Annual Review of Environment and Resources - Volume 39, 2014

Australia is a mineral-rich country with low and variable rainfall and, hence, biological productivity, as well as a predominately coastal population. Since European settlement in 1788, a range of landscape impacts, species introductions, and freshwater conflicts have led to serious environmental issues. Contemporary drivers of environmental change include population growth and associated development; water use for food production; resource extraction by the fishery, forestry, mining, and oil and gas industries; and climate change. A range of international agreements have influenced domestic environmental policy, culminating in Australia's foremost piece of environmental legislation, the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. Despite sound legislative instruments and policy intentions, a range of contemporary environmental issues associated with coal seam gas extraction, freshwater allocation, fisheries, and climate change illustrate that shortcomings in resolving environmental issues and obstacles remain with regard to improving the status of the environment. Given the increasing pressures on the environment, greater oversight and efficient enforcement are needed, particularly given population projections and plans for economic development.

Sustainability and gender have been prominent on the development agenda since the 1980s, but there has been little systematic study of the links between the two. This review draws on ecofeminist theory, feminist political ecology, intrahousehold literature, and natural resource management case studies and reviews to examine how gender shapes the motives, means, and opportunities for men and women to contribute to sustainability. Particular attention is given to evidence on closeness to nature, focus on conservation, rights to resources, opportunities to exploit resources, and constraints to adoption of sustainable practices. Despite early claims that women are naturally more conserving of resources, the empirical literature, in particular, gives a more mixed and nuanced picture. Conservation is influenced not only by gender but also by a host of tangible and intangible factors, including local ecology, context, and culture, that affect incentives and the ability to adopt sustainable extraction and provision practices.

Arctic sea ice decline has led to an amplification of surface warming and is projected to continue to decline from anthropogenic forcing, although the exact timing of ice-free summers is uncertain owing to large natural variability. Sea ice reductions affect surface heating patterns and the atmospheric pressure distribution, which may alter midlatitude extreme weather patterns. Increased light penetration and nutrient availability during spring from earlier ice breakup enhances primary production in the Arctic Ocean and its adjacent shelf seas. Ice-obligate marine mammals may be losers, whereas seasonally migrant species may be winners from rapid sea ice decline. Tundra greening is occurring across most of the Arctic, driven primarily by warming temperatures, and is displaying complex spatial patterns that are likely tied to other factors. Sea ice changes are affecting greenhouse gas exchanges as well as halogen chemistry in the Arctic. This review highlights the heterogeneous nature of Arctic change, which is vital for researchers to better understand.

The land surface comprises the smallest areal fraction of the Earth system's major components (e.g., versus atmosphere or ocean with cryosphere). As such, how is it that some of the largest sources of uncertainty in future climate projections are found in the terrestrial biosphere? This uncertainty stems from how the terrestrial biosphere is modeled with respect to the myriad of biogeochemical, physical, and dynamic processes represented (or not) in numerous models that contribute to projections of Earth's future. Here, we provide an overview of the processes included in terrestrial biosphere models (TBMs), including various approaches to representing any one given process, as well as the processes that are missing and/or uncertain. We complement this with a comprehensive review of individual TBMs, marking the differences, uniqueness, and recent and planned developments. To conclude, we summarize the latest results in benchmarking activities, particularly as linked to recent model intercomparison projects, and outline a path forward to reducing uncertainty in the contribution of the terrestrial biosphere to global atmospheric change.

The Anthropocene is characterized as an epoch when human influence has begun to fundamentally alter many aspects of the Earth system and many of the planet's biomes. Here, we review and synthesize our understanding of Anthropocene changes in tropical forests. Key facets include deforestation driven by agricultural expansion, timber and wood extraction, the loss of fauna that maintain critical ecological connections, the spread of fire, landscape fragmentation, the spread of second-growth forests, new species invasion and pathogen spread, increasing CO2, and climate change. The patterns of change are spatially heterogeneous, are often characterized by strong interactions among different drivers, can have both large-scale and remote effects, and can play out through ecological cascades over long timescales. As a consequence, most tropical forests are on a trajectory to becoming altered ecosystems, with the degree of alteration dependent on the intensity and duration of the current bottleneck of human-induced pressures. We highlight the importance of this understanding to develop the strategies necessary for shaping the transition of tropical forests through the early Anthropocene, as well as highlight the opportunities and challenges for the tropical forest science community in the coming decades.

Phosphorus security is emerging as one of the twenty-first century's greatest global sustainability challenges. Phosphorus has no substitute in food production, and the use of phosphate fertilizers in the past 50 years has boosted crop yields and helped feed billions of people. However, these advantages have come at a serious cost. Mobilizing phosphate rock into the environment at rates vastly faster than the natural cycle has not only polluted many of the world's freshwater bodies and oceans, but has also created a human dependence on a single nonrenewable resource. The 2008 phosphate price spike attracted unprecedented attention to this global situation. This review provides an updated and integrated synthesis of the biophysical, social, geopolitical, and institutional challenges and opportunities for food security. Remaining phosphorus resources are becoming increasingly scarce, expensive, and inequitably distributed. All farmers require fertilizers, yet a sixth of the world's farmers and their families are too poor to access fertilizer markets. Inefficient use of this fossil resource from mine to field to fork calls for substantial reduction in demand through efficiency and recycling. Phosphorus governance at global, regional, and local scales is required to stimulate and support context-specific sustainable strategies to ensure all the world's farmers have sufficient access to phosphorus to feed the world and ensure ecosystem integrity and farmer livelihoods.

Tropical intraseasonal variability (TISV) of the atmosphere describes the coherent variability in basic state variables, including pressure, wind, temperature, and humidity, as well as in the physical phenomena associated with the covariability of these parameters, such as rainfall and cloudiness, over synoptic (∼1,000 km, ∼1–10 days) to planetary (∼10,000 km, ∼10–100 days) scales. In the past, the characteristics of individual TISV modes were studied separately, and much has been learned from this approach. More recent studies have increasingly focused on the multiscale nature of these modes, leading to exciting new developments in our understanding of tropical meteorology. This article reviews the most recent observations of TISV and its associated impacts on regional weather, short-term climate patterns, and atmospheric chemical transports, as well as the ability of numerical models to capture these interacting modes of variability. We also suggest where the field might focus its efforts in the future.

Rangelands cover more of Earth's land surface than any other type of land. They have variable and harsh climates, are sparsely populated and remote from markets, produce significant quantities of livestock, and are mostly used and managed in common. Under this already unpredictable and harsh climate, pastoral peoples and rangelands face new and accelerating political, economic, and climatic stresses that challenge their coupled resilience and ability to adapt. In response, pastoralists are creating new ways to manage rangelands through conservancies and community-based institutions on state, common, and private land. In this review, we focus on recent advances in our understanding of rangeland social-ecological systems, as well as on the causes and consequences of change in these systems. We then explore how pastoral peoples, governments, and businesses are responding to these changes to build resilience to sustain both pastoralism and rangelands. We close with a description of unresolved issues, challenges, and questions for the future.

Almost 20 years ago, the first CO2 capture and storage (CCS) project began injecting CO2 into a deep geological formation in an offshore aquifer. Relevant science has advanced in areas such as chemical engineering, geophysics, and social psychology. Governments have generously funded demonstrations. As a result, a handful of industrial-scale CCS projects are currently injecting about 15 megatons of CO2 underground annually that contribute to climate change mitigation. However, CCS is struggling to gain a foothold in the set of options for dealing with climate change. This review explores why and discusses critical conditions for CCS to emerge as a viable mitigation option. Explanations for this struggle include the absence of government action on climate change, economic crisis–induced low carbon prices, public skepticism, increasing costs, and advances in other options including renewables and shale gas. Climate change action is identified as a critical condition for progress in CCS, in addition to community support, safe storage, robust policy support, and favorable CCS market conditions.

This review discusses research on linkages between biofuels, agriculture, and food security. The literature indicates that biofuel expansion affects land use, puts pressure on food and feed markets, and modestly reduces greenhouse gas emissions. Researchers readily identify these outcomes, as well as the multitude of factors besides biofuels that have driven up food prices in recent years. However, precision in quantifying the extent of the impacts and in attributing effects to various drivers is elusive, resulting in a wide range of estimates. Nevertheless, the central tendency is that a food-versus-fuel trade-off is created through biofuel production from food crops, and the continued expansion of biofuel production increases food commodity prices, reduces the availability of calories, and increases malnourishment in developing countries. Higher food prices particularly reduce the poor's access to food, which has possible long-term, irreversible consequences for health, productivity, and well-being.

Global transportation energy use is steeply rising, mainly as a result of increasing population and economic activity. Petroleum fuels remain the dominant energy source, reflecting advantages such as high energy density, low cost, and market availability. The movement of people and freight makes a major contribution to economic development and social well-being, but it also negatively impacts climate change, air quality, health, social cohesion, and safety. Following a review published 20 years ago in the Annual Review of Environment and Resources (then named the Annual Review of Energy and the Environment) by Lee Schipper, we examine current trends and potential futures, revising several major global transport/energy reports. There are significant opportunities to slow travel growth and improve efficiency. Alternatives to petroleum exist but have different characteristics in terms of availability, cost, distribution, infrastructure, storage, and public acceptability. The transition to low-carbon equitable and sustainable transport will take time but can be fostered by numerous short- and medium-term strategies that would benefit energy security, health, productivity, and sustainability.

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

Economic and population growth result in increasing use of biophysical resources, including land and biomass. Human activities influence the biological productivity of land, altering material and energy flows in the biosphere. The human appropriation of net primary production (HANPP) is an integrated socioecological indicator quantifying effects of human-induced changes in productivity and harvest on ecological biomass flows. We discuss how HANPP is defined, measured, and interpreted. Two principal approaches for constructing HANPP assessments exist: (a) In an area-specific approach, HANPP serves as an indicator of land-use intensity, gauging impacts on terrestrial ecosystems in a defined area; and (b) the consumption-based “embodied HANPP” approach allows assessment of impacts related to individual products or the aggregate consumption of nation-states. The HANPP framework can help to estimate upper limits for the biosphere's capacity to provide humanity with biomass for food, fiber, and bioenergy and to analyze systemic feedbacks between the delivery of these resources. We outline HANPP's global patterns and trajectories and how HANPP relates to planetary boundaries, global resource use, and pressures on biodiversity.

Energy efficiency policies are pursued as a way to provide affordable and sustainable energy services. Efficiency measures that reduce energy service costs will free up resources that can be spent in the form of increased consumption—either of that same good or service or of other goods and services that require energy (and that have associated emissions). This is called the rebound effect. There is still significant ambiguity about how the rebound effect should be defined, how we can measure it, and how we can characterize its uncertainty. Occasionally the debate regarding its importance reemerges, in part because the existing studies are not easily comparable. The scope, region, end-uses, time period of analysis, and drivers for efficiency improvements all differ widely from study to study. As a result, listing one single number for rebound effects would be misleading. Rebound effects are likely to depend on the specific attributes of the policies that trigger the efficiency improvement, but such factors are often ignored. Implications for welfare changes resulting from rebound have also been largely ignored in the literature until recently.

Environmental ethics—the study of ethical questions raised by human relations with the nonhuman environment—emerged as an important subfield of philosophy during the 1970s. It is now a flourishing area of research. This article provides a review of the secular, Western traditions in the field. It examines both anthropocentric and nonanthropocentric claims about what has value, as well as divergent views about whether environmental ethics should be concerned with bringing about best consequences, respecting principles and rights, or embodying environmental virtues. The article also briefly considers two critical traditions—ecofeminism and environmental pragmatism—and explores some of the difficult environmental ethics questions posed by anthropogenic climate change.

Humanity faces an unprecedented set of global environmental problems. We argue that to promote pro-environmental decisions and to achieve public consensus on the need for action we must address individual and collective understanding (cognition) of environmental problems, as well as individual and collective commitments to take action to mitigate or prevent those problems. We review literature pertaining to psychological predispositions, mental models, framing, psychological distance, and the social context of decisions that help elucidate how these goals of cognition and commitment can be achieved. This article reveals the complex and multiply determined nature of environmental decisions. However, we argue that this complexity points to opportunities to reduce the inherent uncertainty surrounding global environmental challenges via appeals to the psychological mechanisms that underpin our decisions.

This article reviews the literature relevant to market environmentalism in the water sector, focusing on five themes: the privatization of resource ownership and management, the commercialization of resource management organizations, the environmental valuation and pricing of resources, the marketization of trading and exchange mechanisms, and the liberalization of governance. For each dimension, the discussion addresses a topic of contemporary academic interest (and policy and political relevance): privatization and protest, the contradictions of commercialization, the distinction between environmental valuation and commodification, the multiplication of modes of marketization, and the limits to the liberalization of environmental governance. Specific attention is given to unresolved questions and tensions in the debate over market environmentalism, particularly the tension between human rights and environmental rights and among state, market, and community roles in water management.

Inspired by the success of evidence-based medicine, environmental scholars and practitioners have grown enthusiastic about applying a similar evidence-based approach to solve some of the world's most pressing environmental problems. An important component of the evidence-based movement is the empirical evaluation of program and policy impacts. Impact evaluations draw heavily from recent advances in the empirical study of causal relationships—the effect of one thing on another. This review highlights the key components of these advances and characterizes the way in which they contribute to better evaluations of the environmental and social impacts of environmental programs. The review emphasizes that a solid understanding of these advances is required before environmental scholars and practitioners can begin to collect the relevant data, analyze them within credible research designs, and generate reliable evidence about the effectiveness of the myriad proposed solutions to the world's environmental and social problems.