Generation of wastes per unit of production

Wernick and Ausubel (1995) estimated the amount of wastes generated annually in the U.S. as the result of fossil fuel and mineral production. Table 4 shows these estimates as tons per year and also as the ratio of tons of waste per ton of material produced. It can be seen that from up to 12 tons of material must be moved aside to produce one ton of fuel, mineral or metal production.

Table 4. Mining and mineral concentration wastes generated per unit of production

	Million tons of wastes	Million tons of production	tons of waste per ton produced
Coal, surface mining Coal, cleaning	10042 84	843	12.0
Oil & gas produced wastes Oil & gas drilling fluids	3318 57.2	1044.7	3.2
Ore wastes in metal mining “Tailings” from ore concentration	755 409	111.6	10.4
Ore wastes in phosphate mining “Tailings” from ore concentration	262 108	39.9	9.3

Fraction of global production used by a nation

A metric that can be of importance in trans-national discussions of emission rights, etc., is the fraction of global production of a specific material that is used by a particular nation. It should be understood that this use encompasses both internal consumption and also export trade. Therefore, large industrial nations are using a fraction of that is disproportionately high to their fraction of the world’s population. For example, Table 5 shows the 1990 global production of various materials and the respective amounts produced/imported and used/exported by the U.S. economy. It can be seen that the U.S., with about 4.5% of the world’s population, used from 6.5% to 31.9% of the global production of various materials.

Table 5

Fraction of global production of materials used by the U.S. economy (1990, ref.)

Material	Global production, million tons	Use by U.S. economy, million tons	U.S. fraction,
Plastics	78.3	25	31.9%
Synthetic ffiber	13.2	3.9	29.5%
Aluminum	17.8	5.3	29.8%
Phosphate	15.7	4.4	28.0%
Copper (new metal)	8.8	2.2	25.0%
Salt	202.3	40.6	20.1%
Potash	28.3	5.5	19.4%
Sand, gravel	133.1	24.8	18.6%
Iron and steel	593.7	99.9	16.8%
Nitrogen	107.9	18	16.7%
Cement	1251.1	81.3	6.5%

Material intensity per service unit and ecological rucksacks

In an attempt to move beyond simple energy analysis with the inclusion of materials and transformations in the environment, the Wuppertal Institute for Climate Environment and Energy in Germany developed the concept of 'ecological rucksacks' or MIPS (material intensity per unit of service) (see Schmidt-Bleek 1998). MIPS measures the total material inputs and transformations that result from products. It overcomes some of the issues of embodied energy by accounting for all materials movements (not just those with energy contents) although it does not discriminate very well between different materials consumed or transformed.