Annual Review of Environment and Resources - Volume 35, 2010

Human involvement in food webs has been profound, bringing about enormous and disproportionate losses of large apex predators on land and in water. The losses have modified or even eliminated concatenations of indirect interactions propagating from predators to herbivores to plants, inter alia. Food webs are a synthesis of bottom-up energy and nutrient flow from plant producers to consumers and top-down regulation of producers by consumers. The trophic cascade is the simplest top-down interaction and accounts for a great deal of what is known about food webs. In three-link cascades, predators suppress herbivores, releasing plants. In longer cascades, predators can suppress smaller mesopredators, releasing their prey animals. Hunting, fishing, and whaling have brought parallel losses of large apex predators to food webs. Without apex predators, smaller mesopredators have often become superabundant, sometimes with unprecedented suppression of their prey, extinctions, and endangerment. Flourishing mesopredators also can reverse the web regulation and suppress apex predators that have become rare owing to hunting and fishing. This can prevent fisheries recovery and lead to persistent alternative ecosystem states. Although food-web modules of large animals are increasingly well understood, the parts of webs consisting of small inconspicuous organisms, such as mutualists and parasites, and webs in obscure places, such as in the soil, are much of the challenge of future research.

Invasive species are a major element of global change and are contributing to biodiversity loss, ecosystem degradation, and impairment of ecosystem services worldwide. Research is shedding new light on the ecological and economic consequences of invasions. New approaches are emerging for describing and evaluating impacts of invasive species, and for translating these impacts into monetary terms. The harmful effects of invasions are now widely recognized, and multiscale programs are in place in many parts of the world to reduce current and future impacts. There has been an upsurge in scientific research aimed at guiding management interventions. Among the activities that are receiving the most attention and that have the most promise for reducing problems are risk assessment, pathway and vector management, early detection, rapid response, and new approaches to mitigation and restoration. Screening protocols to reduce new introductions are becoming more accurate and have been shown cost-effective.

Pharmaceuticals are chemicals that are used because of their biological activity. They are often excreted unchanged and can reach the environment. Throughout developed countries, the pharmaceutical concentrations in the aquatic environment are in the same range (μg L⁻¹ and below); however, it is not clear whether this holds for less-developed countries too. The health risks of active pharmaceutical ingredients (APIs) remain poorly understood. Although there are no known short-term effects on humans, long-term effects cannot be ruled out until there is more research. The significance of metabolites and transformation products resulting from the parent APIs is not yet known. Awareness of the presence of pharmaceuticals in the environment, coupled with some evidence of effects, suggests that precautionary management action to reduce the release of pharmaceuticals to the environment should be considered. As for effluent treatment, no technology works well for all compounds. Advanced effluent treatment is not sustainable because of energy consumption, efficiency, and efficacy. Therefore, its appropriateness must be assessed on a case-by-case basis. Increased handling and use measures at the source and better biodegradable pharmaceuticals are necessary in the long run for the new paradigm called “sustainable pharmacy.”

How well are industrialized nations doing in terms of their energy security? Without a standardized set of metrics, it is difficult to determine the extent to which countries are properly responding to the emerging energy security challenges related to climate change: a growing dependency on fossil fuels, population growth, and economic development. In response, this article first surveys the academic literature on energy security and concludes that it is composed of availability, affordability, efficiency, and environmental stewardship. It then analyzes the relative energy security performance, based on these four dimensions, of the United States and 21 other member countries of the Organisation for Economic Co-operation and Development (OECD) from 1970 to 2007. Four countries are examined in greater detail: one of the strongest (Denmark), one of the most improved in terms of energy security (Japan), one with weak and stagnant energy security (United States), and one with deteriorating energy security (Spain). The article concludes by offering implications for public policy.

Water quality issues are a major challenge that humanity is facing in the twenty-first century. Here, we review the main groups of aquatic contaminants, their effects on human health, and approaches to mitigate pollution of freshwater resources. Emphasis is placed on chemical pollution, particularly on inorganic and organic micropollutants including toxic metals and metalloids as well as a large variety of synthetic organic chemicals. Some aspects of waterborne diseases and the urgent need for improved sanitation in developing countries are also discussed. The review addresses current scientific advances to cope with the great diversity of pollutants. It is organized along the different temporal and spatial scales of global water pollution. Persistent organic pollutants (POPs) have affected water systems on a global scale for more than five decades; during that time geogenic pollutants, mining operations, and hazardous waste sites have been the most relevant sources of long-term regional and local water pollution. Agricultural chemicals and waste-water sources exert shorter-term effects on regional to local scales.

Biological diversity of agriculture consists of several analytic levels and spatial management scales that are subject to complex interactions with global change. The complexity of interactions is related to the bidirectional impacts and influences of global land use and climate change in combination with social-environmental shifts (globalization of agricultural development; market integration; technological change; and regulation through global treaties, policies, and institutions). This article develops a conceptual framework of the complexity of interactions using four thematic nodes—biological diversity in agriculture; global change; management and scale; and social-environmental adaptation, vulnerability, and resilience. It argues for the increased relevance of this framework. Linking expanded scientific research and policy to this group of conceptual nodes yields insight into the impacts of global change on biological diversity in agriculture and into the design of conservation strategies, monitoring approaches, and sustainability policies. Future policy must anticipate interactions of biological diversity, agroecosystem complexity, and global change stemming from the acceleration and integration of region-scale land-use intensification and disintensification.

Contemporary urbanization differs from historical patterns of urban growth in terms of scale, rate, location, form, and function. This review discusses the characteristics of contemporary urbanization and the roles of urban planning, governance, agglomeration, and globalization forces in driving and shaping the relationship between urbanization and the environment. We highlight recent research on urbanization and global change in the context of sustainability as well as opportunities for bundling urban development efforts, climate mitigation, and adaptation strategies to create synergies to transition to sustainability. We conclude with an analysis of global greenhouse gas emissions under different scenarios of future urbanization growth and discuss their implications.

Developing more environmentally sustainable consumption and production systems depends upon consumers' willingness to engage in “greener” consumption behaviors. Research efforts have sought to identify, analyze, and understand the “green consumer.” Initial marketing and economics research, focusing on purchasing activities, has been complemented by research from fields such as industrial ecology and sociology, providing a more holistic picture of green consumption as a process. Much of the research has focused on areas with the greatest environmental impacts, namely peoples' homes and household management, their food choices and behaviors, and their transport behaviors for work, leisure, and travel. The emerging picture of green consumption is of a process that is strongly influenced by consumer values, norms, and habits, yet is highly complex, diverse, and context dependent. There are opportunities for future research that provides greater interdisciplinarity and challenges our assumptions and expectations about consumption and the nature of the consumer society.

Studies of the urban governance of climate change have proliferated over the past decade, as municipalities across the world increasingly place the issue on their agendas and private actors seek to respond to the issue. This review examines the history and development of urban climate governance, the policies and measures that have been put into place, the multilevel governance context in which these are undertaken, and the factors that have structured the posibilities for addressing the issue. It highlights the limits of existing work and the need for future research to provide more comprehensive analyses of the achievements and limitations of urban climate governance. It calls for engagement with alternative theoretical perspectives to understand how climate change is being governed in the city and the implications for urban governance, socioenvironmental justice, and the reconfiguration of political authority.

In the past half-century, the practice and study of global environmental politics and governance have been dramatically rescaled. They have become increasingly complex and interconnected with respect to the level (between local and global) at which they take place, the range of actors engaged in them, and the linkages between them and nominally nonenvironmental issues. Global environmental politics and governance have been rescaled vertically down toward provincial and municipal governments and up toward supranational regimes. They have also been rescaled horizontally across regional and sectoral organizations and networks and across new issues, such as development, security, and trade among others. This rescaling reflects shifts in the magnitude, complexity, and interconnectedness of the global environmental problems humans face as well as epistemological shifts in how humans understand and respond to these problems, and rescaling has implications for both the practice and study of global environmental politics.

At their core, societal decisions about climate policy—whether emissions reductions, adaptation to climate changes, or the implementation of geoengineering—hinge on collective judgments about the extent to which adverse effects to human welfare and ecosystem services will result from changes associated with anthropogenic release of greenhouse gases and the costs associated with the emissions reductions or adaptation activities. In this article, we discuss how risk is understood in the context of climate change, which presents particularly confounding, long-term, and pervasive threats to society and ecosystems. We review theoretical approaches to risk as applied to climate change and policy responses to climate change, focusing especially on the perspectives of individuals, governments, and firms with respect to traditional decision analysis frameworks. We also evaluate the peculiar role of uncertainty in climate debates and how it affects decision making; the origins and nature of the various uncertainties; and how uncertainty is represented, framed, and, at times, wielded by scientists, the Intergovernmental Panel on Climate Change (IPCC), the media, politicians, and others. We conclude by assessing the limitations of and appropriate venues for risk analysis in climate decision making.

The growing complexities of energy systems, environmental problems, and technology markets are driving and testing most energy-economy models to their limits. To further advance bottom-up models from a multidisciplinary energy efficiency policy evaluation perspective, we review and critically analyze bottom-up energy-economy models and corresponding evaluation studies on energy efficiency policies to induce technological change. We use the household sector as a case study. Our analysis focuses on decision frameworks for technology choice, type of evaluation being carried out, treatment of market and behavioral failures, evaluated policy instruments, and key determinants used to mimic policy instruments. Although the review confirms criticism related to energy-economy models (e.g., unrealistic representation of decision making by consumers when choosing technologies), they provide valuable guidance for policy evaluation related to energy efficiency. Different areas to further advance models remain open, particularly related to modeling issues, techno-economic and environmental aspects, behavioral determinants, and policy considerations.

This article reviews the state and evolution of the field of environmental history since about 1970. It focuses chiefly on the work of professional historians, but because environmental history is pursued by many varieties of scholars, it occasionally discusses the work of archeologists, geographers, and others. It offers a working definition of the field and an account of its origins, development, and institutionalization from the 1970s until 2010. It briefly surveys the literature on several world regions, concentrating most heavily on South Asia and Latin America, where environmental history at present has grown especially lively. It considers the prominence of Americanists (that is, historians of the United States, not the same thing as Americans) in the field and how that prominence is now waning. It reviews the utility of environmental history for historians, sketches some of the critiques of environmental history, and comments upon some signal findings of recent years.