Comfort

Based on analysis of various countries, the relationship between per-capita ecological footprint and both happiness and life expectancy is found to be logarithmic. If people's happiness (satisfaction with life) is defined as the current distance from their comfort zone measured as a fraction of the maximum distance, then we can estimate the effects of stressing a population on its consumption and longevity.

If a population's comfort zones ("V") and positions ("E") are measured on a scale from zero to ten, and varied over a range centered on a specific value ("V0" for comfort, "E0" for position), average per-capita consumption will vary -- and with it, life expectancy, happiness, and resource depletion time ("Tmax").

One set of parameters that may match the world is shown in the table below, where "F/P" is global ecological footprint per person, "C/P" is average per-capita mass consumption, and the population is assumed fixed based on projections of the Combined Population Model for 2008. A sample of 1,000 points is used, and the relationship between happiness and lifespan is statistically defined by a sample of nations in 2003 (see Happiness) instead of the more recent definition.

Position E0	E Range	V Range	Happiness (%)	F/P (h)	C/P (lb)	Tmax (yr)	Lifespan (yr)
2.57	0.00	2.57	55	2.1	1,591	96	62
2.57	0.50	2.57	54	2.3	1,764	86	63
2.57	1.00	2.57	54	2.3	1,808	84	63
2.57	1.50	2.57	54	2.3	1,784	85	63
2.57	2.00	2.57	54	2.7	2,101	73	63
2.57	2.57	2.57	54	3.0	2,307	66	63
2.57	3.00	2.57	54	3.7	2,866	53	63
2.57	3.50	2.57	54	3.8	2,947	52	63
2.57	4.00	2.57	55	5.1	3,978	38	63
2.57	4.50	2.57	53	5.3	4,107	37	62
2.57	5.00	2.57	54	4.7	3,653	42	61
2.57	5.50	2.57	53	6.7	5,172	29	63
2.57	6.00	2.57	54	7.7	5,941	26	63
2.57	6.50	2.57	53	8.1	6,260	24	62
2.57	7.00	2.57	54	9.0	7,015	22	63
2.57	7.50	2.57	54	9.5	7,347	21	63
2.57	8.00	2.57	53	10.4	8,094	19	62

Depletion time is plotted below along with two other scenarios where the comfort zone is identical (V0 = 5, V Range = 0) for everyone in the population and the center position (E0) is different for each scenario (2.5 for one and 3.05 for the other). For reference, the projected depletion time is identified by a dashed line.

Clearly, increasing the range of allowable "positions" results in an increase in consumption and a decrease in depletion time (longevity). Similarly, reducing the range of allowable positions can buy only a limited amount of time.

If the range of comfort zones ("V Range") is assumed to be 2.57, as in the first example, and the position and position range ("E0" and "E Range") are adjusted so that the minimum observable per-capita footprint matches the value estimated for 0 A.D., then the resulting scenario may be the best we can achieve in terms of longevity under the current resource constraint. Specifically:

E0 = 1.75; E Range = 0

Tmax = 407 yr; Lifespan = 49 yr

Happiness = 38%

F/P = 0.5 h; C/P = 374 lb

Note that it is possible that such a change would result in population loss (due to the First Law of Consumption).