Grand Challenges in Environmental Sciences (2001) / Chapter Skim
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The Grand Challenges
The Grand Challenges
Pages 14-59
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From page 14... ...
These lists are not intended to be comprehensive; rather, they include only those areas we judge most exciting and likely to yield major breakthroughs in the near future. GRAND CHALLENGE 1: BIOGEOCHEMICAL CYCLES The challenge is to understand how the Earth's major biogeochemical cycles are being perturbed by human activities; to be able to predict the impact of these perturbations on local, regional, and global scales; and to determine how these cycles may be restored to more natural states should such restoration be deemed desirable.
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From page 15... ...
What is less clear is how long these changes in biogeochemical cycles will continue, what effects they are having on the climate system, how these effects will reverberate throughout the Earth system, and how positive and negative feedbacks within the system will interact to accelerate or ameliorate these effects. Human actions strongly influence changes in the Earth's biogeochemical cycles, with potentially devastating effects.
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Human influences on the biogeochemical cycles are not all increasing so dramatically. Recent restrictions on sulfur dioxide (SO2)
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As the broad outlines of the biogeochemical cycles become better delineated, spatial distributions and temporal trends in the parameters of interest will link the cycles in increasingly useful ways to topics of interest within other grand challenges. Scientific Readiness The growth of the field of biogeochemistry during the past 10 to 15 years has led to significant theoretical and experimental developments that can serve as the base for future research, and the study of carbon and nitrogen cycles has greatly benefited from recent technological advances.
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The above are but a few key examples of successes in the field. We are now poised to place our understanding of biogeochemical cycles on a much firmer theoretical and empirical base than now exists.
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3. Assess the impacts of anthropogenic perturbations of biogeochemical cycles on ecosystem functioning and atmospheric and oceanic chemistry, and develop a scientific basis for societal decisions about managing these cycles.
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The research priorities for biogeochemistry are clearly related to those for a number of the other grand challenges in addition to the overlaps noted above. Significant changes in biogeochemical cycles are often driven by extreme weather events, such as those outlined in Grand Challenge 3 on climate variability.
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From page 21... ...
At present, we have a limited appreciation of what is really at risk, of the time scale for losses, and of the environmental consequences of simplifying and mixing the Earth's biota. Nonetheless, a major loss of biological diversity clearly threatens the capacity of the Earth to support human societies.
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From page 22... ...
Area and isolation are fundamentally important, reflecting control of local and regional diversity on shorter time scales by the balance between migration and local extinction. Understanding of the relationship between species diversity and area known as a species-area curve is a powerful tool.
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, loss of species diversity must affect ecosystem functioning, but there is no general principle concerning the impact of decreasing biological diversity on the risk of widespread loss of ecosystem functioning. It is clear that not all species are equally important, but little is known about the general extent to which ecologically similar species can substitute for each other in providing ecosystem services.
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Scientific Readiness The following conditions make a scientific initiative on biological diversity and ecosystem functioning particularly timely. Advances in understanding biogeography, speciation, and extinction.
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Many recent studies have explored aspects of the relationship between the diversity of species (and in some cases the diversity of genotypes or ecosystems) and ecosystem functioning (e.g., Chapin et al.
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Much evidence suggests that biological diversity affects ecosystem functioning
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In short, there is no theory for the role of diversity in ecosystems. A series of experiments is needed to test explicit hypotheses about the mechanistic controls on biological diversity at all scales, and about the relationship between biological diversity and ecosystem functioning, including persistence.
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As a consequence, our ability to assess changes in ENSO over the next century is highly limited. Research on other modes of climate variability is in its infancy, and characterizing those modes is necessary if we are to unambiguously discern long-term climate trends caused by human activities, as well as understand natural variations in the global carbon cycle.
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From page 29... ...
Finally, human societies and economic systems have adapted to historic patterns of climate variability, but may be disrupted to various degrees, depending on their coping capacities, if these patterns change. In addition, human alterations of the landscape may have changed the vulnerability of social systems to climate variations within historic ranges.
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Portions of this research overlap strongly with Grand Challenge 1 (Biogeochemical Cycles) , Grand Challenge 2 (Biological Diversity and Ecosystem Functioning)
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GRAND CHALLENGE 4: HYDROLOGIC FORECASTING The challenge is to predict changes in freshwater resources and the environment caused by floods, droughts, sedimentation, and contamination in a context of growing demand on water resources. Practical Importance Water is an essential natural resource that shapes regional landscapes and is vital for ecosystem functioning and human well-being.
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Scientific Importance Currently, our understanding and predictive ability with regard to hydrologic forecasting are limited by theory, method, and the scope of available models, as well as by data. Recent and evolving developments in remote sensing of parameters such as precipitation, soil moisture, snowpack, river discharge, vegetation cover, and surface topography are beginning to yield spatial and temporal data that are driving a revolution in hydrologic science, making it possible to measure hydrologic phenomena never before seen and thus poorly understood.
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From page 33... ...
A sustained research effort is likely to result in major advances in interpreting the behavior of hydrologic systems across different spatial and temporal scales; forecasting changes in water quantity and quality; and determining the impacts of these changes on surface and subsurface water resources, landscape dynamics, ecological communities, and human systems. These points are elaborated below in the discussion of important areas for research.
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2. Improve understanding of surface water generation and transport.
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New remote mapping capability using radar and infrared satellite data could be coupled with field measurements and new theories in hydrologic science to understand the signature of recharge areas and estimate evapotranspiration rates over vast regions. There are two critical environmental problems to be addressed.
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As noted earlier, land-use changes can have significant hydrologic impacts, and thus the observations and modeling efforts described here must be closely linked with those related to land use (Grand Challenge 7~. The ability to predict climate variability and extreme weather events (Grand Challenge 3)
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This improved understanding would in turn assist in the development of biological, social, and environmental controls for containing the spread of pathogens and toxic organisms; lead to guidelines for avoiding actions that encourage the development of resistance in pathogens; and help identify possible trigger
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First, pathogens are now recognized to play a causal role in many chronic diseases and conditions, including cardiovascular disease, neuropsychiatric disorders, infertility, and ulcers. In addition, infections such as tuberculosis, malaria, and pneumonia have reemerged, and newly recognized pathogens HIV, Nipah virus, West Nile virus, Lyme disease, transmissible spongiform encephalopathies, the hepatitis viruses have grown in medical importance.
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These examples illustrate the range of social issues that need to be considered to fully address the population health impact of infectious diseases. To make progress in understanding emerging infections, it is necessary to develop an ecological understanding of disease.
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As discussed in relation to Grand Challenge 4, Hydrologic Forecasting, and Grand Challenge 7, Land-Use Dynamics, new systems for monitoring (including satellite remote sensing) and for recording data (e.g., geographic information systems)
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From page 41... ...
Likewise, we have little specific understanding of how predicted widespread climate and land-use changes, changes in water and waste management, alterations in the biogeochemical cycles of nutrient compounds, or changes in food production systems may affect the ecology and spread of disease organisms on small or medium scales. Diseases such as malaria, dengue, and cholera may be especially sensitive to environmental and climate change (Lindsay and Birley 1996, Patz et al.
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Existing programs must be expanded to include surveillance of the population ecology of zoonotic hosts, pathogens, vectors, and toxic organisms. Conducting such surveillance will necessitate developing and monitoring molecular and genetic markers of change in disease organisms, and on using geographic information systems to incorporate ecological data from remote and in situ observations with geographically explicit data on the populations of pathogens and toxic organisms.
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From page 43... ...
For example, many thousands of water management institutions some 20,000 governing units in the United States alone provide rules for water rights, each having different impacts on entitlements to water and on water resources. These institutions also establish a variety of rules for paying for water use.
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For instance, open-access resource systems that face increased demand are subject to rapid extraction that threatens ecosystem functioning and human welfare (see, e.g., Bromley 1992, Kasperson et al.
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Scientific Readiness During the past several decades, theoretical and empirical advances in social science have significantly increased the capacity to address resource and environmental management institutions in a systematic fashion and to understand the environmental and social consequences of different institutional forms. The field stands at the threshold of substantial progress as a result of new multidisciplinary empirical studies of resource institutions; advances in institutional design theory in economics and political science; and developments in institutional, environmental, and resource economics.
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Various environmental studies, especially those requiring models to project the impacts of change, need information on the key institutions governing the land, resource, or environmental problem of concern. Thus, research on topics ranging from land-use change, to fishing stocks, to freshwater resources, to atmospheric dynamics ultimately requires consideration of the controlling institutions, especially for regional and global models.
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3. Improve understanding of change in resource institutions.
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Research on this topic should focus on the effects on resource use of different combinations of policy instruments and monitoring activities, and on the effects of differences and conflicts among the incentive structures of local, national, and global institutional arrangements. GRAND CHALLENGE 7: LAND-USE DYNAMICS The challenge is to develop a systematic understanding of changes in land uses and land covers that are critical to biogeochemical cycling, ecosystem functioning and services, and human welfare.
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However, regional and global-level stocks of most land covers and uses, including such essential categories as forest and grassland cover, agricultural uses, and urban and suburban settlement, are still poorly documented and monitored. Theory and assessment models used to address land dynamics are mainly static, economic sector-based, and nonspatial, and do not account for neighboring uses; the roles of institutions that manage land and resources; or biophysical changes and feedbacks in land use and cover, including climate change and anthropogenic changes in terrestrial ecosystems.
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1999~. Documentation and monitoring of these and other trends provide an observational base for efforts to improve understanding of the dynamics of land change, projections of climate change (by better specifying the contribution of land cover)
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The research would also develop increasingly robust models for addressing these dynamics in spatially explicit ways at different spatial scales and in relation to multiple sectors of human activity. Several recent developments make the area ripe for further advances, promising to transform land-use/cover change science.
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These capabilities and the emergence of other kinds of spatially explicit data have triggered interest in land use among new communities of researchers, such as demographers and economists (National Research Council 1998) , and have inspired researchers to develop various modes of spatially explicit, multisectoral land-change models that begin to integrate statistical, diagnostic, and prognostic approaches at the regional level.
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Research in this area should address the causal roles in land dynamics of relative location, past uses (path dependency) , land and resource institutions, and biophysical changes and feedbacks (e.g., climate change, nutrient depletion)
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With the changes brought about by population growth, rapidly evolving technology, more intensive agriculture, and increasing energy usage, global use of technological materials is expected to grow by as much as a factor of four 2 "Materials" includes elements, compounds, alloys, and other substances created or mobilized by human activities, except it specifically excludes the elements that constitute the grand nutrient cycles carbon, nitrogen, sulfur, and phosphorus. (The cycles of these elements have historically been dominated by natural processes, though human activities are now important perturbers; these cycles are the subject of Grand Challenge 1, Biogeochemical Cycles.
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From page 55... ...
The construction of budgets for technological materials would be a natural outgrowth of the interaction of environmental science and the emerging discipline of industrial ecology, and would follow directly from the theoretical and analytic approaches developed for the major biogeochemical cycles (e.g., Bolin and Cook 1983~. In fact, part of the scientific excitement generated by these questions is that they can be adequately addressed only through close collaboration among specialists in the natural sciences, the social sciences, and a variety of engineering disciplines to achieve the following:
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From page 56... ...
A second form of change is behavioral, and involves economic producers and consumers and the forces that determine their adoption of technologies that alter the use of materials. A useful perspective on the intellectual challenges presented by technological material cycles is provided by activities related to the biogeochemical cycles of Grand Challenge 1.
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From page 57... ...
Moreover, the sophisticated techniques and considerable scientific expertise developed to investigate nutrient cycles are directly applicable to questions about material cycles, and thus can be used to initiate research efforts in this area. In addition, as part of the Industrial Transformations project of the International Human Dimensions Programme (1999)
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From page 58... ...
Develop spatially explicit budgets for selected key materials. This research would involve quantifying reservoir contents and flows for the materials in question; constructing spatially resolved maps of these stocks and flows; and combining these results with other environmental, economic, and social data sets to learn more about the causes and consequences of changes in material cycles.
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From page 59... ...
This research would draw on contemporary material budgets, predictions of technological developments, studies of consumption patterns, and assessments of industry structure and environmental law and policy to predict how specific circumstances or policy options might strongly influence industry-environment interactions in the next several decades. Thus, this research constitutes the equivalent for impacts of resource and material use of scenario exercises such as those of the Intergovernmental Panel on Climate Change (1996~.
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