CE1201 Environmental Sustainability Reading Material PDF

CE1201 Environmental Sustainability Course Reading Materials Course Instructor: Prof. Adani Azhoni Department of Civil Engineering National Institute of Technology Manipur Compiled for Internal Use only CE1201 ENVIRONMENTAL SUSTAINABILITY (3-0-0-3) Introduction to Environmental Sustainability. Overview of sustainability and its importance. Sustainable development goals (SDGs). Role of engineers in sustainability. Principles of Sustainable Engineering: Systems thinking in sustainability. Life cycle thinking and assessment. Energy and Sustainability: Energy consumption and its environmental impact. Renewable vs. non-renewable energy sources. Strategies for energy efficiency in engineering. Water Resources Management: Importance of water in sustainable engineering. Water scarcity and its challenges. Sustainable water management practices. Material Use and Sustainability: Impact of material use on the environment. Sustainable material selection. Recycling and reuse of materials. Pollution and Waste Management: Types and sources of pollution. Waste management strategies. Sustainable practices to reduce pollution and waste. Sustainable Design and Manufacturing: Principles of sustainable design. Eco- design and green manufacturing practices, Case studies in sustainable product design. Environmental Impact Assessment: Introduction to environmental impact assessment (EIA), Methods and tools for EIA, Case studies on EIA in engineering projects. Sustainable Infrastructure and Urban Planning: Concepts of sustainable infrastructure, Urban planning for sustainability, Case studies in sustainable urban development. Climate Change and Engineering: Understanding climate change and its impact, Role of engineering in mitigating climate change. Adaptation strategies in engineering practices. Sustainable Engineering Ethics and Policy: Ethical considerations in sustainable engineering, Role of policy and regulations in sustainability, Global and local, sustainability policies, Applications and Future Trends in Sustainable Engineering, Emerging trends in sustainable engineering, Applications of sustainable engineering principles, Future challenges and opportunities in sustainability. TEXTBOOKS: 1. Bhakshi, Bhavik. Sustainable Engineering: Principles and Practice. 2. Basak Anindita, Environmental Studies, Pearson Education South Asia. Sustainable Engineering Principles and Practice Bhavik R. Bakshi The Ohio State University University Printing House, Cambridge CB2 8BS, United Kingdom One Liberty Plaza, 20th Floor, New York, NY 10006, USA 477 Williamstown Road, Port Melbourne, VIC 3207, Australia 314–321, 3rd Floor, Plot 3, Splendor Forum, Jasola District Centre, New Delhi – 110025, India 79 Anson Road, #06–04/06, Singapore 079906 Cambridge University Press is part of the University of Cambridge. It furthers the University’s mission by disseminating knowledge in the pursuit of education, learning, and research at the highest international levels of excellence. www.cambridge.org Information on this title: www.cambridge.org/9781108420457 DOI:10.1017/9781108333726 ±c Bhavik R. Bakshi 2019 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2019 Printed in the United Kingdom by TJ International Ltd, Padstow Cornwall 2019 A catalogue record for this publication is available from the British Library. Library of Congress Cataloging-in-Publication Data Names: Bakshi, Bhavik R., author. Title: Sustainable engineering principles and practice / Bhavik R. Bakshi, Ohio State University. Description: Cambridge, United Kingdom; New York, NY, USA: Cambridge University Press, 2019.| Includes bibliographical references and index. Identiﬁers: LCCN 2018048004 | ISBN 9781108420457 (hardback) Subjects: LCSH: Sustainable engineering. | Environmental protection. | Conservation of natural resources. | Energy conservation. Classiﬁcation: LCC TA163.B35 2019 | DDC 620.0028/6–dc23 LC record available at https://lccn.loc.gov/2018048004 ISBN 978-1-108-42045-7 Hardback Additional resources for this publication at www.cambridge.org/bakshi Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Brief Contents Preface page xvii PART I Introduction and Motivation 1 1 The Basis of Human Well-Being 3 2 Status of Ecosystem Goods and Services 20 3 Sustainability: Deﬁnitions and Challenges 50 PART II Reasons for Unsustainability 73 4 Economics and the Environment 75 5 Business and the Environment 94 6 Science, Engineering, and the Environment 112 7 Society and the Environment 126 PART III Sustainability Assessment 139 8 Goal Deﬁnition and Scope 141 9 Inventory Analysis 153 10 Mathematical Framework 174 11 Footprint Assessment 207 12 Energy and Material Flow Analysis 225 13 Exergy Analysis 246 14 Cumulative Exergy Consumption and Emergy Analysis 270 15 Life Cycle Impact Assessment 297 Preface Engineering aims to enhance human well-being, but also contributes to the degra- dation of ecosystems and depletion of resources. These negative side-effects often appear as unexpected surprises and unintended harm. Given the essential role played by technology in the modern world, it is important to ensure that engi- neering decisions and activities contribute positively to the economy, society, and environment. This book aims to help engineers in meeting this goal. It has grown out of an elective course that I have developed and taught for 20 years, and shorter versions have been co-taught at various institutions across the world. The challenge of sustainable development is of a transdisciplinary nature, and no single discipline is in a position to address it by itself. Therefore, this book adopts an approach that cuts across disciplinary boundaries, mainly to under- stand the challenges and also to learn about possible transdisciplinary solutions that include engineering. Such a broad understanding motivates various engi- neering methods that help in assessing sustainability and in designing systems that contribute positively to the three values of ecology, society, and economy. Knowing the quantitative bias of most engineers, this book relies on equa- tions and quantitative examples to convey various methods in a rigorous but understandable manner for students with a range of mathematical skills and backgrounds. Key Features The key features of this book include: a multidisciplinary introduction to the challenges of sustainable development and potential solutions; systematic and quantitative coverage of methods for assessing the sustainabil- ity of technological alternatives and for devising solutions; nearly 100 solved problems throughout the book; boxes describing practical examples relevant to each topic; a clear introduction to the content of each chapter in the chapter introduction, and a listing of key ideas and concepts at the end; exercises at the end of each chapter; and an introduction to relevant software and its use for solving practical problems available on the companion website. xviii Preface Content of this Book This book is organized in four major parts. Introduction and Motivation. Part I introduces the subject and motivates the need for sustainable engineering. It considers the basis of human well-being and the status of the goods and services that are essential for our well-being. Then the meaning of sustainable development is discussed along with the challenges in achieving sustainability. Reasons for Unsustainability. Part II explores reasons for the unsustainability of human activities. It describes how activities in multiple disciplines, such as economics, business, science, engineering, ethics, and behavior, can con- tribute to unsustainable decisions. Such cross-disciplinary understanding of the problem is essential for ﬁnding effective solutions. Sustainability Assessment. Part III describes methods for assessing the sus- tainability of human activities and technologies. It introduces various popular techniques and ways to solve practical problems. This material is written in such a way that its mathematical rigor may be adjusted as desired. Solutions for Sustainability. Part IV focuses on solutions for achieving sustainability. It describes approaches related to engineering, such as: techno- economic analysis and process design; methods inspired from ecology such as biomimicry, industrial symbiosis, and techno-ecological synergy; and solutions from economics, policy, and societal transformation. Companion Website. This contains information about software for apply- ing various methods covered in the text, statements for individual or group projects, and solutions to selected projects. Updated chapters and errata are also available. Ways of Using this Book The content of this book has been used primarily for junior and senior engineering undergraduate students and for graduate students. The chapters in Parts I and II provide the motivation and understanding of the issues facing sustainable devel- opment, and should be included. Chapters from Parts III and IV may be chosen depending on the students’ backgrounds and interests. Chapters that require a more advanced background include the following. Chapter 10 is mathematically more challenging as it covers the rigorous frame- work of sustainability assessment methods. A proper understanding of this framework requires a background in basic linear algebra. However, the chapter has been written in a manner such that the framework may also be understood without a knowledge of linear algebra. If this chapter is excluded from the syllabus, it is still possible to use the other chapters since the concepts rele- vant to Chapter 10 are covered in a simpler manner (without linear algebra) Preface xix in Chapter 9. Also, most of the examples throughout the book are solved with and without the use of linear algebra. Chapters 13 and 14 rely on the concepts of entropy and the second law of ther- modynamics. If students do not have the necessary background, these chapters may be excluded without any loss of continuity. This book may be used for various types of courses: A semester-long course could include the chapters in Parts I and II, and selected chapters from Parts III and IV. Homework exercises and a larger group project are also recommended. This material may also be covered over two semesters. The ﬁrst semester could focus on Parts I and II and a few chapters from Part III. This course would be on Sustainability Assessment. The second semester would focus on the remaining chapters of Part III and Part IV, along with a substantial course project. This would be on Solutions for Sustainability. Many universities have a freshman-level course on sustainable engineering. For such a course, the syllabus could include chapters from Parts I and II, and selected chapters from Part III, such as Chapter 11 on Footprint Assessment and Chapter 12 on Energy Analysis. Chapters 19 and 20 from Part IV may also be included. Acknowledgments Such a book is impossible without direct and indirect contributions from a large number of individuals. It would be difﬁcult to name them all! I am grateful to the students who have taken this course. Their role has been indispensable. This includes more than 500 students at OSU. It also includes stu- dents at the Institute of Chemical Technology, Mumbai and in short courses at the Massachusetts Institute of Technology, the Indian Institute of Technology, Mumbai, TERI University, New Delhi, the South China University of Technology, Guangzhou, and McGill University, Montreal. The teaching associates for this course and various graduate students and post- doctoral researchers have helped in many ways, such as by reﬁning the content, suggesting and developing teaching material and homework problems, preparing solutions to the exercise problems, and providing constructive suggestions and feedback. They include Jorge Hau, Nandan Ukidwe, Daniel Arthur, Yi Zhang, Jun- Ki Choi, Anil Baral, Vikas Khanna, Geoffrey Grubb, Shweta Singh, Robert Urban, Nathan Cruze, Berrin Kursun, Laura Woods, Erin Gibbemeyer, Rebecca Hanes, Sachin Jadhao, Prasad Mandade, Deepika Singh, Varsha Gopalakrishnan, Shelly Bogra, Xinyu Liu, Tapajyoti Ghosh, Kyuha Lee, Michael Charles, and Utkarsh Shah. Several graduate and undergraduate students have contributed problems to var- ious chapters. They have been acknowledged near each problem. Class projects xx Preface were provided by several corporations, organizations, and individuals, which are too numerous to list individually. I am thankful for their guidance, support, and interest. The chapters were proofread by Xinyu Liu, Tapajyoti Ghosh, Kyuha Lee, Michael Charles, Utkarsh Shah, and Harshal Bakshi. Their diligence has helped to improve clarity and to correct many errors. The material in this book has beneﬁted from conversations and discussions with several colleagues and friends. Joseph Fiksel has been a collaborator for many years from whom I have learned about many things, including corporate sustain- ability and resilience. He has contributed a section to the chapter on business and sustainability. Tim Gutowski and Dusan Sekulic have been co-instructors of the short courses at MIT. The many lively discussions that I have had with them on sustainable engineering and other topics have been entertaining and educational, and have inﬂuenced the content of many chapters. Brian Fath has helped me learn some basics of ecology and has provided valuable feedback on relevant chapters. Yogendra Shastri has provided opportunities to co-teach short courses in India. Mary Evelyn Tucker and John Grimm were instrumental in introducing me to the fascinating intersection of religion and sustainability. They have contributed mate- rial to those chapters. Several anonymous reviewers have also provided valuable feedback at various stages of development of the book. My teachers have taught me a lot and got me started in the direction of sus- tainable engineering. George Stephanopoulos introduced me to the versatility and rigor of process systems engineering. John Ehrenfeld introduced me to the ﬁeld of industrial ecology. Steve Elliott, Nicola Chapman, and others at Cambridge University Press have played an important role in making sure that this book reaches you. My parents have contributed in more ways than I know; their love and under- standing, and curiosity about the natural world, to name a few. My wife, Mamta, and son, Harshal have tolerated many “lectures” on sustainability and have been immensely patient over the hundreds of weekends it took to develop this book. My extended family, including nieces and nephews. After all, this is for their generation and beyond. Bhavik R. Bakshi PART I Introduction and Motivation.............................................................................................................................. I n the ﬁrst part of this book, we will focus on the motivation for learning about sustainable engineering. We will address some basic questions, such as: What needs to be sustained and why? What is the state of human development and what are its side-effects? What do human activities and well-being depend on, and what is the status of these resources? What is sustainable development? How do we make decisions that are sustainable? We will learn that sustaining our well-being requires goods and services from nature. Many human activities, including engineering, are causing the degradation of these goods and services, which cannot be sustained for long. Sustainability is not just about the environment, but needs to consider the economy and society as well as the environment for the sake of current and future generations. 1 The Basis of Human Well-Being Well-being denotes a state of the world that is intrinsically, and not merely instrumentally, valuable to human beings. Anna Alexandrova What does our well-being depend on? This question is fundamental to any effort for improving human well-being and for sustaining it now and in the future. We start by focusing on answering this question, since once we understand the factors that form the basis of human well-being, we can determine whether our activities can continue to sustain our well-being, and then devise approaches and solutions for ensuring sustainability. This insight forms the basis of sustainable engineering and the rest of this book. In this chapter, we will learn about historical trends in human development based on different ways of deﬁning this concept, and then explore the basis of our well-being. 1.1 Trends in Human Development The modern human, Homo sapiens sapiens , is among the most successful species on this planet today. One indication of our success is the growth in our population, as depicted in Figure 1.1. Current estimates are that global population will con- tinue to grow during this century and will increase from the current 7.2 billion to between 9.6 billion and 12.3 billion by 2100 [2, 3]. Of course, success as a species cannot be measured by population numbers alone, as quality of life also matters. It turns out that we have done very well on that front as well. A popular measure of societal well-being commonly used by economists is gross domestic product (GDP). It is the monetary value of all goods and services pro- duced. On the basis of this measure of wealth, our overall standard of living has increased dramatically over the centuries all over the world, as shown in Figure 1.2. GDP only includes monetary aspects and is often criticized because it fails to capture factors such as health and education, which are essential components of our well-being. Indicators of human well-being more comprehensive than GDP have also been developed. Among these, the human development index (HDI) combines factors such as health and education with income, as described in Box 1.1. Figure 1.3 4 1 The Basis of Human Well-Being 8000 7000 Asia Africa sdnasuoht ni noitalupoP 6000 Europe Latin America & Carib. 5000 North America 4000 Oceania 3000 2000 1000 0 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 Year Figure 1.1 Human population over the centuries. 35,000 England/GB/UK 12 W. Europe 30,000 USA 15 L. America )$.tnI 0991( atipac rep PDG 25,000 China India Total Africa 20,000 Total World 15,000 10,000 5000 0 1200 1300 1400 1500 1600 1700 1800 1900 2000 Year Figure 1.2 Trend in global gross domestic product (GDP) in terms of international dollars adjusted for purchasing parity. shows the trend in the HDI for several countries. Using this more comprehensive measure of well-being, we can again see that humanity has done well, since the HDI has been increasing in almost all countries of the world. Of course, there are localized challenges such as war, drought, and poverty that do get reﬂected in these indicators. Thus, the drop in the HDI for Botswana, Cameroon, and Tajikistan reﬂects political troubles. However, such countries are few, and the drop is usually temporary. On the whole, as the GDP and HDI trends indicate, things are going well for us, and seem to have continually improved over the centuries, particularly in the last 50 years. 1.1 Trends in Human Development 5 B O X 1.1 Human Development Index (HDI). The HDI was created to emphasize that people and their capabilities should be the ultimate criteria for assessing the development of a country, not economic growth alone. The HDI can also be used to question national policy choices, asking how two countries with the same level of GNI [gross national income] per capita can end up with different human development outcomes. These contrasts can stimulate debate about government policy priorities. The Human Development Index (HDI) is a summary measure of average achievement in key dimensions of human development: a long and healthy life, being knowledgeable, and have a decent standard of living. The HDI is the geometric mean of normalized indices for each of the three dimensions. The health dimension is assessed by life expectancy at birth, the education dimension is measured by mean of years of schooling for adults aged 25 years and more and expected years of schooling for children of school entering age. The standard of living dimension is measured by gross national income per capita. The HDI uses the logarithm of income, to reﬂect the diminishing importance of income with increasing GNI. The scores for the three HDI dimension indices are then aggregated into a composite index using geometric mean. The HDI simpliﬁes and captures only part of what human development entails. It does not reﬂect on inequalities, poverty, human security, empowerment, etc. 1 0.9 0.8 0.7 0.6 Afghanistan Australia IDH 0.5 Bangladesh Botswana 0.4 Cameroon China 0.3 France Qatar 0.2 Sweden Tajikistan 0.1 0 09 1 29 1 49 1 6 1 8 2 00 2 20 2 40 2 60 2 80 2 01 2 21 2 41 9 9 91 9 9 9 9 0 0 0 0 0 0 0 0 Year Figure 1.3 Trends in the human development index. 6 1 The Basis of Human Well-Being 170 177 150 130 126 110 90 98 70 74 73 73 50 58 55 54 30 36 22 19 10 Sub-Saharan Southern Asia Oceania Cent. Asia North Africa Latin America Africa & Caribbean 1990 2012 Figure 1.4 Under-ﬁve-years child mortality rate. Deaths per 1000 live births. 70 60 50 56 48 51 40 45 )%( 30 30 20 14 12 10 6 5 0 Sub-Saharan Southern Asia South-East Latin America Northern Africa Africa Asia & Caribbean 1990 2010 Figure 1.5 Proportion of people living on less than $1.25 per day. People are living longer and are healthier, as indicated by the increase in aver- age life expectancy at birth from 48 years in 1955 to 65 years in 1995 and 71 years in 2010. By 2025 it is expected that no country will have a life expectancy of less than 50 years. As shown in Figure 1.4, child mortality has almost halved since 1990. In terms of extreme poverty, 1.22 billion people live on less than $1.25 per day, down from 1.91 billion in 1990 and 1.94 billion in 1981 , as depicted in Figure 1.5. These and other indicators of well-being conﬁrm our resounding success as a species. However, as we will learn in Chapter 2, our success has also resulted in an 1.2 What Does Human Well-Being Depend On? 7 increasingly large environmental impact. This raises questions about whether we will be able to sustain this level of well-being and enhance it, particularly for those of us who are not doing too well and for future generations. This includes the 1.22 billion still living in extreme poverty, the 1.6 billion who live without access to electricity, the 1.1 billion with inadequate access to water, and the 2.6 billion lack- ing basic sanitation. If we are to sustain this standard of living and enhance it in parts of the world where it is needed, it would help to know the underlying founda- tion of our well-being. Sustaining the gains in our well-being and extending them to those who have not yet beneﬁted requires that this foundation is preserved. 1.2 What Does Human Well-Being Depend On? The constituents of human well-being include material needs, health and educa- tion, opportunity, community, and security. Understanding what provides basic and critical support to ensure availability of these constituents to individuals and societies is essential to determine whether the trends discussed in the previous section can be sustained, and whether the beneﬁts of development can become more widespread. Broadly speaking, human activities and well-being depend on the following three categories of goods and services: Economic goods and services include things like equipment, energy supply, market for products, industrial waste treatment, food, and transportation. These have monetary value and are traded in markets, which means that people pay money to obtain them. Societal goods and services include labor, educational institutions, intellec- tual capital, legal system, government, and culture. These involve individuals or groups of people. Some societal goods and services, such as labor, have monetary value, while others, like culture, do not. Ecological goods and services come directly from nature and include miner- als, water, air, sunlight, biomass, ocean and river currents, wind, pollination, soil formation, carbon sequestration, and disease regulation. These are usually considered to have no monetary value since they are not traded in markets. There is no monetary transaction with nature since we do not pay trees for the oxygen they provide or the Earth for the crude oil we take from it. Owing to the importance of these three categories of goods and services, they have been called the triple bottom line or triple values. But are the categories equally important? Or are some categories dependent on the availability of others? Let us consider the source of economic goods and services. As depicted in Figure 1.6, economic activities transform ecosystem goods and services into economic 8 1 The Basis of Human Well-Being Natural Sun capital Economic Economy products & services Ecosystem Figure 1.6 Ecosystems form the basis of all economic activities. Innovation Society Economy Technologies Financial & Human Resources Education €$¥ Built Capital Institutions Governance Companies Shareholder Value & Job Security Materials Communities Production Commercial Good & Services Energy Consumption Waste & Pollution Quality of Life Infrastructures Value Chains Value Recovery Human Exposure Environment Air Water Degradation Mitigation Land Soil Restoration Natural Ecosystem Goods Natural Resources and Services Amenities Balance Living Systems Figure 1.7 Interaction between ecosystems, society, and economy. Figure courtesy of J. Fiksel. Adapted from. goods and services. In addition to inputs from nature, economic activities also require societal goods and services such as institutions and governance, as shown in Figure 1.7. Without goods and services from society and nature, economic activities are not possible. Societal well-being requires goods and services from nature because the people that constitute society need natural amenities. Thus, both societal and economic activities rely on ecosystems. Ecosystems can thrive even without societal or economic goods and services, but neither societal nor economic activities are possible without ecosystem goods and services. Thus, ecosystem goods and services form the foundation for economic and societal goods and services. However, couldn’t one argue that human innovation, which has been able to overcome all kinds of constraints imposed by nature by ﬁnding substitutes 1.2 What Does Human Well-Being Depend On? 9 for many ecosystem goods and services, will be able to develop substitutes for ecosystems and all their goods and services? Examples of such success include climate-controlled buildings to maintain comfortable surroundings regardless of the weather outside, vaccinations to overcome the scourge of disease, artiﬁcial lighting to overcome darkness, genetically modiﬁed crops to ﬁght pests, water treatment processes to replace natural water puriﬁcation by wetlands, plastics and metals to replace wood, the International Space Station for human activi- ties in space, and many others. We have developed artiﬁcial organs, synthesized molecules that never existed before, and may even be on the verge of syn- thesizing life itself and creating autonomous intelligent machines. Advances in science and technology have allowed us to ﬁnd and extract more resources, and when faced with scarcities we have been able to ﬁnd substitutes. For exam- ple, for lighting, electricity has replaced kerosene, which replaced whale oil; artiﬁcial fertilizers have replaced guano (accumulated bird droppings), which was being mined in South America and shipped to farmers in Europe, and so on. Given such advances due to human ingenuity, are ecosystems truly essential for economic and societal activities? Can we not artiﬁcially synthesize ecosystems and their goods and services, or ﬁnd substitutes? Because, if we can, then we could overcome any limit imposed by their deterioration. We could even build self-sustaining artiﬁcial biospheres to inhabit outer space and other planets. These questions have intrigued many, and an attempt to develop a self-contained and self-sustaining system was made in the Biosphere 2 project in the early 1990s. As described in Box 1.2, this experiment showed that with the technology available at that time, there was no substitute for Biosphere 1, which is planet Earth. In addition, history abounds with examples where entire societies and civilizations have collapsed owing to the loss of goods and services from nature [8, 9]. One such example is described in Box 1.3. B O X 1.2 Biosphere 2 Project A self-contained site, shown in Figure 1.8, was built in the Sonoran desert near Tucson, Arizona in the early 1990s. It contained various types of ecosystems, including a rain forest, ocean, and desert, and areas for agriculture and human habitation. The buildings were designed to have close to zero exchange with the surroundings of everything except sunlight. Eight “biospherians” spent two years in this complex. It was called Biosphere 2, since planet Earth is Biosphere 1. While many new scientiﬁc insights were obtained from this work, the goal of building an artiﬁcial biosphere was never realized. Among the many problems encountered during this 10 1 The Basis of Human Well-Being experiment was the inability to maintain the desired atmospheric composition: the carbon dioxide concentration kept on going up even though fossil fuels were not being used. What this experiment showed is that even with the beneﬁts of modern science and our ability to artiﬁcially synthesize many things, we are still not able to produce the goods and services that we get from nature. In other words, ecosystem goods and services are truly the foundation of all human (and planetary) activities. Without them, humanity cannot be sustained! Thus, sustainability is ultimately about ensuring the availability of ecosystem goods and services for present and future generations. B O X 1.3 The Lessons of Easter Island The story of Easter Island is about how a thriving civilization can collapse owing to the loss of ecosystem goods and services. This island in the Paciﬁc Ocean is among the most remote inhabited islands on Earth. Polynesians arrived there in the ﬁfth century and found a volcanic island with limited resources. The fresh water was in dormant volcanoes in the center of the island, and the soil was of poor quality, making it difﬁcult to grow much more than sweet potatoes which, with the chickens that they brought with them, formed their diet. From the 20–30 settlers, the population gradually expanded and societies developed along with their culture and rituals. Even though food was limited, acquiring it was easy, and the plenty of spare time helped create a complex and elaborate society. One of the Easter Island rituals involved the construction of huge stone statues along the coast. Each statue was carved into a human head and torso, was about 20 feet tall, and weighed several tons. The stone was obtained from a quarry in the center of the island and transported on logs to the coast. It is estimated that over 600 such statues were constructed. The reason for the collapse of this civilization seems to have been the massive environmental destruction due to the felling of trees to provide logs to transport the rocks to the coast. This was in addition to the trees that must have been cleared for agriculture, fuel for cooking, and boats for ﬁshing. Scientiﬁc studies have shown that the island was completely deforested by about 1600, and owing to the scarcity of trees, the islanders replaced wood with stones and then reeds for constructing their homes. Deforestation also meant the loss of soil due to erosion, which reduced their agricultural yields. The inability to build boats from logs also limited their ability to catch ﬁsh or escape from the island. By 1600, their civilization had started to collapse, and the population fell from a peak of about 7000 inhabitants. When the ﬁrst Europeans arrived in 1722, they found a primitive society of about 3000 living in reed huts, with perpetual warfare between the clans, which were resorting to cannibalism. 1.3 Ecosystem Goods and Services 11 Figure 1.8 Site of the Biosphere 2 project. Photograph by John de Dios (Wikimedia Commons CC-BY-3.0). Thus, there is little doubt about the essential role of ecological systems in sus- taining human well-being. Human ingenuity can certainly ﬁnd substitutes for some individual goods and services, but replacing entire ecological systems and the biosphere involves complex interactions that are beyond our current under- standing and engineering ability. Even substitutes for individual goods result in unexpected surprises and unintended harm, as we will see in subsequent chapters such as Chapter 3. Therefore, at this point, our best and only source of ecosys- tem goods and services to support our well-being is the natural biosphere itself, shown in Figure 1.9. Even if future advances in science and technology are able to develop a Biosphere 2, it still makes sense to protect and preserve our current biosphere, for if the advances toward Biosphere 2 do not happen or are not quick enough, the consequences could be dire indeed. 1.3 Ecosystem Goods and Services Ecosystem goods and services are the beneﬁts that humans derive from nature. They are the ﬂows derived from natural capital, and provide the foundation for all human activities. Natural capital includes natural resources such as minerals, fertile soil, forests, and wetlands. We cannot survive for more than a few min- utes without oxygen – a molecule provided by green plants as a byproduct of 12 1 The Basis of Human Well-Being Figure 1.9 Earth rise as captured by Apollo 8 astronauts on December 24, 1968. One of the astronauts, Jim Lovell said, “The vast loneliness is awe-inspiring and it makes you realize just what you have back there on Earth”. Trees clean air by absorbing Wetlands clean water by CO2, SO2, NOx, and removing solvents, aromatics, filtering particulate matter Oxygen pesticides, etc. Polluted water Biomass Fresh water Co-benefits: Water provisioning, Co-benefits: Flood regulation, soil formation, recreation food provisioning, aesthetic value Figure 1.10 Role of ecosystems in supporting industrial activities. photosynthesis, which in turn depends on carbon dioxide, a byproduct of respira- tion. While such dependence on nature is quite obvious, ecosystems play a much bigger role which is usually ignored in our decisions. Consider a typical company or industrial process and its interaction with the economy, society, and environment, as shown in Figure 1.7. The dependence of this process on raw materials is well-understood, as is the market for the products and byproducts, and the technologies for dealing with wastes. Societal systems that train workers, protect property rights, and regulate markets also exist. In addition to these economic and societal goods and services, the manufacturing process also relies on a variety of ecosystem goods and services, with some spe- ciﬁc interactions shown in Figure 1.10. The availability of water relies on the hydrological cycle, while the mitigation of emissions to air and water relies on 1.3 Ecosystem Goods and Services 13 ecosystem services of air and water quality regulation. This includes the role of air and water currents in dissipating and diluting pollutants, the ability of trees to remove not just carbon dioxide but also particulate matter and the oxides of sulfur and nitrogen, and the ability of water bodies such as wetlands to degrade and remove solvents, oils, greases, pesticides, phosphates, heavy metals, pharma- ceuticals, etc. In addition, ecosystems like trees and wetlands also provide many co-beneﬁts to society, such as ﬂood regulation, water provisioning, and opportuni- ties for recreation. If emissions exceed the ability of nature to absorb and mitigate them, then human and ecological systems may suffer damage and lose their abil- ity to provide various services. Like industrial processes, agricultural activities also rely on ecosystem services such as primary production, regulation of soil fertility, biogeochemical cycles of carbon and nitrogen, availability of fresh water, and the water cycle. Fossil resources are the product of ancient goods and services from nature, but even their current availability relies on the geological cycle that con- centrates them in the Earth’s crust and makes them available for easier extraction. Industry also beneﬁts from the aesthetic and cultural aspects of ecosystems; one example is the use of nature-inspired images in corporate logos, such as the apple in Apple’s logo, the shell in Shell’s logo, the peacock in the logo of NBC, birds in the logos of many airlines such as Singapore Airlines and Lufthansa, the butterﬂy in Microsoft’s logo, and the mouse in Disney’s logo. The large variety of goods and services provided by nature may be categorized as shown in Table 1.1 and described below: Provisioning services are products from ecosystems such as food, fresh water, fuel, ornamental resources, genetic resources, biochemicals, and phar- maceuticals. These are most familiar owing to their direct role in human activities. Regulation and maintenance services are beneﬁts from the maintenance of ecological processes by the regulation of air quality, water quality, climate, soil fertility, pests, and diseases. Cultural services are the non-material beneﬁts that people get from nature in the form of spiritual and religious values, cultural diversity, educational values, aesthetic values, sense of place, social relations, and recreation and ecotourism. These services play a critical role in enabling and enhancing human well-being. As shown in Figure 1.11, ecosystem goods and services provide security, basic materials for a good life, health, and social relations, which in turn enable free- dom of choice and action. Most of these connections are quite obvious, such as the effect of access to nutritious foods and clean water on our well-being. Ecosystem services are also known to have a direct impact on health and the feeling of well- being, since living close to nature reduces overall mortality, cardiovascular disease, Table 1.1 Classiﬁcation of ecosystem services. Section Division Group Cultivated terrestrial plants for nutrition, materials, or energy Cultivated aquatic plants for nutrition, materials, or energy Reared animals for nutrition, materials, or energy Biomass Provisioning (biotic) Reared aquatic animals for nutrition, materials, or energy Wild plants (terrestrial and aquatic) for nutrition, materials, or energy Wild animals (terrestrial and aquatic) for nutrition, materials, or energy Genetic material from all biota Genetic material from plants, algae, fungi, or animals Transformation of biochemical or physical Mediation of wastes or toxic substances of anthropogenic origin by inputs to ecosystems living processes Mediation of nuisances of anthropogenic origin Regulation and Regulation of physical, chemical, and Regulation of baseline ﬂows and extreme events maintenance (biotic) biological conditions Life cycle maintenance, habitat, and gene pool protection Pest and disease control Regulation of soil quality Water conditions Atmospheric composition and conditions Direct, in-situ, and outdoor interactions Physical and experiential interactions with natural environments with living systems that depend on Intellectual and representative interactions with natural environments Cultural (biotic) presence in the environmental setting Indirect, remote, often indoor interactions Spiritual, symbolic, and other interactions with natural environments with living systems that do not require Other biotic characteristics that have a non-use value presence in the environment Water Surface water used for nutrition, materials, or energy Provisioning (abiotic) Ground water for use for nutrition, materials, or energy Other aqueous ecosystem outputs Non-aqueous natural abiotic Mineral substances used for nutrition, materials, or energy ecosystem outputs Non-mineral substances or ecosystem properties use for nutrition, materials, or energy Transformation of biochemical or Mediation of waste, toxics, and other nuisances by non-living processes Regulation and physical inputs to ecosystems Mediation of nuisances of anthropogenic origin maintenance (abiotic) Regulation of physical, chemical, and Regulation of baseline ﬂows and extreme events biological conditions Maintenance of physical, chemical, and abiotic conditions Direct, in-situ, and outdoor Physical and experiential interactions with natural abiotic components of the Cultural (abiotic) interactions with natural physical environment systems that depend on presence in Intellectual and representative interactions with abiotic components of the the environmental setting natural environment Indirect, remote, often indoor Spiritual, symbolic, and other interactions with the abiotic components of the interactions with physical systems natural environment that do not require presence in the environment Source: Adapted from. 16 1 The Basis of Human Well-Being CONSTITUENTS OF WELL-BEING ECOSYSTEM SERVICES Security PERSONAL SAFETY Provisioning SECURE RESOURCE ACCESS FOOD SECURITY FROM DISASTERS FRESH WATER WOOD AND FIBER FUEL... Basic material for good life Freedom ADEQUATE LIVELIHOODS of choice Supporting Regulating SUFFICIENT NUTRITIOUS FOOD and action CLIMATE REGULATION SHELTER NUTRIENT CYCLING ACCESS TO GOODS OPPORTUNITY TO BE SOIL FORMATION FLOOD REGULATION ABLE TO ACHIEVE PRIMARY PRODUCTION DISEASE REGULATION WHAT AN INDIVIDUAL... WATER PURIFICATION VALUES DOING... Health AND BEING STRENGTH FEELING WELL Cultural ACCESS TO CLEAN AIR AESTHETIC AND WATER SPIRITUAL EDUCATIONAL RECREATIONAL Good social relations... SOCIAL COHESION MUTUAL RESPECT ABILITY TO HELP OTHERS LIFE ON EARTH - BIODIVERSITY ARROW COLOR ARROW WIDTH Potential for mediation by Intensity of linkages between ecosystem socioeconomic factors services and human well-being Low Weak Medium Medium High Strong Figure 1.11 Role of ecosystem services in human well-being. and depressive symptoms. In addition, the incidence of many modern diseases and allergies, particularly in high-income countries, is due to lack of exposure to microorganisms that occur in nature. Thus, exposure to green spaces and biodiversity can reduce the occurrence of such diseases and enhance well-being. Ecosystems can also enhance the resilience of communities to extreme events. For example, coastal wetlands and mangroves can protect communities from ﬂooding during storms and hurricanes. 1.4 What about Saving the Planet? So far, our primary focus in this chapter has been on human well-being. This may come as a surprise to you if you were thinking that sustainability is about “saving the planet.” This is a common rhetoric that is often heard. However, “saving the planet” is not the goal of sustainable engineering and other efforts toward sus- tainable development. Even those who talk about saving the planet usually focus 1.6 Review Questions 17 on human well-being. They say that the planet does not need to be saved. It has sustained itself for billions of years, despite dramatic changes, and will most likely continue to do so for many more millennia. Sustainability is ultimately about human beings and and our well-being, not just in the short run, but in the long run as well. As we have learned in this chapter, human well-being is strongly dependent on healthy ecosystems, so sustaining ourselves does require saving the planet. 1.5 Summary Human well-being has improved over the last several centuries, as indicated by enhanced indicators such as population, GDP, and the HDI. This improvement is due to our ability to utilize goods and services from economic, societal and ecological systems. Among these three, ecosystems are most important since they are needed to support the economy and society. Goods and services from nature are categorized as provisioning, regulating, and cultural. Despite various efforts, it has not been possible to generate them by artiﬁcial systems. Thus, the availability of healthy ecosystems is essential for sustaining the well-being of current and future generations. Key Ideas and Concepts Human well-being Gross domestic product Human Development Index Triple values Ecosystem goods and services Biosphere 2................................................................................................... 1.6 Review Questions 1. What are some components of human well-being? 2. Deﬁne economic, societal, and ecosystem goods and services, with examples of each. 3. How has the poverty rate changed since 1990? 4. What are Biospheres 1 and 2? 5. What roles do ecosystems play in our feeling of well-being?................................................................................................... Problems 1.1 Describe some similarities and differences between gross domestic product and the human development index. Why is the latter index considered to be a better indicator of human well-being? 18 1 The Basis of Human Well-Being 1.2 Identify some economic, societal, and ecosystem services that the following systems depend on, and describe the dependence: (a) a coal-burning power plant; (b) driving a car; (c) intensive agriculture. 1.3 Consider a typical single-family dwelling that consists of a house surrounded by a yard. Identify some of the ecosystem services that the yard could provide to the residents of the house and to the larger community. 1.4 The triple value concept conveys that it is important for corporations to consider economic, social, and environmental goals in their decisions. Do companies consider goals in these three categories to be equally important? Explain your response with examples. 1.5 Give examples of how the following activities rely on cultural ecosystem services: (a) the use of logos by corporations; (b) religious and spiritual practices; (c) recreational activities. 1.6 What are the Sustainable Development Goals (SDGs) of the United Nations? Do they account for the critical role of ecosystems in human well-being? 1.7 Which ecosystem goods and services did the residents of Easter Island depend on for building their statues? How did the loss of these goods and services contribute to their demise? 1.8 Identify some ecosystem services for which technological substitutes are not yet available. Will we be able to develop technological substitutes for these services? 1.9 Search the health literature to determine how ecosystems help us in maintaining and improving our health. Focus on aspects such as mental and emotional well-being, resistance to allergens, and the development of new medicines such as antibiotics. 1.10 Ethanol is a required additive in gasoline in many countries. The main steps in producing ethanol from corn include the agricultural step, where corn is grown, and the manufacturing step, where corn sugar is converted to ethanol by fermentation. For these two steps, discuss the ecosystem services that each activity depends on and how each activity impacts ecosystem services.............................................................................................................. References A. Alexandrova. Well-being as an object of science. Philosophy of Science, 79(5):678–689, 2012. P. Gerland, A. E. Raftery, H. Ševčíková, et al. World population stabilization unlikely this century. Science, 346(6206):234–237, 2014. References 19 United Nations World population prospects: the 2017 revision. https://esa.un.org/unpd/wpp/Graphs/Probabilistic/POP/TOT/, 2017, accessed November 22, 2018. The Maddison Project. www.ggdc.net/maddison/maddison-project/ home.htm, 2013 version, accessed November 22, 2018. United Nations Development Program. Human Development Index. http://hdr.undp.org/en/content/human-development-index-hdi, accessed March 25, 2018. World Bank. World Development Indicators 2013. http://data.worldbank.org, 2013, accessed March 25, 2018. J. Fiksel. Resilient by Design: Creating Businesses that Adapt and Flourish in a Changing World. Island Press, 2015. J. Diamond. Collapse: How Societies Choose to Fail or Succeed. Penguin Books, 2006. J. A. Tainter. The Collapse of Complex Societies. Cambridge University Press, 1988. C. Ponting. A New Green History of the World: The Environment and the Collapse of Great Civilizations. Random House, 2011. NASA. Earth rise. www.nasa.gov/multimedia/imagegallery/image_ feature_1249.html, accessed March 25, 2018. G. A. Rook. Regulation of the immune system by biodiversity from the natural environment: an ecosystem service essential to health. Proceedings of the National Academy of Sciences, 110(46):18360–18367, 2013. R. Haines-Young and M. Potschin. Common international classiﬁcation of ecosystem services (CICES) v5.1 and guidance on the application of the revised structure. Technical report, European Environmental Agency, 2018. Millennium Ecosystem Assessment. Ecosystems and Human Well-being: A Framework for Assessment. Island Press, 2003. 2 Status of Ecosystem Goods and Services Every country can be said to have three forms of wealth: material, cultural and biological. The ﬁrst two we understand very well, because they are the substance of our everyday lives. Biological wealth is taken much less seriously. This is a serious strategic error, one that will be increasingly regretted as time passes. E. O. Wilson As we learned in Chapter 1, ecosystems provide the goods and services that are essential for sustaining human activities. Without inputs from nature, neither societal nor economic activities can be sustained. Therefore, the well-being of ecosystems is of critical importance for the well-being of human beings. In this chapter, we will explore the status of ecosystem goods and services. We will con- sider how human development has relied on various natural resources, and the impact of this reliance on their supply and on our environment. Such insight is needed to assess whether the enhancement in human well-being over the previ- ous decades can be sustained. It will also help in identifying underlying reasons for trends in ecosystem services and potential solutions to ensure their sustained availability. We will ﬁrst consider the status of essential ecosystem goods such as fuels, materials, water, and food, and then selected ecosystem services such as the regulation of climate, air and water quality, primary productivity, and pollination. We will end this chapter with a look at the overall global status of ecosystem goods and services. 2.1 Fuels Until the Industrial Revolution, the main fuel used by humanity was biomass. This changed dramatically in the last 200 years owing to the dominance of fossil fuels. These fuels are important ecosystem goods, produced from ancient biomass that was buried and transformed by planetary processes in an oxygen-starved reducing environment. The resulting products of coal, natural gas, and crude oil are highly concentrated hydrocarbons and carbon that have a high fuel value and can be transformed quite easily into many other products. Recent trends in fuel consumption, shown in Figure 2.1, depict this dominant role of fossil fuels. These fuels are nonrenewable because their rate of extraction is 2.2 Materials 21 60,000 50,000 ry/hWT noitpmusnoc ygrenE Oil 40,000 Coal 30,000 Gas 20,000 10,000 Renewable 0 Nuclear 1965 1975 1985 1995 2005 2015 Figure 2.1 Global use of fuel resources. Wikimedia Commons CC-BY-SA-4.0. much greater than their rate of production. Thus, the consumption of nonrenew- able resources must result in their depletion over time. While the overall trend for fossil fuel use in Figure 2.1 shows a continuous increase, attention to speciﬁc geographic locations shows the depletion of some sources and the discovery of others. In general, the total quantity produced from individual oil wells follows an S-curve or logistic curve, which means that the rate of production from a well tends to peak followed by a decline. On the basis of such observations for US wells, Hubbert surmised that the overall production of oil will also peak , and he correctly predicted a peak for US production. His prediction and the actual US oil production are shown in Figure 2.2. Beyond the peak, production cannot keep up with demand, indicating a resource scarcity, and likely price increase. Many researchers predicted a global peak in the early part of this century, but production data in Figure 2.2 for the USA and in Figure 2.3 for the world seem to indicate that the peak may not have been reached yet. Some reasons for the delay in the peak include new discoveries, such as those of shale oil and gas, new technologies for extracting them such as horizontal drilling and hydraulic fracturing (fracking), and reduced consumption due to economic recessions or the adoption of alternate technologies. However, ultimately, for any nonrenewable resource, not just fossil fuels, if extraction continues, a peak is inevitable. To date, the primary ecological degradation associated with fossil fuels has not been their depletion, but the impacts of their use at such a large scale on services such as air quality and climate regulation, as we will see in Sections 2.6 and 2.7. 2.2 Materials Figure 2.4 summarizes global resource use trends for several materials. Total use is shown by gray lines and use per capita by black lines. As can be seen, the total use 22 2 Status of Ecosystem Goods and Services 4000 )raey rep slerrab fo snoillim( noitcudorp lio setats 84 rewoL 3500 Actual Production 3000 2500 2000 1500 1000 Hubbert’s Prediction 500 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 Figure 2.2 Hubbert’s prediction in 1956 about the peak of US oil production versus actual production. Total Petroleum and Other Liquids Production Thousand Barrels Per Day 40,000 30,000 Middle East 20,000 North America Eurasia Africa Asia & Oceania 10,000 Cent. & S. America Europe 0 1985 1990 1995 2000 2005 2010 2015 Africa Asia & Oceania Central & South America Eurasia Europe Middle East North America Figure 2.3 World oil production by regions. for most resources has been increasing, while the per capita use of many resources has been declining. This decline could be due to resource constraints such as the resource being past the peak. Like fossil fuels, any resource that is used in a nonrenewable manner, with a rate of use larger than the rate of replenishment, 2.2 Materials 23 Agricultural land Freshwater withdrawals Wild fisheries harvest 70+E9.4 70+E7.4 70+E5.4 410.0 70+E7 0053 0003 0052 0002 70–E8.6 70–E4.6 70–E0.6 310.0 mk erauqS mk cibuC 210.0 sennoT 70+E5 010.0 010.0 70+E3 700.0 1960 1980 2000 1960 1980 2000 1960 1980 2000 Wood building materials Phosphate production Copper production 90+E2.2 90+E8.1 90+E4.1 2200.0 8100.0 4100.0 54.0 04.0 53.0 03.0 80+E2.1 70+E0.6 70+E0.1 520.0 sennoT sennoT sennoT 60+E0.4 510.0 1960 1980 2000 1960 1980 2000 1960 1980 2000 Coal production Petroleum production Gross domestic product 0009 0007 0005 0003 5.5 0.5 5.4 0.4 5.3 31+E5 31+E3 31+E1 01+E5.2 610.0 210.0 800.0 srallod SU 0991 70+E0.8 sennoT slerraB 01+E5.1 70+E0.2 1960 1980 2000 1960 1980 2000 1960 1980 2000 Year Year Year Figure 2.4 Total global resource use is shown by the gray line, with axis scale on the left, while resource use per capita is shown by the black line with axis scale on the right. will show a peak. In this ﬁgure, the resources of fresh water, phosphate, wood building materials, and wild ﬁsheries harvest seem to show a peak. As discussed in Section 2.1, after the peak, a resource is expected to have difﬁculty meeting demand and its consumption is likely to decline, particularly for those resources that lack substitutes. Phosphates and fresh water are examples of such resources. As has happened with crude oil in the USA, new technologies and discoveries can postpone the ultimate peak, but these approaches are usually more expensive owing to the depleting quality of the resource and greater difﬁculty in extraction. Another way of understanding the extent of human dependence on materi- als is by comparing the mobilization of various elements by human activities 24 2 Status of Ecosystem Goods and Services 3 Ir Positive log Fa/Fn = Anthropogenic Fluxes > Natural Fluxes He Negative log Fa/Fn = Anthropogenic Fluxes < Natural Fluxes 2 Au Os Pt ]xulF larutaN / xulF cinegoporhtnA[ goL Pd Hg Rh Bi Ag 1 Mo Te Zn Ru Fe Sn Ni U Lu Ti Ce Th Rb Mn V HoNbHf Eu Sc Al Cd Re F Er Sm Tm Ta Sb Si Ca C 0 Cr K Na Cu As In Cs Ba Y Be La Yb Nd Gd Tl Se Sr Pb Ge Zr Dy Li W Pr Tb Ga –1 Co B PN S Mg –2 This study with significant (50%) human influence on soil erosion and eolian dust flux Cl –3 Br –4 Figure 2.5 Perturbation of elements due to anthropogenic activities. Reproduced with permission from. with their natural mobilization in the absence of human activities. This ratio of anthropogenic to natural mobilization of various elements in Figure 2.5 shows that for many elements used as catalysts, such as iridium, osmium, platinum, and palladium, anthropogenic mobilization is 1–2 orders of magnitude larger than the natural ﬂows. For most other elements considered in this study, anthro- pogenic mobilization is roughly equal to natural mobilization. Only a few elements like sodium, chlorine, carbon, and calcium have relatively small anthropogenic mobilization. It is the introduction of mobilized elements such as lead, arsenic, mercury, etc. into the environment that causes damage to ecosystem services and human health. If they circulated within the anthropogenic system without escap- ing into the environment, then their mobilization would not be such an important environmental issue. In addition to our reliance on naturally occurring materials, we have syn- thesized over 50,000 new molecules in the last few decades. Their introduc- tion into ecosystems, even in small quantities, can cause signiﬁcant harm because ecosystems would have never encountered them before, and may be unable to beneﬁt from or neutralize their presence. Examples include pes- ticides, heavy metals, and refrigerants. Box 2.1 summarizes the history of one class of compounds that was banned due to its effect on the ecosys- tem service of protecting the Earth from ultraviolet radiation. The effect of these chloroﬂuorocarbon (CFC) compounds on stratospheric ozone is shown in Figure 2.6. 2.2 Materials 25 B O X 2.1 History of Chloroﬂuorocarbons (CFCs) When ﬁrst developed in the 1930s by Thomas Midgeley at General Motors, CFCs were touted as miracle compounds that were non-toxic and stable, with many desirable properties. The ozone hole was predicted by Molina and Rowland and then observed and monitored by satellites , resulting in images like those in Figure 2.6. The dark region shows the ozone hole over the Antarctic, which typically appears during the Antarctic winter. The ozone layer in the stratosphere protects the Earth by blocking the ultraviolet part of sunlight. This regulating ecosystem service has deteriorated because of the use of ozone-depleting agents such as CFCs and other substances that release a chlorine or bromine atom into the Antarctic stratosphere. These compounds had, and some still have, a variety of uses, including as refrigerants, cleaning agents, fungicides, and ﬂame retardants. September 1979 September 1989 September 1999 September 2009 September 2018 30 25 Average ozone 20 hole area from 15 07 Sep to 13 Oct (million sq. km) 10 gnissim 5 0 97 18 38 58 78 98 19 39 59 79 99 10 30 50 70 90 11 31 51 71 91 91 91 91 91 91 91 91 91 91 91 02 02 02 02 02 02 02 02 02 Year Figure 2.6 Evolution of the ozone hole over Antarctica. The darker shade indicates less ozone. Another category of materials that is ubiquitous in modern life is plastics. Figure 2.7 shows regions of the world’s oceans where waste plastics have accumulated. These are expansive ﬂoating islands of large and small plastic materials that dis- rupt marine life. Figure 2.8 shows such items on an otherwise pristine Paciﬁc island. Due to the effect of the ocean and weather, most plastic is much smaller than the light-colored pieces visible in this ﬁgure. While these waste materials may be aesthetically undesirable to humans, they also hurt marine life by entering the foodchain and accumulating in species at the top of the foodchain, such as birds and other marine species. 26 2 Status of Ecosystem Goods and Services Figure 2.7 Oceanic gyres where plastic trash has accumulated. Figure 2.8 Plastic debris and trash is light-colored on an otherwise pristine-looking seashore on the Big Island of Hawaii. Photo courtesy of Harshal Bakshi. 2.3 Water 27 1500 Households 1250 Industry Livestock 1000 Irrigation Actual use Actual use raey/ mk 750 3 500 250 0 1591 4591 7591 0691 3691 6691 9691 2791 5791 8791 1891 4891 7891 0991 3991 6991 9991 2002 Figure 2.9 Global consumptive use of water. 2.3 Water With increasing population, consumption, and development, the human with- drawal of fresh water has also increased, as shown in Figure 2.9. Most of the water is used for growing food, a consequence of agricultural intensiﬁcation to meet global demand. One of the consequences of this high water use is increasing water stress in many parts of the world. As shown in Figure 2.10, water stress, deﬁned as the ratio of water consumed to the available renewable water, is expected to increase across the world in the near future. Figure 2.11 shows the fraction of global agriculture production under high or extremely high water stress. In high-stress areas, this fraction is 40 percent, while in areas under extremely high stress it is 80 percent or higher. Such stress levels indicate high or extremely high vulnerability to disruptions in water availability, and the potential for human conﬂict. Satisfying the human demand for freshwater has also resulted in severe ecolog- ical disruption in most major rivers of the world. This is depicted in Figure 2.12, where dark to light shades indicate strongly impacted, moderately impacted, and unimpacted large river systems. Dams hold back over 6500 km 3 of water, which is about 15 percent of the annual river runoff in the world. Generat- ing electricity, enabling irrigation, and controlling ﬂoods are positive impacts of dams. However, they also cause ecological deterioration due to habitat destruc- tion and the disruption of animal migration patterns. The resettlement of human populations outside the catchment area also has many negative societal side- effects..]11[ erutuf dna tsap - sserts retaw labolG 01.2 erugiF %02 naht ssel %02 ot %04 morf %01 ot %02 morf %04 naht erom retaw elbaliava latot fo egatnecrep a sa lawardhtiw retaW 5202 5991 2.3 Water 29 Irrigated cropland 56% All cropland 28% Major commodity crops Cotton 57% Wheat 43% Maize 35% Oranges 33% Sugar cane 31% Rice 29% Canola 26% Soybeans 19% Rubber 14% Oats 13% Coffee 10% Cocoa 5% Oil palm 5% Crop groups Fiber crops 53% Tree nuts 50% Fruits 38% Cereals 34% Legumes 32% Sugar crops 31% Roots and tubers 26% Fodder crops 25% Oil crops 22% Figure 2.11 Fraction of crops under water stress. Figure 2.12 Impact of dams in large river systems across the world. From dark to light gray, strongly affected, moderately affected, and unaffected rivers, and regions with not enough data. The white regions have no large river systems. Reproduced with permission from. 30 2 Status of Ecosystem Goods and Services 2.4 Food Food is an important provisioning service provided by agroecosystems. Despite the increase in human population shown in Figure 1.1, there is enough food available for everyone on the planet. This is conveyed in Figure 2.13, which shows grain production and supply. While production has continued to increase, the sup- ply quantity in terms of cereals available per person per year has decreased in the last two decades, however. A smaller supply per capita increases price volatility and vulnerability to scarcities. So far, scarcities have been due to challenges in food distribution or purchasing power, not due to inadequate production. The total global wild ﬁsh catch and production from aquaculture are shown in Figure 2.14, and the per capita wild ﬁsh catch is shown in Figure 2.4. The total wild ﬁsh catch has leveled off and, on a per capita basis, it has already peaked. An increasing fraction of ﬁsh comes from aquaculture. Fisheries have collapsed in many parts of the world, and most of the large specimens have been ﬁshed out of the world’s oceans. The impressive increase in food production in the last few decades has been enabled not only by using more land for agriculture, but also by intensifying agri- cultural activities to increase the yield per hectare of land. This intensiﬁcation was the result of “green revolution” technologies of the 1970s, which included hybrid high-yield crop varieties and extensive reliance on irrigation, artiﬁcial fertilizers, and pesticides. This industrialized farming has had many side-effects, which have played a signiﬁcant role in the degradation of ecosystem services such as the bio- geochemical cycles of nitrogen and phosphorus, water provisioning, soil fertility 3000 155 Supply Production (106 tonnes) quantity 150 kg/capita/yr 2500 Supply 145 quantity 2000 140 1500 135 Production

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