LESSON 1- INTRODUCTION TO ENVIRONMENTAL SCIENCE-1.pdf

INTRODUCTION TO ENVIRONMENTAL SCIENCE Jaffy Bustamante Lecturer, Department of Environmental Science College of Science This lesson will help you to understand: The meaning of the term “Environment”. The interdisciplinary nature of Environmenta...

INTRODUCTION TO ENVIRONMENTAL SCIENCE Jaffy Bustamante Lecturer, Department of Environmental Science College of Science This lesson will help you to understand: The meaning of the term “Environment”. The interdisciplinary nature of Environmental Science and acknowledge the contributions of the various fields it is allied to. Explain the fundamental philosophical views, theories and concepts on the contemporary environment issues faced by human population. ENVIRONMENT: The total of our surroundings Environment means the surrounding external conditions influencing development or growth of people, animal or plants; living or working conditions, etc. (Singh, 2006) All things around us with which we interact: 1. Living things (Animals, Plants, Fungi, etc.) 2. Non- living things (Soil, Water, Rocks, etc.) 3. Our built environment (Buildings, human-created living centers) 4. Social relationships and institutions UNDERSTANDING THE ENVIRONMENT THE LITHOSPHERE LITHOSPHERE Lithosphere is a massive and hard solid substratum holding the semisolid, liquid, biotic and gaseous molecules and masses surrounding it. All geomorphic processes happen on this sphere. It is the sphere where all natural resources are existing. It links the cyclic processes of atmosphere, hydrosphere, and biosphere The Earth can be subdivided into layers based on two criteria: Composition differences (density) and Physical properties. COMPOSITIONAL DIFFERENCES CRUST The Crust is the outermost layer of the earth on which all living organisms survive. This is a very thin layer. It is ranging from 5 km under the oceans to 100 km under the mountainous areas of continents. There are two types of crust– the continental crust and the oceanic crust.  The continental crust is the older and more buoyant type of crust. It has an average thickness of 35 km but can be more than 70 km thick in mountainous regions. It has an average composition consisting of granite with a density of 2.7 g/cm3. The oceanic crust is the younger and denser type of crust. It has an average thickness of 7 km, much thinner than the continental crust. It is composed of basalt, a dark igneous rock with a density of 3.0 g/cm3.  Continental vs. Oceanic Crust Category Continental Oceanic Rock Type Granite Basalt Thickness 35 – 70km (Thicker) 3 – 8 km (Thinner) State Solid Solid Crust Age 4 billion years old or Older 180 million years old or Younger Density Less Dense More Dense Element Composition Oxygen, Sodium, Silicon, Aluminum, Iron, Magnesium, Calcium Potassium COMPOSITIONAL DIFFERENCES MANTLE The mantle comprises the majority of the Earth’s volume (more than 80%) and begins where the crust ends, down to a depth of 2,900 km. The boundary between the crust and mantle is called the Mohorovičić discontinuity, which is marked by a change in chemical composition. It can be divided into two parts: the upper mantle and the lower mantle, separated by the Repetti discontinuity. COMPOSITIONAL DIFFERENCES CORE The core begins at the mantle-core boundary, the Gutenberg discontinuity, located at the 2,900 km depth. Although no one has ever been to or sampled the core, scientific investigations led to the conclusion that its composition is made up of a Fe-Ni (iron and nickel) alloy. Due to its composition and the pressure conditions at depth, it is calculated to have a whopping density of around 11 g/cm3. THE ATMOSPHERE  Life-giving gaseous envelope provides the air that we ATMOSPHERE breathe but also protects from ultraviolet (UV) radiation (Skinner and Murck 2011) Mt. Pulag Mt. Pulag Layers of the Thermosphere Earth’s Mesopause Mesosphere Atmosphere Stratopause Stratosphere From top to Tropopause Troposphere Bottom  TROPOSPHERE Lowest and thinnest layer 90% of the atmosphere’s mass Temperature decreases with altitude —6°C per kilometer —Top of troposphere averages —–50°C Where weather occurs Boundary between the troposphere, and the stratosphere is called the tropopause  STRATOSPHERE Extends from 12 km to 50 km above the ground Less dense (less water vapor) Temperature increases with altitude Almost no weather occurrence Contains high level of ozone > ozone layer ❑ Upper boundary is called stratopause  MESOSPHERE Extends to almost 80 km high Gases are less dense. Temperature decreases as altitude increases. Gases in this layer absorb very little UV radiation.  THERMOSPHERE Above the mesosphere and extends to almost 600 km high Temperature increases with altitude Readily absorbs solar radiation Temperature can go as high as 1,500 °C Reflects radio waves  Stratospheric ozone is good ozone — protects Earth from harmful UV radiation — depletion is detrimental to life Structure of Atmosphere Tropospheric ozone is bad ozone — In the troposphere, ozone is a pollutant. CFCs (pollutant)  Atmospheric pressure (millibars) 0 200 400 600 800 1,000 120 75 Temperature 110 65 100 Thermosphere 90 Mesopause 55 Altitude (kilometers) 80 Altitude (miles) Mesosphere 45 70 60 Stratopause 35 50 Stratosphere 40 25 30 Tropopause 15 Ozone layer 20 10 Pressure Troposphere 5 (Sea 0 –80 –40 0 40 80 120 Pressure = Level) 1,000 Temperature (°C) Millibars at ground level THE HYDROSPHERE HYDROSPHERE Dynamic mass of water that is continually on the move, evaporating from the oceans to the atmosphere, precipitating to the land, and running back to the ocean again. Global ocean is certainly the most prominent feature of the hydrosphere, blanketing nearly 71 percent. Freshwater found underground and in streams, lakes, and glaciers. 71% THE BIOSPHERE BIOSPHERE The biosphere is the portion of the Earth that is inhabited by life. ❑ Biosphere- part of Earth where life exists a. Includes all living and non- living parts b. Biota- collection of just living things in biosphere 2. Earth has 4 major connected systems a. Biosphere b. Hydrosphere- all of Earth’s water, ice, water vapor c. Atmosphere- the air blanketing Earth’s solid and liquid surface d. Geosphere- features of Earth’s surface (continents, rocks, sea floor, and everything below Earth’s surface Biotic and Abiotic factors interact in the biosphere 1. All four of Earth’s systems are connected to another 2. Gaia hypothesis- Earth itself is kind of a “living organism” ELEMENTS OF THE ENVIRONMENT Biological Elements Physical Elements Cultural Elements “IN OUR EVERY DELIBERATION, WE MUST CONSIDER THE IMPACT OF OUR DECISIONS ON THE NEXT SEVEN GENERATIONS.” The Great Law of the Iroquois Confederacy ENVIRONMENTAL SCIENCE Is define as the interdisciplinary study of humanity’s relationship with other organisms and the nonliving physical environment. It is the academic field that takes physical, biological, and chemical sciences to study the environment and discover solutions to environmental problems. ENVIRONMENTAL SCIENCE IS AN INTERDISCIPLINARY SCIENCE Environmental science and the issues that it studies are complex and interdisciplinary. Includes concepts and ideas from multiple fields of study. Decisions have impacts in all these fields of study. (AP Environmental Science, n.d.) DRAWING A BRIDGE OF INFORMATION 1. A community decides to use coal for electricity, as it is the cheapest source available. (Economics) 2. The coal must be mined from under the soil. (Geology) 3. The coal must be transported to the population center by road or rail. (Engineering) 4. When it is burned at a power plant, air pollution is released. Some of that pollution is converted to acid in the atmosphere. (Chemistry) 5. This falls as acid rain somewhere downwind. (Meteorology) 6. The acid stresses plants by affecting their nutrient absorption. (Ecology) 7. Laws are passed requiring the plant to install pollution scrubbers. (Politics) WHY WE STUDY ENVIRONMENTAL SCIENCE? Environmental Science is our modern We depend on our environment way of seeking answers to the questions Environmental science teaches us how to protect our environment in the face Our environment improves the quality of rising human population and of our lives anthropogenic activities that degrade natural resources and ecosystems. MAJOR ENVIRONMENTAL PROBLEMS Pollution o Pollution of the air, water and soil caused by toxins such as plastics, heavy metals and nitrates, caused by factors such as toxins and gases released by factories, combustion of fossil fuels, acid rain, oil spill and industrial waste. Global Warming o The emission of greenhouse gases due to human activity causes global warming, which in turn causes an increase in temperature that then leads to rising sea levels, melting of polar ice caps, flash floods and desertification. MAJOR ENVIRONMENTAL PROBLEMS Overpopulation o We are facing a shortage of resources such as food, water and fuel to sustain the rising global population, particularly in developing countries. Intensive agriculture attempting to lessen the problem leads to more damage using chemical fertilizers, pesticides and insecticides. Ocean Acidification o An excessive amount of waste is produced and dumped in the oceans. Nuclear waste is particularly dangerous, as well as plastics and electronic waste. MAJOR ENVIRONMENTAL PROBLEMS Loss of biodiversity o Species and habitats are becoming extinct due to human activity. This causes an imbalance in natural processes like pollination and poses a threat to ecosystems – coral reef destruction is particularly affected. Deforestation o Loss of trees in order to make space for residential, industrial or commercial projects means that less oxygen is produced, and temperature and rainfall are affected. MAJOR ENVIRONMENTAL PROBLEMS Ozone layer depletion o Pollution caused by chlorofluorocarbons (CFCs) in the air creates a hole in the ozone layer, which protects the earth from harmful UV radiation. Public health issues o Lack of clean water is one of the leading environmental problems currently. Pollutants in the air also cause issues such as respiratory disease and cardiovascular disease. ENVIRONMENTAL ETHICS Environmental ethics is the discipline that studies the moral relationship of human beings to the environment. What is the value of the environment? What moral responsibility do we have in dealing with the major environmental problems that result from our resource consumption? Which needs should be given the highest priority in our decision making?  Types of Environmental Ethics Libertarian Extension o Libertarian extension is a type of environmental ethics that focuses on an individual’s right to do whatever they want with the environment and its resources. This concept also stresses that an individual should not impose their own values on others and should instead respect the choices of others.  Types of Environmental Ethics Ecological Extension o Ecological Extension is a type of environmental ethics that focuses on preserving the natural environment and its resources to maintain the balance and health of the ecosystem. This concept stresses the importance of humans working with nature to sustain it for future generations.  Types of Environmental Ethics Conservation Ethics o Conservation Ethics is a type of environmental ethics that focuses on preserving natural resources for future generations by ensuring that current resources are not depleted or damaged beyond repair. This concept encourages individuals to use natural resources responsibly and judiciously so there will be enough for future generations. PRINCIPLES OF ENVIRONMENTAL ETHICS 1.Respect for the intrinsic value of nature 2.Interdependence of species and ecosystems 3.Ecological sustainability 4.Human responsibility 5.Human equity 6.Precautionary principle 7.Right to know 8.Right to participate TWO MAIN CATEGORIES OF ETHICS IN HUMAN CULTURE IN MODERN HISTORY Anthropocentrism It is the view or belief that human beings are superior to all other organisms This set of ethics protects and promotes of human interests or well-being at the expense of all other factors. Often places an emphasis on short-term benefits while disregarding long-term consequences. TWO MAIN CATEGORIES OF ETHICS IN HUMAN CULTURE IN MODERN HISTORY Ecocentrism It is a perspective that places importance on the ecosystem. The preservation of ecosystems or other living things takes priority over human needs.  HETCH HETCHY DEBATE The debate about whether to build a dam in the Hetch Hetchy valley was one of the first big debates between these two philosophies. When the growing city of San Francisco, California proposed building a dam in the Hetch Hetchy Valley to provide a steady water supply, Congress debated whether to make a water resource available or preserve a wilderness between 1908 and 1913. HETCH HETCHY DEBATE The dam was eventually constructed. The justification for building it was best stated by Gifford Pinochet, the first man in charge of the U.S. Forest Service. "Where conflicting interests must be reconciled, the question shall always be answered from the standpoint of the greatest good of the greatest number in the long run.“ RESOURCE CONSERVATIONIST The focus of the resource conservationists was to protect open land. The National Parks system, and the National Forest system were both created during this time. MODERN ENVIRONMENTALISM Rachel Carson published a book in 1962 entitled Silent Spring about the effects of pesticides on large predatory birds, particularly the bald eagle. Rachel Carson documented the impacts that pesticides like DDT were having on wildlife. DDT is persistent, meaning it is not biodegradable and will not break down naturally. This began a public awakening to threats of pollution and toxic chemicals to humans as well as other specie. This movement is called Modern Environmentalism. GLOBAL ENVIRONMENTALISM Global environmentalism explores issues and problems over the entire world, not just within the local community. Following the 1970s, environmentalism began to consider issues that affected the entire planet: Biodiversity loss Food production Climate Change Human population growth Economic inequality between nations THE TRAGEDY OF THE COMMONS A great deal of progress has been made since the birth of modern environmentalism, but many debates still rage on. An ecologist named Garrett Hardin wrote an essay called “The Tragedy of the Commons”, describing the source of environmental problems as a conflict: Short-term interests of individuals versus… Long-term interests of civilization and the Earth itself THE TRAGEDY OF THE COMMONS The tragedy of the commons refers to a situation in which individuals with access to a public resource (also called a common) act in their own interest and, in doing so, ultimately deplete the resource. A small village consists mostly of farmers that raise and sell sheep at a nearby city. The only place for the sheep to graze is a commons in the center of the village. A commons is an area that belongs to no individual; it is shared by the entire society. Likely outcome: Villagers obtain as many sheep as possible, allow to graze in the commons. Maximize short-term financial gain. THE DEMOGRAPHIC DIVIDE Countries are classified across an economic spectrum Developing Countries Developed Countries Economically poor Economically wealthy Less educated More educated Higher fertility rates Lower fertility rates Lower standard of living Higher standard of living Lower rates of consumption Higher rates of consumption CASE STUDY: BHOPAL PESTICIDES PLANT In December of 1984, a pesticide factory located near the town of Bhopal, India leaked a large amount of toxic chemicals into the air. The chemicals resulted in an immediate death toll of about 3,000 people, with 8,000 more dying of long-term health ailments. A total of 558,125 injuries were reported to the Indian government. A settlement of $470 million was reached by Union Carbide and the Indian government. ENVIRONMENTAL PHILOSOPHIES  Deep ecology is a type of ecologism that calls for radical change in the relationship between humans and nature. For deep ecologists, human beings are of equal value to all other DEEP ECOLOGY parts of nature. Nature must not be seen in regard to its utility to human beings. It is the duty of humans to help sustain nature and not the reverse. Society must restructure itself to reflect this.  Ecofeminism is a branch of feminism concerned with critically ECOFEMINISM analyzing and understanding the relationship between gender and the environment.  Environmental pluralism seeks to build a broad political base, encourage ENVIRONMENTAL experimentation, and strive for the higher ground where many, but not all, of the preferred outcomes of multiple stakeholders exist. PLURALISM It strives to overcome the polarization and paralysis symptomatic of contemporary environmental decision making. ENVIRONMENTAL Environmental pragmatism is a new strategy in environmental thought: it argues that theoretical debates are hindering the ability of the PRAGMATISM environmental movement to forge agreement on basic policy imperatives. SOCIAL Social ecology is the study of how individuals interact with and respond to the environment around them, and how these interactions ECOLOGY affect society and the environment as a whole. FOUR BASIC PRINCIPLES OF ENVIRONMENTAL SCIENCE Systematic principle of environment Principle of environmental capacity Symbiosis principle between human and environment Entropy principle  END OF THE PRESENTATION