Goods or services that are not manufactured, but have some value to humans Some examples: metals of the earth, biosphere, forests, grasslands, wetlands, tundra, atmosphere…
The rate of harvest or services produced from the natural capital. Example: ◦ Cherry tree produces cherries ◦ Water cycle produces fresh water ◦ Photosynthesis creates oxygen
Renewable: Living species in ecosystem which can be replaced as fast as they are used Ex. Food, crops, timber Non-Renewable: resources which cannot be replaced (except over VERY LONG TIME) ◦ Using these will deplete a storage that will not be built up again ◦ Ex. Fossil fuels, minerals ◦ To prevent depletion we must 1. Improve efficiency of use 2.Develop substitutes 3. Recycle
Replenishable: non-living resources which can be used continuously restored as fast as they are used Dependent on solar “engine” for renewal Ex. Ozone layer, groundwater
Economic Value: Determined from the market price of the goods and services it produces Timber, crops… Ecological Value: have no formal market price but create something necessary for life. Often taken for granted) Photosynthesis, nitrogen fixation… Aesthetic Value: Nature’s beauty. No price or products
Uranium is only recently valuable to humans because of nuclear technology Value is applied from humans perspective Gold is expensive but also serves little ecological benefit
Goal is to support a society without depleting essential forms of natural capital “Living within the means of nature, on the interest generated by natural capital” Sustainable development ◦ Brundtland report in “Our common future” 1987 ◦ Rio Earth Summit, Agenda
Sustainable Yield (SY) is the annual gain in biomass or energy through growth and recruitment (addition of individuals to population) Calculate SY= ◦ (annual growth and recruitment) – (annual death and emigration) ◦ (biomass/energy at time t +1) – (biomass/energy at time t) The Earth does not have enough resources to support everyone at the rate of consumption enjoyed by the U.S. Europe, and Japan