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- Environmental Science x
Tamara Shapiro Ledley, Juliette Rooney-Varga, and Frank Niepold
The scientific community has made the urgent need to mitigate climate change clear and, with the ratification of the Paris Agreement under the United Nations Framework Convention on Climate Change, the international community has formally accepted ambitious mitigation goals. However, a wide gap remains between the aspirational emissions reduction goals of the Paris Agreement and the real-world pledges and actions of nations that are party to it. Closing that emissions gap can only be achieved if a similarly wide gap between scientific and societal understanding of climate change is also closed.
Several fundamental aspects of climate change make clear both the need for education and the opportunity it offers. First, addressing climate change will require action at all levels of society, including individuals, organizations, businesses, local, state, and national governments, and international bodies. It cannot be addressed by a few individuals with privileged access to information, but rather requires transfer of knowledge, both intellectually and affectively, to decision-makers and their constituents at all levels. Second, education is needed because, in the case of climate change, learning from experience is learning too late. The delay between decisions that cause climate change and their full societal impact can range from decades to millennia. As a result, learning from education, rather than experience, is necessary to avoid those impacts.
Climate change and sustainability represent complex, dynamic systems that demand a systems thinking approach. Systems thinking takes a holistic, long-term perspective that focuses on relationships between interacting parts, and how those relationships generate behavior over time. System dynamics includes formal mapping and modeling of systems, to improve understanding of the behavior of complex systems as well as how they respond to human or other interventions. Systems approaches are increasingly seen as critical to climate change education, as the human and natural systems involved in climate change epitomize a complex, dynamic problem that crosses disciplines and societal sectors.
A systems thinking approach can also be used to examine the potential for education to serve as a vehicle for societal change. In particular, education can enable society to benefit from climate change science by transferring scientific knowledge across societal sectors. Education plays a central role in several processes that can accelerate social change and climate change mitigation. Effective climate change education increases the number of informed and engaged citizens, building social will or pressure to shape policy, and building a workforce for a low-carbon economy. Indeed, several climate change education efforts to date have delivered gains in climate and energy knowledge, affect, and/or motivation. However, society still faces challenges in coordinating initiatives across audiences, managing and leveraging resources, and making effective investments at a scale that is commensurate with the climate change challenge. Education is needed to promote informed decision-making at all levels of society.
Zhanqing Li, Daniel Rosenfeld, and Jiwen Fan
Aerosols (tiny solid or liquid particles suspended in the atmosphere) have been in the forefront of environmental and climate change sciences as the primary atmospheric pollutant and external force affecting Earth’s weather and climate. There are two dominant mechanisms by which aerosols affect weather and climate: aerosol-radiation interactions (ARIs) and aerosol-cloud interactions (ACIs). ARIs arise from aerosol scattering and absorption, which alter the radiation budgets of the atmosphere and surface, while ACIs are connected to the fact that aerosols serve as cloud condensation nuclei and ice nuclei. Both ARIs and ACIs are coupled with atmospheric dynamics to produce a chain of complex interactions with a large range of meteorological variables that influence both weather and climate. Elaborated here are the impacts of aerosols on the radiation budget, clouds (microphysics, structure, and lifetime), precipitation, and severe weather events (lightning, thunderstorms, hail, and tornadoes). Depending on environmental variables and aerosol properties, the effects can be both positive and negative, posing the largest uncertainties in the external forcing of the climate system. This has considerably hindered the ability to project future climate changes and make accurate numerical weather predictions.
Along with ceramics production, sedentism, and herding, agriculture is a major component of the Neolithic as it is defined in Europe. Therefore, the agricultural system of the first Neolithic societies and the dispersal of exogenous cultivated plants to Europe are the subject of many scientific studies. To work on these issues, archaeobotanists rely on residual plant remains—crop seeds, weeds, and wild plants—from archaeological structures like detritic pits, and, less often, storage contexts. To date, no plant with an economic value has been identified as domesticated in Western Europe except possibly opium poppy. The earliest seeds identified at archaeological sites dated to about 5500–5200
The Neolithic pioneers settled in an area that had experienced a long tradition of hunting and gathering. The Neolithization of Europe followed a colonization model. The Mesolithic groups, although exploiting plant resources such as hazelnut more or less intensively, did not significantly change the landscape. The impact of their settlements and their activities are hardly noticeable through palynology, for example. The control of the mode of reproduction of plants has certainly increased the prevalence of Homo sapiens, involving, among others, a demographic increase and the ability to settle down in areas that were not well adapted to year-round occupation up to that point. The characterization of past agricultural systems, such as crop plants, technical processes, and the impact of anthropogenic activities on the landscape, is essential for understanding the interrelation of human societies and the plant environment. This interrelation has undoubtedly changed deeply with the Neolithic Revolution.
Alexander N. Hristov
Agriculture is a significant source of methane, contributing about 12% of the global anthropogenic methane emissions. Major sources of methane from agricultural activities are fermentation in the reticulo-rumen of ruminant animals (i.e., enteric methane), fermentation in animal manure, and rice cultivation. Enteric methane is the largest agricultural source of methane and is mainly controlled by feed dry matter intake and composition of the animal diet (i.e., fiber, starch, lipids). Processes that lead to generation of methane from animal manure are similar to those taking place in the reticulo-rumen. Methane emissions from manure, however, are greatly influenced by factors such as manure management system and ambient temperature. Systems that handle manure as a liquid generate much more methane than systems in which manure is handled as a solid. Low ambient temperatures drastically decrease methane emissions from manure. Once applied to soil, animal manure does not generate significant amounts of methane. Globally, methane emissions from rice cultivation represent about 10% of the total agricultural greenhouse gas emissions. In the rice plant, methane dissolves in the soil water surrounding the roots, diffuses into the cell-wall water of the root cells, and is eventually released through the micropores in the leaves. Various strategies have been explored to mitigate agricultural methane emissions. Animal nutrition, including balancing dietary nutrients and replacement of fiber with starch or lipids; alternative sinks for hydrogen; manipulation of ruminal fermentation; and direct inhibition of methanogenesis have been shown to effectively decrease enteric methane emissions. Manure management solutions include solid-liquid separation, manure covers, flaring of generated methane, acidification and cooling of manure, and decreasing manure storage time before soil application. There are also effective mitigation strategies for rice that can be categorized broadly into selection of rice cultivars, water regime, and fertilization. Alternate wetting and drying and mid-season drainage of rice paddies have been shown to be very effective practices for mitigating methane emissions from rice production.
Deborah L. Nichols
The Basin of Mexico is a key world region for understanding agricultural intensification and the development of ancient and historic cities and states. Archaeologists working in the region have had a long-standing interest in understanding the dynamics of interactions between society and environment and their research has been at the forefront of advances in both method and theory. The Basin of Mexico was the geopolitical core of the Aztec empire, the largest state in the history of Mesoamerica. Its growth was sustained by a complex economy that has been the subject of much research.
Two themes underlie a broad interest in the pre-Hispanic agriculture of the Basin of Mexico. First, how with a Neolithic technology did the Aztecs and their predecessors sustain the growth of large cites, dense rural populations, and the largest state system in the history of pre-Hispanic Mesoamerica? Second, what is the relationship of agricultural intensification and urbanization and state formation? Mesoamerica is the only world region where primary civilizations developed that lacked domestic herbivores for either food or transportation. Their farming depended entirely on human labor and hand tools but sustained large cities, dense populations, and complex social institutions. Intensive agriculture began early and was promoted by risk, ecological diversity, and social differentiation, and included irrigation, terracing, and drained fields (chinampas). Most farming was managed by smallholder households and local communities, which encouraged corporate forms of governance and collective action. Environmental impacts included erosion and deposition, but were limited compared with the degradation that took place in the colonial period.
Worldwide, governments subsidize agriculture at the rate of approximately 1 billion dollars per day. This figure rises to about twice that when export and biofuels production subsidies and state financing for dams and river basin engineering are included. These policies guide land use in numerous ways, including growers’ choices of crop and buyers’ demand for commodities. The three types of state subsidies that shape land use and the environment are land settlement programs, price and income supports, and energy and emissions initiatives. Together these subsidies have created perennial surpluses in global stores of cereal grains, cotton, and dairy, with production increases outstripping population growth. Subsidies to land settlement, to crop prices, and to processing and refining of cereals and fiber, therefore, can be shown to have independent and largely deleterious effect on soil fertility, fresh water supplies, biodiversity, and atmospheric carbon.
John M. Marston
The ancient Near East was one of the earliest centers of agriculture in the world, giving rise to domesticated herd animals, cereals, and legumes that today have become primary agricultural staples worldwide. Although much attention has been paid to the origins of agriculture, identifying when, where, and how plants and animals were domesticated, equally important are the social and environmental consequences of agriculture. Shortly after the advent of domestication, agricultural economies quickly replaced hunting and gathering across Mesopotamia, the Levant, and Anatolia. The social and environmental context of this transition has profound implications for understanding the rise of social complexity and incipient urbanism in the Near East.
Economic transformation accompanied the expansion of agriculture throughout small-scale societies of the Near East. These farmsteads and villages, as well as mobile pastoral groups, formed the backbone of agricultural production, which enabled tradable surpluses necessary for more expansive, community-scale economic networks. The role of such economies in the development of social complexity remains debated, but they did play an essential role in the rise of urbanism. Cities depended on agricultural specialists, including farmers and herders, to feed urban populations and to enable craft and ritual specializations that became manifest in the first cities of southern Mesopotamia. The environmental implications of these agricultural systems in the Mesopotamian lowlands, especially soil salinization, were equally substantial. The environmental implications of Mesopotamian agriculture are distinct from those accompanying the spread of agriculture to the Levant and Anatolia, where deforestation, erosion, and loss of biodiversity can be identified as the hallmarks of agricultural expansion.
Agriculture is intimately connected with the rise of territorial empires across the Near East. Such empires often controlled agricultural production closely, for both economic and strategic ends, but the methods by which they encouraged the production of specific agricultural products and the adoption of particular agricultural strategies, especially irrigation, varied considerably between empires. By combining written records, archaeological data from surveys and excavation, and paleoenvironmental reconstruction, together with the study of plant and animal remains from archaeological sites occupied during multiple imperial periods, it is possible to reconstruct the environmental consequences of imperial agricultural systems across the Near East. Divergent environmental histories across space and time allow us to assess the sustainability of the agricultural policies of each empire and to consider how resulting environmental change contributed to the success or failure of those polities.
Charlene Murphy and Dorian Q. Fuller
South Asia possesses a unique Neolithic transition to agricultural domestication. India has received far less attention in the quest for evidence of early agriculture than other regions of the world traditionally recognized as “centers of domestication” such as southwest Asia, western Asia, China, Mesoamerica, South America, New Guinea, and Africa. Hunter-gatherers with agricultural production appeared around the middle of the Holocene, 4000 to 1500
As a case study for the origins of agriculture, South Asia has much to offer archaeologists and environmental scientists alike for understanding domestication processes and local transitions from foraging to farming as well as the ways in which early farmers adapted to and transformed the environment and regional vegetation. Information exchange from distant farmers from other agricultural centers into the subcontinent cannot be ruled out. However, it is clear that local agricultural origins occurred via a series of processes, including the dispersal of pastoral and agro-pastoral peoples across regions, the local domestication of animals and plants and the adoption by indigenous hunter-gatherers of food production techniques from neighboring cultures. Indeed, it is posited that local domestication events in India were occurring alongside agricultural dispersals from other parts of the world in an interconnected mosaic of cultivation, pastoralism, and sedentism. As humans in South Asia increasingly relied on a more restricted range of plant species, they became entangled in an increasingly fixed trajectory that allowed greater food production levels to sustain larger populations and support their developing social, cultural and food traditions.
Aijun Ding, Xin Huang, and Congbin Fu
Air pollution is one of the grand environmental challenges in developing countries, especially those with high population density like China. High concentrations of primary and secondary trace gases and particulate matter (PM) are frequently observed in the industrialized and urbanized regions, causing negative effects on the health of humans, plants, and the ecosystem.
Meteorological conditions are among the most important factors influencing day-to-day air quality. Synoptic weather and boundary layer dynamics control the dispersion capacity and transport of air pollutants, while the main meteorological parameters, such as air temperature, radiation, and relative humidity, influence the chemical transformation of secondary air pollutants at the same time. Intense air pollution, especially high concentration of radiatively important aerosols, can substantially influence meteorological parameters, boundary layer dynamics, synoptic weather, and even regional climate through their strong radiative effects.
As one of the main monsoon regions, with the most intense human activities in the world, East Asia is a region experiencing complex air pollution, with sources from anthropogenic fossil fuel combustion, biomass burning, dust storms, and biogenic emissions. A mixture of these different plumes can cause substantial two-way interactions and feedbacks in the formation of air pollutants under various weather conditions. Improving the understanding of such interactions needs more field measurements using integrated multiprocess measurement platforms, as well as more efforts in developing numerical models, especially for those with online coupled processes. All these efforts are very important for policymaking from the perspectives of environmental protection and mitigation of climate change.
Geoffrey L. Taylor and Katherine L. Chiou
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
The Andean highland region of South America was a center for the domestication of crops and the development of novel agricultural intensification strategies. These advances provided the social and economic foundations for one of the largest pre-Hispanic states in the Americas—the Inca—as well as numerous preceding and contemporaneous cultures. The legacy created by Andean agriculturalists includes terraced and raised fields that remain in use today as well as globally consumed foods including chili pepper (Capsicum spp.), potato (Solanum tuberosum), and quinoa (Chenopodium quinoa).
Research on modern forms of traditional agriculture in South America by ethnographers, geographers, and agronomists can be grouped into three general themes: (1) the physical, social, and ritual practices of farming; (2) the environmental impacts of farming; and (3) agrobiodiversity and genetic conservation of crop varieties. Due to conquest by European invaders in the 16th century and the resulting demographic collapse, aspects of native knowledge and traditions were lost. Consequently, much of what is known about pre-Hispanic traditional agricultural practices is derived from archaeological research.
To farm the steep mountainous slopes in the quechua and suni zones, native Andean peoples developed a suite of field types ranging from rainfed sloping fields to irrigated bench terracing that flattened the ground to increase surface area, raised soil temperatures, and reduced soil erosion. In the high plains or puna zone, flat wetlands were transformed into a patchwork of alternating raised fields and irrigation canals. By employing this strategy, Andean peoples created microclimates that resisted frost, managed moisture availability, and improved soil nutrient quality.
These agricultural approaches cannot be divorced from enduring Andean cosmological and social concepts such as the ayni and minka exchange-labor systems based on reciprocity and the ayllu, a lineage and community group that also integrates the land itself and the wakas (nonhuman agentive beings) that reside there with the people. To understand traditional agriculture in the highland Andes and how it supported large populations in antiquity, facilitated the rapid expansion of the Inca Empire, and created field systems that are still farmed sustainably by populations today, it is essential to examine not only the physical practices themselves, but also the social context surrounding their development and use in ancient and modern times.
Richard W. Hazlett and Joshua Peck
Satellite reconnaissance of the Earth’s surface provides critical information about the state of human interaction with the natural environment. The strongest impact is agricultural, reflecting land-use approaches to food production extending back to the dawn of civilization. To variable degrees, depending upon location, regional field patterns result from traditional farming practices, surveying methods, regional histories, policies, political agendas, environmental circumstances, and economic welfare. Satellite imaging in photographic true or false color is an important means of evaluating the nature and implications of agricultural practices and their impacts on the surrounding world. Important platforms with publicly accessible links to satellite image sets include those of the European Space Agency, U.S. National Aeronautics and Space Administration, the Centre D’etudes Spatiales, Airbus, and various other governmental programs. Reprocessing of data worldwide in scope by commercial concerns including Digital Globe, Terrametrics, and GoogleEarth in the 21st century enable ready examination of most of the Earth’s surface in great detail and natural colors. The potential for monitoring and improving understanding of agriculture and its role in the Earth system is considerable thanks to these new ways of viewing the planet.
Space reconnaissance starkly reveals the consequences of unique land surveys for the rapid development of agriculture and political control in wilderness areas, including the U.S. Public Land Survey and Tierras Bajas systems. Traditional approaches toward agriculture are clearly shown in ribbon farms, English enclosures and medieval field systems, and terracing in many parts of the world. Irrigation works, some thousands of years old, may be seen in floodplains and dryland areas, notably the Maghreb and the deep Sahara, where center-pivot fields have recently appeared in areas once considered too dry to cultivate. Approaches for controlling erosion, including buffer zones, shelter belts, strip and contour farming, can be easily identified. Also evident are features related to field erosion and soil alteration that have advanced to crisis stage, such as badland development and widespread salinization. Pollution related to farm runoff, and the piecemeal (if not rapid) loss of farmlands due to urbanization can be examined in ways favoring more comprehensive evaluation of human impacts on the planetary surface. Developments in space technologies and observational platforms will continue indefinitely, promising ever-increasing capacity to understand how humans relate to the environment.
Jan Zalasiewicz and Colin Waters
The Anthropocene hypothesis—that humans have impacted “the environment” but also changed the Earth’s geology—has spread widely through the sciences and humanities. This hypothesis is being currently tested to see whether the Anthropocene may become part of the Geological Time Scale. An Anthropocene Working Group has been established to assemble the evidence. The decision regarding formalization is likely to be taken in the next few years, by the International Commission on Stratigraphy, the body that oversees the Geological Time Scale. Whichever way the decision goes, there will remain the reality of the phenomenon and the utility of the concept.
The evidence, as outlined here, rests upon a broad range of signatures reflecting humanity’s significant and increasing modification of Earth systems. These may be visible as markers in physical deposits in the form of the greatest expansion of novel minerals in the last 2.4 billion years of Earth history and development of ubiquitous materials, such as plastics, unique to the Anthropocene. The artefacts we produce to live as modern humans will form the technofossils of the future. Human-generated deposits now extend from our natural habitat on land into our oceans, transported at rates exceeding the sediment carried by rivers by an order of magnitude. That influence now extends increasingly underground in our quest for minerals, fuel, living space, and to develop transport and communication networks. These human trace fossils may be preserved over geological durations and the evolution of technology has created a new technosphere, yet to evolve into balance with other Earth systems.
The expression of the Anthropocene can be seen in sediments and glaciers in chemical markers. Carbon dioxide in the atmosphere has risen by ~45 percent above pre–Industrial Revolution levels, mainly through combustion, over a few decades, of a geological carbon-store that took many millions of years to accumulate. Although this may ultimately drive climate change, average global temperature increases and resultant sea-level rises remain comparatively small, as yet. But the shift to isotopically lighter carbon locked into limestones and calcareous fossils will form a permanent record. Nitrogen and phosphorus contents in surface soils have approximately doubled through increased use of fertilizers to increase agricultural yields as the human population has also doubled in the last 50 years. Industrial metals, radioactive fallout from atomic weapons testing, and complex organic compounds have been widely dispersed through the environment and become preserved in sediment and ice layers.
Despite radical changes to flora and fauna across the planet, the Earth still has most of its complement of biological species. However, current trends of habitat loss and predation may push the Earth into the sixth mass extinction event in the next few centuries. At present the dramatic changes relate to trans-global species invasions and population modification through agricultural development on land and contamination of coastal zones.
Considering the entire range of environmental signatures, it is clear that the global, large and rapid scale of change related to the mid-20th century is the most obvious level to consider as the start of the Anthropocene Epoch.
Arid environments cover about one third of the Earth’s surface, comprising the most extensive of the terrestrial biomes. Deserts show considerable individual variation in climate, geomorphic surface expression, and biogeography. Climatically, deserts range from dry interior environments, with large temperature ranges, to humid and relatively cool coastal environments, with small temperature ranges. What all deserts share in common is a consistent deficit of precipitation relative to water loss by evaporation, implying that the biological availability of water is very low. Deserts develop because of climatic (persistent high-pressure cells), topographic (mountain ranges that cause rain shadow effects), and oceanographic (cold currents) factors that limit the amount of rain or snowfall that a region receives. Most global deserts are subtropical in distribution.
There is a large range of geomorphic surfaces, including sand sheets and sand seas (ergs), stone pavements, bedrock outcrops, dry lakebeds, and alluvial fans. Vegetation cover is generally sparse, but may be enhanced in areas of groundwater seepage or along river courses. The limited vegetation cover affects fluvial and slope processes and results in an enhanced role for the wind. While the majority of streams in deserts are ephemeral features, both intermittent and perennial rivers develop in response to snowmelt in nearby mountains or runoff from distant, more well-watered regions. Most drainage is endoreic, meaning that it flows internally into closed basins and does not reach the sea, being disposed of by seepage and evaporation.
The early study of deserts was largely descriptive. More process-based studies commenced with the study of North American deserts in the mid- to late-1800s. Since the late 20th century, research has expanded into many areas of the world, with notable contributions coming from China, but our knowledge of deserts is still more compete in regions such as North America, Australia, Israel, and southern Africa, where access and funding have been more consistently secure. The widespread availability of high-quality remotely sensed images has contributed to the spread of study into new global field areas. The temporal framework for research has also improved, benefiting from improvements in geochronological techniques. Geochronological controls are vital to desert research because most arid regions have experienced significant climatic changes. Deserts have not only expanded or contracted in size, but have experienced changes in the dominant geomorphic processes and biogeographic environment. Contemporary scientific work has also benefited from improvements in technology, notably in surveying techniques, and from the use of quantitative modeling.
Katrina Wyatt, Robin Durie, and Felicity Thomas
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
The burden of ill health has shifted, globally, from communicable to non-communicable disease, with poor health clustering in areas of economic deprivation. However, for the most part, public health programs remain focused on changing behaviors associated with poor health (such as smoking or physical inactivity) rather than the contexts that give rise to, and influence, the wide range of behaviors associated with poor health. This way of understanding and responding to population ill health views poor health behavior as a defining “problem” exhibited by a particular group of individuals or a community, which needs to be solved by the intervention of expert practitioners. This sort of approach determines individuals and their communities in terms of deficits, and works on the basis of perceived needs within such communities when seeking to address public health issues.
Growing recognition that many of the fundamental determinants of health cannot be attributed solely to individuals, but result instead from the complex interplay between individuals and their social, economic, and cultural environments, has led to calls for new ways of delivering policies and programs aimed at improving health and reducing health inequalities. Such approaches include the incorporation of subjective perspectives and priorities to inform the creation of “health promoting societal contexts.” Alongside this, asset-based approaches to health creation place great emphasis on valuing the skills, knowledge, connections, and potential within a community and seek to identify the protective factors within a neighborhood or organization that support health and wellbeing.
Connecting Communities (C2) is a unique asset-based program aimed at creating the conditions for health and wellness within very low-income communities. At the heart of the program is the belief that health emerges from the patterns of relations within neighborhoods, rather than being a static attribute of individuals. C2 seeks to change the nature of the relations both within communities and with service providers (such as the police, housing, education, and health professionals) to co-create responses to issues that are identified by community members themselves. While many of the issues identified concern local environmental conditions, such as vandalism or safe out-door spaces, many are also contributory determinants of ill health. Listening to people, understanding the social, cultural, and environmental context within which they are located, and supporting new partnerships based on reciprocity and mutual benefit ensures that solutions are grounded in the local context and not externally determined, in turn resulting in sustainable health creating communities.
Sumit Sharma, Liliana Nunez, and Veerabhadran Ramanathan
Atmospheric brown clouds (ABCs) are widespread pollution clouds that can at times span an entire continent or an ocean basin. ABCs extend vertically from the ground upward to as high as 3 km, and they consist of both aerosols and gases. ABCs consist of anthropogenic aerosols such as sulfates, nitrates, organics, and black carbon and natural dust aerosols. Gaseous pollutants that contribute to the formation of ABCs are NOx (nitrogen oxides), SOx (sulfur oxides), VOCs (volatile organic compounds), CO (carbon monoxide), CH4 (methane), and O3 (ozone). The brownish color of the cloud (which is visible when looking at the horizon) is due to absorption of solar radiation at short wavelengths (green, blue, and UV) by organic and black carbon aerosols as well as by NOx. While the local nature of ABCs around polluted cities has been known since the early 1900s, the widespread transoceanic and transcontinental nature of ABCs as well as their large-scale effects on climate, hydrological cycle, and agriculture were discovered inadvertently by The Indian Ocean Experiment (INDOEX), an international experiment conducted in the 1990s over the Indian Ocean. A major discovery of INDOEX was that ABCs caused drastic dimming at the surface. The magnitude of the dimming was as large as 10–20% (based on a monthly average) over vast areas of land and ocean regions. The dimming was shown to be accompanied by significant atmospheric absorption of solar radiation by black and brown carbon (a form of organic carbon). Black and brown carbon, ozone and methane contribute as much as 40% to anthropogenic radiative forcing. The dimming by sulfates, nitrates, and carbonaceous (black and organic carbon) species has been shown to disrupt and weaken the monsoon circulation over southern Asia. In addition, the ozone in ABCs leads to a significant decrease in agriculture yields (by as much as 20–40%) in the polluted regions. Most significantly, the aerosols (in ABCs) near the ground lead to about 4 million premature mortalities every year. Technological and regulatory measures are available to mitigate most of the pollution resulting from ABCs. The importance of ABCs to global environmental problems led the United Nations Environment Programme (UNEP) to form the
Kevin J. Boyle and Christopher F. Parmeter
Benefit transfer is the projection of benefits from one place and time to another time at the same place or to a new place. Thus, benefit transfer includes the adaptation of an original study to a new policy application at the same location or the adaptation to a different location. The appeal of a benefit transfer is that it can be cost effective, both monetarily and in time. Using previous studies, analysts can select existing results to construct a transferred value for the desired amenity influenced by the policy change. Benefit transfer practices are not unique to valuing ecosystem service and are generally applicable to a variety of changes in ecosystem services. An ideal benefit transfer will scale value estimates to both the ecosystem services and the preferences of those who hold values. The article outlines the steps in a benefit transfer, types of transfers, accuracy of transferred values, and challenges when conducting ecosystem transfers and ends with recommendations for the implementation of benefit transfers to support decision-making.
Lora Fleming, Niccolò Tempini, Harriet Gordon-Brown, Gordon L. Nichols, Christophe Sarran, Paolo Vineis, Giovanni Leonardi, Brian Golding, Andy Haines, Anthony Kessel, Virginia Murray, Michael Depledge, and Sabina Leonelli
Big data refers to large, complex, potentially linkable data from diverse sources, ranging from the genome and social media, to individual health information and the contributions of citizen science monitoring, to large-scale long-term oceanographic and climate modeling and its processing in innovative and integrated “data mashups.” Over the past few decades, thanks to the rapid expansion of computer technology, there has been a growing appreciation for the potential of big data in environment and human health research.
The promise of big data mashups in environment and human health includes the ability to truly explore and understand the “wicked environment and health problems” of the 21st century, from tracking the global spread of the Zika and Ebola virus epidemics to modeling future climate change impacts and adaptation at the city or national level. Other opportunities include the possibility of identifying environment and health hot spots (i.e., locations where people and/or places are at particular risk), where innovative interventions can be designed and evaluated to prevent or adapt to climate and other environmental change over the long term with potential (co-) benefits for health; and of locating and filling gaps in existing knowledge of relevant linkages between environmental change and human health. There is the potential for the increasing control of personal data (both access to and generation of these data), benefits to health and the environment (e.g., from smart homes and cities), and opportunities to contribute via citizen science research and share information locally and globally.
At the same time, there are challenges inherent with big data and data mashups, particularly in the environment and human health arena. Environment and health represent very diverse scientific areas with different research cultures, ethos, languages, and expertise. Equally diverse are the types of data involved (including time and spatial scales, and different types of modeled data), often with no standardization of the data to allow easy linkage beyond time and space variables, as data types are mostly shaped by the needs of the communities where they originated and have been used. Furthermore, these “secondary data” (i.e., data re-used in research) are often not even originated for this purpose, a particularly relevant distinction in the context of routine health data re-use. And the ways in which the research communities in health and environmental sciences approach data analysis and synthesis, as well as statistical and mathematical modeling, are widely different.
There is a lack of trained personnel who can span these interdisciplinary divides or who have the necessary expertise in the techniques that make adequate bridging possible, such as software development, big data management and storage, and data analyses. Moreover, health data have unique challenges due to the need to maintain confidentiality and data privacy for the individuals or groups being studied, to evaluate the implications of shared information for the communities affected by research and big data, and to resolve the long-standing issues of intellectual property and data ownership occurring throughout the environment and health fields. As with other areas of big data, the new “digital data divide” is growing, where some researchers and research groups, or corporations and governments, have the access to data and computing resources while others do not, even as citizen participation in research initiatives is increasing. Finally with the exception of some business-related activities, funding, especially with the aim of encouraging the sustainability and accessibility of big data resources (from personnel to hardware), is currently inadequate; there is widespread disagreement over what business models can support long-term maintenance of data infrastructures, and those that exist now are often unable to deal with the complexity and resource-intensive nature of maintaining and updating these tools.
Nevertheless, researchers, policy makers, funders, governments, the media, and members of the general public are increasingly recognizing the innovation and creativity potential of big data in environment and health and many other areas. This can be seen in how the relatively new and powerful movement of Open Data is being crystalized into science policy and funding guidelines. Some of the challenges and opportunities, as well as some salient examples, of the potential of big data and big data mashup applications to environment and human health research are discussed.
Human activities in the Anthropocene are influencing the twin processes of biodiversity generation and loss in complex ways that threaten the maintenance of biodiversity levels that underpin human well-being. Yet many scientists and practitioners still present a simplistic view of biodiversity as a static stock rather than one determined by a dynamic interplay of feedback processes that are affected by anthropogenic drivers. Biodiversity describes the variety of life on Earth, from the genes within an organism to the ecosystem level. However, this article focuses on variation among living organisms, both within and between species. Within species, biodiversity is reflected in genetic, and consequent phenotypic, variations among individuals. Genetic diversity is generated by germ line mutations, genetic recombination during sexual reproduction, and immigration of new genotypes into populations. Across species, biodiversity is reflected in the number of different species present and also, by some metrics, in the evenness of their relative abundance. At this level, biodiversity is generated by processes of speciation and immigration of new species into an area. Anthropogenic drivers affect all these biodiversity generation processes, while the levels of genetic diversity can feed back and affect the level of species diversity, and vice versa. Therefore, biodiversity maintenance is a complex balance of processes and the biodiversity levels at any point in time may not be at equilibrium.
A major concern for humans is that our activities are driving rapid losses of biodiversity, which outweigh by orders of magnitude the processes of biodiversity generation. A wide range of species and genetic diversity could be necessary for the provision of ecosystem functions and services (e.g., in maintaining the nutrient cycling, plant productivity, pollination, and pest control that underpin crop production). The importance of biodiversity becomes particularly marked over longer time periods, and especially under varying environmental conditions.
In terms of biodiversity losses, there are natural processes that cause roughly continuous, low-level losses, but there is also strong evidence from fossil records for transient events in which exceptionally large loss of biodiversity has occurred. These major extinction episodes are thought to have been caused by various large-scale environmental perturbations, such as volcanic eruptions, sea-level falls, climatic changes, and asteroid impacts. From all these events, biodiversity has shown recovery over subsequent calmer periods, although the composition of higher-level evolutionary taxa can be significantly altered.
In the modern era, biodiversity appears to be undergoing another mass extinction event, driven by large-scale human impacts. The primary mechanisms of biodiversity loss caused by humans vary over time and by geographic region, but they include overexploitation, habitat loss, climate change, pollution (e.g., nitrogen deposition), and the introduction of non-native species. It is worth noting that human activities may also lead to increases in biodiversity in some areas through species introductions and climatic changes, although these overall increases in species richness may come at the cost of loss of native species, and with uncertain effects on ecosystem service delivery. Genetic diversity is also affected by human activities, with many examples of erosion of diversity through crop and livestock breeding or through the decline in abundance of wild species populations. Significant future challenges are to develop better ways to monitor the drivers of biodiversity loss and biodiversity levels themselves, making use of new technologies, and improving coverage across geographic regions and taxonomic scope. Rather than treating biodiversity as a simple stock at equilibrium, developing a deeper understanding of the complex interactions—both between environmental drivers and between genetic and species diversity—is essential to manage and maintain the benefits that biodiversity delivers to humans, as well as to safeguard the intrinsic value of the Earth’s biodiversity for future generations.
Peter Kareiva and Isaac Kareiva
The concept of biodiversity hotspots arose as a science-based framework with which to identify high-priority areas for habitat protection and conservation—often in the form of nature reserves. The basic idea is that with limited funds and competition from humans for land, we should use range maps and distributional data to protect areas that harbor the greatest biodiversity and that have experienced the greatest habitat loss. In its early application, much analysis and scientific debate went into asking the following questions: Should all species be treated equally? Do endemic species matter more? Should the magnitude of threat matter? Does evolutionary uniqueness matter? And if one has good data on one broad group of organisms (e.g., plants or birds), does it suffice to focus on hotspots for a few taxonomic groups and then expect to capture all biodiversity broadly? Early applications also recognized that hotspots could be identified at a variety of spatial scales—from global to continental, to national to regional, to even local. Hence, within each scale, it is possible to identify biodiversity hotspots as targets for conservation.
In the last 10 years, the concept of hotspots has been enriched to address some key critiques, including the problem of ignoring important areas that might have low biodiversity but that certainly were highly valued because of charismatic wild species or critical ecosystem services. Analyses revealed that although the spatial correlation between high-diversity areas and high-ecosystem-service areas is low, it is possible to use quantitative algorithms that achieve both high protection for biodiversity and high protection for ecosystem services without increasing the required area as much as might be expected.
Currently, a great deal of research is aimed at asking about what the impact of climate change on biodiversity hotspots is, as well as to what extent conservation can maintain high biodiversity in the face of climate change. Two important approaches to this are detailed models and statistical assessments that relate species distribution to climate, or alternatively “conserving the stage” for high biodiversity, whereby the stage entails regions with topographies or habitat heterogeneity of the sort that is expected to generate high species richness.
Finally, conservation planning has most recently embraced what is in some sense the inverse of biodiversity hotspots—what we might call conservation wastelands. This approach recognizes that in the Anthropocene epoch, human development and infrastructure are so vast that in addition to using data to identify biodiversity hotspots, we should use data to identify highly degraded habitats and ecosystems. These degraded lands can then become priority development areas—for wind farms, solar energy facilities, oil palm plantations, and so forth. By specifying degraded lands, conservation plans commonly pair maps of biodiversity hotspots with maps of degraded lands that highlight areas for development. By putting the two maps together, it should be possible to achieve much more effective conservation because there will be provision of habitat for species and for economic development—something that can obtain broader political support than simply highlighting biodiversity hotspots.
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.