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If sustainability is a journey not a destination, how do we know we’re on the right track?

What should be measured, at what scale, and in which time-frame?

What to measure

In broad terms, an early answer to the question of ‘is it sustainable,’ was to look at the ‘triple bottom line’ – assessing environmental, economic and social features. Those ‘three capitals’ have since been expanded into:

  • ‘Five capitals’ – natural, human, social, manufactured, and financial, then
  • ‘Seven capitals’ – natural, human, social, cultural, political, built and financial.

Frameworks help in consistently and logically exploring ‘sustainability’, but the five and seven capitals frameworks only expand the social and economic considerations, as illustrated below.


It has the subsequent effect of down-playing the environment (one out seven instead of one out of three features). It could imply that thinking about environmental sustainability hasn’t advanced in step with that about economic and social sustainability. We may be failing to adequately consider environmental factors. I doubt that the latter is true, but perhaps there has been a failure to record, share and analyse the thinking which has occurred about environmental sustainability.

A web-search will quickly reveal a plethora of environmental scorecards or report cards; and an equally wide array of parameters reported in them. They tend to report either environmental condition, or consumption and/or emissions. There is often little justification of the parameters used. Some report on the degree of adoption of recommended management practices as a surrogate for environmental condition. That’s a fair approach, but should probably be reported as an aspect of human capital, rather than environmental.

A logically structured approach to environmental sustainability would consider both resource condition and resource efficiency (or throughput).

  • Resource condition is well understood. It is based on the extent (or distribution), abundance (or quantity), condition (or quality), and trend of natural assets. It covers soils, water, vegetation, fauna and the atmosphere. Landform may also be considered.
  • Resource efficiency or through-put requires explanation. In many environments it is a measure of ‘flows and sinks’ – how much comes in, how much is retained or converted, and how much is emitted or flows through. Water use efficiency, nutrient efficiency, energy efficiency are easy examples, as are parameters such as energy consumption, greenhouse gas emissions or outputs of contaminants. In terms of biodiversity it is about population dynamics – how births, recruitment and death affect the population (which is recorded under resource condition).

Some efforts have also been made to assess sustainability by considering ecosystem services or contributions to major cycles, such as water and nutrients cycles. An ecosystems services framework can be very useful in analysing the consequences of changes in resource condition, but resource condition and efficiency determine how sustainable the service provision is. Similarly, condition and throughput dictate the contributions being made to major cycles.

What scale and time-frame

There is no one right geographic or temporal scale for assessing sustainability, but it is important to be conscious of both. Working at several scales is often enlightening as different insights are gained.

  • Geographic scale. An inefficiency at one scale (e.g. water-use efficiency on an irrigation farm) can disappear at another (e.g. an irrigation district with a regional drainage and re-use scheme). Or, a resource use may be benign at one scale (e.g. property) but be impacting resource condition at another scale (e.g. catchment).
  • Temporal scale. Similar things occur when using a range of time scales. If seasonal and annual variations in climate have implications, then one time-scale should be long enough to balance out their impact on the parameters being measured. As examples, energy use for cooling will increase during excessively long, hot summers and ground-water levels may rise during a run of exceptionally wet years, but those changes may not reflect changes in sustainability.

Narrative – Six Capitals

Being clear about environmental condition and efficiency enables better reporting and better integration with social and economic considerations. It becomes possible to make statements such as, ‘We’re using X to produce Y, at an efficiency of Z and changing resource condition to B, while contributing C profit and D social benefit.’ Trade-offs become clearer, making rational assessments of sustainability – and rational management decisions – more feasible.

It is the integration of environmental, social and economic factors and understanding the interplay between them which lies at the heart of sustainability. Being clear that ‘environment’ has condition and efficiency aspects to consider should help toward that end.

Perhaps we should be thinking about Six Capitals.