Grantee Research Project Results
Final Report: Integrated Environmental Futures for the U.S.
EPA Grant Number: R827583Title: Integrated Environmental Futures for the U.S.
Investigators: Bernow, Stephen , Rajan, Sudhir Chella , Cleetus, Rachel
Institution: Tellus Institute
EPA Project Officer: Chung, Serena
Project Period: July 1, 1999 through July 1, 2000 (Extended to March 19, 2001)
Project Amount: $150,000
RFA: Futures: Detecting the Early Signals (1999) RFA Text | Recipients Lists
Research Category: Water , Sustainable and Healthy Communities , Land and Waste Management , Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration
Objective:
The general objective of this study is to develop comprehensive integrated scenarios of alternative environmental futures for the United States over a 50-year timeframe. Given the complex interactions among economic and environmental phenomena and the inherent uncertainties of their evolution over long time periods, it is not meaningful to attempt to provide definitive predictions of the future. Rather, the scenarios are meant to be general quantitative accounts that provide early warning signs of the environmental impacts of the most likely patterns of energy and resource use, as well as alternative pathways involving modest policy interventions that could avert these impacts in the future.Summary/Accomplishments (Outputs/Outcomes):
This study attempts to identify the major environmental threats in the United States over the next 50 years and the basis for mitigating them. Its focus is on the emissions of criteria air pollutants, greenhouse gases (GHGs) and toxics from energy use and industrial production, the land-use and environmental impacts of agriculture and forestry, and water use from these and other activities. We develop two different scenarios for energy, agriculture and forestry, and water use in the United States, driven by major demographic, economic, technological, and institutional factors.Each scenario envisions a future shaped by the continued evolution and expansion of current values and socioeconomic relationships, with no major surprises, sharp discontinuities, or fundamental changes. The reference scenario reflects a continuation of recent trends with no major changes in policy, with the problem of resolving environmental stress arising from population and economic growth left largely to the workings of competitive markets under current policy and regulatory conditions. The policy reform scenario assumes that modest targeted policy interventions are designed to forestall some of the more serious environmental impacts, and sustainability is pursued as a proactive strategic priority, largely through improvements in technologies and production practices.
The investigators used a software tool, PoleStar, to consider economic, resource, and environmental information, and to examine development scenarios. PoleStar also is being used for ongoing scenario development and sustainability discourse in the work of the Global Scenario Group (gsg.org) and the United Nations Global Environmental Outlook reports (GEO 3 forthcoming).
Energy and Environment
The United States accounts for about 40 percent of global energy demand and contributes to roughly a quarter of the world's energy-related GHG emissions. While its energy intensity (primary energy use per GDP) has improved significantly since the early 1970s, continued economic expansion is expected to drive overall energy consumption as well as emissions upwards in the future, unless there are targeted policies to encourage further improvements in efficiency and the increased use of renewable energy resources-especially wind, biomass, solar, and geothermal.
The main drivers for the energy and emissions scenarios are population, economic and income growth, and expected changes in technology and fuel use within each sector of the economy. The reference scenario projects primary fuel use to go up by nearly 50 percent over the next half-century. This increased energy use in the reference scenario will be reflected in increasing emissions of GHGs, criteria air pollutants (except for SO2), and toxics, notwithstanding changes in stock turnover in all sectors towards more efficient processes, equipment, appliances, and devices, as well as existing policies to control emissions.
This scenario sends a set of warning signals, perhaps the most important being the rise in GHGs. Under the reference scenarios of the Intergovernmental Panel on Climate Change (IPCC), global average temperature could rise by about 5 to 10?F over the next century, with greater changes in various regions and time periods. To avoid this, the IPCC and other studies show that global cumulative GHG emissions over the next century should be reduced by at least 50 percent from current trends. This would mean that the worldwide emission would be reduced from about 1 metric ton of carbon per capita per year to about 0.3 tons per capita per year, accounting for population growth. For the United States, this suggests that its current 5.5 tons per capita be reduced almost twenty-fold over the course of the next century. Clearly, the trajectory of our reference case provides early warning of a risky path that deserves policy attention. The increases in emissions of the various other pollutants (and the slow decline in SO2 emissions) also are troubling, given the ample evidence of the ecological and human damages that they are causing at their current levels.
Consequently, we developed a plausible (alternative) policy scenario that would require or induce shifts towards greater energy efficiency and cleaner energy resources. In the policy scenario, fuel consumption decreases by about 30 percent between 2000 and 2020, and remains at that level through 2050, in spite of continued population and economic growth. Thus, in 2020, fuel consumption in the policy scenario is about 55 percent of the reference case, and by 2050 about 45 percent. Moreover, the share of renewables, like wind, geothermal, and solar, as well as biomass (from agricultural and forest wastes and crops), wood, and hydropower, increases to nearly 35 percent of primary fuel use in the policy case in 2050, compared with just under 5 percent in the reference case. The combined effect of alternative energy and emissions control policies introduced in all sectors will result in CO2 emissions being about 50 percent lower than 1998 levels by 2050, with similarly deep reductions for CO, SO2, NOx, PM, and VOC from all emission sources.
Industry. In the industrial sector, reference scenario projections show increasing fuel consumption patterns dominated by bulk chemicals and paper industries. In the policy reform scenario, we expect that incentives to modernize plants, use advanced technology, increase the use of renewables, and adopt combined heat and power (CHP) systems will reduce fuel demand by over 30 percent, and yet result in about a six-fold increase in electricity exports.
Buildings. In households and commercial buildings, space heating will continue to be the dominant end-use in both scenarios, although the entry of efficient heat pumps will reduce the energy intensity of space and water heating and cooling devices. Most significant will be the rapid growth of new intelligent household appliances, including personal computers and device monitors, many of which could play a role in reducing the energy intensity of refrigerators, heaters, and space coolers. In the policy reform case, we assume more rapid entry of heat pumps and the introduction of household natural gas-fired fuel cells in the early years for heat and electricity generation at the household level.
Transportation. In the transportation sector, whereas the reference scenario projects demand for petroleum products to double by 2050, even modest policies can cause a 50-percent reduction in demand for gasoline and diesel. The latter include incentives (such as feebates) to freeze the share of sports-utility vehicles at current levels; a fuel efficiency initiative for light-duty vehicles; a portfolio requirement for sales of electric, fuel-cells and ethanol-powered LDVs; and accelerated introduction of advanced aircraft engine technologies and high-speed rail. Additionally, the policy reform scenario assumes modest reductions in passenger miles traveled through smart growth initiatives and some mode shifting to high-speed rail from intercity air travel.
Electricity Production. Finally, in the electric sector, the reference scenario projects increasing electricity demand by 2050 of around 43 percent, as opposed to around 8 percent in the policy reform case. Also, whereas most of this increased demand in the reference case would be met by increasing supply of new capacity, primarily in the form of coal and gas-fired power plants, the policy case assumes that CHP and renewables (through a portfolio standard) would contribute to a major share of the capacity by 2050. The policy reform scenario results in significant reductions in emissions of SO2, NOx, CO, and CO2 from electricity generation.
The aggregated summary results of the two energy scenarios are shown in Figures 1-7.
Water Demand
Freshwater withdrawal in the United States is dominated by industry, including the electric power generation sector (Figure 8). Aggregate water use has declined since the 1980s, largely due to reductions in hydropower and other industrial use, as well as stagnation in irrigation use, although domestic use has increased roughly with population growth (Figure 9). Total withdrawal in 1998 was around 20 percent of annual renewable water resources in the country, but consumptive use was less than 10 percent of availability. In the reference case, normal efficiency improvements will cause per capita consumption in all sectors to fall by nearly 1 percent per year, whereas per capita availability is expected to decline at roughly the same rate, thereby placing no significant strain on freshwater in the aggregate. However, considerable regional variations can be expected, with the west and the southwest, in particular, likely to face additional stresses in the next half-century. The policy reform scenario assumes per capita consumption is reduced at nearly 2 percent per year through efficiency improvements primarily in industry and agriculture, leading to an overall 36 percent decline in demand through 2050 (Figure 9).
Agriculture, Forests, and Urban Land
The abundance of land in the United States?a large land area and a relatively small population?has allowed multiple land uses and, with the aid of human initiative and technology, very high productivity. With this high productivity and cropland at about one-fifth of its land area, the United States is the largest producer and consumer of agricultural products in the world. The agricultural sector in the United States has been tremendously successful in wresting ever-increasing crop yields from the soil through the use of efficient machinery and modern cultivation practices. As a consequence, it has been possible to produce food and fiber to meet the demands of growing populations, both domestic and global. But this intensive use of arable land, coupled with the use of chemical inputs, also has led to adverse effects on the natural environment. The key environmental issues of concern associated with the practice of agriculture include threats to endangered and other species through loss of habitat, loss of wetlands, soil erosion, threats to water quality through agricultural runoff, the introduction of toxins into the food chain (pesticides and fertilizers), and the possible side effects of the widespread use of biotechnology.
In both the reference and policy reform scenarios, over the next 50 years the agricultural sector will continue to experience steady growth. Export markets are an important factor in fueling this growth. The amount of land devoted to agriculture will remain relatively steady at about 20 percent of land area, or 460 million acres, under both scenarios. Thus, we expect that most of the increases in output will come about through the increased crop yields.
The livestock sector in the United States has expanded in recent years due to low feed prices coupled with high meat prices. In the reference scenario, we expect that these feed prices and growing world demand for meat will continue to provide favorable production conditions in this sector. Meat contributes about 25 percent of dietary calories per capita per day in the United States. The feed requirements of livestock put a big burden on land due to the inherent inefficiency of conversion of feed to meat. In the United States, about 70 percent of animals are grazed and 30 percent raised on feedlots, although this number varies by species of animal. Requirements of crops for feed can be expected to rise by up to a third over the course of 50 years. There will be an increasing trend towards animal production on feedlots instead of in open pasture. Thus, in the reference scenario, agricultural runoff will continue to be the leading source of impairment of water quality in streams, rivers, and lakes, and their associated ecosystems. These include contaminants like soil sediment, nitrates, phosphorous, and potassium, a wide variety of pesticides, minerals and dissolved salts from irrigation water, and pathogens from livestock wastes.
In the policy reform scenario, we assume that crop yields are, on average, higher due to policy-induced improvements in agricultural practices to ensure that increased output does not require more land use. We assume that there will be increased use of sustainable agricultural practices like conservation tillage, rotary hoeing for weed control, less use of pesticides through integrated pest management, crop rotation and biological methods (e.g., the use of carefully selected pest predators, breeding of pest-resistant crop types, diversification of crop species to maximize chances of resistance), adoption of organic supplements and natural herbicides, better irrigation systems, and better management practices to deal with soil erosion. These practices will be adopted without compromising increasing crop yields. There also will be some investment in crops to produce biomass energy. In the livestock sector, we assume a slight decline in beef production, while poultry and pork production continues to rise. We also assume that the meat-to-feed and milk-to-feed ratios for livestock will increase through the use of better nutritional supplements.
The aggregated summary results of the two agriculture scenarios are shown in the attached figures (see Figures 10-13).
The forest products industry is of major importance to the U.S. manufacturing sector. The United States is the world's largest producer and consumer of wood products. It produces about 30 percent of global industrial roundwood and similar proportions of the sawn timber, wood-based panels, pulp, and paper. Pulp and paper is the tenth largest manufacturing industry and accounts for two-thirds of the forest sector manufacturing output. It is the largest self-generator of electricity in American manufacturing and the third largest consumer of electrical energy from the grid. The forest industry also is a major source of exports from the United States. The future growth of demand for wood products from foreign countries will be a major determinant of the demand for timber in the United States.
Forest lands face several environmental threats, some of which could grow over time as production expands, including the danger of forest fires due to buildup of flammable materials; the invasion of non-native plant species; the loss of biodiversity; air pollution and acid rain; the problems created by urban-wildlands interfaces; and the degradation of watersheds. Many of these are the effects of increased commercial activity both inside and outside the forest lands. The multiple uses of forest lands invariably have given rise to competing pressures on these lands. Another reason for loss, fragmentation, and pressures on forest land is conversion to urban-built environments caused by population expansion.
The future health of forests in the United States depends crucially on the sustainability of current harvesting methods. The private sector clearly has shifted operations towards clear-cutting in the belief that this method can be practiced in a sustainable and responsible fashion. A simple measure of whether this is sustainable is provided by the growth-to-removal ratio of growing stock on timberlands, which in 1996 was below 1.0 for inventories on forest industry lands. Such a trend in the long run could lead to a net depletion of forest resources. Additionally, there have been important changes in the makeup of forest lands as determined by the variety of tree species and the density of trees; in the southeastern United States, for example, there is an increasing trend towards single-species pine plantations for timber.
In the policy reform scenario, we assume that harvest practices will change to ensure that the growth-to-removal ratio stays above unity. The rate of afforestation on forest industry lands will increase enough to meet the increasing overall demand for forest products. While per capita consumption of industrial roundwood in the United States is currently 62.5 cubic feet per year, about six times the world average, in the policy reform scenario we assume that this drops to 40 cubic feet by 2050, largely by using non-wood substitutes for building house frames. This substantially lowers the projected demand for wood products that might be expected with population growth.
As the population of the United States has grown, land devoted to urban uses also has expanded, but it is still under 3 percent of total land area. Annually, about 1 to 1.3 million acres of land were converted to urban uses until 1990, but that rate has more than doubled in recent years. Most (72 percent) of the net increase in urban areas comes from pasture, range, forest, or other rural land. The rest comes from cropland. In reference and policy reform scenarios, there is rapid urban growth that will in turn cause some major changes in resource use and lifestyles. In the future, we can expect that most of the urban land area will come from converting forest lands, pastures, or rangelands to built environments. The total urban population will increase from about 200 million in 1996 to about 350 million (about 85 percent of the population) by 2050 (United Nations Population Division, 1997). The growing urban centers will create localized pressures on land, water, air, and energy resources. Thus, if the needs of the inhabitants are to be met in efficient and clean ways, it is clear that cities will have to undertake significant investments in infrastructure. In addition, lifestyle changes will become imperative.
Overall land use area changes will be small over the 50-year horizon. Cropland and forestland are expected to decline marginally-5 percent over 50 years-and pastureland will increase by about 5 percent during the same timeframe. The land area devoted to built environments is expected to increase almost in direct proportion with population growth. In the reference scenario, there will be an increase of about 1.3 percent per year; in the policy reform scenario, the growth is assumed to be about 0.5 percent per year. The policy reform scenario will include changes in urban planning, such as new zoning laws and space-efficient housing, designed to decrease sprawl in large cities (see Figure 14).
Conclusions
We have examined patterns of change in all major sectors of production and consumption in the United States and their consequences for the environment and resource use. These scenarios were developed for a 50-year period in a reference case, involving no major changes in policy or regulatory regime, and for a policy reform case, in which there are important changes in technology and production practices relative to the reference scenario. Although we had originally envisaged the inclusion of critical uncertainties and stresses in the development of the scenarios and a range of possible demographic and economic changes as drivers, we were not able to cover these features as all of our resources had to be directed to the detailed scenario construction and results. Also not included are scenarios for solid waste as well as explicit benchmarks relating to human and resource sustainability.
Across sectors, by 2050, the reference scenario shows significant increases in energy, resource use, and emissions of GHGs, criteria air pollutants, toxics, and water pollutants from agricultural runoff-in some cases as much as double the levels in 1998. The policy scenario, by contrast, shows significant decreases of all these environmental indicators by 2050 as a result of shifts in technology and production practices that could be brought about by relatively modest sectoral policies. These findings suggest that the scenario approach can usefully incorporate complex inter-sectoral connections and environmental path dependencies over a long time horizon. They help illustrate to policymakers and the public in the U.S. context the importance of taking early policy decisions to avoid longer term ecological and resource crises.
Conclusions:
KEY RESULTS
Figure 1. Primary energy consumption in reference and policy reform scenarios | Figure 2. Trends in CO2 emissions (reference and policy reform) |
Figure 3. SO2 emissions (reference and policy reform scenarios) |
Figure 4. NOx emissions (reference and policy reform scenarios) |
Figure 5. Emissions of CO (reference and policy reform scenarios) |
Figure 6. VOC emissions (reference and policy reform scenarios) |
Figure 7. PM10 emissions (reference and policy reform scenarios) |
Figure 8. Primary shares of water use
(1998) |
Figure 9. Total water use trends (historical, reference, and policy scenarios) |
Figure 10. Change in yields for major crop types
(reference and policy reform scenarios) |
Figure 11. Pesticide runoff (reference and policy reform scenarios) |
Figure 12. Nitrate runoff (reference and policy reform scenarios) |
Figure 13. Phosphate runoff (reference and policy scenarios) |
Figure 14. Area used by built environment reform
(reference and policy reform scenarios) |
Supplemental Keywords:
modeling, public policy, multi-attribute, climate, decision-making, renewable resources, innovation, precautionary principle, critical loads, eco-efficiency, resource depletion., RFA, Economic, Social, & Behavioral Science Research Program, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, climate change, Economics, Environmental Monitoring, decision-making, Ecological Risk Assessment, Exp. Research/future, Social Science, Economics & Decision Making, Futures, demographic, eco-efficiency, ecosystem valuation, emerging environmental problems, precautionary systemic approach, human activities, sustainable development, socio-economic changes, climate studies, decision making, risk management, global scenarios, socioeconomics, conservation, environmental policy, precuationary systemic approach, exploratory research, changing environmental conditions, sustainability, legal and policy choices, public policy, global warming, ecological dynamics, integrated ecological economic model, multi-criteria decision analysis, futures research, integrated environmental futuresProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.