Chapter 1 MST Environmental Science PDF

CHAPTER 1: ENVIRONMENTAL SCIENCE Smog ECOLOGY AND ENVIRONMENTAL SCIENCE A mixture of smoke and fog, and it is caused by a layer of warm air developin...

CHAPTER 1: ENVIRONMENTAL SCIENCE Smog ECOLOGY AND ENVIRONMENTAL SCIENCE A mixture of smoke and fog, and it is caused by a layer of warm air developing above a region of colder air. The Ecology warm layer prevents the colder air from escaping. This is - Is the study of the relationships between organisms and called temperature inversion. Smog is not only unpleasant their environment and other organisms. but it can be dangerous. Environmental Science Water Pollution - Is an interdisciplinary science which integrates the From time-to-time oil is spilled into the sea from a tanker biological, physical and social sciences in analyzing, or an off-shore oil rig. explaining and designing solution to environmental Another water pollutant is sewage. If untreated sewage is problems. put into a river or lake, it is decomposed by bacteria which Environment quickly multiply. - All of the factors (living and non-living) that actually affect With so much nitrate to feed on, the algae multiply and the an individual organism or population at any point in the life water turns green. This great growth of algae is called cycle. eutrophication. HUMAN ENVIRONMENTAL RELATIONSHIP Land Pollution How are Our Ecological Footprints Affecting the Earth? There are many examples of land that has been stripped of vegetation by industrial development and disposal of As our ecological footprints grow, we are depleting and waste. degrading more of the earth’s natural capital. Radiation Pollution Ecological footprint Another type of pollution to which we are all exposed is The amount of biologically productive land and water radiation from radioactive materials. needed to supply the people in a particular country or area with resources and to absorb and recycle the wastes and We add to this natural radiation by nuclear power stations pollution produced by such resource use. and nuclear explosions. After a nuclear explosion radioactive materials get into the atmosphere and come Natural Capital = Natural Resources + Natural Services down to the earth as fallout. Why Do We Have Environmental Problems? Controlling Pests Causes of Environmental Problems Man gets rid of pests in two main ways: - Population Growth 1. By spraying the ground with a chemical substance which - Wasteful and unsustainable kills the pest. We call this chemical control. resource use - A chemical substance which kills pests is called pesticides. - Poverty Those which are used against weeds (herbs) are called - Failure to include the harmful environmental costs of herbicides. goods and services in their market price - Insufficient knowledge on how nature works 2. By making use of another organism which kills the pests. We call this biological control. OUR EFFECTS ON THE ENVIRONMENT The advantage of biological control is that it does not involve putting artificial substances into the environment. Pollution Nature is doing the job for us. However, not every pest has Pollution in any process which leads to a harmful increase a predator that will keep its numbers down sufficiently, and in the amount of a chemical substance in the environment. so chemical methods are more often used. These harmful substances are called pollutants. They accumulate more quickly than they can be recycled by the process of nature. Wildlife in Danger Over the centuries many animals and plant species have dwindled in number and some have died out completely. Air Pollution This has been mainly because we have needed the land for A widespread air pollutant is smoke from the burning of farming, industry, reservoirs and houses. fossil fuel such as coal and petrol. The smoke contains Conservation particles of carbon which float through the air and settle on the surface of buildings and trees.  To conserve something means to protect it and keep it in a Biocentrism healthy condition. Applied to our environment, conservation means protecting the animals and plants from Ethical perspective holding that all life deserves equal being harmed. moral consideration or has equal moral standing. Conservation can be achieved in the following ways: Ecocentrism 1. We must reduce pollution as much as possible. Pollution can It comprising all Earth's ecosystems, atmosphere, water damage natural habitats and harm the organisms that live there. and land – as the matrix which birthed all life and as life's sole source of sustenance. 2. Areas which have been devastated by mining should be restored afterwards. This is perfectly possible, though of course HUMANS AND SUSTAINABILITY it costs money. Plants and animal will soon move back into such Sustainability from the latin word sustinere (to hold). areas if conditions are made right for them. Sustain can mean “maintain”, “support”, or “endure”. 3. Animals that are killed for food, or any other purpose, must not be used up quickly. This particularly applies to fish and A strategy by which communities seek economic whales. development approaches that also benefit the local environment and quality of life. 4. Natural forests should not be used extensively as a source of timber. It is better to rely on plantations in which the felled trees PRINCIPLES OF SUSTAINABILITY are replaced by new seedlings. Quite apart from the trees themselves, our woods and forests are a haven for many species 1. CONSERVATION OF OUR ECOSYSTEM: of animals and plants. - Ultimate motive of sustainable development is to protect the 5. One species of animal or plant should not be allowed to ecosystem. Preservation of earth and its resources is essential. flourish at the expense of another. This can upset the balance of 2. DEVELOPMENT OF SOCIETY: nature. - Sustainable development focuses on developing society by 6. Endangered species must be helped to survive. creating equal opportunities for everyone. From creating jobs to In many countries certain areas have been set aside where the the reliable health system, everything gets included under this animals and plants are protected. These are often called principle. National Parks and they contain an abundance of wildlife and 3. CONVERSATION OF BIODIVERSITY: natural scenery which everyone can enjoy. Because of humans, most of the wild animals which used to roam the earth have long - Natural resources are already limited. Exploiting these further since died out. to meet our needs is not acceptable. Protecting our biodiversity is essential to protect our earth from further damage. However, in places such East and South Africa there are large game parks with lions, giraffes, elephants, zebras and many 4. PROTECTING HUMAN RESOURCES: other animals. Here are the animals can roam about in safety. They are carefully managed by game wardens so that their - People play an important role in protecting and conserving numbers are kept at the right level. society. Human resources can be used to save earth. Hence, sustainable development considers human resource an essential ENVIRONMENTAL ETHICS aspect of it. A discipline that studies the moral relationship of human 5. CONSERVATION OF CULTURAL HERITAGE: being to, and also the value and moral status of, the environment and its non-human contents. - Sustainable development highlights the conservation of cultural heritage. Different cultures have an invaluable It deals with issues related to the rights of individuals that contribution to society. By conserving the same a sustainable is fundamental to life and well-being. This concerns not society can be promoted. only the needs of each person today but also those will come after us. It also deals with rights of other living 6. CREATING A COMMUNITY WITHIN THE creatures that inhabit on earth. CAPACITY OF EARTH: BRANCHES OF ENVIRONMENTAL SCIENCE - Sustainable development is all about development a community within the capacity of earth. So, sustainability is all Anthropocentrism about ensuring that our meet the producing capacity of the planet. It is a viewpoint arguing that human beings are the central or most significant entities in the world. Anthropocentrism WHAT IS AN ENVIRONMENTALLY SUSTAINABLE regards humans as separate from and superior to nature and SOCIETY? holds that human life has intrinsic value while other entities are resources that may justifiably be exploited for the Our lives and economies depend on energy from the sun benefit of humankind. (solar capital) and on natural resources and natural services (natural capital) provided by the earth.  Living sustainably means living off the earth’s natural income without depleting or degrading the natural capital that supplies it. An Environmentally Sustainable Society meets current and future basic resource needs of people in a just and equitable way without compromising the environment for future generation. Environment Is everything that affects living organisms. Sustainability The ability of earth’s natural and human cultural system to survive and adapt to changing environmental condition indefinitely. Society The aggregate of people living together in a more or less ordered community. FOUR SCIENTIFIC PRINCIPLES OF SUSTAINABILITY How can we live more sustainably? According to environmental scientists, we should study how life on the earth has survived and adapted to major changes in environmental conditions for billions of years. We could make the transition to more sustainable societies by applying these lessons from nature to our lifestyles and economies. Reliance on Solar Energy: The sun (solar capital) warms the planet and supports photosynthesis used by plants to provide food for themselves and for us and most other animals. Biodiversity (short for biological diversity): The sun (solar capital) warms the planet and supports photosynthesis used by plants to provide food for themselves and for us and most other animals. Population Control: Competition for limited resources among different species places a limit on how much their populations can grow. Nutrient Cycling: Natural processes recycle chemicals that plants and animals need to stay alive and reproduce. There is little or no waste in natural systems.