Course Code: 5443/5998/1421 Course Code: 5443/5998/1421 Course Team Course Development Dr. Hina Fatimah Coordinator / Principal Author Asst. Prof, Department of Environmental Science, AIOU Contributing Authors Prof. Dr. Abdulrauf Farooqi Chairman, Department of Environmental Science, AIOU Dr. Zahidullah, Lecturer, Department of Environmental Science, AIOU Reviewers Dr. Saeed Ahmad Sheikh, Assistant Professor, Department of Environmental Science, Fatima Jinnah Women University, Rawalpind Editor Mr. Abdul Wadood Ms. Humaira Design . Title Ms. Shabnam Irshaad . Typesetting Mr. Muhammad Usman Mr. Shahzad Akram ii Preface On behalf of AIOU and the course team, I appreciate and welcome you to the course “Introduction to Environment”. The word “environment” is usually understood to mean the surrounding conditions that affect people and other organisms. In broader definition, environment is everything that affects an organism during its lifetime. Environmental science stands at the interface between human and earth. It is an interdisciplinary as well as multidisciplinary study that describes problems caused by human use of the natural world. It also seeks remedies for these problems. Learning about this complex field of study helps to understand three things. First, it is important to understand the natural processes (both physical and biological) that operate in the world. Second, it is important to appreciate the role that technology plays in our society and its capacity to alter natural processes. Third, it helps to understand the complex social processes that characterize human populations. The different units of this course will lead you to an understanding of the relationships between the physical and human components of the systems and the Earth’s processes that change the surface of the earth. Primarily the objectives of this course are to: 1. Give a clear understanding of the definition and scope of Environmental Science. 2. Provide an understanding of earth’s spheres: atmosphere, lithosphere, hydrosphere and the Biosphere. 3. Acquaint students with ecological concepts and connections and energy flow through material and energy flow in ecosystem. 4. Provide students an understanding of the biological diversity, man and environment interaction and Pakistan’s environmental settings. The field of Environmental Science is very broad and not many books are written to introduce all the important aspects of the subject particularly to cover the issues related to the developing or the south Asian countries. The study material has therefore been developed using the best available resources in a simple language, understandable figures and examples from Pakistan. This book also includes individual introduction to each unit, suggests small research activities and exercises to develop a better understanding of the topic and self assessment questions at the end. I hope that you find the course useful, interesting and stimulating. Best Wishes Prof. Dr. Abdulrauf Farooqi Chairman Department of Environmental Science iii Course Outline Unit 1 Environment: An Introduction 1.1 Environment: Definitions, History, Scope and Importance 1.2 The World Response 1.3 Perceptions and Attitudinal Changes Unit 2 Frame Work of Ecology 2.1 Levels of Organization in Nature 2.2 Structure of Ecosystem 2.3 Functions of Ecosystem (productivity and energy flow) 2.4 Types of Organism Interactions Unit 3 Atmosphere 3.1 Atmosphere: Composition and Structure 3.2 Solar Radiations in the Atmosphere 3.3 Climate and Urban Microclimate 3.4 Climate Change and Global Warming 3.5 Seasons Unit 4 Lithosphere 4.1 Earth: Structure and Composition 4.2 Geographic Organization of the Land 4.3 Earth Materials 4.4 Soil and its Properties 4.5 Soil Erosion and its Impact on Environment Unit 5 Hydrosphere 5.1 Water: A Unique Solvent and a Vital Resource 5.2 Composition of Hydrosphere 5.3 Water Cycle 5.4 Human Impacts on Hydrological Cycle 5.5 Human Use of Water iv Unit 6 Biogeochemical Cycles 6.1 Nitrogen Cycle 6.2 Carbon Cycle 6.3 Phosphorus Cycle 6.4 Sulfur Cycle Unit 7 Biological Diversity and Its Distribution 7.1 Understanding Biological Diversity 7.2 Biological Evolution 7.3 Levels in Diversity 7.3.1 Ecosystem Diversity 7.3.2 Species Diversity 7.3.3 Genetic Diversity Unit 8 Man Environment Interaction 8.1 Four Principles of Ecosystem Sustainability 8.2 Effect of Human Activity on Environment 8.3 Implications for Human Society Unit 9 Pakistan Environmental Setting 9.1 Location and Extent 9.2 Climate 9.3 Soil and Topography 9.4 Flora and Fauna 9.5 Human Settlement Pattern v UNIT No. 1 Environment: An Introduction Major Topics 1.1 Environment: Definitions, History, Scope and Importance 1.2 The World Response 1.3 Perceptions and Attitudinal Changes Introduction1 Humans have always inhabited two worlds. One is the natural world of plants, animals, soils, air, and water that preceded us by billions of years and of which we the Homo sapiens (human beings) as a species are a part. The other is the world of social institutions and artifacts that we create for ourselves using science, technology, and political organization. Both worlds are essential to our lives, but integrating them successfully causes continuing tensions. Where earlier people had limited ability to alter their surroundings, we now with the advancement of science and technology have the power to extract and consume resources. Further more we produce wastes and modify our world in ways that threaten both our continued existence and that of many organisms with which we share the planet. To ensure a sustainable future for ourselves and future generations, we need to understand something about how our world works, what we are doing to it, and what we can do to protect, improve and sustain it. By sustainability we mean that meeting our needs judiciously and sensibly, so that our future generations get the equal share of resources that we have today. This unit looks more closely at science as a systematic way of knowing, environmental ethics, and other tools that help us analyze and understand the world around us. We will also get an overview on the scope and importance of environmental science as a discipline. An account on people’s perceptions and attitudes towards environment and nature will also be included. After reading this unit the students will be able to: Objectives of the Unit 1. Define environmental science, ecology and its types. 2. Understand the scope and importance of environmental science 3. Comprehend the global response on environmental issues and the need to bring about attitudinal changes. 1 Cunningham, Cunningham and Saigo (2005) Environmental Science a Global Concern. 8th edition Mc. Graw Hill. pp 16 1 Section 1.1 Environment: Definition, Scope and Importance2,3,4 Environment (from the French ‘environner’ to encircle or surround) can be defined as: i. The circumstances or conditions that surround an organism or group of organisms, or ii. The complex of social or cultural conditions that affect an individual or community. This involves three questions: What is surrounded? The answer is: living objects in general and human being in particular. By what surrounded? The physical attributes are the answer to this question, which become environment. In fact, the concern of all education is the environment of humans. However, human beings cannot exist or be understood in isolation from the other forms of life and from plant life. Hence, environment refers to the sum total of conditions, which surround point in space and time. The scope of the term Environment has been widening by the passage of time. In the primitive age, the environment consisted of only physical aspects of the earth ‘land, air and water’ and biological communities. As the time passed on man extended his environment through his social, economic and political functions. Where Surrounded? It is in the nature that physical component of the earth, viz land, air, water etc., support and affect life in the biosphere. Definition of Environment: Another important definition of environment states: ‘A person’s environment consists of the sum total of the stimulation which he receives from his conception (birth) until his death.’ It can be concluded from the above definition that environment comprises of various types of forces such as physical, intellectual, economic, political, cultural, social, moral and emotional. Environment is the sum total of all the external forces, influences and conditions, which affect the life, nature, behavior, growth, development and maturation of living organisms. 2 Q.J. Shammi S.S. Purohit and A.K. Agrawal (2004) Environmental Sciences: A New Approach. Agrobios (India) 3 Cunningham, Cunningham and Saigo (2005) Environmental Science a Global Concern. 8th edition Mc. Graw Hill. pp 16-20 4 Singh, Y. K. (2006) Environmental Science. New Age Intl. publications pp 1-9. 2 History of Environmental Science and Education Environmental Conservation, alleviation of poverty and sustainable development has been high on the agenda of global meetings (UN Conference Stockholm, 1972; the Earth Summit in Rio de Janeiro, 1992; New York, 1997 and Johannesburg, 2002). The start of the environmental education made historical mark with the start of the International Conference on Human Environment at Stockholm in 1972 on global level and in Pakistan. Subsequently, the need for environmental education was for the first time emphasized in 1979 in Belgrade. The Tbilisi conference in the USSR in 1977 was the first major conference on the theme of