David Orr wrote, in response to comments by Nick O'Brien: >Why do you believe wood is preferable to steel frame and concrete block, >for example? The non-wood structure will not rot, and won't burn either. >Termites are not a problem. The added durability certainly increases the >value of the structure. Steel can be cut to exact specifications, whereas >dimensional lumber generates waste pieces when cut. > >I'm curious why you don't think this would be desirable! > Well, here's my unsolicited view. We have to decompose the issue into its component parts. In order to give order to this, we must remind ourselves that there are two major ways to evaluate the question of whether wood products or nonwood substitutes are better construction materials: first, from the financial perspective (i.e., financial analysis); and second, from the perspective of the environmental externalities that both wood and nonwood construction alternatives create. While you could make a case for the financial superiority of nonwood construction materials in certain cases, the financial calculations, as anyone who has studied economics or ecology or biology can tell you, ignore (almost by definition) the environmental externalities of production processes and consumption. If you sit down and consider the environmental externalities of wood and nonwood construction materials in both consumption and production, you will soon come to the conclusion that, at the very least, which one is really better for the environment and human society is really an empirical question. There is a whole field of research and associated literature that seeks to answer such empirical questions. In the research that I've seen and heard about, forest products come out way ahead of their non-wood-based substitutes in environmental friendliness. For example, think about the environmental destruction and energy that go into making steel and concrete block. First there is the mining and excavating. Can you think of anything, short of dropping a nuclear bomb or dumping tons of toxic chemicals, that does more to harm a plot of land than a huge hole in the ground? It destroys practically all life therein. At least with logging, the associated life forms have a fighting chance. While logging is not benign and has some long-term consequences (which are, of course, difficult to measure, but it doesn't mean that people shouldn't try to measure them), its destructiveness to site pales in order of magnitude to that visited upon a site by your average mine. Then there are the inputs required to produce a final product. While some wood panels contain some nasty things, so does steel. Further, to ship from production point to consumption locale, steel requires much more energy, due to its greater weight per unit volume or unit of use in construction. We all know about the multiple externalities associated with fuel extraction and consumption (that description can get very long). It is therefore reasonable to conclude that the negative externalities associated with wood products pale tremendously to those that are created by their steel substitutes. The same arguments could be used to address aluminum studs, concrete block, plastic, etc. Jeff Prestemon Dept. of Forestry UW-Madison Madison, Wisconsin 53706 Internet: prestemo@calshp.cals.wisc.edu
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