Lecture 9: Natural Resources PDF

05/11/2023 LECTURE 9: NATURAL RESOURCES ENVIRONMENTAL SCIENCE Prepared by: DIVINE GRACE S. BATENGA, MSc., LPT Subject Teacher...

05/11/2023 LECTURE 9: NATURAL RESOURCES ENVIRONMENTAL SCIENCE Prepared by: DIVINE GRACE S. BATENGA, MSc., LPT Subject Teacher 1 LEARNING OUTCOMES a) Use evidence to explain that humans depend on many limited natural resources that may be renewed over human lifetimes. b) Demonstrate critical, analytical, and creative thinking in evaluating the options for future energy use. 2 1  05/11/2023 NATURAL RESOURCE A natural resource may be defined as any material given to us by nature which can be transformed in a way that it becomes more valuable and useful. 3 Wood is used for making furniture NATURAL RESOURCE 4 2  05/11/2023 Yarn obtained from cotton is used for weaving cloth NATURAL RESOURCE 5 Various machine, tools and household goods are made of metals. NATURAL RESOURCE 6 3  05/11/2023 These are resources: ✔ Water ✔ Sunlight ✔ Wind ✔ Minerals ✔ Forests ✔ Wildlife 7 CLASSIFICATION OF NATURAL RESOURCES ❑Renewable Resources ❑Non-Renewable Resources 8 4  05/11/2023 What are renewable resources? Resources that can be regenerated, which means new materials can be made or grown again at the same rate as they are being used. ⮚ Trees are renewable resource because new trees can be grown to replace trees that are cut down for use. ⮚ Other example of renewable resource include soil, wildlife, and water. 9 What are renewable resources? Resources that can be regenerated, which means new materials can be made or grown again at the same rate as they are being used. ⮚ However, some resources like soil, have very slow rates of renewal, so we still need to conserve them. ⮚ It is also important to realize that while these resources are in most cases renewable, we can still pollute them. 10 5  05/11/2023 What are renewable resources? Resources that can be regenerated, which means new materials can be made or grown again at the same rate as they are being used. ⮚ Fish are considered a renewable resource because we can take some fish but leave others to reproduce and create new fish for later use. 11 Imagine… ⮚ What can happen if we over-fish, or take too many fish at one time. ⮚ If we over-harvest our trees or wildlife resources. We may not leave enough to let the resource renew itself. 12 6  05/11/2023 What are non-renewable resources? Resources that renew themselves at such slow rates that, practically, they cannot be generated. ⮚ Once we use them up, they are gone for good – or at least for a very, very long time. ⮚ Coal, oil, natural gas and minerals are non-renewable resources. ⮚ It takes millions of years for these materials to form, so if we use them to the point of depletion, new resources will not be made for millions more years. ⮚ WE CAN RUN OUT OF THESE RESOURCES! 13 RENEWABLE RESOURCES 14 7  05/11/2023 SOLAR ENERGY Solar Energy is radiant light and heat from the sun harnessed using a range of ever-evolving technologies such as photovoltaic cells. The Sun is a powerful source of energy that provides the Earth with as much energy every hour as we collectively use in a year worldwide. WIND ENERGY The Electrical energy that is obtained from harnessing the wind with wind mills or wind turbines is called Wind Energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind turbines convert the kinetic energy in the wind into mechanical power. Large wind farms consist of hundreds of individual wind turbines which are connected to the electric power transmission network. 16 8  05/11/2023 HYDRO POWER Hydro power is the energy derived from the falling water or running water. Falling water is channeled through water turbines. The pressure of the flowing water on turbine blades rotates a shaft and drives an electrical generator, converting the motion into electrical energy. But hydroelectric power doesn't necessarily require a large dam. Some hydroelectric power plants just use a small canal to channel the river water through a turbine. 17 GEO-THERMAL ENERGY Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma. 18 9  05/11/2023 NON- RENEWABLE RESOURCES 19 OIL Liquid petroleum -crude oil- is the only nonrenewable resource in fluid form. A fossil fuel that is being used up faster than new reserves are discovered, the oil supply may only last through the middle of this century. Industrial nations, with the U.S. far in the lead, are the biggest consumers of crude oil. Gasoline, heating oil, and diesel fuel are the primary uses of the resource, although manufacturers utilize oil as the base for such products as plastics and industrial chemicals. 20 10  05/11/2023 NATURAL GAS Natural gas is a fossil fuel formed when layers of buried plants, gases, and animals are exposed to intense heat and pressure over thousands of years. The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in natural gas. It is primarily composed of methane, but contains ethane, propane and butane as well. According to the current usage statistics and the volume of world reserves, the supply of natural gas should last another century. 21 COAL Coal, is the product of millions of years of pressure on original organic matter from plants buried underground. It is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. Anthracite, the purest form of coal, contains about 94 - 95% of carbon. At the power plant, coal is commonly burned in a boiler to produce steam and the steam is run through a turbine to generate electricity. The global supply of coal, given the current rate at which it is used, should last at least two more centuries.AC 22 11  05/11/2023 NUCLEAR ENERGY Nuclear power, or nuclear energy, is the use of exothermic nuclear processes, to generate useful heat and electricity. The term includes nuclear fission, nuclear decay and nuclear fusion. Presently the nuclear fission of elements in the actinide series of the periodic table produce the vast majority of nuclear energy in the direct service of humankind. 23 COMMON MATERIALS WE USE FROM THE EARTH What do these have in common? 24 12  05/11/2023 We depend on natural resources for just about everything that we eat and use to keep us alive, as well as the things that we use for recreation and luxury! 25 Objects and Their Required Resources Common Object Natural Resources Used Are These Resources Renewable or Non-renewable? Cars 15 different metals, such as iron, lead, and chromium to make Non-renewable the body Jewelry Precious metals like gold, silver, and platinum; gems like Non-renewable diamonds, rubies, emeralds, Turquoise Electronic appliances Many different metals like copper, mercury, gold Non-renewable Clothing Soil to grow fibers such as cotton; sunlight for the plants to Renewable grow; animals for the fur and leather Food Soil to grow plants; wildlife and agricultural animals Renewable Bottled water Water from streams or springs; Non-renewable and renewable petroleum products to make plastic bottles Fuel Petroleum drilled from wells Non-renewable Household electricity Coal, natural gas, solar power, wind power, hydroelectric power Non-renewable and renewable Paper Trees, sunlight, soil Renewable Houses Trees for timber; rocks and minerals for construction materials, Non- renewable for example; granite, gravel, sand 26 13  05/11/2023 Human Population and Resource Use As the human population grows, so does the use of our natural resources. A growing population creates a demand for more food, more clothing, more houses and cars, etc. Population growth puts a strain on natural resources. 27 Resource Availability You can see from the previous table that many of the resources we depend on are non-renewable. We will not be able to keep taking them from the Earth forever. Also, non-renewable resources vary in their availability, some are very abundant and others are rare. 28 14  05/11/2023 Exploitation of our Natural Resources Deforestation – with deforestation, ecological balance maintain by nature breaks away. Timber Extraction Mining Reclamation of Mined Areas Dams Over-utilization of Water 29 Conserving Natural Resources ✔ Purchase less stuff. ✔ Reduce excess packaging. ✔ Recycle materials like metal cans and plastic bottles. ✔ Purchase products made from recycled materials. ✔ Keep air and water clean by not polluting in the environment. ✔ Prevent soil erosion. ✔ Plant new trees to replace ones that we cut down. ✔ Drive cars less, take public transportation, bicycle, or walk. ✔ Conserve energy at home. 30 15  05/11/2023 END OF LECTURE 31 References: Akre B, Brainard J, Goose H, Rogers-Estable, and Stewart R (2011). Introduction to Environmental Science, FlexBook Platform, USA. 32 16