Defining terms

One of the challenges in studying green manufacturing is the definition of terms. And one of the toughest terms to define is "sustainability". I consider green as a subset of sustainability (and, thus, green manufacturing as a subset of sustainable manufacturing). The term "sustainable" is heavily used, and mostly misused, today.

We could start with a more academic definition derived, for example, from early United Nations studies (like the Brundtland Commission, 1983, formally called World Commission on Environment and Development (WCED)) but a simple definition has been offered by the Japanese copier company Ricoh and can be found on their website (updated 3/26/13). Ricoh defines sustainability, in terms of development and progress, as follows: "We are aiming to create a society whose environmental impact is below the level that the self-recovery capability of the natural environment can deal with." And they go on to give a simple example: "For example, the reduction target of CO2 emissions is generally based on the 1990 emission level, but in the future we need to limit emissions based on the estimated emission level that the self-recovery capability of the Earth could deal with.”

So this definition points out the key elements: there is a strong social component in addition to the usual business and environmental emphasis (we usually define three "legs" to sustainability as economic benefits, environmental benefits, and social benefits), there is a comparison to a "sustainable level" that has natural roots (for example the ability of the environment to accomodate the inputs/impacts we make to it), and the need to adjust our level of impact to be consistent with that. And, Ricoh illustrates the need to adjust the target to insure we stay within acceptable levels of impact - that is, adjust our definition of the level of sustainability we are aim targeting.

This offers real challenges to engineers, specially with respect to manufacture and production of goods. If we are not today operating at a "sustainable level" (think Ricoh example and the level of energy/material/water/other resources used for manufacturing or the impacts of manufacture) then we need to adjust our processes, systems and enterprises to get to that level over time.

This is not easy. With population growth and the accompanying growth in demand (even in the teeth of a recession!) just "business as usual" will drive increased unsustainable trends. This means we need to have a compounded reduction in our impact/use that considers both the increases in demand and the difference between a sustainable and unsustainable level of consumption/impact. This mismatch is the so-called "wedge" pointed out by the excellent paper on stabilization wedges (Pacala and Sokolow, 2004. ). I've written about the use of these wedges of technology by manufacturers to provide a set of solutions to the mismatch between where we are today and where we need to be in the future (we'll get to that in due time!).

Green manufacturing deals with technologies and solutions that provide these wedges - help to "turn the supertanker" if you will and, ideally, with enough wedges we transition from business as usual to a sustainable level of impact/consumption. And, our premise is that this can be done to our competitive advantage and profitably.

We'll pick here next time.

FYI Department: Check out the article by Alan Richter in "Cutting Tool Engineering", July 2009 edition on "Power Down - Reducing a machine tool's energy consumption helps achieve 'green manufacturing'" - http://www.ctemag.com/aa_pages/2009/0907_GreenMachining.html; good overview and he includes some of the conversation he and I had on the subject.