Measuring Sustainability: Calculations, Indices, and Indicators

I’m not a math-guy myself, but I do realize the significance of quantitative analysis. From engineering design to counting your macros, numbers count.

Sustainability, a difficult concept to define to begin with, is often accompanied by a broad range of tools and techniques to track progress, initiatives, and so forth. Here’s a brief on some of the number-heavy methods that are currently used.

Calculations

Formulas are centrally used to make complex problems simpler. I = PAT is a formula that was first developed in 1970 as a relatively simple way to understand sustainability efforts. The ‘impact’ is here measured as (I), which is a combination of population (P), affluence (A), and technology (T).

A second method used in this sector is Energy Return on Investment (EROI). Factored against the amount of energy needed to acquire it (investment), this calculation measures the amount of usable energy (return) from a particular resource. In this way, energy sources can be measured as net ‘gains’ or losses.’ It does not take into account the pollutive attributes of an energy source, however. Coal has a high EROI and corn has a negative net return, yet the opposite is true for pollutive outcomes, for example.

Indices & Indicators

What an index does is take a host of valid and relevant indicators and measures them against one another through a weighting system to produce a statistical measure of change. Just as the S&P 500 takes the 500 largest U.S. publicly traded companies and provides a capitalization-weighted calculation based on the American stock market, numerous indices have been established to track sustainability.

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The Human Development Index takes data on life expectancy, education, and per capita income levels to provide a more-rounded figure to GDP. Align with this, the Genuine Progress Indicator takes GDP and adjusts for other factors such as population and environmental damage. Another popular index is the Happy Planet Index. Established in 2006, this index is aimed at measuring quality of life, rather than economic wealth.

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Indices are essentially useless in themselves and are only useful in drawing relative comparisons such as growth or decline. Indices, while helpful, are also conflict-laden. Disagreements extend to determining which indicators are most relevant (viz., ‘weights’) and when to change or update the index itself—both topics that do not reach consensus and are often open for debate.

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Notes:

1.    For the 2012 HPI Costa Rica topped the list in 2012 whereas Canada and the U.S. did not make the top 50.

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