He views this industrial metabolism (this is what the Japanese call the input-process- output chain), from the point of view of what is irreplaceably extracted from the bosom of Mother Earth, and what is put back into it - this would most often include the waste products - toxic and burdensome at times.
Will there ever be `green` foundries?
Industrial ecologists approach a system by studying the materials flow into and out of it. To an ecologist, armed with the intention of attaining sustainability in manufacturing processes, inputs are tantamount to resource damage - necessary evils in other words, while the process of conversion of these input raw materials into the end-products amounts to utilization of energy - almost always, non-renewable fossil fuels depletion. The output to him would mean just a percentage of the inputs - materials and energy - and not the monetary tag attached to the products in the market.