Resource intensity is a measure of the resources (e.g. materials, energy and water) required for the provision of a unit of a good or service. It is usually expressed as a ratio of materials used to value (expressed, for example, in money, mass, volume). Resource productivity, the inverse of resource intensity, is a measure of the output (expressed either as units produced or as economic value) per unit of resource input. Resource productivity and resource intensity are essential concepts for measuring the progress of dematerialisation and other efficiency-led strategies.
Resource intensity is determined by two factors: changes in the mix of materials used to produce individual goods and services, and the product composition of output. The resource intensity of an economy may change due to a number of factors, namely (Cleveland and Ruth, 1999):
• technical improvements that decrease the quantity of materials used to produce a good or service, e.g. metal use in the beverage container industry
• substitution of new materials with more desirable properties for older materials, e.g. the substitution of optical fibres for metal wire in communications
• changes in the structure of the mix of goods and services produced and consumed by an economy over time, due to shifts among sectors (as in the rise of the service sector), or shifts within sectors (as with the increasing dominance of computers and other high-technology goods within the manufacturing sector)
•the saturation of bulk markets for basic materials, whereby as an economy ‘matures’ and population stabilises, there is less demand for new infrastructure such as bridges, roads, railways and steel factories, reducing the need for steel, cement and other basic materials
•government regulations that alter material use, as in the case of the regulation of lead additives in gasoline and other products that contributed to a sharp decline in the use of lead
The intensity concept can be applied to different resources/pressures such as materials input, energy consumption, greenhouse gas emissions and water use, with different indicators. An early indicator of resource intensity is MIPS – Material Intensity Per Service unit (Schmidt-Bleek, 1994), which takes into account the entire lifecycle from cradle to cradle (extraction, production, use, waste/recycling). Material intensity analyses are conducted on the micro-level (focusing on specific products and services), as well as on the macro-level (focusing on national economies).
Energy intensity, an indicator often used in energy policy and climate change debates, is a national measure of energy efficiency, calculated as the amount of energy consumed per unit of GDP generated in the economy. This indicator is also used to measure the energy efficiency of products and services such as appliances and buildings, vehicles and transportation systems.
Water productivity is also a widespread concept, particularly in the context of agricultural water use. The UN Food and Agriculture Organization (FAO) defines crop water productivity as ‘the amount of water required per unit of yield’, but in reality this is a measure of crop water intensity.
Several critiques have been raised on the use of concepts such as resource intensity and dematerialisation as guiding principles and measuring sticks for the formulation of sustainability strategies. Different materials have quite different environmental impacts and a reduction in the amount used can actually lead to higher environmental burdens if it is the result of replacing some materials by more environmentally harmful substitutes (that are for instance more toxic). In addition, when the denominator is expressed as an economic value, an observed decrease in resource intensity may be due to a reduction in the amount of materials used or to an increase in the economic value of the products. Another important issue is the discussion around the so-called rebound effect or Jevons’ paradox, whereby increases in resource productivity lead to lower costs, triggering even greater consumption of resources.
References
Cleveland, C., Ruth, M. (1999) Indicators of Dematerialization and the Materials Intensity of Use, Journal of Industrial Ecology, 2 (3) 15-50.
Schmidt-Bleek, F. (1994) Revolution in resource productivity for a sustainable economy—a new research agenda. Fresenius Environmental Bulletin, 2 245-490.
For further reading:
Huber, J., (2000) Towards Industrial Ecology: Sustainable Development as a Concept of Ecological Modernization, J. Environ. Policy Plann., 2, 269–285.
This glossary entry is based on a contribution by Paula Antunes
EJOLT glossary editors: Hali Healy, Sylvia Lorek and Beatriz Rodríguez-Labajos
