ESE71-RC PDF - Environmental Science and Engineering

ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering CHAPTER 1 Environment, Ecosystem, and Biodiversity The word environment is derived from the French word “Environ” which means “to encircle...

ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering CHAPTER 1 Environment, Ecosystem, and Biodiversity The word environment is derived from the French word “Environ” which means “to encircle or surround”. Our surroundings include biotic (living) factors like human beings, plants, animals, microbes, etc. and abiotic (non-living/ physical) factors such as light, air, water, soil, temperature, etc. Biotic factors – related to all the living entities present in an ecosystem. It is divided into three main groups: Figure 1-1: Biotic factors three main groups. 1. Producers Known as Autotrophs. Using inorganic materials and energy, they prepare their own food. It is considered the first life form because in early days of origin, there were no consumers to feed on. Two major classes of producers: o Photoautotrophs ▪ They use sunlight as the source of energy and carbon dioxide as the source of carbon. ▪ They mostly use the pigment, chlorophyll for capturing the photon from the sun. ▪ Similarly, there are also pigments like rhodopsin and carotenoids which are found in some bacteria, algae, and phytoplankton. They are used for photosynthesis. ▪ Later they produce essential things like sugar, protein, lipids, etc. Engr. Angelo Gabriel T. Suano, ECT Page 1  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering o Chemoautotrophs ▪ They use chemical agents like hydrogen, iron, and sulfur as their source of energy. ▪ They are usually found in places where the plants cannot grow. ▪ They are found at the bottom of the ocean or in acidic hot springs. ▪ They are also involved in nitrogen fixation. ▪ Examples include methanogens; they are microorganisms which can make methane gas. 2. Consumers Known as Heterotrophs. They don’t prepare their own food by themselves as the producers. 3. Decomposers They are also known as Detritivores. They use organic compounds as the source of energy from the producers and consumers. In an ecosystem, decomposers play a vital role, as the complex substances are broken down into simpler forms. Such a simpler form can be further utilized again by other organisms. It includes different soil bacteria, fungi, worms, and flies. When the animals die, they get decomposed because of decomposers. Even plants and fruits start rotting, it’s because of decomposers. Decomposers play an important role in metabolizing waste products. Abiotic factors – It is the non-living part of an environment. It includes all the physical and chemical aspects of an ecosystem. It contributes to the continuity of life on earth by supporting the survival and reproduction process. The component also depends upon the type of ecosystem. For example, rainfall contributes to tropical rainforest ecosystems, sand in desert ecosystems and water, salinity, ocean currents, pressure in the marine ecosystem. Environment is complex of many variables, which surrounds man as well as the living organisms. The environment includes water, air and land and the interrelationships which exist among and between water, air, and land and human beings and other living creatures such as plants, animals, and micro-organisms. The environment consists of an inseparable whole system constituted by physical, chemical, biological, social and cultural elements, which are interlinked individually and collectively in myriad ways. The natural environment consists of four interlinking systems namely, the atmosphere, the hydrosphere, the lithosphere and the biosphere. These four systems are in constant change and such changes are affected by human activities and vice versa. Engr. Angelo Gabriel T. Suano, ECT Page 2  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering 1. Atmosphere – implies the protective blanket of gases surrounding the earth: (a) Composed of about 78% nitrogen, 21% oxygen, 0.9% argon, and 0.1% other gases. Trace amount of carbon dioxide, methane, water vapor, and neon are some of the other gases that make up the remaining 0.1 percent. (b) It stretches from the surface of the planet up to as far as 10,000 kilometers (6,214 miles) above. After that, the atmosphere blends into space. Not all scientists agree where the actual upper boundary of the atmosphere is, but they can agree that the bulk of the atmosphere is located close to Earth’s surface—up to a distance around eight to 15 kilometers (five to nine miles). (c) It sustains life on earth. (d) It saves it from the hostile environment of outer space. (e) It protects life on earth by shielding it from incoming ultraviolet (UV) radiation, keeping the planet warm through insulation, and preventing extremes between day and night temperatures. There are five concentric layers within the atmosphere, which can be differentiated based on temperature and altitude, and each layer has its own characteristics. Figure 1-2: Layers of the atmosphere. Troposphere Almost all weather develops in the troposphere because it contains almost all the atmosphere’s water vapor. Clouds, from low-lying fog to thunderheads to high- altitude cirrus, form in the troposphere. Air masses, areas of high-pressure and low- pressure systems, are moved by winds in the troposphere. These weather systems lead to daily weather changes as well as seasonal weather patterns and climate systems, such as El Niño. Engr. Angelo Gabriel T. Suano, ECT Page 3  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Air in the troposphere thins as altitude increases. There are fewer molecules of oxygen at the top of Mount Everest, Nepal, for example, than there are on a beach in Hawaii. This is why mountaineers often use canisters of oxygen when climbing tall peaks. Thin air is also why helicopters have difficulty maneuvering at high altitudes. In fact, a helicopter was not able to land on Mount Everest until 2005. As air in the troposphere thins, temperature decreases. This is why mountaintops are usually much colder than the valleys beneath. Solar heat penetrates the troposphere easily. This layer also absorbs heat that is reflected back from the ground in a process called the greenhouse effect. The greenhouse effect is necessary for life on Earth. The atmosphere’s most abundant greenhouse gases are carbon dioxide, water vapor, and methane. Stratosphere Strong horizontal winds blow in the stratosphere, but there is little turbulence. This is ideal for planes that can fly in this part of the atmosphere. The stratosphere is very dry, and clouds are rare. Those that do form are thin and wispy and are called nacreous clouds. Sometimes they are called mother-of- pearl clouds because their colors look like those inside a mollusk shell. The stratosphere is crucial to life on Earth because it contains small amounts of ozone, a form of oxygen that prevents harmful UV rays from reaching Earth. The region within the stratosphere where this thin shell of ozone is found is called the ozone layer. The stratosphere’s ozone layer is uneven, and thinner near the poles. The amount of ozone in the Earth’s atmosphere is declining steadily. Scientists have linked the use of chemicals such as chlorofluorocarbons (CFCs) to ozone depletion. Mesosphere The mesosphere has the coldest temperatures in the atmosphere and has the atmosphere’s highest clouds. In clear weather, you can sometimes see them as silvery wisps immediately after sunset. They are called noctilucent clouds, or night-shining clouds. The mesosphere is so cold that noctilucent clouds are actually frozen water vapor—ice clouds. Shooting stars—the fiery burnout of meteors, dust, and rocks from outer space—are visible in the mesosphere. Most shooting stars are the size of a grain of sand and burn up before entering the stratosphere or troposphere. However, some meteors are the size of pebbles or even boulders. Their outer layers burn as they race through the mesosphere, but they are massive enough to fall through the lower atmosphere and crash to Earth as meteorites. Thermosphere The thermosphere is the thickest layer in the atmosphere. Only the lightest gases—mostly oxygen, helium, and hydrogen—are found here. Here, thinly scattered molecules of gas absorb x-rays and ultraviolet radiation. This absorption process propels the molecules in the thermosphere to great speeds and high temperatures. Engr. Angelo Gabriel T. Suano, ECT Page 4  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering The Hubble Space Telescope and the International Space Station (ISS) orbit Earth in the thermosphere. Even though the thermosphere is the second-highest layer of Earth’s atmosphere, satellites that operate here are in “low-Earth orbit.” Aurora, the northern and southern lights are also found in this region. Exosphere Exosphere is the outermost layer of the atmosphere. It expands and contracts as it comes into contact with solar storms. In solar storms particles are flung through space from explosive events on the sun, such as solar flares and coronal mass ejections (CMEs). Many weather satellites orbit Earth in the exosphere. The lower part of the exosphere includes low-Earth orbit, while medium-Earth orbit is higher in the atmosphere. The upper boundary of the exosphere is visible in satellite images of Earth. Called the geocorona, it is the fuzzy blue illumination that circles the Earth. Table 1-1: Summary of the key features of the layers of the atmosphere: Engr. Angelo Gabriel T. Suano, ECT Page 5  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering 2. Hydrosphere – comprises all types of water resources such as oceans, seas, lakes, rivers, streams, reservoirs, polar icecaps, glaciers, and ground water. It functions in a cyclic nature, which is termed as hydrological cycle or water cycle. (a) 97% of the earth's water supply is in the oceans. (b) About 2% of the water resources are locked in polar icecaps and glaciers. (c) Only about 1% is available as fresh surface water - rivers, lakes streams, and ground water fit to be used for human consumption and other uses. 3. Lithosphere – the mantle of rocks constituting the earth’s crust. The earth is a cold spherical solid planet of the solar system, which spins in its axis and revolves around the sun at a certain constant distance. (a) The word lithosphere comes from Ancient Greek, with lithos meaning ‘rocky’ and sphaira meaning ‘sphere’. (b) Mainly consists of minerals occurring in the earth’s crust and the soil e.g. minerals, organic matter, etc. Lithosphere is divided into three layers – crusts, mantle, and core (outer and inner). Figure 1-3: Layers of the lithosphere. Crust – the outer layer of the rock on which humans and animals live and plants grow. It is composed of the denser oceanic crust and thicker continental crust. Mantle – a semi-solid magma layer consisting of iron, magnesium, and silicon. The mantle is divided into the lower mantle (mesosphere) and the outer mantle (asthenosphere). It is about 1,800 miles (2,900 km) thick and makes up nearly 80 percent of the Earth's total volume. Core – it is a dense ball of the elements iron and nickel. It is divided into two layers, a solid mass of metal (inner core), and a liquid mass of iron and nickel (outer core). Density and temperature are highest in the inner core. Engr. Angelo Gabriel T. Suano, ECT Page 6  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering 4. Biosphere – it is otherwise known as the life layer. (a) It refers to all organisms on the earth’s surface and their interaction with water and air. (b) It consists of plants, animals and micro-organisms, ranging from the tiniest microscopic organism to the largest whales in the sea. Biology is concerned with how millions of species of animals, plants and other organisms grow, feed, move, reproduce and evolve over long periods of time in different environments. Its subject matter is useful to other sciences and professions that deal with life, such as agriculture, forestry, and medicine. (c) The richness of biosphere depends upon several factors like rainfall, temperature, geographical reference etc. (d) Apart from the physical environmental factors, the man-made environment includes human groups, the material infrastructures built by man, the production relationships and institutional systems that has devised. The social environment shows the way in which human societies have organized themselves and how they function to satisfy their needs. Multidisciplinary nature of environmental studies Environmental Science is an interdisciplinary academic field that integrates physical, chemical and biological sciences, (including but not limited to Ecology, Physics, Chemistry, Biology, Soil Science, Geology, Atmospheric Science and Geography) to the study of the environment, and the solution of environmental problems. Environmental science provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems. Related areas of study include environmental studies and environmental engineering. Environmental studies incorporate more of the social sciences for understanding human relationships, perceptions and policies towards the environment. Environmental engineering focuses on design and technology for improving environmental quality. It is the application of Science and Engineering principles to minimize the adverse effect of human activity on the environment. Environmental scientists work on subjects like the understanding of earth processes, evaluating alternative energy systems, pollution control and mitigation, natural resource management, and the effects of global climate change. Environmental issues almost always include an interaction of physical, chemical, and biological processes. Environmental engineers used engineering disciplines in developing solutions to problems of planetary health. Their work may involve concerns such as waste treatment, site remediation, and pollution control technologies. Engr. Angelo Gabriel T. Suano, ECT Page 7  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Figure 1-4: Illustration of interdisciplinary studies of environmental science and engineering through a Venn diagram. Biology – a branch of science that deals with the scientific study of life and living organisms. Medicine – the science and practice concerned with the maintenance of health and the prevention, alleviation, or cure of disease. Sociology – the scientific study of human social relationships and institutions. Political science – uses scientific methodologies to study government, political policies and the distribution of power. Religion – a range of socio-cultural systems, including designated behaviors and practices, morals, beliefs, worldviews, sanctified places, prophecies, ethics, or organizations, that generally relate humanity to supernatural, transcendental, and spiritual elements. Mathematics – is the science and study of quality, structure, space, and change. Physics – a field of science that deals with matter, motion, energy, and force. Chemistry – a branch of natural science that deals principally with the properties of substances, the changes they undergo, and the natural laws that describe these changes. Engineering – the application of science to the optimum conversion of the resources of nature to the use of humankind. Geology – the study of structure, evolution, and dynamics of the Earth and its natural mineral and energy resources. Forestry – the science and practice of establishing, managing, using, and conserving forests, trees and associated resources in a sustainable manner to meet desired goals, needs, and values. Ecology – the study of organisms and how they interact with the environment around them. Geography – the study of places and the relationships between people and their environments. Engr. Angelo Gabriel T. Suano, ECT Page 8  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Importance of environment science Environmental studies enlighten us about the importance of the protection and conservation of our environment. It has become significant for the following reasons: 1.Environment issues being of international importance It has been well recognized that environmental issues like global warming, ozone depletion, acid rain, and marine pollution are not merely national issues but are global issues and hence must be tackled with international efforts and cooperation. 2. Problems cropped in the wake of development Development, in its wake gave birth to urbanization, industrial growth, transportation systems, agriculture and housing etc. Environmental science helps us understand the complex interactions that occur in ecosystems and the impacts humans have on them. It’s easy for people in the modern world to forget how interconnected we are with nature, but everything we do has cascading effects on the environment around us. Scientists help us understand these effects and how to minimize them. 3. Need for an alternative solution Environmental science guides sustainable resource management by helping us understand and preserve biodiversity as well as maintain soil and water quality. We’re already seeing alarming trends from climate change that are predicted to worsen over the coming years, including rising sea levels, more extreme storms, droughts in some areas, and increased wildfires. Some of these impacts may be reversible, while others can only be mitigated at this point. To do anything impactful, we need professionals who fully understand the extent of the problem and have the skills to create new, innovative solutions. 4. Need to save humanity from extinction It is incumbent upon us to save humanity from extinction. Healthy environmental systems not only improve natural systems, but also human wellbeing- based public health systems. Furthermore, applying and developing environmental engineering techniques and knowledge to solve environmental issues such as pollution, and public health issues such as hazardous risk prevention, is crucial. Accordingly, environmental engineering approaches to solutions are fundamental to maintaining healthy environmental systems; and to reducing public health hazards, such as contamination-control, -treatment, and -prevention (e.g., water, air, soil), for hazard exposure reduction. 5. Need for wise planning of development Scientists encourage companies, governmental agencies, and individuals to consume natural resources in responsible and sustainable ways. Depending on their specialization, environmental scientists may work as consultants for businesses or in parks, fisheries, or forests. Not only has scientific research led to the creation of laws and regulations aimed at protecting the environment, but environmental scientists are often responsible for conducting field site surveys and other tests to ensure compliance with those laws and regulations. Engr. Angelo Gabriel T. Suano, ECT Page 9  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Seven Environmental Principles The concept of seven environmental principles which is formulated by Barry Commoner, a well-known biologist and environmentalist, and then later improved by other environmental scientists and educators offers protection to our natural world. They serve as a guide for lawmakers, judges, and decision-makers giving laws and policies its ideal shape and meaning. Environmental principles work together to ensure high environmental standards by directing how judges and other decision makers should interpret the law. These are also used in planning and management. 1. Natures knows best (Ang kalikasan ang mas nakakaalam) This principle is the most basic and in fact encompasses all the others. Humans must understand nature and must abide by the rule’s nature dictates. One must not go against the natural processes if one would like to ensure a continuous and steady supply of resources. One natural process that needs serious attention is nutrient cycling. In nature, nutrients pass from the environment to the organisms and back to the environment. For example, burning of farm wastes instead of allowing them to decompose naturally disrupts the cycle. In burning, most of the organic compounds are lost. Nature has also its built-in mechanisms to maintain balance of homeostasis. For example, the rat population is controlled by the presence and number of its predators, e.g., snakes. The use of chemical pesticides and fertilizer disrupts check and balance in the ecosystem. Pesticides can either kill vital organisms directly or induce genetic changes that result in resistant pests or organisms. Chemical fertilizers increase the acidity of the soil through time making a number of nutrients unavailable and thus, unfit for the survival of plants and other organisms. 2. All forms of life are important (Ang lahat ng may buhay ay mahalaga) Each organism plays a fundamental role in nature. Since such occupational or functional position cannot be simultaneously occupied by more than one species, it is apparent that all living things must be considered as invaluable in the maintenance of homeostasis in the ecosystem. For instance, it has been customary for many to step on any wriggling creature (e.g. earthworm) without even considering why God made them in the first place. People also react adversely to the presence of snakes. At home, spiders are looked at with disdain. Awareness of the snakes’ role in limiting the rat population and of the spiders’ role in checking the population of mosquitoes and flies may, however, change this attitude. 3. Everything is related to everything else (Ang lahat ng bagay ay magkaugnay) This principle is best exemplified by the concept of the ecosystem. In an ecosystem, all biotic and abiotic components interact with each other to ensure that the system is perpetuated. Any outside interference may result in an imbalance and the deterioration of the system. In a lake ecosystem, the organisms are linked to one another through their feeding habit/level and are also dependent on other physico - chemical factors in the lake (e.g. amount of nutrients, amounts and types of gases, temperature, Ph, etc.). The fertilizers that reach the lake cause a faster growth of phytoplankton, which may lead to algae bloom, red tide, or other such phenomena. Deforestation in the mountains may affect the lowlands through floods, drought, and erosion. Engr. Angelo Gabriel T. Suano, ECT Page 10  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Whatever happens to one country may affect other countries. An example of this is the Chernobyl accident, which affected a lot of countries through the transfer of radioactive substances by natural agents such as wind and water. 4. Everything changes (Ang lahat ay nagbabago) It is said that the only permanent thing is change. Change may be linear, cyclical or random. As example of linear change is evolution of species, which has brought about higher and more complex types of organisms. Cyclical change may be exemplified by seasons and the rhythms in floral and faunal life stages that go with the seasons. An example of random change is the eruption of Mt. Pinatubo, which brought about great upheaval in many parts of Luzon and changes in the topography of the land. The environment is constantly changing. Organisms also evolve over time. However, man’s technology has affected these natural changes often to a problematic extent. Although mutation is a natural change, pesticides have induced insect mutation, which, however, are not matched by natural checks and balances. Changes that they think may be beneficial to the environment often turn out to be disastrous. Environmental technologies should be given priority if man would want more positive changes in the environment. 5. Everything must go somewhere (Ang lahat ng bagay ay may patutunguhan) When a piece of paper is thrown away, it disappears from sight, but it does not cease to exist. It ends up elsewhere. Gases released in smokestacks may disperse but it will end up a component of the atmosphere or brought down by rains. Since waste is not lost to oblivion, and even goes back to one’s own backyard in some other forms, it is important that one becomes aware of the different types of waste – whether they are hazardous or not. Classification of wastes facilitates their proper disposal and minimizes, if not prevents the entry of toxic wastes in vital ecosystems and ensures reconversion into useful forms. 6. Our is a finite earth (Ang kalikasan ay may hangganan) The earth’s resources can be classified as either renewable or non-renewable. Renewable resources are those that can easily be replenished by natural cycles (e.g. water, air, plants, and animals. Non-renewable resources are those that cannot be replenished through natural cycles (e.g. ores of various metals, oil, coal). Awareness of the earth’s limited resources leads to a conscious effort to change one’s consumerist attitude as well as to develop processes and technology that would bring about effective recycling of a great number of resources. 7. Nature is beautiful, and we are stewards of God’s creation (Ang kalikasan ay maganda at tayo ay tagapangasiwa ng lahat ng nilikha ng Diyos) Among all creatures, humans are the only ones made in God’s image and have been given the right to have dominion over all His creations. Being the most intelligent and gifted with reason, humans are capable of manipulating creation to their own advantage. Yet, creation exists not to be ravaged or abused but to be taken care of. Humans cannot exist without nature. They are co-natural with the environment they live in. This principle is inherent in all religious and tribal beliefs. Teachings of Christianity, Buddhism, and Islam enjoin everyone to respect all life and the order of nature. Engr. Angelo Gabriel T. Suano, ECT Page 11  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Letter written in 2070 (A document published in the magazine “Crόnica de los Tiempos” – April 2002) We are in the year 2070. I just turned 50 years old, but I look 85. I experience major kidney problems, because I drink very little water. I think that I don’t have much more time to live. Today, I am the oldest person living in this society. I remember, when I was 5 years old everything was different. There were lots of trees in the parks, houses had beautiful gardens, and I could enjoy long baths and stay in the shower for one whole hour. Now, we have to clean ourselves by using disposable towelettes moisturized with mineral oil. Before, women were proud of their beautiful hair. Now, we have to shave our head to keep it clean without using water. Before, my father used to wash his car with water that came out of a hose. Today, children find it hard to believe that one ever could use water to perform such a task. I remember the many warnings: “Don’t waste water” but nobody paid attention. People assumed that water was unlimited. Today, rivers, dams, lagoons, and underground water are all either irremediably polluted or completely dried up. The landscape that surrounds us has turned into nothing more than an immense desert. Gastro-intestinal infections, and skin, and urinary tract diseases have now become the main causes of death. Industry is paralyzed, and the jobless rate reached a dramatic level. Desalination plants are the main employers. They give one drinking water instead of a salary. People are constantly being mugged for water on the deserted streets. 80% of the food is synthetic. Before, it was recommended that an adult drink 8 glasses of water a day. Today, I am allowed only half a glass. Since we cannot wash our clothes, we throw them, which increases the amount of trash. We had to go back to using septic tanks, just like in the past century, because the sewage system stopped working due to the lack of water. People look scary: their bodies are weak; parched by extreme dehydration; covered by sores caused by ultraviolet rays that the atmosphere can no longer filter since the ozone layer is depleted. Engr. Angelo Gabriel T. Suano, ECT Page 12  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Due to the dryness of her skin, a young 20-year-old woman looks more like 40. Scientists perform all types of research and investigations, but there is no solution in sight. We cannot produce water. The lack of trees reduces the amount of oxygen available, which in turn lowers the intellectual quotient of up-coming generations. The morphology of many individuals’ spermatozoa was altered which results in children being born with all sorts of deficiencies, mutations, and malformations. The government even makes us pay a tax for the air we breathe: 137 m 3 per adult per day (31, 102 gallons). Those who can’t pay the tax are expulsed from the “ventilated areas” that are equipped with gigantic mechanical lungs, powered by solar energy. The air supplied in the “ventilated areas” is not of very good quality, but at least one can breathe there. The average age is 35. Some countries succeeded in preserving a few islands of vegetation with their own streams. These areas are closely monitored by the army. Water has become a rare commodity, a highly sought after treasure, infinitely more valuable than gold or diamonds. Here, though, there are no more trees because it hardly ever rains. And whenever it does rain, it is acid rain that comes down. There are no more seasons. Climatic changes such as the greenhouse effect and the polluting activities we indulged in during the twentieth century took care of that. We were warned about the need to take care of our environment, but nobody bothered. When my daughter asks me to tell her how it was when I was young, I describe the beauty of the forests. I tell her about the rain, about the flowers, about how pleasurable it was to bathe, to fish in the rivers and the lakes, and being able to drink as much water as one desired. I tell her about how healthy people used to be. She asks me: Daddy, why is there no water anymore? I feel a lump in my throat. I can’t help feeling guilty, because I belong to the generation that completed the destruction of our environment by simply not taking seriously any of the warnings and there were so many of them. I belong to the last generation who could have made a difference, but who chose not to act. Today, our children pay the hefty price. Quite frankly, I think that, within short, life on this Earth will no longer be possible, because the destruction of our environment reached its point of no return. How I wish I can go back in time and get the human race to understand this, at a time when it was still possible for us to do something to save our planet Earth. Engr. Angelo Gabriel T. Suano, ECT Page 13  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Environmental Activism The term “environmental activism” is defined as the actions of individuals or groups that protect or aid the environment. Those involved in the movement identify issues that threaten the planet’s viability, from community to global concerns, and then develop strategies to promote awareness or produce solutions that directly address the problem. There are several ways to undertake this, from local grassroots strategies to nationwide campaigns. In some cases, advocating for the environment can also include other important activism, such as civic and social justice. Holistic – one who seeks harmony with planet Earth, accepts humans as transitory life-form and recognizes that planet Earth is more important than individual humans or even whole nations or cultures. Cross-Cultural – one who seeks harmony with others; transcends individual and cultural desires and sees need for “community”. Internal – one who seeks harmony with self and is willing to challenge the rules of others if these rules are felt to be inappropriate. Institutional – one who is dependent upon the rules of others; and is intolerant of those who do not follow these rules. Asocial – one who is strictly “me” centered; does not care about rules unless the rules are a definite benefit to him or her. Regardless of how it’s performed, the goal of environmental activism is clear: to create a harmonious living environment that can be handed down from generation to generation without succumbing to poor human stewardship. Figure 1-5: The three stages of environmental activism Engr. Angelo Gabriel T. Suano, ECT Page 14  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Environmental Issues It is essential to make the public aware of the formidable consequences of the environmental degradation, if not retorted and reformative measures undertaken would result in the extinction of life. We are facing various environmental challenges. It is essential to get the country acquainted with these challenges so that their acts may be eco-friendly. 1. Population Growth Population growth is the increase in the number of humans on Earth. In population ecology, it is the change in the number of members of a certain plant or animal species in a particular location during a particular time period. Factors affecting population growth include fertility, mortality, and, in animals, migration—i.e., immigration to or emigration from a particular location. The average change in a population over time is referred to as the population growth rate. A positive growth rate indicates a population increase, and a negative growth rate indicates a population decrease. The upper limit of a population in a given environment, referred to as the environment’s carrying capacity, is determined by the amount and availability of resources that are life-sustaining for that population. Population dynamics The natural environment plays a crucial role in population growth through its carrying capacity. The life-sustaining resources in an environment are limited and can be reduced for individual species members by greater population density and competition from other species, among other factors. Moreover, fertility, mortality, and migration are all affected by food availability, mate availability, and environmental stress factors such as pollution and natural disasters. Figure 1-6: Exponential versus logistic population growth Graphs representing exponential population growth (left) and logistic population growth. Engr. Angelo Gabriel T. Suano, ECT Page 15  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Population growth dynamics may be graphically depicted in an S-shaped curve, known as a logistic curve, as depicted in Figure 1–5. The logistic curve (right) represents an initial lag in growth, a burst of exponential growth, and finally a decline in population growth. When population density is high, mortality tends to increase because of competition for resources, predation, or increased disease transmission, resulting in the plateau in growth at the end of the curve. Most populated countries in the world (2024) Table 1-2: Top 10 most populated countries in the world (Source: Worldometer) Population growth rates may also fluctuate in correlation with seasonal variations in the environment. For example, in deep lakes, a spring thaw causes colder, deeper waters to rise to the lake’s surface, releasing nutrients that then cause bursts in the growth of plankton, including algae, bacteria, and protozoans (see water bloom). The population growth of different species may also be determined by predator-prey relationships—for example, following an increase in the population of zooplankton (minute aquatic animals), the population of their algae prey may decrease or grow at a slower rate. This results in an oscillating population pattern, such as the cyclical fluctuation of the snowshoe hare and lynx populations. 2. Wasteful use of natural resources The high standard of living that we enjoy depends entirely on the availability of natural resources. Apart from abiotic and biotic raw materials, we use water, soil, air, biodiversity and land as habitats and for recreational purposes; and for energy, we use wind power, solar power and tidal flows. Engr. Angelo Gabriel T. Suano, ECT Page 16  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering These resources also serve as emission sinks, waste dumps, and as indispensable production factors for farming and forestry. But unfortunately – and inevitably – resource use across the entire supply chain generates environmental pollution; plus, worldwide resource use is growing steadily. 3. Consumption and depletion of natural resources The overconsumption of natural resources leads to environmental degradation and negative impacts on our society. We are quickly consuming our way toward a world where there will be few resources left for future generations. The environment is sensitive to the changes we make to it. Humans have increased the global temperature since the Industrial Revolution just by emitting carbon dioxide, so it is clear our actions have significant impacts on our planet. The changes we make to some natural resources have a direct impact on the environment by altering landscapes and harming biodiversity. Other natural resources are harvested as part of industries that cause greenhouse gas emissions and carbon emissions, accelerating global warming and climate change. Every action we take has some effect on our environment. Take the construction industry, for example. The construction industry requires metals that are mined from the Earth for use in machinery and building supplies. It also requires the use of sand and lumber as building materials. The industry’s operations come with the consequences of burning fossil fuels. The toll of this entire industry plays a large role in the overall status of the environment when you take account of all the natural resources that must be harvested and used. There are many industries like construction that rely on a chain of natural resources that ultimately contribute to the overconsumption of natural resources and the deterioration of the environment. Protecting our lands and oceans through a switch to sustainable resources and using them responsibly is our best opportunity for the preservation of Earth’s many ecosystems. 4. Poverty The state of one who lacks a usual or socially acceptable amount of money or material possessions. Poverty is said to exist when people lack the means to satisfy their basic needs. In this context, the identification of poor people first requires a determination of what constitutes basic needs. These may be defined as narrowly as “those necessary for survival” or as broadly as “those reflecting the prevailing standard of living in the community.” The first criterion would cover only those people near the borderline of starvation or death from exposure; the second would extend to people whose nutrition, housing, and clothing, though adequate to preserve life, do not measure up to those of the population as a whole. The problem of definition is further compounded by the non-economic connotations that the word poverty has acquired. Engr. Angelo Gabriel T. Suano, ECT Page 17  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering Poverty has been associated, for example, with poor health, low levels of education or skills, an inability or an unwillingness to work, high rates of disruptive or disorderly behaviors, and improvidence. While these attributes have often been found to exist with poverty, their inclusion in a definition of poverty would tend to obscure the relation between them and the inability to provide for one’s basic needs. Whatever definition one uses, authorities and laypersons alike commonly assume that the effects of poverty are harmful to both individuals and society. Poorest Countries Table 1-3: World’s poorest countries in 2024, based on GDP per capita GDP (Gross domestic product) – standard measure of the value added created through the production of goods and services in a country during a certain period. Income earned from the production of goods or total amount spent on final goods. GDP per capita means purchasing power – the sum of gross value added by all resident producers in the economy plus any product taxes not included in the valuation of output (net value), divided by mid-year population. Engr. Angelo Gabriel T. Suano, ECT Page 18  ROGATIONIST COLLEGE ESE71 – Environmental Science and Engineering 5. Pollution Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants. Pollutants can be natural, such as volcanic ash. They can also be created by human activity, such as trash or runoff produced by factories. Pollutants damage the quality of air, water, and land. Many things that are useful to people produce pollution. Cars spew pollutants from their exhaust pipes. Burning coal to create electricity pollutes the air. Industries and homes generate garbage and sewage that can pollute the land and water. Pesticides—chemical poisons used to kill weeds and insects—seep into waterways and harm wildlife. All living things—from one-celled microbes to blue whales—depend on Earth’s supply of air and water. When these resources are polluted, all forms of life are threatened. Pollution is a global problem. Although urban areas are usually more polluted than the countryside, pollution can spread to remote places where no people live. For example, pesticides and other chemicals have been found in the Antarctic ice sheet. In the middle of the northern Pacific Ocean, a huge collection of microscopic plastic particles forms what is known as the Great Pacific Garbage Patch. Engr. Angelo Gabriel T. Suano, ECT Page 19