HUMANKIND’S INVENTION WITH NATURE After studying this chapter, you should be able to 1. Discuss how ancient people affected the environment. 2. Explain the progress made in the field of agriculture. 3. Identify the advances in the area of medicine. 4. Enumerate the new technologies brought about by advances in engineering. 5. Get a glimpse of the bad side of human beings impact on the environment. 6. Enumerate some bad effects of modern technologies. 3.1. BALANCE OF NATURE Scientists estimated that the earth is already around three billion years old, and it will exists for another three billion years. The life of the earth depends mainly on the sun. If the gravitational pull of the sun remains constant, the earth will continue to revolve around the sun in its present speed. There is a delicate balance between the centrifugal force of the earth as is goes around the sun. If the sun continue to shine the way it is now, then the earth will continue to receive radiant energy needed by the living creatures. Again, there is a delicate balance here. Too much sunshine will make the earth too hot for most living beings to survive. In short, the balance of nature is so delicate that any action that might upset such balance could have catastrophic results. For millions of years, this balance of nature has been maintained. The animals that antedated humans for thousands of year did not really disturb the environment. The effect they made on the environment was minimal and Mother Nature easily recovered. During the dawn of civilization, humans and the predators lived in very similar ways. Both hunted for food and dwelt in natural habitats, like caves. With this kind of life, they did not alter the environment. But, since humans were more intelligent and more cunning, plus the fact that they walked erect and made use of their hands, they were able to invent weapons to help them. Axe from stones and spears from sharp object made them better hunters than the animals. And when they learned the use of fire, they cooked their food with it, warmed their bodies by it, and heated a lot of things to help them survive. That was when humans proved their superiority over animals. When they learned to eat green leafy vegetables and learned how to cultivate them, they started to alter the environment. They made clearings in the forests and planted vegetables. When the land was no longer that fertile, they abandoned the place and cleared other lands. That was the beginning of forest destruction. Then they learned how to domesticate animals and lived in a permanent dwelling which was made of the products of the environment, like wood for the structure and leaves for roofing. They had to change the environment some more. Fortunately, there were not so many people at that time, so the environment was able to recover. The balance of nature remained. As the population increased and the needs of people became more complex, they put greater and greater pressure on the environment. Larger houses were constructed from different materials, strong fences to protect them from enemies, irrigation canals for agriculture, and large enclosures for animals, all these required more change in the environment. But even then, there was no serious damage to the environment from which nature was unable to recover. It could be said then that by and large, humans lives for many, many years in harmony with the environment. The rise in civilization of the Sumerians, the Babylonians, the Egyptians, the Greeks, and the Romans placed additional burden on Mother Earth, especially in the terms of land used for public buildings, monuments, and, of course, houses. With more lands used for agriculture and the upkeep of animals, especially those used in war, changes in the environment became more permanent. But even then, they were not causes for worry. It was only during the rapid progress in knowledge about the world, followed by the so-called industrial revolution, when humans made greater impact on the environment. Guide questions 1. Explain in details the meaning of balance of nature 2. Name some ways by which humans upset the balance of nature. 3.2. PROGRESS IN AGRICULTURE, ENGINEERING, AND MEDICINE Because of their superior intelligence, aided by the virtues of curiosity, imagination, and creativity, humans were able to discover the many laws of nature, and they used this knowledge to control parts of nature mostly for the benefit of humankind, in general. In the field of agriculture, the knowledge of genetics produced larger and better varieties of fruits and vegetables. These varieties gave better yields per area planted and were more resistant to diseases. Some examples will be enumerated to highlight the point. Better yielding varieties of rice, wheat, and potatoes have resulted in bumper harvest in many parts of the world. As the direct consequence, the problem of feeding the growing populations was partly solves by these discoveries. Scientists were able to breed seedless grapes and seedless papayas. Mangoes are now harvested all year round. And perhaps, the other fruits may soon be grown seedless, like melons, and watermelons. Large varieties of guavas and Santo are now in abundance. In the field of medicine, doctor and the scientists were able to discover the cure for many diseases, thus prolonging and preserving producing healthier babies. The end result of all these are a much faster rate of population increase. In the field of animal science, researchers were able to improve the breed of animals used for food. Faster- growing chickens and pigs and cultured fish are some good examples. Artificial hatching of eggs was invented. All these resulted in more food for the fast-growing population of the world. In the field of engineering, scientists invented better means of transportation on land, at sea, and in the air. The more recent inventions include the bullet train that can run up to 500 kilometers (km) per hour, airplanes that can carry up to 700 passengers, and large ships powered by nuclear fuel. Landscapes have been altered to improve services to the people. For instance, dams were built to produce electricity for homes and factories. Oil, coal, and other fossil fuels were mined to power these new inventions. For more comfort at home, scientists invented artificial lighting, air-conditioning systems, refrigerator to preserve food better, radio and television for faster and better dissemination of information and for entertainment, and all those electric gadgets in the kitchen to the delight of many housewives. In the field of food technology, we can choose from a very wide variety of food available in the market, caned goods of all kinds, powered milk, packed lunches, preserved fruits and vegetables, and many others. All there may be considered as the good impact humans have made on the environment. As a result of these inventions and new technology, people are living better food, live in more comfortable homes, enjoy their vacations more, get better health services, travel faster, and dress better. In short, they can do a lot better than their ancestors. 3.3. ADVERSE EFFECTS OF PEOPLE’S ACTIVITIES Humankind’s intervention with nature has its adverse effects too. These include the pollution produced by modern technology and its ill effects on the environment (disruption of the atmosphere which causes greenhouse effect, ozone depletion and acid rain); among others; pollution of the water system, deforestation, improper disposal of solid wastes, as well as nuclear wastes; and noise pollution. 3.3.1. The greenhouse effect Figure 3.1: The greenhouse effect Too much carbon dioxide and other gases emitted by factories are accumulating in the atmosphere. These gases allow sunlight to penetrate the earth’s atmosphere but unfortunately, they also trap radiant heat and revert its escape into outer space. The immediate consequence is global warming, which is better known as the green-house effect. The rise in the average temperature of the earth could have serious consequences. Among them is the melting of ice and glaciers in the North and South poles. This will raise the water level in many areas of the world, resulting in the submersion of the low-lying coastal towns and cities. 3.3.2. Ozone depletion High above the earth’s atmosphere, between 15 and 59 km above the earth, is a layer of ozone (O 3 ). It is formed when ultraviolet radiation (UV) splits a molecule of oxygen (O 2 ), and the free oxygen atoms (O) combine with other oxygen molecules. Ozone acts as a filter in the upper atmosphere, preventing the harmful ultraviolet radiation of the sun from reaching the earth. Scientists discovered that compounds of carbon such as carbon dioxide (CO 2 ) and chloroflofuorocarbons (CFCs), nitrogen oxides (NO) and methane break up ozone molecules, thereby gradually depleting it. Figure 3.2: Ozone depletion In fact a large ozone hole was discovered above the tip of South America. The people directly below it may experience skin irritations and soreness in their eyes. This may be due to the higher intensity of harmful ultraviolet radiations hitting them. Ozone levels, on the average, have declined by around 2 percent between 1969 and 1988. But in some parts of the world, the decrease in much higher. For example, in Melbourne of Australia, ozone levels dropped by as much as 10 percent in 1987, causing a 20 percent increase in ultraviolet radiation reaching the ground. 3.3.3. Acid rain Sulfur and nitrogen oxides are released from industrial factories, electrical power plants, smelting plants, and motor vehicles. Figure 3.3: Acid rain When these gases combine with the moisture in the atmosphere, they return to the ground as sulfuric acids and nitric acids. These are popularly known as acids rain. Acid rain brings damage to lakes, the soil, forest, and buildings. Acid rain and limestone Trees affected by acid rain Figure 3.4: Effects of acid rain Many lakes in the Scandinavian countries are seriously affected by acid rain. Acid rain has brought extensive damage to the trees of Europe and the eastern part of the United States. Famous buildings like the Taj Mahal in India are now being damaged by acids from local oil refineries. 3.3.4. Water pollution Industrial wastes disposed of in streams and rivers have polluted these bodies of water, making them unfit for fish and other aquatic animals to inhabit. When the water from these streams and rivers flows into lakes and oceans, then these bodies of water also become polluted. Wastes from industrial factories along the riverbanks polluted the river so much that for all practical purposes, the river is dead. Most of the industrial factories that dump their wastes into around rivers make water pollution. The immediate consequence is the large reduction in fish catch. Drainage water pollution Solid wastes disposed to water Severe water pollution Oil pollution Figure 3.5: Water pollution There are many rivers and lakes in our country suffering from pollution, perhaps to a lesser extent but nevertheless a serious threat to the environment. If you add the bodies of water in other countries that are also polluted, then you will feel how serious this threat is to the earth’s environment. 3.3.5. Deforestation Deforestation occurs at an alarming rate. Twenty-three percent of the Earth's land surface is covered by tropical rainforest; however, these forests disappear at a rate of 4.6 million hectares a year. Forests are an integral part for the well being of life on Earth. Figure 3.6: Deforestation Many environmental problems such as flooding of rivers, the loss of biodiversity, accelerated soil erosion, resulting in the loss of the fertility of the land; flooding during heavy rains because there are no more trees to hold and store the water; silting of rivers and lakes with soil and rocks carried by the floods; loss of habitat to many animal and plant species. Resulting in their extinction; and deforested areas becoming barren and useless. 3.3.6. Solid waste disposal Progress produces a large amount of garbage. Much of these are nonbiodegradable (do not decay into useful fertilizer) or hazardous materials. Figure 3.7: Solid waste disposal How to dispose of them is a big problem in many countries. The most efficient way is landfills. In Vietnam, garbage collection is not efficient. With an indifferent population, garbage is one of the main sources of pollution especially in large population centers like Ho Chi Minh City. When garbage is not collected on time, people tend to dump them almost everywhere, resulting in very unsanitary surroundings, clogged waterways, and polluted creeks and rivers. Improper garbage disposal is known to have triggered the spread of diseases, epidemics, and other adverse effects on people’s health. 3.3.7. Nuclear waste Nuclear power is among the most efficient and relatively cheap sources of energy. But the technology is highly sophisticated and the possibility of nuclear disaster is not remoted. Figure 3.8: Nuclear waste The resulting nuclear radiations are very harmful to human beings and heavy dozes are fatal. The thousands of deaths due to the atomic bombings of Hiroshima and Nagasaki during the Second World war and the hundreds of fatalities in the Chernobyl accident in the former Soviet Union are grim reminders of what could happen in the case of nuclear accidents. Figure 3.9: Hiroshima and Nagasaki disasters Figure 3.10: the Bombing of Hiroshima and Nagasaki 3.3.8. Noise pollution Figure 3.11: Noise pollution from speaking-trumpet Figure 3.12: Air and noise pollution Noise pollution is a direct result of industrial revolution. Noisy engines in factories, the noise produced by motor vehicles, the irritating noise produced by the jackhammer, and the most unbearable noise from jet engines are some example. Perhaps noise pollution is the least paid . HUMANKIND S INVENTION WITH NATURE After studying this chapter, you should be. they used this knowledge to control parts of nature mostly for the benefit of humankind, in general. In the field of agriculture, the knowledge of genetics