects, as in energy
development more broadly, struggles over knowledge persist in the pre-operational phases of exploratory
access and environmental review when political-legal rights and scientific facts are coordinated, codified, and
contested. Contested knowledge about extractive mineral development beyond the 100th meridian, once more
narrowly limited to proximate environmental impacts like water quality, now more broadly encompasses
themes of scalar governance, landscape-level conservation, and local resource access. The case studies
covered here demonstrate that a regional scale approach to political ecology provides utility as a heuristic to
conceptually frame the concepts of governance, resource access, and ecological degradation between larger
processes of economic restructuring and more localized micro politics. A case study approach is used to
empirically support the claim that region provides a meso-scale of analysis in terms of: scalar resource control
– state versus federal (southeast Utah); biocentric values – preserving nature for nature's sake (southern
Arizona); and anthropocentric values – newly touted, but grounded in age-old utilitarianism (northeast
Wyoming).
Energy production in the United States for domestic use and export is predicted to rise 27% by 2040. We quantify projected energy sprawl (new land required for energy production) in the United States through 2040. Over 200,000 km² of additional land area will be directly impacted by energy development. When spacing requirements are included, over 800,000 km² of additional land area will be affected by energy development, an area greater than the size of Texas. This pace of development in the United States is more than double the historic rate of urban and residential development, which has been the greatest driver of conversion in the United States since 1970, and is higher than projections for future land use change from residential development or agriculture. New technology now places 1.3 million km² that had not previously experienced oil and gas development at risk of development for unconventional oil and gas. Renewable energy production can be sustained indefinitely on the same land base, while extractive energy must continually drill and mine new areas to sustain production. We calculated the number of years required for fossil energy production to expand to cover the same area as renewables, if both were to produce the same amount of energy each year. The land required for coal production would grow to equal or exceed that of wind, solar and geothermal energy within 2–31 years. In contrast, it would take hundreds of years for oil production to have the same energy sprawl as biofuels. Meeting energy demands while conserving nature will require increased energy conservation, in addition to distributed renewable energy and appropriate siting and mitigation.
The Williston Basin in the Northern Great Plains has experienced rapid energy development since 2000. To evaluate the land cover changes resulting from recent (2000-2015) development, the area and previous land cover of all well pads (pads) constructed during this time were determined, the amount of disturbed and reclaimed land adjacent to pads was estimated, land cover changes were analyzed over time for three different well types, and the effects from future development were predicted. The previous land cover of the 12,990ha converted to pads was predominately agricultural (49.5%) or prairie (47.4%) with lesser amounts of developed (2.3%), aquatic (0.5%), and forest (0.4%). Additionally, 12,121ha has likely been disturbed and reclaimed. The area required per gas well remained constant through time while the land required per oil well increased initially and then decreased as development first shifted from conventional to unconventional drilling and then to multi-bore pads. For non-oil-and-gas wells (i.e. stratigraphic test wells, water wells, and injection wells), the area per well increased through time likely due to increased produced water disposal requirements. Future land cover change is expected to be 2.7 times greater than recent development with much of the development occurring in five counties in the core Bakken development area. Direct land cover change and disturbance from recent and expected development are predicted to affect 0.4% of the landscape across the basin; however, in the core Bakken development area, 2.3% of the landscape will be affected including 2.1% of the remaining grassland. Although future development will result in significant land cover change, evolving industry practices and proactive siting decisions, such as development along energy corridors and placing pads in areas previously altered by human activity, have the potential to reduce the ecological effects of future energy development in the Williston Basin.
Unconventional shale gas activity has presented both challenges and opportunities for conservation. The unique nature of horizontal drilling used in shale exploration allows for a reduction in the footprint of shale-related activity in the landscape. However, existing policies regulating shale activity across the Northeast, particularly in Pennsylvania, largely miss an opportunity to encourage such consolidation, which would result in substantial ecosystem conservation. Using satellite land cover data for the years 2006 and 2011 combined with data on shale drilling activity in Pennsylvania, we show that a consolidation of wells to underutilized well pads would have resulted in a forest conservation gain of over 112,838 acres between 2006 and 2015. While likely an overestimate, this suggests that small changes in policy such as moving toward a quantity-based market mechanism to regulate the number of well pads would result in substantial conservation gains.
This article reviews recent literature relevant to the ongoing shale gas boom and introduces the Journal of Political Ecology's Special Section on hydraulic fracking. We highlight the need for ethnographic studies of the tumultuous social and physical transformations resulting from, and produced by, an unfolding frontier of energy production that unsettles social, economic, and ecological landscapes. We examine how intercommunity connections are vital to recognizing the shared structural conditions produced by the oil and gas industry's expansion, through examining the roles played by the oil field services industry, the sequestration of information and agnotology (the deliberate production of ignorance), divide and conquer tactics, and shared experiences of risk and embodied effects. Summarizing the contributions of the five articles included in the Special Section, we offer recommendations for further inquiry. We examine how social science studies of hydraulic fracking are producing new and innovative methodologies for developing participatory academic and community research projects.
Key words: digital media, embodiment, energy, hydraulic fracturing, oil field services industry, shale gas
Exploring both ecological and political-economic histories sheds light on the long-term effects of social and environmental changes. Wetlands provide an excellent context for examining the re-working of society-nature relations in a landscape over a long duration. Wetland conditions and social-ecological dynamics show changes rapidly and visibly because they are frequently re-engineered to account for changes in both technology and social preferences. Wetlands are subject to multiple, concurrent property and access regimes that have consequences for both management and ecosystem health. We discuss the social-natural history of the Scamandre Marshes in the western part of the Camargue Biosphere Reserve using a historical political ecology approach to analyze the shifting dynamics between power relations under a variety of political-economic arrangements, and the ecology of the marsh environment. The approach highlights how historical political ecology is a means of identifying historical socio-natures and how European or national conservation actors’ constructions of a place as “natural” affect its use, conservation, and management. We show that contemporary ecological dynamics are best explained by past conflicts related to property claims, access to natural resources, and their effects on the flows and composition of water in the marsh. A general model of wetland transformation stresses repeated cycles of stability and upheaval, emphasizing that the lack of historical analysis threatens both wetlands and conflict resolution. No landscape is produced locally or ahistorically. We emphasize here that history is not only a hallmark of political ecology, but a way of understanding ecological changes that can help advance biodiversity conservation science and policy. © 2015 by the author(s). Published here under license by the Resilience Alliance.
Mapping of oil reserves involves the use of seismic lines (linear disturbances) to determine both their location and extent. Conventional clearing techniques for seismic assessment have left a legacy of linear disturbances that cause habitat fragmentation. Little is known, however, about how local and landscape factors affect natural regeneration patterns of trees and shrubs on seismic lines that facilitate mapping and future projections of regeneration patterns. To understand factors affecting early forest regeneration and to predict future trends in regeneration of legacy seismic lines we used LiDAR, forest stand databases and a disturbance inventory of conventional seismic lines to model seismic line regeneration to a 3 m height in a 1806 km2 area in northeastern Alberta, Canada. Regeneration to 3 m was inversely related to terrain wetness, line width, proximity to roads (as a proxy for human use of lines), and the lowland ecosites. Overall, terrain wetness and the presence of fen ecosites had the strongest negative effect on regeneration patterns; the wettest sites failed to recover even after 50 years post-disturbance. Predictions of future regeneration rates on existing lines suggested that approximately one-third of existing linear disturbance footprints in this boreal landscape will remain un-regenerated 50 years later resulting in persistent habitat fragmentation. Model predictions estimating regeneration probability are particularly valuable for estimating current and future forest regeneration trajectories on linear disturbances which are a conservation concern and a focus for restoration and planning by government, industry and conservation organizations.
Recent work on legal geographies has arguably paid far too little attention to the environment as both an object of governance and a terrain of struggle with respect to the law. Conversely, political ecology as a field, with its focus on informal and extra-legal dynamics, has arguably engaged too little with the legal geographies that are central to environmental conflicts in many locations. This paper examines and theorizes the legal geographies that have been essential elements of the recent boom in extraction of natural gas from the Marcellus Shale in Pennsylvania. Specifically, it examines the ways in which laws and the authority of the state more broadly have been changed, deployed, and invoked, particularly through the passage of Act 13, to enable the extraction of the gas in the shale and its circulation as a viable commodity. This analysis of the relevant multiscalar legal geographies illustrates the productivity of a more direct engagement between political ecology on one hand, and legal geography on the other.
The development of hydrocarbon resources in northwestern Canada has resulted in a vast network of seismic lines. Seismic lines are a conservation concern because they are believed to alter the use of space by predators and ultimately change predator-prey relationships. Such changes are believed to be a key factor influencing declines in boreal woodland caribou (Rangifer tarandus caribou). Using remote wildlife cameras, we measured the behavioral response of a known caribou predator, the black bear (Ursus americanus), to seismic lines at 2 spatial scales. At the line scale, we compared black bear use of lines that varied in width and vegetation recovery state to undisturbed forest interior locations. At a 5-km2 scale, we compared the probability of bear use across a continuum of seismic line density. At both spatial scales, we also tested for an interaction between bear use of seismic lines and use of upland and lowland forest types. Black bears used most types of seismic lines more frequently than undisturbed forest interior and upland forest more than lowland forest. We found no evidence of an interaction between lines and forest type, as the relative difference in seismic line versus forest interior use was the same in lowland and upland forest. At the 5-km2 scale, we found no evidence of increased use of lowland forest in areas with greater seismic line density. Thus, seismic lines did not appear to increase black bear use of lowland forest types per se. However, bears used seismic lines more than forest interiors, which might alter their ability to locate and capture caribou and other ungulate prey, thereby creating the potential for altered predator-prey dynamics in landscapes with seismic lines. Bears do not appear to use seismic lines ≤2 m wide more often than the forest interior. We suggest that where new seismic lines are constructed, those seismic lines should be a maximum width of 2 m to reduce the potential for altered predator-prey dynamics in areas being developed for oil and gas extraction. © 2014 The Wildlife Society.
In 2022, the Rocky Mountain Association of Geologists (RMAG) celebrated its centennial anniversary. Founded on January 26, 1922, RMAG (called Rocky Mountain Association of Petroleum Geologists until 1947) grew out of a desire and need for petroleum geologists in Denver to come together in a collegial environment. Petroleum geology had become an important component of exploration and development, with significant discoveries in the greater Denver Basin (Florence Field) as well as east-central Wyoming (Salt Creek Field) and northwest Colorado (Rangely Field). Through the first 25 years (1922–1947), membership hovered around 50, reflecting an initial boom of World War I through the 1920s, and then surviving the Great Depression and World War II. Post-World War II through the early 1980s, the world saw a huge increase in demand for oil (less-so for natural gas), spurring the “golden years” of Rocky Mountain exploration and development of many now-famous discoveries. Denver grew as a petroleum business center with large (major) to small (independent) companies, leading to steady RMAG membership growth, which peaked at 4,524 in 1984. During this period, RMAG established a legacy of publishing (The Mountain Geologist and the Geologic Atlas of the Rocky Mountain Region, aka “the Big Red Book”), sponsored multi-day field trips and symposia, hosted weekly luncheons with 200–300 attendees at the peak, and maintained a dedicated office staff located in downtown Denver. The legacy “golden” years ended with the “crash” in oil prices in 1985–86, and membership declined about 7% per year until the mid-1990s, levelling out at 1,900 members. Within the ashes of the 1984–1995 period, however, RMAG began its On the Rocks field trip series (1986) and published several sold-out guidebooks. It inaugurated the 3D Seismic Symposium (1995) co-hosted with the Denver Geophysical Society (DGS) and hosted several successful AAPG and Rocky Mountain Section AAPG annual meetings. In the 1990s, natural gas hosted in “unconventional” reservoirs began an exploration/development revolution, spurred on by federal price supports and construction of a major gas pipeline to the West Coast in 1992. By 2000, huge natural gas resources locked in Rocky Mountain “tight gas” reservoirs became economically viable with improved hydraulic fracturing technology and increasing gas prices. RMAG membership began growing along with the increased natural gas-drilling activity, and RMAG offered multiple well-attended symposia and publications highlighting unconventional gas plays. A new boom began in 2008 with the advent of horizontal drilling for oil in the Bakken Shale of the Williston Basin and Niobrara Formation of the Denver Basin, and a massive increase in oil price. Consequently, RMAG membership reached a secondary peak of 2,978 in 2012. However, as oil prices began declining steadily in 2014, membership also decreased. By 2016, oil price decline led to the familiar cycle of company closings and layoffs. In 2020, the Covid-19 pandemic shut down all in-person RMAG activities, heavily impacting the organization. RMAG pivoted to online (virtual) luncheons, symposia, and field trips. Even so, membership declined to about 1200 members in 2022. The challenges that the RMAG will face in the next 100 years will be daunting. Long-term sustainability of the RMAG will require its members and member-leaders to recognize and embrace changes as they occur.
An intensification of water use per well for hydraulic fracturing (HF) has been observed in different regions of the U.S. during the last 20 years. Water-scarce regions undergoing the most intensive unconventional reservoir development also face water and wastewater management issues to support HF activities. In this review, we analyze the current state of water use related to HF, focusing on the implications of shale gas development on groundwater resources within water-limited regions in the U.S. Recent concerns of HF water management highlight the importance of wastewater treatment and reuse to decrease the dependence on freshwater sources and to minimize the hazards of wastewater disposal.
The Permian Basin is one of the most prolific oil and natural gas geologic basins in the US. With soaring production in the last decade, the economic impact of oil and gas development in the basin has become a pressing policy question to answer. This paper presents the first basin-wide study that examines both the employment effect and the income effect of the Permian Basin development. We consider not only the local impact but also the spatial spillover effect and the industry-level spillover effect. To correct for the estimation bias due to the potential simultaneity between drilling decisions and economic activities, an instrumental variables (IV) regression model is proposed. We find that both the employment effect and the income effect of shale development in the basin are highly significant. We also show that there are significant spatial spillover effects and spillover effects onto the indirect industries. Relevant policy implications for the long-run economic prosperity in the Permian Basin are discussed.
Northeast British Columbia (BC) Canada, is a region in which natural gas production has undergone rapid development since 2007. We used nitrogen dioxide (NO2) and sulphur dioxide (SO2) data products of the Ozone Monitoring Instrument (OMI) to assess the impact of natural gas development activity on air quality in this region from 2005 to 2018. We noticed that values of both pollutants were elevated in the immediate vicinity of large emission sources within the Montney formation and Horn River Basin – regions, which have experienced an increase in unconventional natural gas activities. Places with elevated NO2 Vertical Column Densities (VCDs) are Fort St. John, Taylor, and Dawson Creek located in the Montney formation, and higher SO2 VCDs are found near the Fort Nelson gas plant situated in the Horn River and Liard Basin areas. Although all the OMI data products consistently reported relatively high NO2 VCDs in the same areas, VCD values vary substantially with data products largely due to differences in Air Mass Factor (AMF) calculations. The rate of increase in NO2 VCDs and mass between 2005 and 2018 in the Dawson Creek area was assessed at 2.34% yr⁻¹ and 4.32% yr⁻¹, respectively, and these rates of change are statistically significant. Although we obtained an overall increasing trend for NO2 in Northeast BC, we also noticed a decreasing trend in the period of 2011–2013, which may be attributed, in part, to compliance and enforcement of regulations concerning flaring activities from oil and gas activities in Northeast BC, or due to less development activities. From our analysis, we suggest that the current air quality monitoring network in Northeast BC should be expanded to capture the spatial distribution of SO2 by deploying one additional station near Fort Nelson equipped with meteorology and SO2 monitoring systems.
This study used Landsat TM, Landsat ETM +, and OLI data from 1986, 2003, and 2017, and topographic attributes derived from ASTER digital elevation model respectively, to map land use/land cover (LU/LC) in a predominantly agricultural region of Northwestern Highlands Ethiopia. LU/LC maps were created using supervised classification, and LU/LC change the mapping for the 1986–2003 and the 2003–2017 period determined using post-classification comparisons. The study found the proportion of agricultural land increased from 85.4% of the total area in 1986 to 93.3% in 2017. This increase coincided with a 3.5% decrease in a forested area, a 1.9% decrease in grazing land, and a 1.8% decrease in shrubland. The LU/LC changes mostly occurred in areas having a slope between 0 and 30°. This study has the potential to provide new and practical information for managers and planners for an infrequently studied region and contribute to the growing literature on the topographic factors for LU/LC changes.
Understanding the interconnection between land use processes and land change patterns is yet to be fully achieved. Land change researchers have posited that the lack of understanding is not due to lack of effort but rather the difficulty in the task of seeking understanding, theoretically and practically. In this study, to understand forest change patterns from shale oil and gas (SOG) land use, we combine geospatial approach with metrics from landscape ecology to compare and contrast forest change from SOG infrastructure development in the four shale gas plays in British Columbia (BC). The study finds that cumulatively, between 1975 and 2017, the Cordova, Horn, Liard, and Montney shale gas plays have lost 0.30%, 0.25%, 0.14%, and 0.36% of forest cover, respectively, due to the construction of SOG well pads, access roads, and pipelines. Also, we find that the shale gas plays with the largest quantity of forest cover loss from SOG infrastructure construction have the highest amount of forest fragmentation and the vice versa. The results, however, suggest that differences in the intensity of forest cover change from shale gas land use is likely to create different ecologically significant forest fragmentation patterns. From a broader perspective, this study demonstrates how different levels of human-environment interactions yield different levels of anthropogenic land use impacts on the environment. The study provides land managers with a context for understanding the land use intensities and forest change pattern, which is relevant for sustainable land management in the shale gas plays in British Columbia.
Political ecology, initially conceived to better understand the power relations implicit in management and distribution of natural resources in the developing world, came “home” to the American West in the 1990s and 2000s. This groundswell of research did much to problematize socio-environmental conflicts in the region, long typified by tensions over land and resources, identity and belonging, autonomy and authority. Since first touching down in the West, however, the “big tent” of political ecology has only grown bigger, incorporating new perspectives, epistemologies, and ontologies. At the same time, the nexus of environment and society is perhaps even more salient today, amid a regional conjuncture of populist revolt, climate change, and rapid political economic transformation. Here we reflect on three longstanding regional concerns – energy development, wolf reintroduction, and participatory governance – leveraging the pluralism of contemporary political ecology to better understand their contemporary incarnations. In so doing, we highlight the need to bring together insights from both “traditional” approaches and newer directions to better understand and engage contemporary challenges, with their heightened stakes and complexity. Such an approach demonstrates what we might learn about global processes in this place, as well as what insights regional praxis (often woefully provincial) might gain from elsewhere – new ways of seeing and doing political ecology. Our goal is to generate discussion among and between political ecologists and regional critical scholars, initiating new collaborative engagements that might serve the next wave of political ecology in the 21st century American West.
Land elements like slope, soil depth, land use/land cover, water holding capacity, soil texture, soil erosion, elevation, potential of hydrogen, etc. determine the suitability for agriculture. Land suitability analysis is a one of the methods of assessment of detecting inherent capacities, potential and suitability levels of the lands for agriculture, and was utilized with the same land elements in this study. A multi-criterion decision making approach using IRS P6 LISS-IV satellite dataset within a GIS environment was used to identify suitable areas for agriculture in the Darna catchment. Experts’ opinions, literature review, and correlation technique were used to decide influencing criteria, assign scores to sub-criteria, and judgment formation in pairwise comparison matrix. All thematic layers of criteria were integrated with each other in GIS using the weighted overlay technique and generated agriculture suitability map into four classes according to FAO. About 23% of the area is under agriculture in the study region. This area can extend up to 69% under agriculture converting fallow land, scrub land, and sparse forest according to soil qualities with suitability levels, i.e., highly suitable (19%), moderately suitable (16%), and marginally suitable (34%). About 31% (19,219 ha) of reviewed area are classified in the class permanently “not suitable” for agriculture. Moderately and marginally suitable land requires the irrigation facility for efficient agriculture. This study emphasizes that about 46% area has potential as agriculture land and it will help improve the financial condition of the farmers.
Seismic lines are corridors cut through forest and wetland land covers for geophysical exploration of oil and gas deposits. Here we present a localised case study of the impacts of seismic lines on proximal boreal forest and wetland ecosystem vegetation structural characteristics. The study concentrates on a relatively undisturbed area of the Oil Sands Region of the Boreal zone in north central Alberta using airborne multi-spectral lidar and publically available geospatial data. The results of this study indicate that significant variations in adjacent forest/wetland edge vegetation structure occur proximal to 30 seismic lines identified within the study area. The variations observed in this area depend on the environmental characteristics of the seismic lines. Often taller trees and greater fractional cover extends to a distance of up to 55 m from the seismic line, especially in land covers adjacent to wider seismic lines. Random forest analysis of spatial correspondence between environmental and proximity-based variability associated with seismic lines indicates that distance, incident radiation and the potential for accumulation of surface water based on local geomorphology (inferred from topographic position) are the most important variables affecting height and fractional cover of proximal vegetation. Combined variables including distance from the seismic line, width of the seismic line, cardinal direction and incident radiation, topographic position and underlying surface geology may be used to predict spatial variability of vegetation height to an accuracy of 70% (adjusted (adj.) R²). From this research, we suggest continued sampling/testing of lidar/high resolution optical imagery and geospatial data to examine the impacts of seismic lines in other parts of the Oil Sands Region using the methods developed in this case study. Reclamation management plans for oil and gas exploration areas should focus on reclaiming wider seismic lines first as these have the greatest impact on proximal ecosystems.
Unconventional oil and gas development has expanded dramatically in the United States during the last 15 years. This change in the energy industry has developed, modified, and fragmented large areas of the terrestrial landscape, resulting in hundreds of millions of dollars of annual ecosystem services costs, including negative effects on agricultural production, plant and wildlife populations, animal migrations, and human well-being. The locations of the most active unconventional oil and gas regions overlap ecologically valuable and, in some cases, relatively intact natural habitats, but there are few detailed studies that comprehensively investigate local ecosystem services impacts of this recent activity. We highlight impacts on the terrestrial landscape in three areas of the U.S. that deserve particular attention: the eastern temperate deciduous forest of the mid-Appalachian region, the prairies of the Great Plains, and the Chihuahuan Desert of west Texas and southern New Mexico. These regions cover large geographic areas that are rich in ecosystem services, and recently they have experienced some of the highest levels of unconventional oil and gas activity. We make a call for targeted studies to improve our understanding of how this development will impact these ecosystem services and which strategies can mitigate the negative impacts. The lessons learned from these analyses could be applied to new energy development abroad, which is currently under consideration by many nations with probable unconventional oil and gas resources
Understanding long-term implications of energy development on ecosystem function requires establishing regional datasets to quantify past development and determine relationships to predict future development. The Piceance Basin in western Colorado has a history of energy production and development is expected to continue into the foreseeable future due to abundant natural gas resources. To facilitate analyses of regional energy development we digitized all well pads in the Colorado portion of the basin, determined the previous land cover of areas converted to well pads over three time periods (2002-2006, 2007-2011, and 2012-2016), and explored the relationship between number of wells per pad and pad area to model future development. We also calculated the area of pads constructed prior to 2002. Over 21million m(2) has been converted to well pads with approximately 13million m(2) converted since 2002. The largest land conversion since 2002 occurred in shrub/scrub (7.9million m(2)), evergreen (2.1million m(2)), and deciduous (1.3million m(2)) forest environments based on National Land Cover Database classifications. Operational practices have transitioned from single well pads to multi-well pads, increasing the average number of wells per pad from 2.5 prior to 2002, to 9.1 between 2012 and 2016. During the same time period the pad area per well has increased from 2030 m(2) to 3504 m(2). Kernel density estimation was used to model the relationship between the number of wells per pad and pad area, with these curves exhibiting a lognormal distribution. Therefore, either kernel density estimation or lognormal probability distributions may potentially be used to model land use requirements for future development. Digitized well pad locations in the Piceance Basin contribute to a growing body of spatial data on energy infrastructure and, coupled with study results, will facilitate future regional and national studies assessing the spatial and temporal effects of energy development on ecosystem function.
The Receiver Operating Characteristic (ROC) is widely applied to assess the performance of spatial models that produce probability maps of the occurrence of certain events such as the land use / land cover changes, the presence of a species or the likelihood that landslides will occur. In this technical note, the construction of the ROC curve and the calculation of the Area Under the Curve (AUC) index are presented.
Low-impact seismic (LIS) techniques were developed to reduce the environmental footprint of oil exploration. Though relatively narrow (∼2–3 m) and constructed with light-weight equipment, these lines cause forest fragmentation, and with their high density and potential edge influence extending into adjacent forest, their impact may be considerably underestimated. We assessed the effects of 3- to 4-year-old LIS lines in upland coniferous sub-boreal forests in northwestern Alberta (Canada) by investigating the distance of influence from the LIS line centre, through the edge and into the adjacent forest on vascular and non-vascular plant species diversity and cover and on several environmental factors. We also assessed whether cardinal orientation of the edge affects influence on plants and environmental factors. Edge orientation had no effect on extent of edge influence on plants or environmental variables, but distance from seismic line edge did. Species diversity of herbaceous plants was lowest from the seismic line edge up to 15 m into the adjacent forest, when compared to mid- (25 m) and far-interior (75 m) forest. In contrast, cover was lower 5 m from the seismic line edge in comparison to far-interior forest, but conditions on the seismic lines did not differ from the seismic line edge or any sampled distance up to 75 m from the edge. Non-vascular species had lower diversity and cover on the seismic lines and along the edges in comparison to any distance away from the edge. There was no effect of distance from the seismic line edge on live woody plants, but deadwood was more frequently encountered near the seismic line edges in comparison to interior forest. Soil temperature was higher on the seismic lines and along the line edges whereas soil moisture on the seismic lines was about twice as high as at the edges and adjacent forest. Seismic lines and edges also received more light than the forest near the edge, but not more than the far-interior forest. With edge influence detectable up to 15 m from edge 3 to 4 years post-construction, long-term and regular monitoring of LIS lines is recommended, as active management and remedial reclamation actions might be required to bring the recovery of these disturbances on the right trajectory.
The emergent patterns of land change resulting from the development of shale oil and gas infrastructure is a result of many small decisions and interactions. This research focuses on the land change associated with the development of shale oil and gas infrastructure in the Marcellus and Utica shale formations in two geographically proximate and physically similar counties, Carroll County, OH, and Washington County, PA. Land-cover data used to measure feature-scale change was digitized from aerial photography and then used to update NLCD data used in the calculation of forest fragmentation for the entire study areas. The amount and pattern of land change was very similar between the two counties even though they are drawing oil and gas from different shale formations. Less than one percent of the total forest for each county was lost but the fragmentation impacts are amplified by the pattern of infrastructure on the landscape.
Large, continuous forest provides critical habitat for some species of forest dependent wildlife. The rapid expansion of shale gas development within the northern Appalachians results in direct loss of such habitat at well sites, pipelines, and access roads; however the resulting habitat fragmentation surrounding such areas may be of greater importance. Previous research has suggested that infrastructure supporting gas development is the driver for habitat loss, but knowledge of what specific infrastructure affects habitat is limited by a lack of spatial tracking of infrastructure development in different land uses. We used high-resolution aerial imagery, land cover data, and well point data to quantify shale gas development across four time periods (2010, 2012, 2014, 2016), including: the number of wells permitted, drilled, and producing gas (a measure of pipeline development); land use change; and forest fragmentation on both private and public land. As of April 2016, the majority of shale gas development was located on private land (74% of constructed well pads); however, the number of wells drilled per pad was lower on private compared to public land (3.5 and 5.4, respectively). Loss of core forest was more than double on private than public land (4.3 and 2.0%, respectively), which likely results from better management practices implemented on public land. Pipelines were by far the largest contributor to the fragmentation of core forest due to shale gas development. Forecasting future land use change resulting from gas development suggests that the greatest loss of core forest will occur with pads constructed farthest from pre-existing pipelines (new pipelines must be built to connect pads) and in areas with greater amounts of core forest. To reduce future fragmentation, our results suggest new pads should be placed near pre-existing pipelines and methods to consolidate pipelines with other infrastructure should be used. Without these mitigation practices, we will continue to lose core forest as a result of new pipelines and infrastructure particularly on private land.
Awareness of the impact of the global energy industry and associated landuse change on biodiversity conservation has been steadily growing amongst conservation biologists. Across Canada, 28 of 57 populations of boreal woodland caribou (Rangifer tarandus caribou) are declining and 20 of 25 southern mountain populations are in decline with several recent high-profile extirpations. Declines stem from widespread landuse change from energy development and forestry that will take decades to recover, if ever. In Western Canada's Boreal forest, a globally significant oil and gas industry has emerged that is the biggest source of foreign oil to US markets. All woodland caribou populations overlapping oil and gas development in oil-rich Alberta are in rapid decline, shrinking by 50% every 8 years. After a decade of delay, the Federal government released recovery plans under the Canadian Species-at-Risk Act (SARA) in 2012 and 2014 for these two caribou ecotypes, and will audit provincial compliance in 2017. Yet recovery actions have been inadequate, and have relied on wolf control as a short-term solution. Given the stark reality, conservation triage might be expected. Instead, the conservation objective at Federal and Provincial levels remains legally committed to recovery of all populations despite the paradox of continued declines. I suggest the reason for ineffective conservation planning is the staggering cost of effective habitat protection that far exceeds $150 billion (CDN) in Alberta alone. Declines of woodland caribou also allegedly violate Canadian Aboriginal treaty rights that have been challenged in court. This complex conservation case-study urgently illustrates the need for strategic conservation triage at provincial and national levels. And more generally, caribou conservation demonstrates the challenge of using national endangered species legislation to retroactively counteract the global energy industry without strategic conservation planning coordinated with energy and cultural policies.
This article explores competing interpretive frames regarding shale gas in Bulgaria, Poland, and Romania. These countries face the choice of embracing shale gas as a potential revolutionizing domestic source of energy, against the backdrop of Russia serving as the dominant gas supplier. This makes them interesting cases for studying how policy narratives and discourses coalesce around a novel technology. The findings, which are based on sixty-six semistructured research interviews, point to differing and indeed competing frames, ranging from national security, environmental boons, to economic sellout and authoritarianism, with different sets of institutions sharing those frames. This suggests that enhancing energy security by way of deploying novel energy technologies such as shale gas fracking is not simply a function of resource endowments and technological progress. Instead, it is the result of complex dynamics unfolding among social stakeholders and the related discursive processes, which eventually will determine whether—or not—shale gas will go global.
Forests can be dissected or internally fragmented by anthropogenic linear clearings. Much research has focused on roads but in forests overlying oil and gas reserves, seismic lines (narrow exploration trails) also internally fragment forests and alter landscape structure. Seismic lines are of particular interest because they already exist in western North America and exploitation of future reserves may require new seismic line clearing over vast forest areas. An assessment was needed to compare their relative contribution to forest fragmentation against other more well-known linear forest clearings. This study was conducted across an area of 4022 km² of boreal forest in western Canada. Seismic lines directly occupied a relatively small area (1% of all land), but were five times longer than roads and rail lines. Seismic line density was more than twice that of roads, rail lines, power lines and pipelines combined and accounted for 80% of all edges. Seismic lines have the potential to indirectly influence more forest than all these other types of linear forest clearings. Seismic lines consistently decreased the size of forest patches, and increased the number of patches across spatial scales from 5.0-4900 ha but tended to have a greater impact at larger spatial extents. While roads are the most important agents of fragmentation in some forests, in forests where oil and gas reserves are exploited, seismic lines have the greatest impact on forest fragmentation. © 2016 by the Northwest Scientific Association. All rights reserved.
The purpose of this chapter is to explore the dynamics of the largest oil producer in the Gulf of Guinea (Nigeria), and to offer a political–ecological analysis of the recent history of an archetypical petro-state. Nigeria is a poster-child of the so-called resource curse, a ‘fragile and conflicted state’ condemned to embark upon a ‘postconflict transition’. Exclusionary political settlements and extractive institutions of the sort found in Nigeria are associated with high levels of violence and political conflict. However, the inventory of institutional failures of ‘oil development’ must not blind us to the fact that the combination of oil and nation-building has produced a durable and expanded federal system, a democracy of sorts (albeit retaining an authoritarian and often violent cast) and important forms of institution building. I argue that the state has been informalized for particular purposes, vested with certain capabilities and made ‘functional’ while at the same time generating considerable civic and political violence including an insurgency and endemic conflict in the oil-producing Niger Delta region. Oil and its political logics are central to this complex and contradictory picture of uneven state capabilities coupled with spatial fragmentation and conflict.
Shale production on a significant scale arose quite recently and is so far limited to the US with gas having a few years' lead on oil. Shale has already had a significant impact on US gas and oil output. Further sizable production increases can be expected in the US, and the shale revolution is likely to spread, with a lag, across the globe. This will result in fundamental repercussions for international energy markets. The resources in focus of our attention, comprising shale gas and coalbed methane along with tight gas and tight oil, typically lack strict definitions and they often overlap. However, they are all characterized by low permeability that yields commercially insufficient flows from vertical drilling. The shale revolution is the result of technological breakthroughs in horizontal drilling and hydraulic fracturing that have made vast dormant gas and oil resources economically exploitable.
Shale fever is more and more epidemic in present China especially when China's technically recoverable shale gas resources was announced to rank first in the world with nearly 32 trillion m3 and when the 12th Five-Year National Plan of shale gas development was released. The success or failure of such an investment decision will rely on both geological and economic evaluation of shale gas resources, but few studies on shale gas development economy can be found at home and abroad. In view of this, an economic analysis was made in a case study of the Marcellus Shale Play in the USA, with about 41 groups of economic data on this shale play being collected from 11 energy companies during 2011-2012. The following findings were obtained. First, a set of methodologies from ideas to procedures were built, such as Cash Flow Analysis, Sensitivity Analysis, etc. Second, the main controlling factors on shale gas economy included gas price, initial output and cost, and the initial output is the most fundamental one. Therefore, an economic analysis of shale gas development should be based on the initial production (IP) of a shale gas well. Third, economic evaluation charts were established according to wellhead gas price, capital expenditure, operating expense and royalty in the Marcellus Shale Play. This study provides important economic parameters and methodologies for China's energy enterprises to develop shale gas resources, and valuable references for Chinese government to formulate reasonable policies about shale gas royalty.
Marcellus Shale development is occurring rapidly and relatively unconstrained across Pennsylvania (PA). Through 2013, over 7400 unconventional wells had been drilled in the Commonwealth. Well pads, access roads, and gathering lines fragment forestland resulting in irreversible alterations to the forest ecosystem. Changes in forest quantity, composition, and structural pattern can result in increased predation, brood parasitism, altered light, wind, and noise intensity, and spread of invasive species. These fragmentation effects pose a risk to PA's rich biodiversity. This study projects the structure of future alternative pathways for Marcellus shale development and quantifies the potential ecological impact of future drilling using a core forest region of Bradford County, PA. Modeling presented here suggests that future development could cause the level of fragmentation in the study area to more than double throughout the lifetime of gas development. Specifically, gathering lines are responsible for approximately 94% of the incremental fragmentation in the core forest study region. However, by requiring gathering lines to follow pre-existing road routes in forested regions, shale resources can be exploited to their full potential, while essentially preventing any further fragmentation from occurring across the core forested landscape of Bradford County. In the study region, assuming an estimated ultimate recovery (EUR) of 1–3 billion cubic feet (Bcf) per well, this policy could be implemented for a minimal incremental economic investment of approximately 0.005–0.02 per Mcf of natural gas produced over the modeled traditional gathering line development.
The relative operating characteristic (ROC) is a widely-used method to measure diagnostic signals including predictions of land changes, species distributions, and ecological niches. The ROC measures the degree to which presence for a Boolean variable is associated with high ranks of an index. The ROC curve plots the rate of true positives versus the rate of false positives obtained from the comparison between the Boolean variable and multiple diagnoses derived from thresholds applied to the index. The area under the ROC curve (AUC) is a summary metric, which is commonly reported and frequently criticized. Our manuscript recommends four improvements in the use and interpretation of the ROC curve and its AUC by: (1) highlighting important threshold points on the ROC curve, (2) interpreting the shape of the ROC curve, (3) defining lower and upper bounds for the AUC, and (4) mapping the density of the presence within each bin of the ROC curve. These recommendations encourage scientists to interpret the rich information that the ROC curve can reveal, in a manner that goes far beyond the potentially misleading AUC. We illustrate the benefit of our recommendations by assessing the prediction of land change in a suburban landscape.
This study evaluates the economic feasibility of five emergent shale gas plays on the European Continent. Each play is assessed using a uniform field development plan with 100 wells drilled at a rate of 10 wells/year in the first decade. The gas production from the realized wells is monitored over a 25 year life cycle. Discounted cash flow models are used to establish for each shale field the estimated ultimate recovery (EUR) that must be realized, using current technology cost, to achieve a profit. Our analyses of internal rates of return (IRR) and net present values (NPVs) indicate that the Polish and Austrian shale plays are the more robust, and appear profitable when the strict P90 assessment criterion is applied. In contrast, the Posidonia (Germany), Alum (Sweden) and a Turkish shale play assessed all have negative discounted cumulative cash flows for P90 wells, which puts these plays below the hurdle rate. The IRR for P90 wells is about 5% for all three plays, which suggests that a 10% improvement of the IRR by sweet spot targeting may lift these shale plays above the hurdle rate. Well productivity estimates will become better constrained over time as geological uncertainty is reduced and as technology improves during the progressive development of the shale gas fields.
Based on the 2011 Annual Cultural and Political Ecology Specialty Group Lecture, this paper makes the case for a political ecology of the subsoil. Arguing that subsoil resources have received comparatively little attention within the wider corpus of political ecological writing, the paper explores several ways in which the extraction of mineral and hydrocarbon resources is constitutive of, and constituted by, wider capitalist political, economic and institutional arrangements. Drawing on material from El Salvador and the Andean countries, the paper explores the contemporary governance of extractive industries, and points to significant convergence among the approaches taken by neoliberal and ostensibly post-neoliberal regimes alike. The intersections between the extractive economy, livelihoods and patterns of social protest are also explored. Through these examples, the paper also highlights the ways in which “activist political ecologists” play important roles in counter-movements seeking to re-govern the extractive economy. These countermovements are found in both civil society and different parts of the state. Such activist political ecologists are central to the broader enterprise of an “underground political ecology” and are often vital to the success of scholarly interventions in such political ecologies.