My environmental philosophy Lifeng Li (July 2009) Environmental science and engineering is so complicated that my knowledge on it is still negligible after 10 years of study. The protection of the earth by all mankind is not satisfactory either. As stated in Global Environment Outlook-4 (UNEP, 2007, p. 464), the importance of environment and sustainable development is now recognized everywhere and good progress has been made in some regions, but the complex and macro-scale problems (such as all the major issues highlighted by the Brundtland Commission) “have not been effectively managed anywhere”. To model and control the macro-scale and long-term environmental change is almost beyond the capability of any creature, especially considering the greed of man. Ten years ago, people were asked not to leave suffering to the next generations, but now it seems that we have already become the generation of suffering. Previous successes are far from enough, but previous failures also should not stop our efforts. There is no time for procrastination on this urgent issue, but I am no longer worrying about our destiny, because I eventually realized by myself that worrying is helpless and what I can do is focusing on my environmental work. 1. Learn from nature As concluded in Silent Spring (Carson, 1962, p. 81), “Nature herself has met many of the problems that now beset us, and she has usually solved them in her own successful way. Where man has been intelligent enough to observe and to emulate Nature he, too, is often rewarded with success”. Especially in science and engineering, the importance of learning from nature needs to be always kept in mind, because we proudly tend to go to our own ways. When I finished my undergraduate study in environmental science, I was excited about the popular concept “sustainable development”, which requires us to learn from nature and pursue harmony of environment and economy. I published some articles in the popular media, involving my immature philosophies and suggestions, such as treating environment as a productive force (Li, 2003), applause for the rising of “circular economy” in China (Li, 2004a), supporting “eco-agriculture” by summarizing several successful cases in the world (Li, 2004b), and so on. I was also concerned about the unpredictable risks of human activities, so I joined an opposition of environmentalists to the construction of a super dam on Salween River in southwestern China (Li, 2004c). 1.1. Philosophy of nature When I had more research experience, I recognized a basic philosophy in environmental research, which requires careful attention in both big picture view and deep details. The way the earth is designed demonstrates exactly this philosophy. However, as humans we usually cannot successfully balance both the big picture and the minute details of our natural environment. Half century ago, the disadvantages of chemical methods were revealed, but until today there are still many or even more 1

chemical additives and methods proposed and applied in many disciplines such as agriculture and pharmacy. Many biological and ecological methods have shown promise but there is still a long way to go. 1.2 Be creative learners Environmental scientists and engineers need to be creative learners. However, over-estimating human smartness can be dangerous in environmental work. Sometimes, a solution can be simple, as long as it conforms to the philosophy of nature. For example, waste sewage sludge can be reused (after proper pretreatment) in highway pavement and soil remediation (Li and Yang, 2005a; Li and Yang, 2005b). The emissions of ammonia, a severe air pollutant, from dairy cattle wastes can be reduced by reducing the dietary N with optimizing the protein compositions. A more efficient solution both for the cows and for us was found, without using any chemical additives, interrupting the living of cows, or affecting the milk production level (Li et al., 2008; Li et al., 2009a; Li et al., 2009b). 2. Environment and sustainable development Environmental problems are always systematic problems, especially when involving biological activities. Healthy ecosystems can exist in some industries like conventional agriculture, but in many more cases, economical development is still threatening living creatures in unpredictable ways. Let us take the sustainable development in agriculture as an example, which can provide good ideas for other industries. 2.1 Recycling of mass and energy The term "recycling" can be heard everywhere now, but I was deeply impressed by the real recycling in the nature, especially within agricultural animals, plants and ecosystems. The highest efficiencies of mass recycling and energy utilization are usually from living creatures, rather than artificial machines. Based on the natural recycling, people are developing mass and energy recycling systems. For example, in a modern dairy farm, the complete N cycle is formed from cow diet protein, to milk protein, manure N as fertilizer, N absorbed by crop, and finally, back to cow diet protein. Energy can also be partly recycled through fertilizer use and bioenergy production from animal wastes. 2.2 New products – Bioresource and Bioenergy New bioresource and bioenergy have caught the attention of many, causing a revolution in modern agriculture. Bioresource includes not only fertilizers such as agricultural wastes, which are more reusable, but also biomaterials and enzyme products. More popularly, bioenergy production is becoming an important industry all over the world. Instead of bioethanol, biodiesel and biohydrogen, I see biogas and biooil more promising. The former three bioenergy forms are mostly produced from crops or other competitive biomaterials, which are not necessarily market competitive, because the current worldwide economical downturn has already driven down the price of fossil energy. In addition, they provide an alternative energy source but don't help a lot in solving environmental problems. In 2

comparison, the latter two bioenergy forms can be produced from agricultural or other organic wastes, giving new energy with low cost, and at the same time, reducing pollution to the environment. Biogas technology is one of the oldest green technologies, but it is still very promising in terms of reducing green house gases and carbon footprint. The energy production efficiency and cost effectiveness still needs to be improved, e.g., by co-digestion of different waste materials (Li and Arogo, 2009). 2.3 “Biological systems engineering” A promising direction for bridging human activity and the nature is “biological systems engineering”. A “biological systems engineer” should not only focus on engineering; rather, he/she has to learn from and cooperate with non-engineers, such as planners, economists, policy-makers and philosophers. This is consistent with the current trend of interdisciplinary studies in the environmental area. For example, in environmental impact analysis and environmental planning processes, we need to emphasize potential ecosystem responses. In agricultural and many other industries, we need to use planning tools to achieve best-management-practices objectives (such as nutrient balance, waste reusing, energy optimization, etc.). We also need big picture view and creative strategies, e.g., transferring air pollutants to nutrient and energy. Computer tools, of course, have irreplaceable functions (e.g., mathematical modeling, geographical information system, planning software, etc.). Mathematical modeling can be used now in most environmental systems (Parkhurst, 2006). More reliable process-based models in addition to statistical models are needed, and qualitative models can still be very helpful to simulate and predict complex environmental problems (Puccia and Levins, 1985). As environmental problems become global, international cooperation in environmental studies also becomes crucial. Learning and cooperation between developing and developed countries should be mutual. Modern technologies and management tools need to be widely used, but many conventional technologies are still useful, too (e.g., the cost-effective ways of anaerobic digestion in India and China). Some eastern cultures, which naturally ask for green lifestyles, are also very valuable. Any opportunities of international cooperation should be encouraged. For instance, China is a new country with sufficient funding and very high concern for environmental problems, which can be a potential funding source for research projects in countries with leading environmental technologies.

References: Carson, R. L. 1962. Silent spring. New York, NY: Mariner Books (40th anniversary edition, 2002). Li, L. 2003. Environment can be a productive force. Xinmin Evening Newspaper, Shanghai, China. Li, L. 2004a. Rising of "Circular Economy" in China. Xinmin Evening Newspaper, Shanghai, China. Li, L. 2004b. Several eco-agriculture cases around the world. Xinmin Evening Newspaper, Shanghai, China. Li, L. 2004c. Think twice before building the super dam in Salween River. China Youth Daily, Beijing, China. 3

Li, L., and Arogo, J. 2009. Co-digestion of dairy manure and poultry processing wastewater. Renewable Energy. submitted. Li, L., Arogo, J., Marr, L., Knowlton, K. F., Hanigan, M. D., and Gay, S. W. 2008. Ammonia emissions from dairy manure storage tanks. ASABE Annual International Meeting, ASABE, Providence, RI. Li, L., Cyriac, J., Knowlton, K. F., Marr, L., Gay, S. W., Hanigan, M. D., and Arogo, J. 2009a. Effects of reducing dietary nitrogen on ammonia emissions from manure on the floor of a naturally ventilated free stall dairy barn at low (0 to 20 °C) temperatures. Journal of Environmental Quality. 38(6): 2172-2181. Li, L., Knowlton, K. F., Marr, L., Gay, S. W., Hanigan, M. D., and Arogo, J. 2009b. Ammonia emission rates from dairy manure storage tanks affected by dietary treatments, manure removal practices and environmental factors. prepared. Li, L., and Yang, H. 2005a. Reuse of biosolids in highway construction. Environmental Protection in Transportation (China). 26(3): 67-69. Li, L., and Yang, H. 2005b. Utilization of sewage sludge in highway pavement structure. International Conference on Pollution Control and Resource Reuse, Shanghai, China. Parkhurst, D. F. 2006. Introduction to applied mathematics for environmental science. New York: Springer. Puccia, C. J., and Levins, R. 1985. Qualitative modeling of complex systems : an introduction to loop analysis and time averaging. Cambridge, Mass.: Harvard University Press. UNEP. 2007. Global Environment Outlook 4: environment for development. Nairobi, Kenya: United Nations Environment Programme.

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