Sustainability and Engineering Aran Eales & Mike Clifford Copyright © University of Nottingham, 2013 Published at Smashwords The University Of Nottingham, University Park, Nottingham NG7 2RD, UK http://www.nottingham.ac.uk First published: January 2013 Except for third party materials (materials owned by someone other than The University of Nottingham) and where otherwise indicated, the copyright in the content provided in this resource is owned by the University of Nottingham and licensed under a Creative Commons Attribution-NonCommercial-ShareAlike UK 2.0 License (BY-NC-SA). This eBook is a U-NOW resource. For the online version follow this link: http://unow.nottingham.ac.uk/resources/resource.aspx?hid=1c4d7433-74db-9779- b605-7681374bc79a This eBook has been put together using material generated by The University Of Nottingham, in combination with material from third-party ‘Creative Commons’ sources. The principle of sustainability has been upheld through the production of this eBook through the re-use of the openly licensed material. This resource is in turn being made openly available for anyone with an interest in learning. We would like to thank all of the individuals and organisations whose Creative Commons resources are included, or have been adapted, as part of this publication. Table of Contents Chapter 1: Module Outline Chapter 2: Energy Chapter 3: Materials Chapter 4: Water Chapter 5: Food and Agriculture Chapter 6: Buildings Chapter 7: Social Dimensions of Sustainability and Engineering Chapter 8: Economics Chapter 9: Moving Forward Chapter 1: Module Outline This module is intended to give you a broad understanding of issues related to environmental sustainability in the context of engineering. The environmental problems facing our world are becoming more apparent day by day, and the term “sustainability” is used more frequently in the media. This module will explore the concept of sustainability and discuss some of the issues surrounding the subject. Each chapter will begin with an overview of the content, and will then introduce key factors and the current world systems in place for the subject matter such as energy, materials, food, water and shelter. The social and economic factors of sustainability in an engineering context will also be covered. The problems associated with these systems will then be highlighted, specifically their environmental or social impacts and what part of the systems that could be considered unsustainable. Alternatives will then be introduced and outlined including what options there are and what are the challenges involved in implementing them. Scope of Module The issues around sustainability are enormous, and it is not the role or scope of this module to cover everything in great depth, as there is enough information on any single subject for a masters or Ph.D. The aim of this module instead is to introduce the key concepts of hazards facing the global community in the coming years, how we got to our current state and ideas for what can be done to modify the current trajectory. Teaching Method The module is self taught through online resources. You will be expected to work through the content at your own pace. There will be several resources included in the body of the module such as links to websites, podcasts or videos online, which you can browse as necessary. As mentioned, the module is intended to introduce certain concepts around sustainability and instigate interest for you to conduct personal research in topics of interest. Assessment The assessment will be an essay or presentation for which you must research a topic of your choice related to the module content. The essay will become part of the learning resources for this module – essays and presentations will be published on line for use by people doing the module in the future. There will be more information about the assessment towards the end of the module – but bear it in mind as you are going through the chapters – make a note if anything specifically interests you or you feel you would want to research more about a particular topic. Introduction “We do not inherit the Earth from our ancestors - we borrow it from our children” (Anon) Rapid expansion of population, resource consumption and associated pollution by the human race has put a strain on the natural ecosystems of the Earth we rely upon to survive. The limits to our expansion are beginning to show, as significant issues such as resource depletion, climate change, scarcity of water, soil fertility depletion and changes in biodiversity occur. A term “sustainable development” has emerged and is being used increasingly by the media to describe a need for constructing a way of organising ourselves that doesn't detrimentally harm the planet or society. This chapter aims to explore the term “sustainability” and put it into context with engineering, a profession that has contributed to the current problematic system as much as providing a platform for creating solutions to the problems. Definitions of sustainability will be given, followed by an introduction to ethical issues behind the topic. The concept of exponential growth will then be explored in detail and applied to global patterns of growth and consumption. Finally the limits to this growth will be outlined, before discussing the role of an engineer in the sustainability agenda. Figure 1 : Sustainable Development is based around 3 core considerations; economic, social and environmental (or ecological – see 1.2) Figure 1 sourced from The Open University under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence http://openlearn.open.ac.uk/mod/oucontent/view.php?id=405678§ion=4 A definition of Sustainability The word “sustain” when used as an action or a process is associated with concepts such as “to carry on” or to “keep going”. For example you sustain your body by giving it sufficient nutrients, food and water. However you could keep your body going on stimulants and unhealthy food which would prolong survival, but with a poor standard of living and probably not for very long. Thus it could be called an unsustainable health program. Similarly environmental sustainability embodies this concept of endurance applied to the Earth’s natural systems and our relationship with them as a human race. It is a concept of organising ourselves with a long term view of the future; aiming for a system that will sustain us and the world and not cause significant catastrophe to either. The most common definition of sustainability comes from the 1987 Bruntland report and is as follows: "Meeting present needs without compromising the ability of future generations to meet their needs" (Bruntland Report, 1987) Several other definitions of sustainability have since been suggested, which include: "Sustainable means using methods, systems and materials that won't deplete resources or harm natural cycles" (Rosenbaum, 1993). Sustainability "identifies a concept and attitude in development that looks at a site's natural land, water, and energy resources as integral aspects of the development" (Vieira,1993) "Sustainability integrates natural systems with human patterns and celebrates continuity, uniqueness and placemaking" (Early, 1993) “Sustainable developments are those which fulfil present and future needs (WECD, 1987) while [only] using and not harming renewable resources and unique human- environmental systems of a site: [air], water, land, energy, and human ecology and/or those of other [off-site] sustainable systems (Rosenbaum 1993 and Vieria 1993).” Definitions Source: [ see reference 2] Above text sourced from Wikispaces under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Licence http://meangreenwikimachine.wikispaces.com/Sustainability Key words and themes from these definitions are as follows: Needs – humans have basic needs for survival Resources – the world provides resources for these needs Natural cycles/systems/balance – planet earth is a self-sustaining system without humans, we affect these systems when we use resources for our needs Continuity – finding ways of meeting our needs through using nature's resources without affecting the natural cycles in a way that will detriment future survival Now watch this 15 minute doculecture from the University of Idaho about the definitions of sustainability: http://webpages.uidaho.edu/sustainability/chapters/ch02/ch02-p01.asp Activity What does sustainability mean to you? Write down key words you associate with the word “sustainability”. From these words then draw up a definition of sustainability. Ethics of Sustainability Motivations for exploring sustainability can be different depending on your world view: logic, emotion or instinct can be the drivers. Generally they are based around concepts of humanity inherently striving for survival. The following are three viewpoints for sustainability: The Ecologist Doesn't s ee the human race as a separate entity from the planet and its resources, but part of it. Their motivations for preserving the planet are that nature and humanity have an inherent value and should be protected because of that. The Environmentalist Sees nature or the planet as separate from the human race. It is there for humans, and as such humans should have stewardship over the world. They see the planet as something to be preserved so that humans can survive and evolve. The Economist Understands the measures of unsustainability arising from a consumer led culture treating finite resources as an income, but has faith that market forces and a “business as usual” approach will result in a natural crisis aversion occurring; that the system will sort itself out through technological advances if left to its own devices. It is not intended to go deeply into philosophy in this module, but it is important to consider for yourself what motivations you may have, (if any) on this subject. To assess motivations you first need to place yourself with or in the world, and this is a subjective experience. Engineers have a role in society to design and implement systems that benefit humanity. Before an engineer can undertake a project, they must first have a full grasp of their motivations for being an engineer, and whether the aims and objectives of the project fit in with their ethical standpoint. Activity Imagine you work for a civil engineering company and your company has been asked to build a road through ancient woodland. The construction of the road will destroy the habitat of an endangered snail. Opponents to the road say that ancient woodland has an inherent value, and it is a travesty to wipe out the only place this snail lives in the world. Supporters of the road argue that it will bring social and economic benefits to the village it is connecting, which is inhabited by many people living in poverty. They argue that the economic benefits of the road will increase the quality of life for the residents of the village. The company you work for stand to make a large profit by securing the contract to build the road. What would be the primary concerns for an ecological engineer, an environmental engineer and an economical engineer? Would anything change if it was panda rather than a snail that was endangered? Worldwide trends will now be presented to illuminate the concepts of why people are talking about sustainability. These come under two themes: exponential growth of population and consumption (the needs as expressed above) and associated limits to growth due to depleted resources and increasing pollution resulting from the consumption of the resources. Exponential Growth Figure 1.3.1 adapted and sourced from Wikipedia (Author: McSush) under a the Creative Commons CC0 1.0 Universal Public Domain Dedication License http://en.wikipedia.org/wiki/File:Exponential.svg The above graph shows three different functions increasing over time. The y axis is the amount of something; the x axis is increasing time. The red graph increases proportionally, the blue increases cubically, and the green graph increases exponentially. In this example the exponential graph doubles over a set period of time but it could triple, quadruple or increase by any factor of x over time. The green graph is the important one as it is this model that many world systems such as population growth and resource consumptions follow. The shape of that graph and the concepts it introduces are essential to understanding the trajectory of patterns in society. Example: A bacteria is introduced to a lake of a finite size. The bacteria cover a set area of the surface of the lake, and this area doubles in size every hour. After 1 hour the bacteria covers 1% of the lake. How many hours will it take to cover the whole lake? It takes 6 hours for the bacteria to cover just under one third of the lake (32%), but in the next hour and a half, it covers the whole of the lake. This example is intended to demonstrate the nature of exponential growth – amounts become very large very quickly. It could be considered that we are now in that final hour, where the amount of water left on the lake is our remaining resources. If it is known that the world is strained with our presence currently, those strains will double in a short period of time, and double again after that unless radical changes are made. World Population and Associated Impacts Real life situations follow the pattern of exponential growth. The most familiar of these is the world population graph, which you have probably seen before: Figure 1.4.1 World Population since AD 1000 Figure 1.4.1 sourced from Slideshare.net (Author: Toni Menninger) under a creative commons attribution-non commercial license http://www.slideshare.net/amenning/growth-in-a-finite-world-sustainability-and-the-exponential-function Global population has just reached 7 billion people. 100 years ago there were about 1.6 billion people in the world and in the 1960's there were about half the people there are today. In the last 50 years the population has doubled, and this trend shows no signs of changing. Each person on the world requires resources to survive so naturally there will follow exponential graphs for world resource use over the same time period. Although a bigger population generally means more mouths to feed, there is not an even distribution of consumption patterns throughout the world. One of the biggest indicators of unsustainability is in the misdistribution of wealth. Over a third of the world still live in poverty with limited access to energy, water or food. In 2006, a team of scholars with the United Nations University’s World Institute for Development Economics Research published the first paper to tally, for the entire world, all the major elements of household wealth, everything from financial assets and debts to land, homes, and other tangible property. This research, based on year 2000 data, found that the richest 1 percent of the world’s adult population, individuals worth at least $514,512, owned 39.9 percent of the world’s household wealth, a total greater than the wealth of the world’s poorest 95 percent, those adults worth under $150,145 who hold, together, just 29.4 percent of the world’s wealth. [ see reference 5] Personal wealth is distributed so unevenly across the world that the richest two per cent of adults own more than 50 per cent of the world’s assets while the poorest half hold only 1 per cent of wealth [ see reference 5] . The USA consumes 25% of the world's energy with a share of the world population of 4.5% [see reference 6] . The figures for material, water and food consumption between the richest nations and the poorest display a similar level of disparity. Population growth is much higher in developing countries, while resource consumption and pollution is higher in developed countries. The gap between the ends of the spectrum has been increasing in a similar exponential fashion. The focus of sustainability is as much on humanity (the social corner of the sustainability triangle) as it is on nature (the ecological), and to reduce this inequality and provide a basic standard of living conditions for the earth's inhabitants is paramount to the sustainability challenge.