Measuring Progress Towards Sustainability

The sustainable development movement originated from the notion that globally industrial development occurring at an accelerated pace created a polluted environment, became a threat to human health and life, caused widening income gaps between the wealthy and the poor, and posed a dangerous depletion of natural resources that sustain life on earth. The Brundtland Commission provided the crucial impetus to the idea of development that is sustainable. United Nations’ Millennium Development Goals were constructed to motivate progress towards sustainability. From an engineer’s viewpoint, one could follow the history of environmental protection in the USA to realize that much work was already done in alleviating the environmental ills to reach a point that is conducive to the adoption of the ideas of sustainable development without radical changes. Industry already has been innovating under the ideas of waste minimization and pollution prevention, and engineering was central to that development.

Over a couple of centuries, technological innovations have produced an enormous beneficial change in man’s lifestyle and level of comfort. That outcome required the use of massive use of the earth’s natural resources. Wastes being a consequence of development, much pollution resulted in air, water and land. In the beginning the innovations were mainly about profit maximization, later they were also geared to resource use minimization. Sustainable development teaches an optimization that is supposed to provide economic benefits along with environmental protection and societal uplifting. This is the biggest challenge to innovation. Businesses and entrepreneurs are engaged and many innovations are happening especially in the product and process level. Much larger challenges remain in the bigger areas of concern such as drastic reduction of greenhouse gases, making non-fossil energy financially sound, approximating zero discharge, and solving problems of water quality and quantity.

International and national trades critically rest on standards provided by reputable standards organization, some of them are government laboratories, others nongovernmental. Products or process systems that can be claimed as sustainable and that change hands or cross borders must have their quality credibly supported by measurement standards. International organizations such as ISO and others have been producing documents to guide the development of such standards. The system of standards for sustainability is not mature yet, and much research needs to be conducted to provide common and acceptable standards. A conceptual framework for standards for sustainability has been proposed here. It provides ideas on the development of methods that would be useful for building standards.

Sustainability is related to a defined system. Sustainability assessment of a system is a determination of the sustainability performance of the system compared to a similar system with the same attributes. Indicators are representatives of the attributes that characterize the system. Since sustainability consists of three interacting dimensions: environmental, economic, and societal, a Venn diagram representation shows the classification of the intersections that can be represented by chosen indicators. For example, a three dimensional indicator will be placed at the intersection of the three dimensions. In this chapter we show how indicator dimensionality can be determined. We also recognize the types of systems—global, regional, business, and technology—to which an assessment can be applied. A general framework for implementing such an assessment of a system sustainability is presented. The same framework is applicable to a system belonging to any of the four system types. The specific indicators that adequately characterize one type of system are necessarily different from those of another type of system. Once the set of indicators is satisfactorily decided upon, data collections can begin for conducting an assessment using the framework.

This chapter provides a review of the current state of the art in sustainability indicators or metrics for business and technology scales. These are the two scales at which the scientists and engineers have the most control over sustainability performance. At the business scale the purpose is to ensure investments to be secure and profitable, and for business to provide adequate support for the environment and the society. Three measurement systems are analyzed: the Global Reporting Initiative, the Dow Jones Sustainability Index, and an emerging method developed by the American Institute of Chemical engineers (AIChE), the first two being widely used. Of the technology systems, we cover the ones provided by the professional societies. The indicator system suggested by the Institution of Chemical Engineering (UK) explicitly lists the indicators under environmental, societal, and economic categories, but the AIChE system lists the most important technical indicators. Environmental Impact Assessment (EIA) and Life Cycle Assessment techniques are also presented to provide the context and tools needed for sustainability assessment at these scales.

Computer-aided simulation has been an established technique for designing and optimizing new and retrofit processes, especially in chemical process industries. Process optimization has given rise to highly useful techniques of process integration and process intensification that over the years have reduced resource use and cost. These reductions contribute to sustainable technologies no doubt but do not capture the totality of sustainability as understood in the context of simultaneous reduction of environmental, economic, and human health impacts of technologies. More and more researchers are beginning to be engaged in attempts at incorporating the remaining sustainability indicators in simulation methods. Various commercially available tools can be used as springboard for developing newer tools that would be useful to designing processes that from a holistic viewpoint are more sustainable. This chapter is a discussion on such opportunities. The field of computer-based methods of design and optimization is already very mature. This discussion is not a tutorial in that sense but an introduction to the possibilities ahead.

Sustainability assertions are holistic in nature because they represent commentaries on the impacts of process and products on three dimensions of sustainability: environmental, economic, and societal. A large number of indicators (or metrics) may be used to observe the sustainability behavior of a process or product system. Because of the complex way these indicators interact with each other in influencing system performance, it is useful to construct a holistic measure to observe sustainability performance. The Euclidean distance, composed of the indicator values representing a system, was introduced as such a measure, and has been called the sustainability footprint. In this chapter detailed computations are shown on a test system to illustrate how the sustainability footprint is calculated and how it is used to compare among competing alternatives of a system in terms of sustainability. This method based on Euclidean distance is compared with other proposed methods for indicator aggregation, such as Vector Space Theory, Canberra distance, zCanberra distance, and Mahalanobis distance. In addition, two other objectives are achieved. First, by applying the principal component analysis, the redundant indicators are identified, and second, the rank order of the indicators in terms of their contribution to sustainability is calculated. This information will be helpful in improving sustainability performance at the redesign stage based on the relative contributions of the indicators and their controllability.

Treatment of indicator data for computing sustainability footprints of systems is shown in detail in this chapter. Three representative systems have been chosen for sustainability assessment. Sustainability footprint is the Euclidean distance of a system, D_e, from a reference point of the same system, where D _e is characterized by chosen indicators . Thus for comparing different process options of a system, this distance gives an overall sustainability performance of the contending options. These three cases show how the calculations are made for obtaining the footprints. Additionally these cases also deal with statistical analysis of the covariance data of the indicator values to arrive at two important findings: first which of the indicators are necessary and sufficient for decision making and second, of the necessary indicators what are the rank orders of the indicators in terms of importance.

Energy and water use is generally correlated with the prosperity of a nation or a community. Availability of energy and safe water are vital for development and are rightly described as the most important sustainability issues for civilized society. Energy is vastly more complicated than water because there are many different kinds of sources for power and transportation: carbon based fossil energy, non-fossil such as solar, wind, and biomass-based, and nuclear and geothermal. The global warming worries make a strong case for non-fossil but in the market-place, at the current state of development, non-fossils are not competitive, creating affordability issues for communities. Energy sustainability can be approached first by attaining energy use efficiency, and ultimately by developing inexpensive non-fossil energy-carriers. Indicators are used for both water and energy sustainability in much the same way we approach general sustainability issues for communities, ecosystems, and technologies. Water can also be affected by climate change. A strong nexus exists between energy and water, which is why in closely defined systems both should be taken together for simultaneous energy–water sustainability. Energy sustainability can belong to global, regional, business, or technology scale. Water, on the other hand has a stronger spatial meaning. Since, unlike energy, water is usually not traded across borders. It typically belongs to a regional scale, and on the business and technology scale, can be controlled by process designers. Energy–water sustainability solution for a regional scale cannot be easily exported to a different region because the scales are mismatched. In this chapter, we examine the complicated multifaceted problems that need to be solved for the future.