A
agroforestry growing both tree and food crops on the same piece of land.

B
biosphere all areas on earth that contain life forms, including air, soil, land, and water.

C
capital stock the existing quantity of capital in a given region, including manufactured, human, and natural capital.

critical natural capital elements of natural capital for which no good human-made substitutes exist, such as basic water supplies and breathable air.

E
exponential growth a value that increases by the same percentage in each time period, such as a population increasing by the same percentage every year.

extractive reserves a forested area that is managed for sustainable harvests of non-timber products such as nuts, sap, and extracts.

G
green subsidies subsidies on a good or service based on the reduction of environmental impact.

green taxes taxes based on the environmental impact of a good or service.

I
incremental costs costs of environmental protection in developing countries in excess of what the country is prepared to pay without foreign assistance.

industrial ecology the application of ecological principles to the management of industrial activity.

L
logistic curve an S-shaped growth curve tending toward an upper limit.

M
macroeconomic (system) scale the total scale of an economy; ecological economics suggests that the ecosystem imposes scale limits on the macroeconomy.

N
natural capital the available endowment of land and resources including air, water, soil, forests, fisheries, minerals, and ecological life-support systems.

nongovernmental organizations (NGOs) privately-funded, and commonly nonprofit, organizations involved in research, lobbying, provision of services, or development projects.

R
recycling the process of using waste materials as inputs into a production process.

renewable energy sources energy sources supplied on a continual basis such as wind, water, biomass, and direct solar energy.

revenue-neutral tax shift policies designed to balance tax increases on certain products or activities with reductions in other taxes, such as a reduction in income taxes that offsets a carbon-based tax.

S
sink function the environment’s ability to absorb and render harmless the by-products of human activity.

social sustainability the maintenance of social structure and traditions, for example among indigenous peoples.

steady state economy an economy that maintains a constant level of natural capital by limiting the throughput of material and energy resources.

strong sustainability the view that natural and humanmade capital are generally not substitutable and, therefore, natural capital levels should be maintained.

structural adjustment policies to promote market-oriented economic reform in developing countries by making loans conditional on reforms such as controlling inflation, reducing trade barriers, and privatization of businesses.

sustainable development development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

T
technological lock-in the tendency of an industry to continue to use a given technology despite the availability of more efficient or cheaper technologies.

W
weak sustainability the view that natural capital depletion is justified as long as it is compensated for with increases in humanmade capital; assumes that humanmade capital can substitute for most types of natural capital.