Sustainability & Population Growth

World Population

IPAT Equation

I = P x A x T

ImpactPopulationAffluence

Technology

Sustainability Impact Equation

SI = P x C/P x I/C

Sustainability Impact Population

Consumption per capitaImpact per consumption

Sustainability Impact Equation: Double Population

2SI = 2P x C/P x I/C

Sustainability Impact Population

Consumption per capitaImpact per consumption

Sustainability Impact Equation: Double Consumption per Person

2SI = P x 2C/P x I/C

Sustainability Impact Population

Consumption per capitaImpact per consumption

Sustainability Impact Equation: Lowering Impact per Consumption

½ SI = P x C/P x I/2C

Sustainability Impact Population

Consumption per capitaImpact per consumption

ManhattanLimitation of IPAT

IPAT Terms are Co-dependent

I = P(A,T) × A(P,T) × T(A,P) Impact

PopulationAffluence

Technology

For the math geeks…

Human ExperienceOther Factors: Human Experience

Health and WealthOther Factors: GDP

As GDP per person increases (x-axis) so does life expectancy (y-axis). Note that Japan, the country with highest life-expectancy, has a very high GDP per person

Happiness and Affluence

As GDP per person increases (x-axis) so does self-reported life satisfaction (y-axis)Note that the happiest country – Denmark – also has a very high GDP per person.

Not All Consumption is Equal

References• Schwen, Daniel. 2005. “NYC wideangle south from Top of the Rock.” Wikimedia Commons. http://en.wikipedia.org/wiki/File:NYC_wideangle_south_from_Top_of_the_Rock.jpg

• Tompkin, Jonathan. 2012. “Too-rigorous application of IPAT style thinking discounts the human experience.”

• Rosling, Hans. 2011. “Gapminder World Chart 2010 Version May 2010b.” Gapminder. http://www.gapminder.org/GapminderMedia/wp-uploads/pdf_charts/GWC2010.pdf

• Heston, Alan; Summers, Robert; and Aten, Bettina. 2006. “Penn World Table Version 6.2.” Center for International Comparisons of Production, Income and Prices at the University of Pennsylvania.

http://pwt.econ.upenn.edu/php_site/pwt62/pwt62_form.php

• Theis, Tom and Jonathan Tomkin, editors. Sustainability: A Comprehensive Foundation. http://cnx.org/content/col11325/latest/