Annual Review of Environment and Resources - Volume 42, 2017

Synthetic organic polymers—or plastics—did not enter widespread use until the 1950s. By 2015, global production had increased to 322 million metric tons (Mt) year⁻¹, which approaches the total weight of the human population produced in plastic every year. Approximately half is used for packaging and other disposables, 40% of plastic waste is not accounted for in managed landfills or recycling facilities, and 4.8–12.7 Mt year⁻¹ enter the ocean as macroscopic litter and microplastic particles. Here, we argue that such mismanaged plastic waste is similar to other persistent pollutants, such as dichlorodiphenyltrichloroethane (DDT) or polychlorinated biphenyls (PCBs), which once threatened a “silent spring” on land. Such a scenario seems now possible in the ocean, where plastic cannot be easily removed, accumulates in organisms and sediments, and persists much longer than on land. New evidence indicates a complex toxicology of plastic micro- and nanoparticles on marine life, and transfer up the food chain, including to people. We detail solutions to the current crisis of accumulating plastic pollution, suggesting a Global Convention on Plastic Pollution that incentivizes collaboration between governments, producers, scientists, and citizens.

This review explores what past environmental change in Africa—and African people's response to it—can teach us about how to cope with life in the Anthropocene. Organized around four drivers of change—climate; agriculture and pastoralism; megafauna; and imperialism, colonialism, and capitalism (ICC)—our review zooms in on key regions and debates, including desertification; rangeland degradation; megafauna loss; and land grabbing. Multiscale climate change is a recurring theme in the continent's history, interacting with increasingly intense human activities from several million years onward, leading to oscillating, contingent environmental changes and societally adaptive responses. With high levels of poverty, fast population growth, and potentially dramatic impacts expected from future climate change, Africa is emblematic of the kinds of social and ecological precariousness many fear will characterize the future globally. African people's innovation and adaptation to contingency may place them among the avant-garde with respect to thinking about Anthropocene conditions, strategies, and possibilities.

The Intergovernmental Panel on Climate Change (IPCC) conducts policy-relevant but not policy-prescriptive assessments of climate science. In this review, we engage with some of the key design features, achievements, and challenges that situate and characterize the IPCC as an intergovernmental organization that is tasked with producing global environmental assessments (GEAs). These include the process of working through consensus to assess and summarize climate science and the need to include knowledge from as many of the 195 IPCC nation-states as possible, despite the structural inequalities between developed and developing countries. To highlight salient features that are unique to the IPCC but that offer lessons for other organizations that conduct GEAs, we include case studies on the politics of climate denialism, the use of geoengineering in mitigation scenarios, and the links between adaptive capacity, adaptation, and global development. We conclude with a discussion of institutional reflexivity. We consider how the IPCC can model an ethical and participatory response to climate change by critically examining, and being transparent about, the relation between science and politics.

The Anthropocene, the concept that the Earth has moved into a novel geological epoch characterized by human domination of the planetary system, is an increasingly prevalent framework for debate both in academia and as a wider cultural and policy zeitgeist. This article reviews the proliferation of literature surrounding this concept. It explores the origins and history of the concept, as well as the arguments surrounding its geological formalization and starting date ranging from the Pleistocene to the twentieth century. It examines perspectives and critiques of the concept from the Earth system sciences, ecological and geological sciences, and social sciences and humanities, exploring its role as a cultural zeitgeist and ideological provocation. I conclude by offering a personal perspective on the concept of the Anthropocene and its utility.

The presence of human-made chemical contaminants in the environment has increased rapidly during the past 70 years. Harmful effects of such contaminants were first reported in the late 1950s in wildlife and later in humans. These effects are predominantly induced by endocrine disrupting chemicals (EDCs), chemicals that mimic the actions of endogenous hormones and leave marks at several levels of organization in organisms, from physiological outcomes (phenotypes) to molecular alterations, including epigenetic modifications. Epigenetic mechanisms play pivotal roles in the developmental processes that contribute to determining adult phenotypes, through so-called epigenetic programming. While there is increasing evidence that EDC exposure during sensitive periods of development can perturb epigenetic programming, it is unclear whether these changes are truly predictive of adverse outcomes. Understanding the mechanistic links between EDC-induced epigenetic changes and phenotypic endpoints will be critical for providing improved regulatory tools to better protect the environment and human health from exposure to EDCs.

Conceptual confusion revolves around how to define, assess, and overcome land, ecosystem, and landscape degradation. Common elements link degradation and recovery processes, offering ways to advance local, regional, and global initiatives to reduce degradation and promote the recovery of ecosystems and landscapes in forest biomes. Biophysical attributes of degradation and recovery can be measured, but the relevance of selected attributes across scales is subject to values that determine preferred states. Degradation defined in the context of a resilience-based approach is a state where the capacity for regeneration is greatly reduced or lost, recovery is arrested, core interactions and feedbacks are broken, and human intervention is required to initiate a trajectory of recovery. Another approach combines degradation and recovery processes through the concept of recovery debt, the cumulative lost benefits incurred, relative to a target state during phases of degradation and recovery. Degradation and recovery can also be described in terms of societal willingness to invest in improved management or restoration. Interventions can facilitate recovery to new stable or persistent states that provide multiple social and ecological benefits at land, ecosystem, and landscape scales. Multiple trajectories of recovery, as well as historic and ongoing chronic environmental change, might, however, mean that recovery to an original reference state is not possible.

Human actions are transforming ecosystems across the globe. Six frameworks aid in understanding the forces that drive human stress on the environment and human responses to this stress. Two of them, the stochastic impacts by regression on population, affluence and technology (STIRPAT) model and decomposition analysis, are approaches to analyzing data. Four describe the interrelated system of human actions and environmental responses: driving forces, pressures, states, impacts, responses (DPSIR); the Millennium Ecosystem Assessment (MA) framework; coupled human and natural systems (CHANS) and telecoupling; and social-ecological systems (SES). In applying these frameworks, attention must be given to the scale of analysis and to the effects of context. In addition to the frameworks there are four substantial research literatures providing theory and empirical analysis of how drivers place stress on the environment: a macrocomparative tradition, work on household energy consumption, land change science, and research on commons. Although these traditions remain somewhat separate, they are largely complementary.

Urbanization is one of the biggest social transformations of modern time, driving and driven by multiple social, economic, and environmental processes. The impacts of urbanization on the environment are profound, multifaceted and are manifested at the local, regional, and global scale. This article reviews recent advances in conceptual and empirical knowledge linking urbanization and the environment, focusing on six core aspects: air pollution, ecosystems, land use, biogeochemical cycles and water pollution, solid waste management, and the climate. We identify several emerging trends and remaining questions in urban environmental research, including (a) increasing evidence on the amplified or accelerated environmental impacts of urbanization; (b) varying distribution patterns of impacts along geographical and other socio-economic gradients; (c) shifting focus from understanding and quantifying the impacts of urbanization toward understanding the processes and underlying mechanisms; (d) increasing focus on understanding complex interactions and interlinkages among different environmental, social, economic, and cultural processes; and (e) conceptual advances that call for articulating and using a systems approach in cities. In terms of governing the urban environment, there is an increasing focus on public participation and coproduction of knowledge with stakeholders. Cities are actively experimenting toward sustainability under a plethora of guiding concepts that manifests their aspirational goals, with varying levels of implementation and effectiveness.

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.

Transportation systems contribute significantly to air pollution and ∼15% globally and ∼25% in the United States to emissions climate-changing gases. In the United States, the Corporate Average Fuel Economy (CAFE) standards for motor vehicles were significantly raised in 2012 for the first time in almost three decades. The standards now call for an average across manufacturers of 54.5 miles per gallon (mpg) for new passenger cars by 2025, or 163 grams per mile (g/mi) of greenhouse gas (GHG) emissions, and of 47 mpg (196 g/mi) by 2021. The light truck standards, which include minivans and sport utility vehicles, call for fuel economy levels of 31 mpg (287 g/mi) in 2021 and of 40 mpg (222 g/mi) in 2025. Given approximately equal expected splits between car and light truck sales, these estimates imply combined car and light truck fleet averages of ∼40 to 41 mpg (217 to 222 g/mi) in 2021 and 50 mpg (178 g/mi) in 2025. However, because automakers have strategies to reduce GHGs in parallel with fuel economy, the actual in-use fuel economy of the fleet is expected to be somewhat lower. In this review, several automobile technology advances are described and assessed for providing relatively cost-effective solutions to meet CAFE standards for fuel economy and GHG reductions through 2025. The key points this review makes are that (a) loopholes in the current regulations will allow automakers to meet CAFE program goals with relatively minor incremental improvements to current technologies through 2025 and that (b) going beyond the current program, past 2025 to higher fuel economy levels and lower GHG emissions approaching 100 g/mi, is likely to involve heavier use of newer technologies especially including drivetrain electrification.

We review future global demand for electricity and major technologies positioned to supply it with minimal greenhouse gas (GHG) emissions: renewables (wind, solar, water, geothermal, and biomass), nuclear fission, and fossil power with CO2 capture and sequestration. We discuss two breakthrough technologies (space solar power and nuclear fusion) as exciting but uncertain additional options for low-net GHG emissions (i.e., low-carbon) electricity generation. In addition, we discuss grid integration technologies (monitoring and forecasting of transmission and distribution systems, demand-side load management, energy storage, and load balancing with low-carbon fuel substitutes). For each topic, recent historical trends and future prospects are reviewed, along with technical challenges, costs, and other issues as appropriate. Although no technology represents an ideal solution, their strengths can be enhanced by deployment in combination, along with grid integration that forms a critical set of enabling technologies to assure a reliable and robust future low-carbon electricity system.

In this review, we examine the debate surrounding the role for organic agriculture in future food production systems. Typically represented as a binary organic–conventional question, this debate perpetuates an either/or mentality. We question this framing and examine the pitfalls of organic–conventional cropping systems comparisons. The review assesses current knowledge about how these cropping systems compare across a range of metrics related to four sustainability goals: productivity, environmental health, economic viability, and quality of life. We conclude by arguing for reframing the debate, recognizing that farming systems fall along gradients between three philosophical poles—industrial, agrarian, and ecological—and that different systems will be appropriate in different contexts. Despite evidence for lower yields in organic crop systems, we found considerable evidence for environmental and social benefits. Given these advantages, and the potential for improving organic systems, we echo calls for increased investment in organic and ecologically based cropping systems research and extension.

Hundreds of millions of the world's poorest people directly depend on smallholder farming systems. These people now face a changing climate and associated societal responses. We use mapping and a literature review to juxtapose the climate fate of smallholder systems with that of other agricultural systems and population groups. Limited direct evidence contrasts climate impact risk in smallholder agricultural systems versus other farming systems, but proxy evidence suggests high smallholder vulnerability. Smallholders distinctively adapt to climate shocks and stressors. Their future adaptive capacity is uncertain and conditional upon the severity of climate change and socioeconomic changes from regional development. Smallholders present a greenhouse gas (GHG) mitigation paradox. They emit a small amount of CO2 per capita and are poor, making GHG regulation unwarranted. But they produce GHG-intensive food and emit disproportionate quantities of black carbon through traditional biomass energy. Effectively accounting for smallholders in mitigation and adaption policies is critical and will require innovative solutions to the transaction costs that enrolling smallholders often imposes. Together, our findings show smallholder farming systems to be a critical fulcrum between climate change and sustainable development.

Vehicle-grid integration (VGI) describes various approaches to link the electric power system and the transportation system in ways that may benefit both. VGI includes systems that treat plug-in electric vehicles (PEVs) as controllable load with a unidirectional flow of electricity, such as “smart” or “controlled” charging or time-of-use (TOU) pricing. VGI typically encompasses vehicle-to-grid (V2G), a more technically advanced vision with bidirectional flow of electricity between the vehicle and power grid, in effect treating the PEV as a storage device. Such VGI systems could help decarbonize transportation, support load balancing, integrate renewable energy into the grid, increase revenues for electricity companies, and create new revenue streams for automobile owners. This review introduces various aspects and visions of VGI based on a comprehensive review. In doing so, it identifies the possible benefits, opportunities, and barriers relating to V2G, according to technical, financial, socio-environmental, and behavioral components. After summarizing our sociotechnical approach and the various opportunities and barriers indicated by existing literature, we construct a proposed research agenda to provide insights into previously understudied and unstudied research objectives. We find that the majority of VGI studies to date focus on technical aspects of VGI, notably on the potential of V2G systems to facilitate load balancing or to minimize electricity costs, in some cases including environmental goals as constraints. Only a few studies directly investigate the role of consumer acceptance and driver behavior within such systems, and barely any studies address the need for institutional capacity and cross-sectoral policy coordination. These gaps create promising opportunities for future research.

The global demand for water and energy is projected to grow, but there likely will be significant constraints in our ability to keep meeting it. These constraints will be imposed partly by the interdependence between water, energy, and climate change. If left unchecked, these connections can exacerbate water and energy shortages and aggravate climate change impacts: Energy is used to supply and treat water; moreover, emissions from energy generation contribute to climate change, which affects water supplies and increases the demand for energy to sustain Earth's growing population and economy. The linkage between water and energy can offer opportunities for better meeting expected demand while minimizing damage from shortages of either. This article focuses on the technological and engineering aspects of various connections in the water-energy nexus where advancements can enable greater supply of one or both. It also outlines the benefits and challenges associated with each connection.

Landscape approaches have become en vogue in the past couple of decades. Originating from nineteenth-century landscape geography, this renewed popularity since the 1980s is fueled by debates on—among others—nature conservation, landscape restoration, ecosystem services, competing claims on land and resources, sectorial land-use policies, sustainable development, and sense of place. This review illuminates the ambition and potential of these landscape approaches for interdisciplinary and cross-sectoral collaboration. To show this, we work with a T-shaped interdisciplinary model. After a short history of the landscape approaches, we dive into their key dimensions—from ecology to economics and culture to politics. Thereafter, we bring these dimensions together again and reflect on the integrative potential of landscape approaches for offering common ground to various disciplines and sectors. Two examples of applications are also dealt with: a landscape governance framework and a landscape capability framework.

We review the literature that investigates the relationship between foreign direct investment (FDI) and the environment. After reviewing the theoretical literature, we discuss two broad strands of research. First, the impact of environmental regulations on the choice of plant location and second, the impact of FDI on the emissions of various pollutants and the related question of whether we can observe environmental spillovers from foreign to domestic firms. Finally, we review the more recent literature on environmental outsourcing as an alternative to FDI and conclude with suggestions for future research.

Clouded titles to land in remote rural areas of the Global South have recently prevented increases in agricultural productivity and payments for environmental services (PES), so making land tenure more secure has become a priority for policymakers. The historical dynamics surrounding land tenure transitions suggest a strategy for reform. Colonial regimes stripped indigenous peoples of most rights to land. Newly independent states restored these rights for some smallholders through land reforms. Later, neo-liberal regimes made secure titles more expensive, and, in so doing, made insecure land tenure more pervasive. Spots of secure land tenure did emerge when indigenous groups, with outside support, resisted efforts by powerful outsiders to expropriate indigenous homelands. Because insecure land tenure persists in most forested rural areas, a focus on afforestation in deforested areas, where earlier episodes of reform secured smallholder land tenure, offers a promising direction for future PES and REDD+ (Reducing Emissions from Deforestation and Degradation) efforts.

This article discusses the conservation challenges of volant migratory transborder species and conservation governance primarily in North America. Many migratory species provide ecosystem service benefits to society. For example, insectivorous bats prey on crop pests and reduce the need for pesticides; birds and insects pollinate food plants; and birds afford recreational opportunities to hunters and birdwatchers. Migration is driven by the seasonal availability of resources; as resources in one area become seasonally scarce, individuals move to locations where resources have become seasonally abundant. The separation of the annual lifecycle means that species management and governance is often fractured across international borders. Because migratory species depend on habitat in different locations, their ability to provide ecosystem services in one area depends on the spatial subsidies, or support, provided by habitat and ecological processes in other areas. This creates telecouplings, or interconnections across geographic space, of areas such that impacts to the habitat of a migratory species in one location will affect the benefits enjoyed by people in other locations. Information about telecoupling and spatial subsidies can be used to craft new governance arrangements such as Payment for Ecosystem Services programs that target specific stakeholder groups and locations. We illustrate these challenges and opportunities with three North American case studies: the Duck Stamp Program, Mexican free-tailed bats (Tadarida brasiliensis mexicana), and monarch butterflies (Danaus plexippus).