Environmental Trade-Offs

The environmental trade-offs between PLA and petro-polymers result from agricultural production of PLA raw materials. Agriculture is one of the major nonpoint source contributors to eutrophication and hypoxia (e.g., within the Gulf of Mexico in the United States) due to the extensive use of fertilizers. Com, which serves as the primary feedstock for PLA in the United States, is one of the worst offenders. Nitrogen and phosphoms are applied as fertilizers to agricultural crops and result in N and P nutrient emissions, which are the primary contributors to hypoxia and eutrophication [29, 30], 

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It is often taken for granted that reduction of a waste will have environmental benefits. Though this is generally true, there are exceptions to the rule. For example, reducing one waste may give rise to pH imbalances or may produce another waste which is more difficult to treat, resulting in a net environmental disadvantage. Hence, there may be environmental trade-offs between the status quo and the alternatives identified. 

Analyze environmental trade-offs among alternative products or processes... 

Koch, D. G., and Kuta, C. C., Assessing environmental trade-offs Procter Gamble s approach to life cycle analysis. In Inside Environment. 1991. 

Although extraction of methane from the ocean floor offers tremendous potential benefits, it also carries risks. Methane is a "greenhouse gas"—its presence in the atmosphere helps to trap the heat from the sun. As a result, any accidental release of the methane from the ocean could produce serious warming of the earth s climate. As usual, environmental trade-offs accompany human activities. 

Miller, S.A., Landis, A., and Theis, T.L (2007) Environmental trade-offs of biobased production. Environ. Sci. Technol., 41, 5176-5192. 

The investigation described in the first paragraph must include winning the most basic raw materials such as crude oil, mineral ores or trees the steps to manufacture the article the packaging and transport in-use consumption (e.g. water and electricity) durability and results of disposal, to be able to justify the term LCA. Less complete studies can only address limited issues and may well miss environmental trade-offs from other parts of the cycle. 

During the last two decades, there has been increasing interest in use of life-cycle assessment techniques to evaluate the environmental trade-offs associated with manufacturing and purchasing decisions. The philosophy behind life-cycle assessment is that the entire life cycle of a process or producL from acquisition of raw materials to eventual waste disposal, must be considered in evaluating the effects of that process or product on the environment. If only a portion of the life cycle is considered, then decisions about which of two alternatives has lesser adverse environmental impacts may be flawed, as looking at only a portion of the life cycle may result in ignoring serious impacts and lead to comparisons that are not accurate. 

As a general rule, it is best if feedstocks come from renewable sources rather than depletable resources. A biomass feedstock, for example, can be obtained as a renewable resource grown by plants on land, whereas a petroleum-based feedstock is obtained from depletable crude oil resources. However, the environmental trade-offs between these two sources may be more complex than they first appear in that the petroleum feedstock may be simply pumped from a few wells in Saudi Arabia, whereas the biomass may require large areas of land, significant quantities of fertilizer, and large volumes of irrigation water for its production. Another important decision is whether or not the feedstock should be made entirely from virgin materials or at least in part from recycled material. 

LCA is a tool that quantifies the environmental impacts resulting from the production, use, and disposal of a product or process. LCA has many benefits for making informed environmental decisions (i) products are compared in defined environmental impact categories, which can be conceptualized by real environmental detriment, (ii) unintended environmental trade-offs can be identified between impact categories, and (iii), a standardized methodology allows LCAs from separate studies to be used to compare product choices [150]. Lankey et al. points out the... 

After each issue outlined in the evaluation criteria has been developed for each corrective measure, the selection of the most appropriate alternative can be made. Trade-offs among health risks, environmental effects and other pertinent technical, environmental and human health factors enter into this decisionmaking process. In the RCRA context, cost is not a factor in the selection process except when two or more corrective measure alternatives are determined by EPA to provide similarly adequate levels of protection of human health and the environment. 

Baitz, M., Wolf M.A., Faltenbacher, M. (2001) Life-Cycle Related Technical-Environmental Multi-Parameter Trade-Off Optimisation of Processes. Journal of Advances in Science, 13(3), 199-202. 

The siting, design, construction and management of any disposal option needs to be done to minimise negative environmental impacts. In some instances, there may be a trade off between desalination plant performance and the environmental suitability of the brine. Plants with high recovery rates that produce a more concentrated brine must have the means to dispose of this concentrate solution in a safe and environmentally friendly manner. When safe concentrate management is not achievable, the recovery of a plant may need to be compromised. 

To answer they behave that way because the lawn is important to them is entirely unsatisfactory. Why do we want what we want What places demands on us neighbors, large companies, family, and even the turfgrass itself How do we come to understand and trade-off our aesthetics, environmental values, and community desires What are the implications for our health and our communities In this sense, the questions that need to be asked extend beyond the boundaries of the lawn, to something larger in our ecological polity. 

Such is not necessarily the case in other parts of the world, however. Pesticides, DDT in particular, are among the most effective agents known for the prevention of malaria. Some nations have accepted the environmental risks posed hy DDT and other TOCs as a reasonable trade-off for the protection they offer against malaria and other infectious diseases. At the beginning of the 21st century, then, DDT and other toxic pesticides were still being used in the public health programs of a number of countries around the world. 

Making decisions about risks to health and the environment is difficult for Congress, for regulatory agency administrators, for officials of industry, and for the public that awaits the decisions. Questions about science, economics, trade-offs, and uncertainty seldom have clear-cut answers. Many countries, many international treaties, and many environmental organizations have offered the precautionary principle as a shibboleth, a near-magic principle, to guide decisions about risks. 

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