Timelines Model (Version 5)

The following graph shows the relationships between global variables tracked in the Timelines model. Roll over to see the definitions as a function of phase.

Definitions of variables and terms used here and elsewhere are as follows. Variable names are capitalized, and references to other entries are italicized.

adjusted impact	Amount of Impact after it has been changed by human activity (typically Consumption)
Age	Median age of a population, in years
Birth Rate	Births per year as a fraction of the population
C	Average Consumption per person in a group
Capacity	Total amount of ecological resources available to, and used by, a group (see Rtotal)
Cap/p	Capacity per person
C-low	Simulation that reduces consumption at a roughly constant rate to offset external Impact
Consumption	Ecological footprint of group expressed in ecological resources(see R)
cum, cumulative	Sum of values for a variable as a function of another variable
$ current	U.S. dollars inflation adjusted for a given year
Death Rate	Deaths per year as a fraction of the Population
ecological footprint	Measure of ecological products and services used by humanity, typically expressed as a unit of land area
ecological resource	Unit of ecological footprint corresponding to an average person's annual basic needs
Efficiency, E	Variable affecting the distribution of Population in a group
epoch	Period of time corresponding to when part of a group is in a given Phase.
global variable	A variable that describes a charcteristic of interest for one or more groups
Green	The simulation that is the best match to historical values of global variables
group	A set of people with specific Population, Consumption, and Capacity
GWP	Gross World Product in U.S. dollars (2010 value unless otherwise indicated)
GWP/p	Average GWP per person in U.S. dollars (2010 value unless otherwise indicated)
Happiness, H	Life satisfaction of members of a group (on a scale from 0 to 1, typically expressed in %)
Impact, self-sustained impact	Change in ecological resources (typically a reduction) continually caused by a non-human source
Life Expectancy, L	Expected lifetime (in years) of a person or group born in a given year
Max Phase	The maximum phase in a group
Min Phase	The minimum phase in a group
mixed group	A group resulting from interaction of groups based on maximum Weights of Population, C, and Capacity
Needs	Maximum ecological resources consumed for basic survival
Normalized	Expressed as a fraction of a given value (such as the maximum expected value or value in a given year)
Normalized Population / Nature	Sratio / 1.126; also: Sr
P	Cumulative population as a function of a variable such as phase (P = E^Phratio - E).
Phase	Activity type; each phase is expressed as a fraction of its Sr range
Phase Ratio, Phratio	Phratio = (Max Phase - Phase) / (Max Phase - Min Phase)
Pmax	Maximum world population as a function of Sratio
Population	The number of people in a group
R	Total amount of ecological resources consumed by a group (P * C)
Rdiff	Amount of total Wants consumed by a given group
region	An arbitrary collection of resources and people (also group)
resource	Ecological resource
Rs	Amount of ecological resources remaining in a region or the world, usable by people and other species
Rtotal	Capacity
$Convert	Global inflation of U.S. dollars, as multiple of a value in 2010
simulation	Set of mathematical projections of observable variables (typically global variables) that define a universe
Sr	Normalized Population / Nature
Sratio	Ratio of minimum Consumption by people (Needs) to remaining resources (P / Rs)
state	The combined characteristics of an entity (such a group) based on the values of a set of global variables
summed group	A group with the sums of interacting groups' Population, Consumption, and Capacity
$T	Trillion U.S. dollars
total consumption	The Consumption of everyone in a group
universe, world	Theoretical reality defined by a simulation, based on history in the real world
variable	A mathematical quantity whose value is based on the values of other quantities
Wants	Resources consumed for purposes other than needs (R - Needs)
Waste	Consumption in excess of half the total resources in the world (R - Rtotal / 2)
Wealth	Wealth in U.S. dollars (2010 value unless otherwise indicated)
Wealth/p	Average wealth per person in U.S. dollars (2010 value unless otherwise indicated)
Weight	Multiplier of a variable used to calculate the value of another variable
weighted group	A group resulting from groups interacting based on Weights of Population, Consumption, and Capacity
world group	All the people and regions in the world identified as one group
Year	Middle of given calendar year (A.C.E.)

The following summary shows the distribution of variables across the world's population for the year 2019, and a time series of values for simulation Green (the best fit to historical data).