Our Changing Planet FY 1995
While human activities have long influenced local environments where people live, only since the start of the Industrial Revolution and the rapid population explosion have human activities begun to significantly influence the global environment. Measurements indicate that these activities are inducing changes in the Earth system which may have significant environmental consequences.
Climate Change and Greenhouse Warming, which relates to the potential for greenhouse gases and aerosols emitted as a result of human activities to alter the global climate and cause significant impacts on the natural environment and societal activities;
Ozone Depletion and UV Radiation, which relates to the effects of emissions from human activities on the atmospheric ozone layer, and the consequent reduction in the ability of the atmosphere to screen out ultraviolet (UV) radiation; and
Significant Variations of the Seasonal Climate, which relates to the agricultural, economic, and related effects on human activities of sharp fluctuations and variations in the seasonal to interannual climate, particularly the extended heavy precipitation and drought episodes associated with El Niñ o-Southern Oscillation (ENSO) events in the tropical Pacific Ocean.
These three issues are by no means the only issues of global environmental concern. Extension of agriculture and rapid increases in population are leading to major changes in land use, including deforestation and dryland degradation, which often have detrimental effects on the resilience and complexity of ecosystems. The development of coastlines is altering beach processes, reducing coastal habitats, and making communities more vulnerable to severe weather and sea level change. USGCRP agencies support additional research directed toward better understanding of these issues.
To meet the challenge of a changing environment, it is essential to continue to undertake research to improve the predictions of consequences and the effectiveness of options for responding to the impacts of global change.
Increases in the concentrations of CO2 and other gases are enhancing the Earth's greenhouse effect, the popular term for referring to the trapping of infrared (heat) energy in the atmosphere. In the absence of offsetting factors such as variable solar radiative output, climate models predict that increases in greenhouse gas concentrations will raise the temperature of the Earth with potentially disruptive consequences. Reconstructions of past changes in climate over the Earth's history and theoretical understanding of how atmospheric, oceanic, and biological processes combine to determine the climate suggest that the increase in global average temperature may reach 1.5-4.5°C over the next century; in addition, zones of significant precipitation may shift, generally poleward and perhaps closer to coastal regions. Recent evidence, however, has shown that increases in atmospheric aerosols, which can scatter solar energy and alter cloud cover, may offset some of the effects of increases in greenhouse gas concentrations. Because of the inhomogeneous distribution of aerosols and because of uncertainties in their influence on cloud formation and hence on radiative transfer, their impact on climate remains difficult to quantify (see discussion of Volcanic Cooling).
The U.N. Framework Convention on Climate Change is prompting governments to contemplate (and take) action to reduce greenhouse gas emissions. To establish the scientific basis for national and international policy formulation and decisions relating to human- induced emissions of radiatively-active substances, it is necessary to monitor and understand the changes in concentrations of radiatively- active gases and aerosols in the Earth's atmosphere and to quantify the effects of those changes on the radiative forcing of climate. Greenhouse gases of major policy significance include CO2, CH4, N2O, the CFCs and their substitutes, and ozone in the lower stratosphere and troposphere. The atmospheric concentrations of all of these gases are changing as a result of human activities. Recent findings have provided important new insights:
Because projected acceleration in the rate of change is vitally important, it is essential to explore national and international options that may be available for reducing the extent and momentum of human influences on global change. One aspect of such an effort is the development and utilization of new technologies. In the energy sector, contributing research is underway to develop alternative technologies that are renewable and more sustainable; in the agricultural and food supply sector, new efforts are ongoing to improve crops and their resistance to pests and other stresses. Another aspect of exploring response options depends on improving the capability to understand and predict human behavior and to understand the abilities and willingness of societies to change, both sociologically and technologically. The FY 1995 USGCRP budget proposes more concentrated research on the economic and social effectiveness of potential policy options, especially those that encourage more sustainable patterns of resource use and management.
Ozone-layer depletion, the associated increase in ground-level ultraviolet radiation, and the impacts on human health and biota are significant environmental problems (see discussion of UV Monitoring). Human-produced chemicals containing chlorine and bromine, collectively referred to as halocarbons, are depleting the stratospheric ozone layer. Even if the control measures of the United Nations Montreal Protocol (1987) and its amendments are fully implemented, ozone depletion will continue for nearly another decade. Because of the long atmospheric lifetimes (up to 100 years) of many of the halocarbons, the earliest recovery from the Antarctic ozone "hole" is several decades away, and a return to near the natural atmospheric levels of chlorine and bromine, and therefore of ozone, will take centuries. Ozone-layer depletion is also known to be linked to global climate change. National and international decision makers continue to turn to the scientific community for predictions of the future condition of the stratospheric ozone layer and for scientific advice on how best to manage its rehabilitation.
Very recent measurements have shown that the rates of increase of CFCs and halons are beginning to slow, while substitute CFCs are beginning to accumulate in the atmosphere. These results, documented through a worldwide measurement network, verify that international decisions regarding emissions controls are beginning to have effects on atmospheric halogen levels.
Long-term global satellite and ground-based monitoring activities have demonstrated that stratospheric ozone depletion is occurring over most of the globe, except in the tropics. Downward trends of several percent per decade are now observed in all seasons at mid- latitudes (poleward of 20° ), with winter and springtime declines of as much as 6 - 8% per decade observed poleward of 45 ° . Global ozone depletion was observed to be significantly worse in 1992 and 1993, including wintertime depletions of up to 25% over populated regions in the high latitudes of the Northern Hemisphere.
The observations of unexpected and unprecedented ozone depletion in the past two years, coinciding with the period following the eruption of Mt. Pinatubo, have revealed new gaps in understanding and, hence, in prognostic capabilities. While ozone levels may have been perturbed by the Mt. Pinatubo eruption, either by changes in stratospheric temperature and/or circulation, or by enhanced heterogeneous chemistry, the magnitude and timing of the recent, large ozone decreases are not fully explained by the current understanding of these effects. Consequently, evaluation of the heterogeneous chemistry associated with surface reactions on aerosols through laboratory studies, atmospheric observations, and modeling remains a key research priority that requires an enhanced focus.
Stratospheric ozone depletion is linked to changes in the surface climate. Loss of lower-stratospheric ozone is predicted to lead to a cooling tendency at the surface. As a result of this effect, ozone decreases offset some of the greenhouse warming of the halocarbons that caused the ozone change. Such indirect couplings complicate projection of changes in the global climate.
Variability within the natural climate system is historically perhaps the single most fundamental environmental factor affecting the course of human development. Societies, economies, and cultures throughout the world have been developed based in large part on the effectiveness of their ability to adapt to their climate. When temperatures and precipitation patterns depart significantly from historical means, the consequences, especially if unanticipated, can be catastrophic. Examples of the global implications associated with year-to-year variations in the climate include extreme drought such as that experienced in southern Africa in 1991-92; severe flooding, including the recent deluge in the midwestern United States; and complete elimination of critical sectors of national economies, such as the 1972-73 collapse of the Peruvian anchoveta fisheries.
Successful simulation of the mutual evolution of the atmosphere and ocean through coupled modeling has yielded a demonstrated capacity to predict the onset of the ENSO warm events, known to be central to short-term variability in the Earth's climate system. Progress in climate prediction has been stimulated by the development of a variety of models used for simulating ENSO events, by empirical studies that have better defined the global impacts of ENSO, by theoretical studies that have elucidated the underlying oceanic and atmospheric processes accounting for the predictability of ENSO, and by the development of substantially improved observing capabilities in the Pacific for initializing and verifying models under development for ENSO prediction. Compared to the early 1980's, when observational techniques were inadequate even to monitor the evolution of an ENSO event once underway, observations are ongoing to detect day-to-day changes in surface winds, sea surface temperature, upper ocean thermal structure, and ocean currents on a basin scale in the tropical Pacific. The capability to forecast the onset of ENSO phenomena, up to a year in advance, represents a near-term return on the USGCRP investment (see discussion of ENSO Forecasts).
To ensure that advances in climate prediction continue and are most appropriately suited to the specific needs of affected populations, a Seasonal-to-Interannual Climate Prediction Program (SCPP), based on the evolution of existing USGCRP program efforts to observe, research, model, and assess the ocean and the atmosphere, is currently being established. The Program will be based on an integrated approach that addresses climate variability from its origins in coupled atmospheric and oceanic behavior through its physical manifestations and socio-economic impacts. A fundamental component of the SCPP is the plan to establish a multinational network of research and application centers to develop and issue experimental seasonal to interannual climate predictions based on global ocean-atmosphere modeling of the ENSO phenomenon. The resulting forecasts will be disseminated to those nations and regions that are particularly impacted by climate variability associated with the ENSO phenomenon. International Application Centers will refine the global forecasts and tailor guidance to the specific conditions and needs of the localities they serve.
Many of the countries most affected by ENSO events are developing countries with economies that are largely dependent upon their agricultural and fishery sectors as a major source of food supply, employment, and foreign exchange. These countries often rely on a regular and predictable climate cycle (e.g., monsoon rains) to provide food and water for their populations. Climate information that can be used by local decision makers to prepare for anomalous precipitation and temperature patterns will provide the means to maintain and enhance their agricultural, fishery, and economic productivity.
This new ability to forecast seasonal to interannual anomalies accurately, along with strong indications of the potential for continued progress in predicting anomalies in mid-latitudes, represents a seminal contribution to the understanding of Earth systems processes. Through application of this new "technology," this scientific breakthrough can be turned into an effective tool that will contribute to the quality of human life, and to increased economic efficiency.
The development of a predictive understanding of how human activities are affecting and affected by the Earth system is among the most complex of all scientific undertakings. This complexity arises for many reasons. Human influences and interactions with the global environment cover spatial scales from local to global and extend over time scales from days and seasons to decades and centuries, both back into the past and forward into the future. The influences and interactions involve all sectors of global society and all components of the Earth system, meaning that predictive capabilities must be developed for social and institutional systems as well as physical, chemical, and biological systems. Because the environment is so intimately tied to people's lives, all are impacted by any changes that might occur and all are interested in the character and quality of the predictions.
To ensure a coordinated focus that addresses questions ranging from understanding what is happening and what will happen, to determining what the societal consequences will be and what can be done to moderate or mitigate these impacts, the USGCRP is functionally organized into a framework of six coupled streams of research activity (see figure):
These streams of research activity are being designed and implemented to provide sound scientific information in support of national and international policy debate and decision making concerning the broad spectrum of natural and human-induced changes occurring in the global and regional environment.
To support coupling of USGCRP research activities to the national and international scientific community and the communication of research results to the public, the USGCRP includes two activities focusing on outreach and integration:
Because of the need for improving understanding of the complex and diverse relationships between human activities and global change, the USGCRP will substantially increase support for programs that develop tools for assessing policies and options, especially in the area of integrated assessment methods. It also will increase support for research in the social, economic, and policy sciences, and for research that examines the impacts of and responses to global change. With higher levels of support, USGCRP programs will be able to improve understanding of the impacts of global change on human health, economic systems, settlements, and societal structures. Increased support in programs contributing to the USGCRP will also facilitate research on options for mitigation and adaptation strategies and the development of technologies to implement those strategies. Most significantly, new research in FY 1995 will result in better connection of research to policy making. Of special interest to policy makers will be the development of new decision analysis tools and methodologies for integrating assessments of global change, its impacts, and potential response options.
Linking research to policy requires the development of new programs on the human dimensions of global change. New social and economic research will focus on present and future patterns of greenhouse gas emissions, actions that can be taken to modify those patterns, and the effectiveness and potential benefits and costs of these actions. Contributing research will improve understanding of the effects on natural systems of factors like population growth, economic growth, technological change, and international trade.
Just as uncertainties remain with respect to the response of the climate system to changing emissions of greenhouse gases, important gaps in knowledge persist as to how people and institutions respond to changes in natural and human environmental conditions. These uncertainties will affect future levels of emissions, and they will influence the consideration and effectiveness of specific policies to reduce those emissions.
Integrated assessments bring research results from natural, social, and policy sciences into a framework that helps decision makers identify and evaluate actions to respond to environmental changes. Integrated assessments can help set priorities for the natural as well as the social and policy science research areas by providing information about the relative value to decision makers of information that is likely to result from research investments. Another major objective of integrated assessment is to develop information about interactions of complex, linked systems and problems and to make this information available in the decision- making process. Integrated assessments can advance the state of research by providing a framework for synthesizing findings and data from the physical, chemical, geological, biological, economic, social, and health sciences (see figure).
For FY 1995, the USGCRP proposes to markedly increase its support of integrated assessment activities. Some of the increase will support the development of methods and tools. One set of tools, integrated assessment models (IAMs), are an emerging type of model that link human forcing functions (e.g., greenhouse gas emissions), the effects of those forcings on the Earth-system, the resulting impacts on humans and ecosystems, and the economic and environmental consequences of potential responses. The models allow different global climate change policy options to be evaluated in terms of their influence on various parameters, such as their effect on Gross Domestic Product or employment. A number of the climate change IAMs have evolved from cost models developed primarily in the 1970's and 1980's that predicted emissions and calculated the cost of meeting various emission or concentration goals.
IAMs can be of various types, depending on the issue being addressed. Some IAMs are globally aggregated and do not, for example, distinguish the United States from the rest of the world. Such models can be used to study sequential decisions and the value of additional information. These models cannot, however, facilitate evaluation of policy instruments such as appliance efficiency standards, automobile efficiency standards, or having separate taxes on different fuels.
IAMs can also be spatially disaggregated, dividing the world economy into up to a few dozen regions. These larger models include more realism in their treatment of specific aspects, such as regional emission patterns and economic activity by sector. This type of IAM will be better suited to answer policy questions such as how to trade off the different greenhouse gases using economic as well as natural science criteria. For example, a biomass energy option or carbon sequestration program may become less effective if climate change is harmful to forest systems. Similarly, the model may indicate that international application of policies such as are required in the United States by the Clean Air Act may induce changes in future climate (e.g., through requirements for reduced emissions of particulate and sulfur) that need to be considered in evaluations of climate changes due to greenhouse gas emissions policies.
Phenomena associated with global change can affect currently stable regional environments and indigenous natural resources, and could have profound implications for land-use management. Regional-scale integrated assessment models are being developed based on detailed modeling of physical, chemical, geological, biological, and human systems. In many cases these models can define critical thresholds of environmental change. Early work is proceeding on such models for regions including the Great Lakes, the Great Plains, and the Southwest.
USGCRP support for integrated assessment methods will enhance efforts to develop reduced-form models that mimic the more complete natural science process models. The program will also encourage examination of a variety of methodological issues related to integrated modeling, including development of additional quantitative and qualitative approaches for integration. Related research will include: (a) modeling and evaluating the implications of rates of global change in addition to the extent of absolute change; (b) evaluating the impact of an increased frequency of extreme events; (c) uncertainty analysis of physical, economic, and biological parameters; (d) review of the successes and shortcomings of past integrated assessment studies (e.g., acid precipitation, stratospheric ozone, supersonic transport); and (e) comparison and evaluation of integrated assessment methodologies.
International population trends and the human condition
Patterns of trade and global economic activity
Adaptation and mitigation, including environmental resource use and management
New research within the USGCRP will focus on activities that drive global change and which will be affected by it. A number of specific questions confront policy and decision makers in governments and in many different economic sectors as they consider the management and use of resources such as energy, land, water, soils, and forests. Foremost among these questions are "How is global change likely to affect the availability and quality of resources?" and "How will policies and actions designed to mitigate or adapt to global change affect the supply, cost, and use of resources?" Research on resource management is especially important in situations where resources have multiple uses (see figure). The vulnerability of large-scale resource management investments to global change, especially in developing countries where resource investments often provide critical and life- sustaining services, is another important issue.
Another priority is the valuation of environmental goods, services, and assets, which requires fundamental research on how changes in the availability and quality of these resources are understood and measured in social terms. Environmental accounting poses significant definition and characterization problems. Unlike economic systems, environmental systems do not have a calibrating mechanism such as market prices to determine relative unit values. While numerical values exist for environmental goods, the consistency and interpretation of these values is a problem. Existing techniques to measure environmental values, such as contingent valuation, will be the focus of further development, testing, and validation through research conducted as part of the USGCRP. Alternative paradigms of valuation, derived from other social and behavioral sciences that reflect the psychological, cultural, and ethical dimensions of environmental values, will be studied.
Policy science research within the USGCRP will also focus on data, analytical methods, computational issues, and modeling requirements of policy analysis. Significant data issues include availability, organization, validation, reliability, and use of expert judgment techniques to fill data gaps. Analytical issues include developing methods for extracting general relationships from case studies, which are important for historical evidence as well as for studies on environmental services and benefits.
The President's Climate Change Action Plan, a $280 million program in FY1995 (not part of the USGCRP budget), to limit greenhouse gas emissions to the atmosphere consists of almost 50 actions involving all sectors -- industry, transportation, homes, office buildings, forestry and agriculture. Several USGCRP agencies are participating in biennial reviews of progress under the Action Plan to report on emissions trends and to adapt existing programs to evolving circumstances. Improved land and agricultural management will be encouraged through technical and economic assistance to private, non-industrial landowners. New residential appliance standards and a renewable technology consortium are being established to encourage improved efficiency and commercialization of renewable technologies. Another program is encouraging the use of more energy-efficient lighting equipment.
Funding for greenhouse gas mitigation research to develop energy-efficient technologies for reducing emissions from all sectors is proposed to increase about 40%. Examples include energy supply and fuel usage in the utility, industrial, commercial and residential sectors; process and operation studies in energy-intensive industries such as primary metals, chemical and petroleum, cement, and pulp and paper; fuels and efficiency improvements within the transportation sector, as well as transportation modes and influences of urban planning; energy consumption, biomass burning practices, and fertilizer usage in the agriculture and forestry; afforestation/reforestation efforts and maintenance of soil carbon pools; coal mining practices; and CFC alternatives and new refrigeration, air conditioning and fire-retarding technologies (see figure). This additional research, outside of the USGCRP, contributes, however, to the overall goals and objectives of the USGCRP.
Impacts and adaptation research includes understanding the effects of global change on water supply and quality; review of water utilization and related technologies; understanding the effects of global change on food, fiber and timber supply, and ways to reduce vulnerability in these areas; understanding vulnerability and adaptability of species habitats and maintaining the health and diversity of natural systems; understanding the interactions and effects of global change on humans; and researching human adaptability to change. The SGCR along with the CENR Subcommittee on Environmental Technologies and Engineering Research, is reviewing all activities within the Federal government that are important to understanding the impacts of global change, the potential for adaptation to changes that might occur, and means of mitigating change.
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