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Emerging Challenges, Sustainability, Resiliency, and Sustainable and Resilient Engineering

Chapter Goal and Objectives

This chapter aims to introduce the drivers and concepts of sustainability and resilience, highlighting the importance of integrating them into engineering practice. The specific objectives are to (i) provide examples of emerging challenges that necessitate a focus on sustainability and resilience, (ii) explain the definitions of sustainability and resilience and clarify the differences between these two concepts, and (iii) emphasize the importance of sustainable and resilient engineering in promoting sustainable development.

1.1 Introduction

The concepts of resiliency and sustainability are everywhere. In recent years, ever-growing numbers of people around the world have become more aware of strains placed on the Earth. These strains have been manifested in a variety of ways - accelerated exploitation of natural resources, increased waste generation, pollution of air, soil, and water, and climate change. Not only have private citizens taken notice, but governments and the business world have also taken steps to address sustainability. Numerous intra- and intergovernmental initiatives and agreements have been developed to address the strains on the environment and to identify measures that encourage more sustainable practices. Businesses, too, have realized that sustainability is a good practice for a variety of reasons. New systems and products have been developed that are more protective and less wasteful of resources, and the pursuit of the "triple bottom line" (TBL) of sustainability has been increasingly applied in new projects and products. The TBL is the reference framework in sustainability that accounts for financial as well as social and environmental metrics.

Similarly, the increasing impacts of climate change, along with other uncertainties such as economic instability and social unrest, make it essential for the world to embrace the concept of resilience. In engineering, technical robustness against both expected and unexpected shocks has historically been the primary focus of design and implementation. This approach can be seen as a form of resiliency consideration. However, growing concerns over climate change and other uncertainties necessitate the engineering community to consider other dimensions of resiliency, such as environmental, economic, and social impacts of a failure. Despite the importance of these dimensions of resiliency, they are often overlooked during engineering decision-making processes.

Several key questions have emerged that necessitate contemplation. What emerging challenges are forcing us to think about sustainability and resiliency? What is sustainability? What is resiliency? How do we take action to further these concepts? What are sustainable engineering (SE), resilient engineering (RE), and integrated sustainable and resilient engineering, and what role can they play in sustainable development? Of equal importance, how do we determine success in pursuit of these initiatives, and how do we measure our progress toward these goals? These evolving and increasingly significant concepts are the focus of this book.

This chapter describes the broader emerging challenges that are forcing us to think about sustainability and resiliency. Next, the general definitions and interpretations of the meaning of sustainability and resiliency are presented. Finally, sustainable and resilient engineering and its role in achieving sustainable development are described.

1.2 Emerging Challenges

Before we delve into the concepts, applications, methods, and measures related to sustainability and resiliency, let us examine several acute problems and related examples that are faced worldwide and are increasingly having a measurable, detrimental effect on the planet.

1.2.1 Increased Consumption and Depletion of Natural Resources

A key consideration of sustainability focuses on our ability to preserve resources for future generations. This is extremely important, as many essential resources (e.g. precious metals, fossil fuels) are non-renewable and are limited in quantity. For many of these resources, we are on a current trajectory of utilization/exploitation in which near-total depletion of economically viable reserves is a very realistic possibility. The alarming rates of consumption of a number of resources not only spell trouble for the availability of these resources for future generations but also cause unintended secondary, yet catastrophic, side effects on the environment.

1.2.1.1 Easter Island Example

A classic example of the catastrophic consequences of the primary and secondary effects of natural resource depletion is the collapse of a civilization on Easter Island. Located in the southeastern Pacific Ocean and arguably the most remote habitable region on the planet, Easter Island gained its name from the sighting/discovery of the island on Easter Sunday, 1722, by Dutch sailors. It was subsequently annexed by Chile in 1888. Large stone statuary called moai, created by early Rapa Nui peoples, were important monuments to a sophisticated culture and civilization that had once flourished on Easter Island but had devolved into a small, primitive culture at the time of European discovery (DiNapoli et al. 2021).

Although Easter Island is subject to a cold and dry climate, it was at one time heavily forested with palms, conifers, and sandalwood. The first Polynesians arrived at Easter Island in the fifth century and numbered no more than 20 or 30. The harsh climate and nutrient poor soils restricted agricultural activity to the cultivation of sweet potatoes. Nevertheless, a sophisticated and advanced society flourished among the Rapa Nui. To allow for agricultural activity, much of the land was deforested. Trees were also harvested to provide structural materials for housing and boat fabrication and for use as fuel. However, a significant number of trees were also harvested to create a track system to maneuver the large moai from quarry locations to sites where they were erected. As the population grew upward of 7000 persons, these resources were further utilized to meet increasing demand.

By the 1600s, the entire island had been deforested. The lack of timber resources eliminated the ability to construct fishing boats and wooden structures. The elimination of bark materials prevented the fabrication of cloth materials. Furthermore, the deforestation greatly accelerated soil erosion, and the agricultural capacity of the already nutrient-poor soils was again severely reduced. Elaborate rituals centered around the moai statuary diminished, placing even greater strain on the social fabric of the declining society, including the breakdown of social and religious conventions. Because boats could no longer be fabricated without timber, the Rapa Nui were trapped on the remote island. Eventually, they were forced to resort to primitive cultural practices where available shelter had been reduced to available caves. Ongoing turbulent conditions fueled conflict/warfare, slavery, and even reports of cannibalism.

Ultimately, the once great civilization had collapsed. At the time of European discovery, the population had declined precipitously. The collapse of island's agricultural capacity and activity resulted in widespread, ongoing starvation. Subsequent contacts from seafaring groups, such as whalers, introduced sexually transmitted diseases and smallpox. Peruvian slave parties also captured numerous Rapa Nui for use in the slave trade. By 1877, only 111 Rapa Nui remained on Easter Island, and at the time of Chilean annexation, the Chilean government confined the remaining inhabitants to one village.

Rapa Nui remain on Easter Island to this day. Archaeologists brought attention to the island in the mid-twentieth century, which in turn has stimulated tourism and led to the restoration of some of the moai statuary. Conditions have improved for the Rapa Nui, although unemployment remains high and alcoholism and related social strains are quite prevalent. Additionally, they are still dependent on imported food.

Nevertheless, the story of the Rapa Nui has been repeated with other people - the Mayan and Inca people of Central and South America as well as the ancient Greeks and Romans. All of these people offer a cautionary tale - when a society disregards the health of its environment, places excessive strains on vital resources, such as soil and water, can lead to a collapse of agricultural activity and other aspects of economy and culture. When basic necessities such as food, clothing, and shelter become scarce, a disparity between "haves" and "have-nots" is often exacerbated, leading to mistrust and resentment between classes. As the problem grows, conflict is inevitable, and collapse of the underlying civilization will occur.

1.2.1.2 Metallic Ores Consumption Example

Several examples can be presented with respect to unsustainable utilization of natural resources. Let us take the example of the usage of metallic ores, and as an example, let us examine the use of zinc (Graedel and Allenby 2010). Consider zinc use over a sustainability design period of 50 years and a global population of 7.5 billion people. Estimated global zinc reserves consist of 330 × 1012 g (330 Tg) of zinc. Considering a 50-year period (after which all resources will be depleted), 6.6 Tg may be...