▼ VIEWPOINT
Recognizing the LIMITS of Environmental Science and Technology Science and technology alone cannot solve pollution problems or meet the challenge of MICHAEL H. HUESEMANN PAC I F I C N O RT H W E S T N AT I O N A L L A B O R AT O RY
sustainable development.
he public, many policymakers, and even some environmental professionals believe that science and technology can solve most pollution problems, prevent future environmental impacts, and pave the way for sustainable development through the design of clean industrial processes. This article questions the validity of this optimistic viewpoint and presents several important and critical limits to environmental science and technology.
© 2003 American Chemical Society
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The failure of reductionism The very success of western science during the past 200 years is based on reductionism—explaining nature in terms of mechanistic processes and attempting to understand the whole of nature by studying its isolated parts (1). By generating detailed knowledge that has made it possible to expand the exploitation of nature while being incapable of determining all of the possible side effects, western science may actually be considered a principal causative factor of many current environmental problems (2, 3). Considering that environmental science currently cannot elucidate all of the complex interrelationships found in nature and that there will never be enough research funding to investigate more than a few isolated causeand-effect relationships (which, in turn, almost guarantee that extremely important issues will be overlooked), it follows that present scientific methods are intrinsically incapable of providing sufficient knowledge to protect the environment.
Limits imposed by the conservation of mass principle Most physical treatment technologies attempt to reduce the risk posed by a pollutant using various strategies, such as limiting contaminant dispersal (e.g., landfilling), reducing toxic effects by dilution (e.g., smokestacks), or transferring contaminants from one medium to another (e.g., air-stripping of contaminated water). However, according to the conservation of mass principle, the total mass of the pollutant is simply contained, diluted, or transferred—not reduced, and thus, it is unlikely that many physical treatment technologies can provide long-term solutions to pollution problems (3). For example, landfill integrity cannot be maintained indefinitely, so any pollutants that do not degrade over time (e.g., metals) are likely to be released at some later time, thereby transferring the associated risks to future generations. Similarly, diluting or transferring pollutants to another medium does not necessarily render them less harmful. In reality, the risks appear to be reduced only because current scientific methods are limited to detecting the most obvious toxic effects of the pollutant before treatment, while being unable to determine more subtle and remote environmental impacts of contaminants that have been diluted or transferred to another medium. In short, many physical treatment technologies are incapable of permanently solving pollution problems; rather, they transfer risks from one place to another, or from the present into the future.
Order at the expense of more disorder The second law of thermodynamics implies that for each unit of “order” (neg-entropy) generated during an environmental remediation process that restores a site to its original condition, more than one unit of “disorder” (entropy) is created somewhere else in the environment. A number of environmental scientists have suggested that an increase in entropy is correlated with environmental disruptions (3–6). Thus, a localized environmental cleanup can only be achieved at the expense of more environmental disturbance elsewhere. For example, concentrating dispersed groundwa260 A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / JULY 1, 2003
ter contaminants during pump and treat is associated with the wide dispersal of air pollutants, such as SO2 or CO2, from fossil fuel-powered engines, which will cause environmental problems elsewhere. It is clear from a practical and thermodynamic perspective, human intervention is unlikely to ever remove the most highly dispersed persistent contaminants, such as chlorinated pesticides or toxic trace metals, from the environment. Instead, the long-term fate and risk of these compounds are determined by the slow pace of naturally occurring processes, such as chemical and biological transformation, immobilization, dispersion, and dilution. Because remediation technologies are not very effective in dealing with dispersed contaminants and the secondary negative consequences of cleanup operations are inherently unavoidable, some have proposed redesigning industrial processes so that emissions are minimized and serious environmental pollution is prevented in the first place. Consequently, some environmental research began to focus more on pollution prevention, and a new academic discipline, industrial ecology, emerged during the past decade with the mission of designing more environmentally compatible industrial processes (7, 8). The primary focus of these pollution prevention efforts has been to improve “eco-efficiency”, which is defined as environmental impact per unit industrial output, and to reduce the dispersal of wastes by enhancing recycling with the objective of “closing the materials cycle”. The ultimate goal of industrial ecology is to develop industrial processes that have minimal impact on the environment, thereby paving the way for future sustainable development. However, there are numerous reasons why it is unlikely that industrial processes with sufficiently minimal environmental impact can be designed.
Myths about recycling and renewable energy There is no question that increased efforts in recycling materials, such as scrap metals, used packaging, or spent industrial solvents, will greatly reduce the amounts of wastes released into the environment. However, it should be recognized that the “dissipative” use of many consumer products results in highly dispersed wastes, which become so diluted that their recovery becomes impractical because of the excessive energy requirements involved (9). For example, how will it ever be possible to recycle the numerous chlorinated organic hydrocarbons that have bioaccumulated in animal and human tissues across the globe, the copper dispersed in fungicides, the lead in widely applied paints, or the zinc oxides present in the finely dispersed rubber powder that is abraded from automobile tires? Consequently, the lofty goal of isolating the industrial economy from the environment by “closing the materials cycle” will probably not be realized because complete waste recycling is impossible in practice. Even if it were possible to design “zero-emission” industrial processes by completely “closing the materials cycle”, significant negative environmental impacts related to generating energy would still be unavoidable. In order for future industrial systems to be sustainable, © 2003 American Chemical Society
the energy required to run modern economies must come from renewable resources. However, many have assumed that renewable energy is more environmentally friendly than nonrenewable energy sources such as fossil fuels or nuclear power. Although this assumption may be correct, it must be realized that the capture and conversion of solar energy will still have significant negative environmental impacts, especially if used on a large scale to supply a substantial fraction of the U.S.’s energy demand (10, 11). This is because, according to the second law of thermodynamics, solar energy is required to maintain the complexity of organisms, ecosystems, biodiversity, and the carbon and nitrogen cycles. If humans divert a significant fraction of solar energy away from the environment for their own purposes, less is available to maintain these complex ecosystems, and this will, in turn, translate into various environmental disturbances (3, 9).
The technology factor can be reduced but not eliminated The total environmental impact of human economic activities is not solely caused by polluting technologies (T), but also depends on societal factors such as population size (P) and per capita affluence (A). According to the commonly used “IPAT equation”, the cumulative environmental impact (I) can be estimated as the product of technological (T) and societal factors (P and A) (7, 12): I = P A T = Population GDP/Person Environmental impact/Unit GDP = GDP Eco-efficiency
(1)
in which GDP is the gross domestic product. The term “Environmental impact/Unit GDP” is often referred to as the “technology factor”, reflecting that technological improvements in eco-efficiency can be relied on as the main strategy in reducing the environmental impact of current economic activities. As previously noted, T cannot be reduced to zero because complete recycling is impossible and the environmental impacts of renewable energy generation are inherently unavoidable. In addition, the second law of thermodynamics sets an upper limit beyond which eco-efficiency cannot be improved. The second law also implies that for each unit of “order” or neg-entropy that is created in the human economy, more than one unit of “disorder” or entropy is created in the surrounding environment (3, 9, 13). In short, the environmental impact of current industrial and economic activities may be reduced through R&D in industrial ecology and its allied disciplines, but it can never be eliminated.
False hope A cursory analysis of Equation 1 shows that eco-efficiency improvements could have a positive effect if the GDP were to remain constant. However, historical evidence indicates that technological innovation has never been used to stabilize the size of the economy. In fact, technology’s main role has always been the opposite—that is, to enhance industrial productivity, consumption, and economic growth. For example, labor-saving machinery and automation were
introduced to increase the efficiency of industrial production and thereby overcome the limitations that slow and expensive manual labor pose to economic expansion. Similarly, eco-efficiency improvements attempt to reduce the constraints that environmental pollution makes on industrial productivity growth. Ironically, eco-efficiency improvements are developed to ameliorate the various negative environmental impacts associated with economic growth while simultaneously promoting further industrial and economic expansion. Because industrial ecology and pollution prevention strategies address only the symptoms (e.g., pollution) of economic growth while ignoring that economic growth is inherently unsustainable, it can be concluded that most ecoefficiency enhancements are nothing more than shortterm “techno-fixes” that delay the problems until they reappear in even more serious forms later (9). On the basis of this analysis, it is unlikely that science and technology alone will be sufficient to protect the environment now or in the future. Therefore, we must address the root causes of environmental problems: our society’s preoccupation with economic expansion (14), which is driven by the desire for affluence, and a lack of limits on population growth (as shown in Equation 1). Thus, long-term protection of the environment and sustainable lifestyles are not primarily technological problems, but social and moral ones. Short-term techno-fixes are basically useless, unless we use the limited time they buy to radically change our values and behavior. Unfortunately, the public is led to believe that science and technology will solve all our problems and that no change in values or behavior is necessary. Nothing could be further from the truth. Michael H. Huesemann is a senior environmental research scientist at Pacific Northwest National Laboratory. Direct correspondence to
[email protected]. The views expressed in this article are solely those of the author and do not necessarily reflect the official position of Battelle Memorial Institute, Pacific Northwest National Laboratory, or the U.S. Department of Energy.
References (1) Longino, H. E. Science as Social Knowledge: Values and Objectivity in Scientific Inquiry; Princeton University Press: Princeton, NJ, 1990. (2) Sarewitz, D. Frontiers of Illusion: Science, Technology, and the Politics of Progress; Temple University Press: Philadelphia, PA, 1996. (3) Huesemann, M. H. Ecol. Econ. 2001, 37, 271–287. (4) Ayres, R.; Martinas, K. Economie Appliquee. 1995, 48, 95–120. (5) Kümmel, R. Ecol. Econ. 1989, 1, 161–180. (6) Glasby, G. P. Ambio 1988, 17, 330–335. (7) Graedel, T. E.; Allenby, B. R. Industrial Ecology; Prentice Hall: Englewood Cliffs, NJ, 1995. (8) Allenby, B. R. Industrial Ecology: Policy Framework and Implementation; Prentice Hall: Englewood Cliffs, NJ, 1999. (9) Huesemann, M. H. Clean Technologies and Environmental Policy 2003, 5, 21–34. (10) Holdren, J. P.; Morris, G.; Mintzer, I. Annu. Rev. Energy 1980, 5, 241–291. (11) Pimentel, D.; et al. Bioscience 1994, 44, 536–547. (12) Ehrlich, P.; Holdren, J. P. Science 1971, 171, 1212–1217. (13) Georgescu-Roegen, N. The Entropy Law and the Economic Process; Harvard University Press: Cambridge, MA, 1971. (14) Daly, H. E. Economics, Ecology, Ethics: Assays Toward a Steady-State Economy; W. H. Freeman and Company: New York, 1980. JULY 1, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 261 A
