ETV Secondary Level Enviromental Education Series – Enviroment and Sustainable Development

you you from the 1950s to 70s there were a large number of fishing grounds in Hong Kong’s territorial waters it was quite easy for fishermen to obtain large caches in these fishing grounds in the 1940s and 50s there were a lot of fishermen my daily catch was up to one or two thousand caddies there were a lot of fish in the 1970s there were a lot of fishing boats in cycle catching fish brought us our comfortable living but we found the fish population was dropping in the 1980s and 90s we couldn’t find enough fish to catch in the 1990s fishermen in tune moon also found that their catches were miserably small Hong Kong’s marine fishery resources had been exhausted vast areas in China had been hit by drought for many years we have a fairly limited what resources and the average water resources for China’s per person or we call per capita it’s only one quarter of the world average this situation in northwest China in northern China is more serious because the China’s water resources is not evenly distributed in our northern China we only have 1/8 of the water resources in northwest China we only have 100 force word average and with so little water we have to feed so many people most vehicles and modern cities run on petroleum others are fueled by LPG or electricity our domestic appliances also use electricity in power plants heat energy released during the combustion of coal petroleum or natural gas is converted into electricity petroleum and LPG our products of oil coal oil and natural gas are the products of very slow changes over hundreds of millions of years to the remains of ancient living things hence they’re known collectively as fossil fuels since fossils cannot be produced in a short time it’s impossible to regenerate them and so they are called non renewable energy sources it is estimated that the Earth’s stock of fossil fuels will be used up in the near future we are living under the threat of a shortage of energy resources there’s a high frequency of heavy rainfall in June this beaker is for collecting raindrops falling from the sky dip a blue litmus paper strip into the rain water then remove it and take a look it’s turned red that means the rainwater is acidic this is called acid rain the rain water is polluted it’s absorbed acidic matter from the atmosphere and so acid rain is an indicator of air pollution acid rain is formed when sulfur dioxide and

nitrogen monoxide dissolve in rainwater these two gases are waste products of burning fossil fuels acid rain damages land plants and aquatic organisms it corrodes metals and buildings fine weather with blue sky makes for a pleasant day but those days are getting fewer over the past decades air quality in Hong Kong has been deteriorating smog occurs throughout the year and the daily roadside API figures have been consistently high the polluted air is choking us the major sources of air pollution are the exhaust fumes from power plants and vehicles the exhaust fumes contain large quantities of carbon dioxide sulfur dioxide nitrogen oxides compounds of fluorine and mercury you carbon monoxide hydrocarbons and so on these substances pollute the air and are harmful to the human body carbon dioxide also has a profound impact on the global environment when the sunlight penetrates the atmosphere and hits the Earth’s surface it’s converted to infrared rays which are reflected away some of these infrared rays are absorbed by the carbon dioxide in the air and are converted to heat energy the heat energy dissipates and warms up the air in this way carbon dioxide works like the glass windows of a greenhouse the transparent glass admits sunlight into the greenhouse but stops the outward passage of infrared rays which warm up the air inside the greenhouse the warming effect of carbon dioxide in the atmosphere is therefore known as the greenhouse effect and carbon dioxide is labeled a greenhouse gas over the past decades there has been a rapid rise in consumption of fossil fuels a massive amount of carbon dioxide has been emitted into the atmosphere meanwhile vast stretches of forests have been cleared for urban and agricultural development this has reduced the Earth’s capacity to absorb carbon dioxide the consequences are the accumulation of carbon dioxide in the atmosphere and a greatly enhanced greenhouse effect research conducted by the United Nations IPCC has revealed that the average global atmospheric temperature rose 0.6 degrees Celsius over the course of the 20th century this rise in temperature has brought about global warming a March phenomena is the melting of glaciers on high mountains and at the poles the IPCC forecasted that if the current trend of global warming continues global atmospheric temperatures might show a rise of 1.8 to 4 degrees Celsius by 2100 the IPCC estimated the global warming in the 20th century has caused a 17 centimeter rise in the global sea level as a result of the melting of glaciers it forecasted that if global warming continues there will be an 18 to 59 centimeter rise in the global sea level and a large number of coastal cities will be submerged you as global warming advances major tropical pandemic diseases will come to prevail in Hong Kong and other parts of the northern hemisphere sleeeeep populated their populations produce large quantities of solid wastes daily municipal solid waste consists largely of materials related to construction and demolition work shop wastes and domestic rubbish solid wastes dumped at random create eyesores

blocking paths breathing germs and pests emitting pungent smells and releasing toxic substances their presence causes nuisances to people and constitutes a serious form of pollution according to regulations builders are obliged to transfer the construction and demolition waste to landfills shaf and domestic waste are collected and transferred to landfills by contractors Hong Kong 7 million people produce 1,800 tons of trash daily the solid wastes are transferred to three strategic landfills according to the EPD the last landfill will be full in six years we’re competing with solid wastes for space world population has grown from 2.5 billion people in 1950 to around 6.8 billion today the cumulative effect of the rise in population and industrial and economic development is the consumption of large quantities of natural resources and the emergence of various pollution problems the way we’ve used resources over the last 60 years has exhausted most of them for those alive today if we continue will deprive future generations of the right and opportunity to use these resources in fact environmental pollution may even render the earth unsuitable for human survival in its 1987 report entitled our common future the United Nations W CED advocated sustainable development and defined it thus development that meets the needs of the present without compromising the ability of future generations to meet their own needs with referenced context the chief executive in his policy address of 1999 elaborated on this definition of sustainable development and spoke of finding ways to increase prosperity and improve the quality of life while reducing overall pollution and waste meeting our own needs and aspirations without doing damage to future generations prospects and reducing the environmental burden we put on our neighbors and helping to preserve common resources the concept of sustainable development is based on the assumption that the natural environment has the capacity to recover by itself after being damaged is this assumption a valid one we see hope in the countryside of Hong Kong Hong Kong was invaded and occupied by the Japanese Army during 1941 to forty five the countryside was badly damaged during this period of occupation when the Japanese army surrendered and withdrew in 1945 all that was left in the countryside were bare hills the Hong Kong government managed to reforest the countryside since then twenty four country parks have been established covering 40% of the land in the territory since 1977 laws to conserve the natural environment and wildlife in the country parks have been enacted and enforced thanks to persistent conservation efforts over the last thirty years we have today unpolluted hills and waterways in the country parks with rich vegetation providing shelter for a diversity of animals it’s obvious that the natural environment is capable of regeneration ecologist have an explanation for this phenomenon a living thing needs a living space or habitat a living thing and the environment in its habitat mutually influence each other they interact and form an ecosystem in an ecosystem green plants absorb sunlight and convert the light energy into chemical energy which is stored in the body matter of plants herbivorous animals like rabbits feed on plants

carnivorous animals like snakes consume the bodies of herbivorous animals a top carnivore like an eagle feeds on other carnivores such a feeding relationship among organisms is called a food chain an animal feeding on a plant or another animal usually leave some remains of it in the environment these remains as well as feces and dead bodies are decomposed by bacteria and fungi in a food chain green plants are known collectively as producers because they produce substances that make up bodies animals consume the body matter produced by green plants hence they are known collectively as consumers bacteria and fungi are collectively as decomposers as they break down the body matter of plants and animals into simple substances as green plants convert the light energy of sunshine to chemical energy through photosynthesis they absorb compounds of carbon hydrogen and oxygen from the environment and produce glucose as a result glucose is converted to other carbohydrates through a series of metabolic reactions incorporating nitrogen phosphorus sulfur and other elements absorb from the environment other substances including proteins lipids and nucleic acids are formed chemical energy is stored in the bonds between atoms in the substances which make up the body plants carry out respiration to release the stored energy to meet the needs of the various processes essential for the maintenance of life a certain portion of the energy dissipates into the environment as heat herbivorous animals eat plants carnivorous animals eat herbivores and some are themselves eaten by other carnivores in this way the body matter of green plants with stored energy is transferred along the food chain to the bodies of animals metabolic reactions in animals convert the material of green plants to that of animals respiration in the animal body releases the energy stored in the body matter to drive various life processes and some of the energy dissipates into the environment as heat you food remains dead bodies and animal feces are products of the body matter of living things when they are decomposed by bacteria and fungi the stored energy is dissipated into the environment as heat and the complex molecules of the body matter are broken down to simple substances which are returned to the environment if absorbed by other green plants these substances enter another round of cyclical flow through living things you the flows of energy and matter take place simultaneously in an ecosystem the energy flow is a form of one-way traffic light rays from the Sun hit the earth after entering into an ecosystem light energy is converted to chemical energy and flows through the bodies of living things along the food chains eventually being converted to heat energy and dissipating into the environment the unlimited supply of solar energy sustains the operation of the ecosystem the flow of a matter is cycling process simple substances in the environment are absorbed into the bodies of plants where they are bonded together to form complex organic substances through metabolic reactions the complex organic substances in the plant body move into the bodies of various animals

along the food chains they are eventually decomposed by bacteria and fungi into simple substances these simple substances return to the environment and enter another cycle if they are absorbed by plants and gain we see that in an ecosystem the energy flow drives various matter cycles leading to the sustainable development of living things and the environment a rabbit eats grass a snake eats the rabbit and an eagle eats the snake a food chain is formed but a snake also eats frogs and mice it is therefore the common member of three food chains like wise and eagle eat snakes mice and rabbits it serves as a link to more food chains similarly other animals are linked up in many more food chains all the food chains in an ecosystem are therefore interwoven into a large food web which embraces all the living things there in some conditions the food web gets extremely complicated if a population of a certain species drops or disappears the overall effect may be hard to predict the survival of one or more other species may be adversely affected to be safe we need to conserve all the species existing in an ecosystem in a mature ecosystem the number of species and the population of each species are relatively stable over a period of time at the same time the energy flow and matter cycles among living things and between living things and the environment are stable – leading to a state of dynamic balance this state is called ecological balance a mature and stable ecosystem is capable of self adjustment whenever as a result of external factors there is a change in structure and function of any item the ecosystem quickly responds and undergoes appropriate adjustments to resume its ecological balance however if the ecosystem is affected by strong and persistent human factors and the damage done is too large for its recovering capacity the ecological balance will be broken and the ecosystem will decline and even collapse this is a state of ecological imbalance the various problems of resource shortages and environmental crises are in fact examples of ecological imbalances the key to resolve the crises and achieve sustainable development is to take immediate action to alleviate and eliminate all the harmful human factors so as to give the ecosystem an opportunity to resume ecological balance technological innovations lend strong support to the implementation of sustainable development air pollution global warming and energy crisis are the consequences of human exploitation of fossil fuels as the major energy sources these problems will be solved if technological innovations can provide low cost pollutant free and renewable means of power supply as alternatives to fossil fuels solar power and wind power are wise choices for Hong Kong given the constraints of its area and population solar power technology converts energy and sunlight to electrical energy these solar panels are the most commonly used solar energy converters each panel is an array of solar cells which are made of silicon crystals each cell generates a direct current under sunlight a large number of solar panels are installed on the roof of a building they’re connected to a charge controller who stores the electrical energy in a battery connection to an inverter will convert the direct current to alternate current which can provide power to drive the electrical appliances in the building a wind turbine is a combination of a

windmill and a generator wind blows on the windmills blades which turn on their axle this causes the rotor of the generator to rotate within the stator this relative movement generates an alternate current the current is made available for use for domestic electrical appliances sustainable development facilitated if we can solve the problems of removing pollutants and solid wastes professor Bowen of the Hong Kong Polytechnic University invented a method to deal with both problems together we try to recycle the construction ways.i crushing the concrete robos rocks and into recovery cycle aggregate like this okay and we try to put them into the eco blocks and in the first generation of eco blocks it complies more than 70 percent of recycle educate that is the construction waves will further enhance the performance of the Eco blocks we will try to incorporate waste glass into our blocks last bottles like this is a major waste problem Hong Kong as well Hong Kong is producing more than 300 tons per day of these glass bottles the incorporation of the waste glass into the blocks not only how to recycle the glass is also help to improve the property form of the blocks it could improve the appearance of the blocks expressed at night because it would give a shiny appearance and also it will improve the water absorption capability of the blocks in our third generation of eco blocks we not only put recycle material including construction waste glass into the blocks