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Sustainability Challenges

1.1 Introduction

Sustainability is the goal or endpoint of a process known as (ecologically) sustainable development. Sustainable development consists of a large number of pathways to reach this endpoint that sees a balance between the provision of ecosystem services, and human access to natural resources to meet the basic needs of life. Engineering sustainability challenges are focused on managing this challenge and coming up with innovative technological solutions to help sustain the earth, given the fact that the earth's existing resources will be inadequate in meeting the demands of future estimated population growth. The latest data from the global footprint network suggests that the humanity used an equivalent of 1.7 earths in 2016 (Vandermaesen et al. 2019), while the United Nations predicted that the global population will increase from 7.7 billion in 2019 to 11.2 billion by the end of this century (United Nations 2020). At the rate at which we consume the earth resources, future generations will require approximately (1.7?×?11.2/7.7) or 2.4 planets to provide equivalent resources by the end of this century. However, we only have one planet.

Worldwide human population growth has been supported by the industrial revolution and the invention of steam engine in the eighteenth century and mass production. This industrial revolution gave birth to our modern civilization and systematically improved living standards resulting in a population explosion from 0.5 to 7.7 billion only over 253?years (1776-2019) (Cilluffo and Ruiz 2019). The exploitation of minerals, fuels, biomass, and rocks for transport, agriculture, building, and manufacturing increased rapidly during this time to deliver the goods and services necessary to support the growth of modern civilization. Technologies have advanced over these years significantly to exploit rare-earth materials and scarce resources to meet the growing demand of an increasing population and to run the modern economy. The scarcity of important materials that are limited resources is only now being understood (Whittingham 2011).

Humanity currently thus uses resources 1.75 times faster than they can be regenerated by nature or provided by our planet (GFN 2019). Apart from population growth, factors which are causing the rapid decline of the earth's resources are our increased dependences on non-renewable resources, energy and material intensive technologies, and uncontrolled production and consumption. Global demand for materials has increased 10-fold since the beginning of the twentieth century and is set to double again by 2030, compared with 2010 (European Commission 2020). Resource producers have been increasingly able to deploy a range of technological options in their operations, even mining and drilling in places that were once inaccessible, increasing the efficiency of extraction techniques, switching to predictive maintenance, and using sophisticated modelling tools to identify, extract, and manage resources. The major emphasis has been on economic growth to meet the demands of a growing population, technological progress based on throughput-increasing (or resource exploitation) without consideration of the bio-physical limits of our non-renewable resources (e.g. coal, gas, ore, rocks). These resources require hundreds of thousands of years to form below the earth, and it raises questions as to what will happen to future generations when all finite non-renewable resources are exhausted due to uncontrolled production and consumption. In addition to the exponential growth of resource use, technology that is used for converting earth resources to products (e.g. construction, automobiles, electronic items) and services (e.g. electricity, internet, transportation, communication system, water supply) to meet our growing demands have resulted in emissions of global warming gases (mainly CO2). The consequence of global warming includes flooding, increased bushfire, and the destruction of ecosystems. By 2050, between 70% and 80% of all people are expected to live in urban areas (United Nation 2018), which are resource intensive and artificial environments made by man, to further improve living standards. The engineering challenge is to minimise land use and conserve resources whilst meeting the demands of the world population through energy efficient buildings, water conservation, compact cities, and efficient transportation systems in our built environment.

Population control, rapid technological innovation, and behavioural change are also required to enhance resource efficiency. It is now crucial for the present generation to change their behaviour and mindsets, which will enable them to sustain adequate resources for future generations (inter-generational equity). According to the Brundtland report (1987), 'Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs'. The widely used Brundtland's definition on sustainable development, was published in 'Our Common Future' in 1987.

While population density of developed nations is far less than that of developing nations, overconsumption by the former has already exceeded their bio-capacity resulting in their need to source resources from developing nations. The UN Development Program reports that the richest 20% of the world's population consume 86% of the world's resources while the poorest 80% consume just 14% (UN 1999). This highlights the intra-generational social equity aspects of sustainability and the increased gap between rich and poor people. The rapid progress in technology has fuelled this social inequality. According to David Grusky, Director of Stanford's Center on Poverty and Inequality, 'One of the largest and most prominent debates in social sciences is the role of technology in inequality' (Rotman 2014). The biggest social inequity is that the technology-driven economy greatly favours a small group of people by amplifying their inherent skills and wealth. Human capital being continuously replaced with man-made capital (e.g. self-service cash register, food processors) has increased unemployment. Increased unemployment on the other hand increased social problems, such as poverty, crime, corruption, and domestic violence.

Secondly, technologies have not only enabled wealthy nations to control world resources but have also increased the overconsumption (luxurious pollutions), which is responsible for further environmental degradation. Poverty in a poor nation that causes environmental degradation is known as the pollution for the survival. For example, many children in developing nations are sent outside to collect low grade fuels like leaves and twigs as their parents cannot afford to purchase high quality fuel like gas or wood. Therefore, their children do not go to school spending the whole day gathering fuels to meet the daily cooking energy demand. The collection of low grade fuels not only affects the children's education but also causes ecological imbalance by depriving soil from nutrient rich organic matter.

Thirdly, sea level rise (SLR) due to global warming will affect a large portion of land of developing nations in densely populated countries in the Asia Pacific region.

Planned obsolescence of business strategy in recent times have made technologies obsolete, unfashionable or no longer usable before their natural end of life (EoL), which has created unsustainable consumption. For at least half a century, the mainstream fashion industry has purposely produced goods of inferior quality to increase sales to gain short term financial benefits. In essence, it means that a company is deliberately designing and manufacturing products with a shorter life span, by making them non-functional or unfashionable earlier than necessary and increasing the waste sink if these items are not designed for disassembly or reuse or remanufacturing.

Addressing inter- and intra-generational social inequities requires a reduction in the investment in unnecessary luxury items, controlled economic growth, sustainable behaviour and life style changes, and to design technology/products for repurposing and dematerialisation (e.g. accessing materials online reduced to need of hard copies, virtual conferences reduce travelling). A paradigm shift is urgently necessary to switch from resource intensive technologies that are currently being used (e.g. power plant, car, infrastructure) to more resource saving technologies (e.g. replacing a new engine with a remanufactured engine, super light car with reduced fuel consumption reduces long run costs and emissions). Secondly, it is important to encourage the technological race to enhance both inter- and intra-generational social equity. More dependence on technology means we need more energy and material resources to produce, operate, and maintain them in an increasingly resources scarce world. We need to achieve a balance between technology and human capital for enhancing intra-generational social equity while maintaining economic growth. In a nut shell, social equity means 'equal opportunity of access to basic needs' for all people on earth.

Innovative technological design for converting EoL product to new product will reduce land, energy, and the material consumption associated with virgin material...