BigPic Explorer Glossary

Acronym/Term	Definition
Bha	Billion hectares.
Capacity	The amount of resources that are regenerated or reusable, typically within one year.
Capacity Growth	Annual rate of increase in capacity (%).
Capita	Unit of population, typically a person.
Change Year	Year that a change in variable value takes effect.
Comfort Zone	An environment in which a person is most happy and productive.
Community	Group of people who interact regularly, typically for survival.
Consumption	Resources used per unit of time.
Consumption Laws	Also: Jarvis's Laws of Consumption.
Consumption Model	Population-consumption model.
Consumption Potential	Electrical equivalent of consumption.
CPC	Consumption per capita.
Depletion Time	Amount of time a constant population takes to deplete its resources at a fixed rate (consumption).
Ecological Debt	Cost of hectares consumed beyond what is available (capacity). Expressed in pounds or dollars.
Ecological Footprint	Global ecological footprint.
Ecological Resources	Natural resources, including air, land, water , and the species that maintain them. Measured by the Global Ecological Footprint.
Energy	World energy production (quadrillion Btu).
Environment	1. The full set of circumstances that affects a person's wellbeing at a particular time. 2. From EPA: "The sum of all external conditions affecting the life, development and survival of an organism."
Expected Value	A combination of several projections into one representative projection. Uses the PERT method, which approximates a statistical bell curve to calculate the mean [Expected Value = (Low Estimate + 4 * Mode Estimate + High Estimate)/6].
Footprint	Global Ecological Footprint.
Global Ecological Footprint	Bioproductive land that provides ecological resources (see WWF Living Planet Report 2006).
Group	1. A number of people with one or more common characteristics. 2. The smallest unit of a community (between 12 and 36 members; typically 24).
GWP	Gross World Product (typically in trillions of 2005 dollars).
Happiness	People's satisfaction with their lives, usually measured in percent. (See pages Happiness, World Comfort.)
Hectare (ha)	Unit of area that provides ecological resources, equivalent to one global hectare (used in Global Ecological Footprint).
High Growth	Population-consumption scenario where resources areincreased to accommodate current trends. Unless otherwise noted, speed limits are not imposed.
Ideality	Average of life expectancy and happiness, where life expectancy is in years and happiness is in percent of maximum (100).
Ideal World Index	IWI. The product of ideality and population, normalized to the end of the year 2000 (IWI=1.0 on 12/31/00).
Initial Population	Value of the population function for the first year of the data used to make projections.
Initial Year	First year of the data used to make projections.
Intelligence	A measure of a person's perception of where they are relative to their preferred position.
IWI	Ideal World Index.
IWIsum	"Ideal World Index Sum." The sum of the annual values of the Ideal World Index over a span of time (starting in 2000). Used to evaluate scenarios.
Laws of Consumption	Laws relating consumption to population, speed, and life expectancy.
Life Expectancy	The average time that a person can be expected to live when born in a given year, measured in years.
Lifespan	Life expectancy.
Longevity Function	The relationship between depletion time, resources, and speed.
Max. Capacity	Maximum allowable capacity.
Max. Speed	Maximum allowable speed.
No Growth	Population-consumption s cenario involving no population growth or decline and no change in per capita consumption.
Non-renewable Resource	A resource that, once consumed, is not replaced by Nature (at least within the span of time of interest).
Normalized	Expressed as a fraction of a specific number (usually the value for a given year).
Oil	One of several fossil fuels used for energy.
Peak	The maximum value of a mathematical function, typically the point in time where a variable stops increasing and either levels off or begins dropping.
Per Capita Consumption Function (CPC A, CPC B)	Mathematical function used to compute consumption per person. Consumption in year "t" is C(t) = A*t^B. "A" is referred to as "CPC A" and "B" is referred to as "CPC B."
Population	Amount of people consuming a resource. Also: Population size.
Population-Consumption Model	A model relating population to available resources. Also referred to as "consumption model."
Population Crash	The end of a drastic decline in population size, typically to zero.
Population Function (Pop. A, Pop. B)	Mathematical function used to compute population size in the consumption model. Population in year "t" is P(t) = A(t)t^B where the amount of resources is R(t), and A(t) = A(t-1)R(t-1)/R(t-2). "A" is referred to as "Pop. A" and "B" is referred to as "Pop. B" or "Population B."
Power	The fraction of distance between the starting position and the preferred environment ("comfort zone") that a person can cover in an arbitrary interval of time.
Renewable Resource	A resource which is regenerated or replaced by Nature after it is consumed (typically within a year).
Resource	Something which can be used.
Resource Density	Amount of resources per unit of volume. Used to calculate the resources in a sphere whose radius is increasing at a given speed.
Resource Growth	Annual rate of increase in available resources (%), independent of consumption.
Speed	1. Distance per unit time that the radius of a sphere changes. 2. Average distance traveled to access and move resources per unit of time.
Space Settlement	The establishment of communities on other worlds.
Speed Limit	Limit to how fast resources can be reached and moved. See Speed.
Speed Model	A model relating speed to consumption and population. See Speed and Population page.
Tmax	Maximum time for resources to be depleted by a fixed, isolated population.