The emergence of environment as a security imperative is something that could have been avoided. Early indications showed that if governments did not pay attention to critical environmental issues, these would move up the security agenda. As far back as the Club of Rome 1972 report, Limits to Growth, variables highlighted for policy makers included world population, industrialization, pollution, food production, and resource depletion, all of which impact how we live on this planet.
The term environmental security didn’t come into general use until the 2000s. It had its first substantive framing in 1977, with the Lester Brown Worldwatch Paper 14, “Redefining Security.” Brown argued that the traditional view of national security was based on the “assumption that the principal threat to security comes from other nations.” He went on to argue that future security “may now arise less from the relationship of nation to nation and more from the relationship between man to nature.”
Of the major documents to come out of the Earth Summit in 1992, the Rio Declaration on Environment and Development is probably the first time governments have tried to frame environmental security. Principle 2 says: “States have, in accordance with the Charter of the United Nations and the principles of international law, the sovereign right to exploit their own resources pursuant to their own environmental and developmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other States or of areas beyond the limits of national.”
In 1994, the UN Development Program defined Human Security into distinct categories, including:
• Economic security (assured and adequate basic incomes).
• Food security (physical and affordable access to food).
• Health security.
• Environmental security (access to safe water, clean air and non-degraded land).
By the time of the World Summit on Sustainable Development, in 2002, water had begun to be identified as a security issue, first at the Rio+5 conference, and as a food security issue at the 1996 FAO Summit. In 2003, UN Secretary General Kofi Annan set up a High-Level Panel on “Threats, Challenges, and Change,” to help the UN prevent and remove threats to peace. It started to lay down new concepts on collective security, identifying six clusters for member states to consider. These included economic and social threats, such as poverty, infectious disease, and environmental degradation.
By 2007, health was being recognized as a part of the environmental security discourse, with World Health Day celebrating “International Health Security (IHS).” In particular, it looked at emerging diseases, economic stability, international crises, humanitarian emergencies, and chemical, radioactive, and biological terror threats. Environmental and climate changes have a growing impact on health. The 2007 Fourth Assessment Report (AR4) of the UN Intergovernmental Panel on Climate Change (IPCC) identified climate security as a key challenge for the 21st century. This was followed up in 2009 by the UCL-Lancet Commission on Managing the Health Effects of Climate Change—linking health and climate change.
In the run-up to Rio+20 and the launch of the Sustainable Development Goals, the issue of the climate-food-water-energy nexus, or rather, inter-linkages, between these issues was highlighted. The dialogue on environmental security has moved from a fringe discussion to being central to our political discourse—this is because of the lack of implementation of previous international agreements.
Vincent Moreau and Guillaume Massard
The concept of metabolism takes root in biology and ecology as a systematic way to account for material flows in organisms and ecosystems. Early applications of the concept attempted to quantify the amount of water and food the human body processes to live and sustain itself. Similarly, ecologists have long studied the metabolism of critical substances and nutrients in ecological succession towards climax. With industrialization, the material and energy requirements of modern economic activities have grown exponentially, together with emissions to the air, water and soil. From an analogy with ecosystems, the concept of metabolism grew into an analytical methodology for economic systems.
Research in the field of material flow analysis has developed approaches to modeling economic systems by assessing the stocks and flows of substances and materials for systems defined in space and time. Material flow analysis encompasses different methods: industrial and urban metabolism, input–output analysis, economy-wide material flow accounting, socioeconomic metabolism, and more recently material flow cost accounting. Each method has specific scales, reference substances such as metals, and indicators such as concentration. A material flow analysis study usually consists of a total of four consecutive steps: (a) system definition, (b) data acquisition, (c) calculation, and (d) interpretation. The law of conservation of mass underlies every application, which implies that all material flows, as well as stocks, must be accounted for.
In the early 21st century, material depletion, accumulation, and recycling are well-established cases of material flow analysis. Diagnostics and forecasts, as well as historical or backcast analyses, are ideally performed in a material flow analysis, to identify shifts in material consumption for product life cycles or physical accounting and to evaluate the material and energy performance of specific systems.
In practice, material flow analysis supports policy and decision making in urban planning, energy planning, economic and environmental performance, development of industrial symbiosis and eco industrial parks, closing material loops and circular economy, pollution remediation/control and material and energy supply security. Although material flow analysis assesses the amount and fate of materials and energy rather than their environmental or human health impacts, a tacit assumption states that reduced material throughputs limit such impacts.
Christopher Morgan, Shannon Tushingham, Raven Garvey, Loukas Barton, and Robert Bettinger
At the global scale, conceptions of hunter-gatherer economies have changed considerably over time and these changes were strongly affected by larger trends in Western history, philosophy, science, and culture. Seen as either “savage” or “noble” at the dawn of the Enlightenment, hunter-gatherers have been regarded as everything from holdovers from a basal level of human development, to affluent, ecologically-informed foragers, and ultimately to this: an extremely diverse economic orientation entailing the fullest scope of human behavioral diversity. The only thing linking studies of hunter-gatherers over time is consequently simply the definition of the term: people whose economic mode of production centers on wild resources. When hunter-gatherers are considered outside the general realm of their shared subsistence economies, it is clear that their behavioral diversity rivals or exceeds that of other economic orientations. Hunter-gatherer behaviors range in a multivariate continuum from: a focus on mainly large fauna to broad, wild plant-based diets similar to those of agriculturalists; from extremely mobile to sedentary; from relying on simple, generalized technologies to very specialized ones; from egalitarian sharing economies to privatized competitive ones; and from nuclear family or band-level to centralized and hierarchical decision-making. It is clear, however, that hunting and gathering modes of production had to have preceded and thus given rise to agricultural ones. What research into the development of human economies shows is that transitions from one type of hunting and gathering to another, or alternatively to agricultural modes of production, can take many different evolutionary pathways. The important thing to recognize is that behaviors which were essential to the development of agriculture—landscape modification, intensive labor practices, the division of labor and the production, storage, and redistribution of surplus—were present in a range of hunter-gatherer societies beginning at least as early as the Late Pleistocene in Africa, Europe, Asia, and the Americas. Whether these behaviors eventually led to the development of agriculture depended in part on the development of a less variable and CO2-rich climatic regime and atmosphere during the Holocene, but also a change in the social relations of production to allow for hoarding privatized resources. In the 20th and 21st centuries, ethnographic and archaeological research shows that modern and ancient peoples adopt or even revert to hunting and gathering after having engaged in agricultural or industrial pursuits when conditions allow and that macroeconomic perspectives often mask considerable intragroup diversity in economic decision making: the pursuits and goals of women versus men and young versus old within groups are often quite different or even at odds with one another, but often articulate to form cohesive and adaptive economic wholes. The future of hunter-gatherer research will be tested by the continued decline in traditional hunting and gathering but will also benefit from observation of people who revert to or supplement their income with wild resources. It will also draw heavily from archaeology, which holds considerable potential to document and explain the full range of human behavioral diversity, hunter-gatherer or otherwise, over the longest of timeframes and the broadest geographic scope.
Richard G. Lawford and Sushel Unninayar
The global water cycle concept has its roots in the ancient understanding of nature. Indeed, the Greeks and Hebrews documented some of the most some important hydrological processes. Furthermore, Africa, Sri Lanka, and China all have archaeological evidence to show the sophisticated nature of water management that took place thousands of years ago. During the 20th century, a broader perspective was taken and the hydrological cycle was used to describe the terrestrial and freshwater component of the global water cycle. Data analysis systems and modeling protocols were developed to provide the information needed to efficiently manage water resources. These advances were helpful in defining the water in the soil and the movement of water between stores of water over land surfaces. Atmospheric inputs to these balances were also monitored, but the measurements were much more reliable over countries with dense networks of precipitation gauges and radiosonde observations.
By the 1960s, early satellites began to provide images that gave a new perception of Earth processes, including a more complete realization that water cycle components and processes were continuous in space and could not be fully understood through analyses partitioned by geopolitical or topographical boundaries. In the 1970s, satellites delivered quantitative radiometric measurements that allowed for the estimation of a number of variables such as precipitation and soil moisture. In the United States, by the late 1970s, plans were made to launch the Earth System Science program, led by the National Aeronautics and Space Agency (NASA). The water component of this program integrated terrestrial and atmospheric components and provided linkages with the oceanic component so that a truly global perspective of the water cycle could be developed. At the same time, the role of regional and local hydrological processes within the integrated “global water cycle” began to be understood.
Benefits of this approach were immediate. The connections between the water and energy cycles gave rise to the Global Energy and Water Cycle Experiment (GEWEX)1 as part of the World Climate Research Programme (WCRP). This integrated approach has improved our understanding of the coupled global water/energy system, leading to improved prediction models and more accurate assessments of climate variability and change. The global water cycle has also provided incentives and a framework for further improvements in the measurement of variables such as soil moisture, evapotranspiration, and precipitation. In the past two decades, groundwater has been added to the suite of water cycle variables that can be measured from space. New studies are testing innovative space-based technologies for high-resolution surface water level measurements. While many benefits have followed from the application of the global water cycle concept, its potential is still being developed. Increasingly, the global water cycle is assisting in understanding broad linkages with other global biogeochemical cycles, such as the nitrogen and carbon cycles. Applications of this concept to emerging program priorities, including the Sustainable Development Goals (SDGs) and the Water-Energy-Food (W-E-F) Nexus, are also yielding societal benefits.
Elisabet Lindgren and Thomas Elmqvist
Ecosystem services refer to benefits for human societies and well-being obtained from ecosystems. Research on health effects of ecosystem services have until recently mostly focused on beneficial effects on physical and mental health from spending time in nature or having access to urban green space. However, nearly all of the different ecosystem services may have impacts on health, either directly or indirectly. Ecosystem services can be divided into provisioning services that provide food and water; regulating services that provide, for example, clean air, moderate extreme events, and regulate the local climate; supporting services that help maintain biodiversity and infectious disease control; and cultural services.
With a rapidly growing global population, the demand for food and water will increase. Knowledge about ecosystems will provide opportunities for sustainable agriculture production in both terrestrial and marine environments. Diarrheal diseases and associated childhood deaths are strongly linked to poor water quality, sanitation, and hygiene. Even though improvements are being made, nearly 750 million people still lack access to reliable water sources. Ecosystems such as forests, wetlands, and lakes capture, filter, and store water used for drinking, irrigation, and other human purposes. Wetlands also store and treat solid waste and wastewater, and such ecosystem services could become of increasing use for sustainable development.
Ecosystems contribute to local climate regulation and are of importance for climate change mitigation and adaptation. Coastal ecosystems, such as mangrove and coral reefs, act as natural barriers against storm surges and flooding. Flooding is associated with increased risk of deaths, epidemic outbreaks, and negative health impacts from destroyed infrastructure. Vegetation reduces the risk of flooding, also in cities, by increasing permeability and reducing surface runoff following precipitation events.
The urban heat island effect will increase city-center temperatures during heatwaves. The elderly, people with chronic cardiovascular and respiratory diseases, and outdoor workers in cities where temperatures soar during heatwaves are in particular vulnerable to heat. Vegetation and especially trees help in different ways to reduce temperatures by shading and evapotranspiration. Air pollution increases the mortality and morbidity risks during heatwaves. Vegetation has been shown also to contribute to improved air quality by, depending on plant species, filtering out gases and airborne particulates. Greenery also has a noise-reducing effect, thereby decreasing noise-related illnesses and annoyances. Biological control uses the knowledge of ecosystems and biodiversity to help control human and animal diseases.
Natural surroundings and urban parks and gardens have direct beneficial effects on people’s physical and mental health and well-being. Increased physical activities have well-known health benefits. Spending time in natural environments has also been linked to aesthetic benefits, life enrichments, social cohesion, and spiritual experience. Even living close to or with a view of nature has been shown to reduce stress and increase a sense of well-being.
Confidence in the projected impacts of climate change on agricultural systems has increased substantially since the first Intergovernmental Panel on Climate Change (IPCC) reports. In Africa, much work has gone into downscaling global climate models to understand regional impacts, but there remains a dearth of local level understanding of impacts and communities’ capacity to adapt. It is well understood that Africa is vulnerable to climate change, not only because of its high exposure to climate change, but also because many African communities lack the capacity to respond or adapt to the impacts of climate change. Warming trends have already become evident across the continent, and it is likely that the continent’s 2000 mean annual temperature change will exceed +2°C by 2100. Added to this warming trend, changes in precipitation patterns are also of concern: Even if rainfall remains constant, due to increasing temperatures, existing water stress will be amplified, putting even more pressure on agricultural systems, especially in semiarid areas. In general, high temperatures and changes in rainfall patterns are likely to reduce cereal crop productivity, and new evidence is emerging that high-value perennial crops will also be negatively impacted by rising temperatures. Pressures from pests, weeds, and diseases are also expected to increase, with detrimental effects on crops and livestock.
Much of African agriculture’s vulnerability to climate change lies in the fact that its agricultural systems remain largely rain-fed and underdeveloped, as the majority of Africa’s farmers are small-scale farmers with few financial resources, limited access to infrastructure, and disparate access to information. At the same time, as these systems are highly reliant on their environment, and farmers are dependent on farming for their livelihoods, their diversity, context specificity, and the existence of generations of traditional knowledge offer elements of resilience in the face of climate change. Overall, however, the combination of climatic and nonclimatic drivers and stressors will exacerbate the vulnerability of Africa’s agricultural systems to climate change, but the impacts will not be universally felt. Climate change will impact farmers and their agricultural systems in different ways, and adapting to these impacts will need to be context-specific.
Current adaptation efforts on the continent are increasing across the continent, but it is expected that in the long term these will be insufficient in enabling communities to cope with the changes due to longer-term climate change. African famers are increasingly adopting a variety of conservation and agroecological practices such as agroforestry, contouring, terracing, mulching, and no-till. These practices have the twin benefits of lowering carbon emissions while adapting to climate change as well as broadening the sources of livelihoods for poor farmers, but there are constraints to their widespread adoption. These challenges vary from insecure land tenure to difficulties with knowledge-sharing.
While African agriculture faces exposure to climate change as well as broader socioeconomic and political challenges, many of its diverse agricultural systems remain resilient. As the continent with the highest population growth rate, rapid urbanization trends, and rising GDP in many countries, Africa’s agricultural systems will need to become adaptive to more than just climate change as the uncertainties of the 21st century unfold.
David E. Clay, Sharon A. Clay, Thomas DeSutter, and Cheryl Reese
Since the discovery that food security could be improved by pushing seeds into the soil and later harvesting a desirable crop, agriculture and agronomy have gone through cycles of discovery, implementation, and innovation. Discoveries have produced predicted and unpredicted impacts on the production and consumption of locally produced foods. Changes in technology, such as the development of the self-cleaning steel plow in the 18th century, provided a critical tool needed to cultivate and seed annual crops in the Great Plains of North America. However, plowing the Great Plains would not have been possible without the domestication of plants and animals and the discovery of the yoke and harness. Associated with plowing the prairies were extensive soil nutrient mining, a rapid loss of soil carbon, and increased wind and water erosion. More recently, the development of genetically modified organisms (GMOs) and no-tillage planters has contributed to increased adoption of conservation tillage, which is less damaging to the soil. In the future, the ultimate impact of climate change on agronomic practices in the North American Great Plains is unknown. However, projected increasing temperatures and decreased rainfall in the southern Great Plains (SGP) will likely reduce agricultural productivity. Different results are likely in the northern Great Plains (NGP) where higher temperatures can lead to increased agricultural intensification, the conversion of grassland to cropland, increased wildlife fragmentation, and increased soil erosion. Precision farming, conservation, cover crops, and the creation of plants better designed to their local environment can help mitigate these effects. However, changing practices require that farmers and their advisers understand the limitations of the soils, plants, and environment, and their production systems. Failure to implement appropriate management practices can result in a rapid decline in soil productivity, diminished water quality, and reduced wildlife habitat.
Resilience thinking in relation to the environment has emerged as a lens of inquiry that serves a platform for interdisciplinary dialogue and collaboration. Resilience is about cultivating the capacity to sustain development in the face of expected and surprising change and diverse pathways of development and potential thresholds between them. The evolution of resilience thinking is coupled to social-ecological systems and a truly intertwined human-environment planet. Resilience as persistence, adaptability and, transformability of complex adaptive social-ecological systems is the focus, clarifying the dynamic and forward-looking nature of the concept. Resilience thinking emphasizes that social-ecological systems, from the individual, to community, to society as a whole, are embedded in the biosphere. The biosphere connection is an essential observation if sustainability is to be taken seriously. In the continuous advancement of resilience thinking there are efforts aimed at capturing resilience of social-ecological systems and finding ways for people and institutions to govern social-ecological dynamics for improved human well-being, at the local, across levels and scales, to the global. Consequently, in resilience thinking, development issues for human well-being, for people and planet, are framed in a context of understanding and governing complex social-ecological dynamics for sustainability as part of a dynamic biosphere.
Although the concept of biodiversity emerged 30 years ago, patterns and processes influencing ecological diversity have been studied for more than a century. Historically, ecological processes tended to be considered as occurring in local habitats that were spatially homogeneous and temporally at equilibrium. Initially considered as a constraint to be avoided in ecological studies, spatial heterogeneity was progressively recognized as critical for biodiversity. This resulted, in the 1970s, in the emergence of a new discipline, landscape ecology, whose major goal is to understand how spatial and temporal heterogeneity influence biodiversity. To achieve this goal, researchers came to realize that a fundamental issue revolves around how they choose to conceptualize and measure heterogeneity. Indeed, observed landscape patterns and their apparent relationship with biodiversity often depend on the scale of observation and the model used to describe the landscape. Due to the strong influence of island biogeography, landscape ecology has focused primarily on spatial heterogeneity. Several landscape models were conceptualized, allowing for the prediction and testing of distinct but complementary effects of landscape heterogeneity on species diversity. We now have ample empirical evidence that patch structure, patch context, and mosaic heterogeneity all influence biodiversity. More recently, the increasing recognition of the role of temporal scale has led to the development of new conceptual frameworks acknowledging that landscapes are not only heterogeneous but also dynamic. The current challenge remains to truly integrate both spatial and temporal heterogeneity in studies on biodiversity. This integration is even more challenging when considering that biodiversity often responds to environmental changes with considerable time lags, and multiple drivers of global changes are interacting, resulting in non-additive and sometimes antagonistic effects. Recent technological advances in remote sensing, the availability of massive amounts of data, and long-term studies represent, however, very promising avenues to improve our understanding of how spatial and temporal heterogeneity influence biodiversity.
Leon C. Braat
The concept of ecosystem services considers the usefulness of nature for human society. The economic importance of nature was described and analyzed in the 18th century, but the term ecosystem services was introduced only in 1981. Since then it has spurred an increasing number of academic publications, international research projects, and policy studies. Now a subject of intense debate in the global scientific community, from the natural to social science domains, it is also used, developed, and customized in policy arenas and considered, if in a still somewhat skeptical and apprehensive way, in the “practice” domain—by nature management agencies, farmers, foresters, and corporate business. This process of bridging evident gaps between ecology and economics, and between nature conservation and economic development, has also been felt in the political arena, including in the United Nations and the European Union (which have placed it at the center of their nature conservation and sustainable use strategies).
The concept involves the utilitarian framing of those functions of nature that are used by humans and considered beneficial to society as economic and social services. In this light, for example, the disappearance of biodiversity directly affects ecosystem functions that underpin critical services for human well-being. More generally, the concept can be defined in this manner: Ecosystem services are the direct and indirect contributions of ecosystems, in interaction with contributions from human society, to human well-being.
The concept underpins four major discussions: (1) Academic: the ecological versus the economic dimensions of the goods and services that flow from ecosystems to the human economy; the challenge of integrating concepts and models across this paradigmatic divide; (2) Social: the risks versus benefits of bringing the utilitarian argument into political debates about nature conservation (Are ecosystem services good or bad for biodiversity and vice versa?); (3) Policy and planning: how to value the benefits from natural capital and ecosystem services (Will this improve decision-making on topics ranging from poverty alleviation via subsidies to farmers to planning of grey with green infrastructure to combining economic growth with nature conservation?); and (4) Practice: Can revenue come from smart management and sustainable use of ecosystems? Are there markets to be discovered and can businesses be created? How do taxes figure in an ecosystem-based economy? The outcomes of these discussions will both help to shape policy and planning of economies at global, national, and regional scales and contribute to the long-term survival and well-being of humanity.