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1、-资源环境科学专业英语-第 21 页Unit 1 The Environment and Environmental Problems Humans have always inhabited two worlds. One is the natural world of plants, animals, soils, air, and water that preceded us by billions of which we are a part. The other is the world of social institutions and artifacts that we cre
2、ate for ourselves using science, technology, and political organization. Both worlds are essential to our live, but integrating them successfully causes enduring tensions. Where earlier people limited ability to alter their surroundings, we now have power to extract and consume resources, produce wa
3、stes, and modify our world in ways that threaten both our continued existence and that of many organisms with which we share the planet. To ensure a sustainable future for ourselves and future generations, we need to understand something about how our world works, what we are doing to it, and what w
4、e can do to protect and improve it.Environment and Environment Science Environment (from the French environner : to encircle or surround) can be defined as(1) the circumstance or conditions that surround an organism or group of organisms, or(2) the complex of social or cultural conditions that affec
5、t an individual or community. Since humans inhabit the natural as well as the “built” or technological, social, and cultural world, all constitute important parts of our environment, Environmental science, then, is the systematic study of our environment and our proper place in it. A relatively new
6、field, environmental science is highly interdisciplinary, integrating natural of the world around us. In contrast to more theoretical disciplines, environmental science is mission-oriented. That is, it seeks new, valid, generalizable knowledge about the natural world and our impacts on it, but obtai
7、ning this information creates a responsibility to get involved in trying to do something about the problems we have created. As distinguished economist Barbara Ward points out, for an increasing number of environmental issues, the difficulty is not to identify remedies. Remedies are now well underst
8、ood. The problem is to make them socially, economically, and politically acceptable. Foresters know how to plant trees, but not to establish conditions under which villagers in developing countries can manage plantations for themselves. Engineers know how to control pollution, but not how to persuad
9、e factories to install the necessary equipment. City planners know how to build housing and design safe drinking water systems, but not how to make them affordable for the poorest members of society. The solutions to these problems increasingly involve human social systems as well as natural science
10、s.Environmental Dilemmas Imagine that you are an astronaut returning to earth after a long trip to the moon or Mars. What a relief it would be to come back to this beautiful, bountiful planet after experiencing the hostile, desolate environment of outer space. Although there are dangers and difficul
11、ties here, we live in a remarkable prolific and hospitable world that is, as far as we know, unique in the universe. Compared to the conditions on other planets in our solar system, temperatures on the earth are mild and relatively constant. Plentiful supplies of clean air, fresh water, and fertile
12、soil are regenerated endlessly and spontaneously by geological and biological cycles.Perhaps the most amazing feature of our planet is the rich diversity of life that exists here. Millions of beautiful and intriguing species populate the earth and help sustain a habitable environment. This vast mult
13、itude of life creates complex, interrelated communities where towering trees and huge animals live together with, and depend upon, tiny life-forms such as viruses and fungi. Together, all these organisms make up delightfully diverse, self-sustaining communities, including dense, moist forests, vast
14、sunny savannas, and richly colorful coral reefs. From time to time, we should pause to remember that, in spite of the challenges and complications of life on earth, we are in credibly lucky to be here. We should ask ourselves: what is our proper place in nature? What ought we to do and what can we d
15、o to protect the irreplaceable habitat that produced and support us? These are some of the central questions of environmental science.While there are many things to appreciate and celebrate about the world on which we live, many pressing environmental problems cry out for out attention. Human popula
16、tions have grown at alarming rates in this century. Nearly 6000 million people now occupy the earth and we are adding 100 million more each year. In the next decade, our numbers will increase by nearly as many as are now alive in China. Most of the growth will be in the poorer countries where resour
17、ces and services are already strained by present populations.Some demographers believe that this unprecedented growth rate will slow in the century and that the population might eventually drop back below its present size. Others warn that the number of humans a century from now could be for five ti
18、mes more than that of our present population if we dont act quickly to birth rates into balance with death rates. Whether there are sufficient resources to support 6 billion humans-let alone 25 billion-on a sustainable basis is one of the most important questions we face. How we might stabilize popu
19、lation and what level of resource consumption future generations we can afford are equally difficult parts of this challenging equation.Food shortages and famines already are too familiar in many places and may increase in frequency and severity if population growth, soil erosion, and nutrient deple
20、tion continue at the same rate in the future as they have in the past. We are coming to realize, however, that food security often has more to do with poverty, democracy, and equitable distribution that it does with the amount of food available. Water deficits and contamination of existing water sup
21、plies threaten to be critical environmental issues in the future for agricultural production as well as for domestic and industrial use. Many countries already have serious water shortages and more than one billion people lack access to clean water or adequate sanitation. Violent conflicts over cont
22、rol of natural of natural resources may flare up in many places if we dont learn to live within natures budget.How we obtain and use energy is likely to play a crucial role in our environmental future. Fossil fuels (oil, coal, and natural gas) presently supply about 80% of the energy used in industr
23、ialized countries. Supplies of these fuels are diminishing at an alarming rate and problems associated with their acquisition and use-air and water pollution, mining damage, shipping accidents, and political insecurity-may limit where and how we use remaining reserves. Cleaner renewable energy resou
24、rces-solar power, wind, and biomass-together with conservation, may replace environmentally destructive energy sources if we invest in appropriate technology in the next few years.As we burn fossil fuels, we release carbon dioxide and other heat-absorbing gases that cause global warming and may brin
25、g about sea-level rises and catastrophic climate changes. Acids formed in the extensive damage to the building materials and sensitive ecosystems. in many place.Continued fossil fuel use without pollution control measures could cause even more extensive damage. Chlorinated compounds ,such as the chl
26、orofluorocarbons used in refrigeration and air conditioning, also contribute to global warming. As well as damaging the stratospheric ozone which protects us from cancer-causing ultraviolet radiation in sunlight . Destruction of tropical forest, coral reefs, wetland, and other biologically variety a
27、nd abundance that could severally limit our future options. Many rare and endangered species are threatened directly or indirectly by human activities. In addition to practical values, aesthetic and ethical considerations suggest that we should protect these species and the habitat necessary for the
28、ir survival.Toxic air and water pollutants, along with mountains of solid and hazardous wastes, are becoming overwhelming problems in industrialized countries. We produce hundred of millions of tons of these dangerous materials annually, and much of it is disposed of in dangerous and irresponsible w
29、ays .no one wants this noxious stuff dumped in his or her own backyard, but too often the solution is to export it to someone elses. we may come to a political impasse where our failure to decide where to put our wastes or how to dispose of them safely will close down industries and result in wastes
30、 being spread everywhere. The health effects of pollution toxic wastes. Stress , and the other environmental ills of modern society have become a greater threat than infectious diseases for many of us in industrialized countries.This and other similarly serious problems illustrate the importance of
31、environmental science and environmental education for everyone. What we are doing to our world ,and what that many mean for our future and that of our children is paramount concern as we enter the twenty-fist century.Unit 2 Population Resources and Environment Population Explosion All too often, ove
32、rpopulation is thought of simply as crowding: too many people in a given area, too high a population density. Between 1900 and now, the worlds population has roughly quadrupled from about 1.6 billion in 1900 to about 6 billion today and is currently growing at an annual rate of 1.2%, or 77 million p
33、eople per year. Six countries account for half of this annual growth: India for 21%, China for 12%, Pakistan for 5%, Nigeria for 4%, Bangladesh for 4%, and Indonesia for 3%. By 2050, world population is expected to be between 7.9 billion (low variant) and 10.9 billion (high variant), with the medium
34、 variant producing 9.3 billion. There would be a rapid aging of the worlds population. In the past, the median age for the worlds population has been between 20 and 25 years. It is now about 26 years. By 2050, the median age for a depopulating globe would be about 42 years. In the more developed reg
35、ions the median age of population would be over 50. That is to say: for every person under the age of 50, there would be someone over the age of 50. A complete transformation of the profile of the world would thus occur. The explosion of world population is an outgrowth of the industrial age, and th
36、ree key factors are to blame: increased food production, disease control, and better sanitation. These advances greatly increased the survival rate of newborns, but this great change occurred in many countries without any decrease in the number of birth. Population growth is at the root of virtually
37、 all environment problems, including pollution and resources depletion, and indirect social disruptions. Such as housing shortages, malnutrition and inadequate health care, rapid growth in population creates difficulties in meeting the basic needs of people, crowding may cause mental illness, drug a
38、buse and various forms of antisocial behavior. Hunger, starvation, disease, poverty, illiteracy, pollution, unemployment, and barren landscapes are, to many observers, signs that the human population is much too big for the earths resources. Among the negative trends they bet would continue were: Ri
39、sing global temperature; Shrinking amount of cropland per person; Decline in amount of wheat and rice grown per person; Shrinking area of tropical moist forests; Declining human sperm count; Growing gap between rich and poor. Population grown would have to be stopped; family planning and limited eco
40、nomical development are ways to bring the human population back in liner. Family planning allows couplesto determine the number and spacing of offspring programs may be voluntary, extended voluntary, or forced. Many experts believed that family planning that promotes economic development, jobs for w
41、omen, health and education. To have an effective family planning program, we also have an effective economy-where jobs are available, where health facilities are adequate. Small-scale economic development improved education, better health care, and contraception can reduce birth rates. The critical
42、thing skills suggest that solutions require many approaches. Family planning is a case in point. Developed nations can contribute to a solution by reducing consumption and population size. They can assist the less fortunate with population control, agriculture, health care, and appropriate technolog
43、y through financial aid and, especially, information sharing. Many developing nations have population control programs, although funds are often inadequate. Increasing expenditures on such programs could have many long-rang benefits. To be effective, programs in such countries must take into account
44、 the effects of religious beliefs, psychological factors, and educational levels.Unit 3 Energy Source BasicsEnergyEnergy means the power which does work and drives machines.All living thing (including humans) rely on the sun as a source of energy. Coal , petroleum, and natural gas are energy sources
45、 available today because organisms in the past captured sunlight energy and stored it in complex organic molecules that made up their bodies, which were then compressed and concentrated.CoalThe general term coal describes a large range of solid fossil fuels derived from partial degradation of plants
46、. The characteristics of the major classes of coal differentiate largely by percentage of fixed carbon, percentage of volatile matter, and heating value (coal rank).Chemically, coal is a very complex material and is by no means pure carbon. For example, a chemical formula for Illinois No.6 coal, a t
47、ype of bituminous coal, would be something like C100H85SNO.PetroleumPetroleum means a mineral oil obtained from below the surface of the earth, and used to produce various chemical substances. Liquid petroleum is found in rock formations ranging in porosity from 10% to 30%. Up to half of the pore sp
48、ace is occupied by water. The oil in these formations must flow over long distances to an approximately 6-inch diameter well from which it is pumped. The rate of flow depends on the permeability of the rock formation, the viscosity of the oil, the driving pressure behind the oil, and other factors.P
49、etroleum as it comes from the ground is not in a from of suitable for use. It must be refined. Processing crude oil to provide useful products generates a variety of problems. All of these processing activities are opportunities for accidental or routine releases that cause air or water pollution. The petrochemical industry is the major contributor to air pollution.Na