In the four previous chapters the committee examined the environmental metrics used or under development by four industry sectors. That information is summarized here to explore how much common ground exists among the sectors. Table 8-1 lists common or particularly utilitarian metrics. As in the sector chapters, no prioritization of these metrics is implied.

The meaning of most of the metrics is straightforward. "Supply chain" indicates corporations are looking at the environmental performance of their suppliers, using one or more metrics to do so. In the case of the pulp and paper sector, supply chain refers to the forestry part of the industry. "Emissions" indicates releases to land, water, and air; emissions to each medium are often tracked separately. "Percent of land preserved" refers to the use of land at corporate facilities; the metric is not yet precisely defined. Many of the metrics require normalization by some measure of business activity, such as energy use per unit of product or energy use per dollar of sales. "Sustainability" is undefined at present. The development of a suitable metric to address sustainability issues seems desirable.

As can be seen from Table 8-1, a number of metrics—emissions, energy use, materials use, water use, packaging, percent of recycled material used, and various measures of worker safety—are relatively common across all sectors, although the exact definitions may differ somewhat. Several sectors are dealing in some way with the question of sustainability, either by looking at the use of land, the emission of greenhouse gases, or by searching for an appropriate metric. A major difference among the sectors is in the area of product-related metrics, which are tracked extensively by the automotive and electronics sectors. For

industry sectors whose products are largely raw materials for others (i.e., chemical) or have essentially no impacts during the product-use phase (i.e., pulp and paper), product-related metrics do not appear to be useful.

If the metrics set identified in Table 8-1 were tentatively regarded as a suitable generic set for the four industrial sectors analyzed in Chapters 4–7, how well might the set serve other manufacturing industries? To investigate this question, the committee briefly examined the suitability of the set for six additional sectors: agriculture, appliance manufacture, metal fabrication, mining, pharmaceuticals, and recycling facilities. The following conclusions resulted from that analysis:

• The supply chain metrics (M₁, M₅) are generally suitable for all sectors. Even for a sector whose products are at the front of the supply chain (e.g., agriculture or mining), the metric could be applied to suppliers of equipment (e.g., combines, cranes) rather than to suppliers of raw materials.

• Emissions metrics (M₂, M₃) are applicable to all sectors.
• Resource metrics (M₄, M₆, M₇) are applicable to all sectors.
• Health and safety metrics (M₈, M₉) are applicable to all sectors.
• A land-use metric (M₁₀), while not yet well defined, applies equally well to these sectors as to the four sectors studied in detail by the committee.
• The product-packaging metric (M₁₁) is generally appropriate for all sectors, but packaging may not be required for some products (such as iron ore).
• Product-centered metrics (M₁₂–M₁₅) appear to be useful only for industrial sectors whose products have the potential for significant environmental impacts (e.g., appliance manufacturers).
• Until sustainability is better defined, the suitability of a sustainability metric (M₁₆) across sectors cannot be addressed.

Hence, it would appear that a provisional set of generic metrics might consist of:

GM₁—Materials use (normalized in some appropriate way)

GM₂—Water use (normalized in some appropriate way)

GM₃—Energy use (normalized in some appropriate way)

GM₄—Percent of recycled materials in products

GM₅—Percent of products that are leased

GM₆—Resource consumption and/or emissions during product use

GM₇—Average use of packaging

GM₈—Emissions from manufacturing (normalized in some appropriate way)

GM₉—Recordable health and safety incident rate

GM₁₀—A sustainability metric of some type

One could go on from this point to ask whether a generic environmental metrics set would be suitable not only for manufacturing industry sectors but also service industry sectors. To study that question, the committee imagined the use of such metrics in a set of hypothetical service-based businesses: a retail appliance store (A), a barber shop (B), a grocery store (G), a hospital (H), a lawyer's office (L), and a package delivery service (P). Table 8-2 assesses the suitability of the metrics set for these businesses. It appears from this table that the generic set, if carefully defined, is probably as useful to service industries as it may be to manufacturing industries.