In my last entry, I spoke of Icarus, with his wings of wax and feathers, achieving human powered flight through brilliant engineering and an understanding of the world around us. I compared the evolution of human flight from this starting point to Aeronautical Engineering, with the evolution of Sustainability from pre-capacity communities, through the early adopters of ‘Green’ approaches , and now to Triple Bottom Line , and in the future to real Sustainability Engineering. This series of articles is a vision of where we are heading, rather than a step-by-step set of instructions to reaching that future. A set of mile markers, as it were, to inform the profession of the direction we are going.
Sustainability Engineering is creating or enhancing the systems of infrastructure so that there is an expectation of a return on that investment into the future, when considering only the resources available in perpetuity to the community and the time required to meet needs within the community.
In any community, there is a relationship between the resources used by the community and the time it takes people to meet their needs. Using a definition of needs that is ‘something that prevents the degradation of the self, family, or community’, the human activities that are measured in time use studies can be separated to ‘Needs’ and ‘not Needs’. The boundary of the concept of ‘Needs’ has to be set by the Community, and is independent of the engineer. Thus if Food is a need, the community may decide that Transporting Food is a need, but Importing Food is not. Likewise, the community would determine the symptoms that would be expected if a need was not adequately met.
Using the boundary of needs provided by the community, the time use and resource use throughout the community can be plotted against each other. The engineer would then find the unique Time/Resource curve for each community that is sensitive to their boundaries, resources, climate, technology, culture, etc. This can be done in advance of any design effort, much like building code tables and other references
When establishing the formula for this relationship, it is important to note:
• If a community is consuming more resources than it is able to provide in perpetuity from the territory that it manages, then at some time in the future the excess resource consumption will not be available to the community.
• The loss of resource use will automatically cause the population to shift their time and resource use to the left of the curve, only until consumption is below Capacity for that community.
• Therefore the minimum relationship between time and resource consumption is the slope of the Resource/Time curve at Capacity.
Figure 1 shows the relationship in Canada from 2005. Each data point is the average from one decile of household income. Because of the form the data is available in, the 9th and 10th decile of household income is shown as a single point. Please refer to my previous blog for the data sources that went into this graph.
Figure 1 – Canada 2005
The line shown in Figure 1 has a R2 of greater than 98%. T’LUBC = -9.49 min/GHa. Consumption of resources that produces an Ecological Footprint that is greater than Locally Used BioCapacity will have an associated Future Time Cost = (EFc-Cc)T’, in addition to the curve shown above.
To be consistent with the Second Principals, and considering the relationship of time and resources, the method to be used to find the most Sustainable alternative is:
• Cradle to Cradle Life Cycle Analysis of Time Used, and Resources Used to create, use, maintain, and decommission project, for each alternative, including Do Nothing .
• For each alternative:
1. Time cost to create, operate, maintain, and decommission project
2. Improvement in Time Used to meet needs within community, as Time Benefit relative to Do Nothing
3. Resources Used from sources being managed per Daly by community
4. Resources Used from sources not being managed per Daly by community
a) Not from resources managed by community; imported EF
b) Will exhaust over lifecycle of project
5. Find costs and penalties
a) Convert (4a) to a Future Time Cost using the slope of the R/T curve at LUBC
b) Convert (4b) to a Time Penalty using the mass ratio of (4b) to total mass used x longevity ratio of time to peak over lifespan of project.
6. Subtract (2)+(5a) from (1) =Net Time Benefit
7. Divide (6) by cost =Sustainable Value
• All alternatives that have a Net Time Benefit > 0 makes the community more Sustainable
• The alternative with the greatest Net Time Benefit makes the community the most Sustainable
• The alternative with the greatest Sustainable Value produces the greatest improvement in Potential Quality of Life in the community per dollar spent = best investment.
• If the per capita Community Managed Ecological Footprint is less than Capacity, the community has the potential to be Sustainable. Human Development activities would be required to actualize that potential.
This approach is consistent with the Triple Bottom Line methods of accounting, with the difference that the Economy component is implicit, and the Social component is not fully incorporated. This method is intentionally not ‘Social Engineering’, but rather taking consideration of the unique aspects of each community.
By using the unique relationship found within each community between resource consumption and time use to meet needs, designs that are sensitive to the availability of skills, technology, and resources in the community can be created. This provides the rate equations that apply at any chosen scale, and from there we can find near optimal solutions to address the needs of that population.
Icarus may have flown as the result of spectacular engineering, and may have landed badly because he didn’t pay attention to the limits he was bound to. Our culture don’t need to crash if we pay strict attention to the limits imposed on us by our finite world, and use the spectacular engineering skills that we have developed. This is both our opportunity and our obligation.
In the next entry, I will provide an example of how this would be used in typical Civil Engineering projects. Note that this approach can be applied to all forms of engineering, to provide Sustainable Technological Development.