1、Unit 1 EnvironmentEarths Health in Sharp Decline, Massive Study Finds大规模研究发现：地球的“健康”每况愈下The report card has arrived from the largest ever scientific Earth analysis, and many of the planets ecosystems are simply not making the grade.有史以来对地球进行的最大规模的科学分析结果表明，地球上的许多生态系统都达不到标准。The UN-backed Millennium Ec
2、osystem Assessment Synthesis Report found that nearly two-thirds of Earths life-supporting ecosystems, including clean water, pure air, and stable climate, are being degraded by unsustainable use.由联合国主持的千年生态系统评估综合报告指出，由于不可持续的使用，地球上将近三分之二的用来维持生命的生态系统（包括干净的水源、纯净的空气以及稳定的气候）正遭受破坏。Human has caused much o
3、f this damage during the past half century. Soaring demand for food, fresh water, timber, fiber and fuel have led to dramatic environmental changes, from deforestation to chemical pollution, the report says. The already grim situation may worsen dramatically during the first half of the 21st century
4、, the reports authors warn.以上大部分的破坏都是人类在过去的半个世纪里造成的。据报告分析，随着人类对食物、淡水、木材、纤维以及燃料等资源的需求日趋激增，环境发生了极大的变化，引发了诸如滥伐森林、化学污染等问题。因此，该报告的作者警告说，照此下去，本已岌岌可危的生态环境将会在21世纪的上半叶进一步恶化。Over 1,300 governmental and private-sector contributors from 95 countries collaborated to create the landmark study. For four years they
5、 examined the plants many habitats and species and the systems that bind them together. The United Nations Environment Programme compiled the report and released the results yesterday in Beijing, China.这项历史性的研究由来自世界95个国家的政府部门以及民间组织的1,300多位科学家共同完成。四年来，他们考察了地球上许多生物的生长环境、物种以及将他们联系起来的生态体系。联合国环境规划署对该报告进行
6、了编辑整理并于昨天在中国北京公布了研究结果。“Only by understanding the environment and how it works, can we make the necessary decisions to protect it,”UN Secretary General Kofi Annan said in a press statement accompanying the reports release.“Only by valuing all our precious natural and human resources, can we hope to b
7、uild a sustainable future.”在公布该报告的新闻发布会上，联合国秘书长科菲安南指出：“只有了解环境及其运作过程，我们才能制定出必要的措施加以保护它。”他还说，“只有珍惜所有宝贵的自然资源和人类资源，我们才有希望去建设一个可持续发展的未来。”Socioeconomic Impact对社会经济的影响The report paints a rather bleak picture for biodiversity throughout much of the natural world. Perhaps 10 to 30 percent of earths mammal bi
8、rd and amphibian species are facing extinction.该报告对自然界的大部分生物多样性持悲观态度，地球上可能有10%30%的哺乳动物，鸟类以及两栖动物濒临灭绝。The massive ecological survey was begun in response to Annans Millennium Development Goals, a UN initiative that aims to dramatically reduce socioeconomic problems, such as hunger and extreme poverty,
9、 by 2015.这次大规模生态调查是根据安南的千年发展目标展开的，该发展目标是由联合国发起的，旨在2015年之前大幅减少饥饿与极度贫困等社会经济问题。“The Millennium Ecosystem Assessment give us, in some ways for the first time, an insight into the economic importance of ecosystem services and some new and additional arguments for respecting and conserving the Earths life
10、-supporting systems.”said Klaus Toepfer, executive director of the Nairobi-based UN Environment Programme.总部位于内罗毕的联合国环境规划署执行主席克劳斯托普弗说：“从某些方面来说，千年生态系统评估综合报告让我们首次认识到生态系统服务功能的经济价值，并使我们对尊重和保护地球生命维护系统有了新的见解。”Current human usage patterns of Earths environment have increased the global food supply, albeit
11、too slowly to accomplish the UN goal of halving word hunger by 2015.目前由于人类社会对地球环境的开发利用，食物供应不断增加，然而增长的速度仍然太慢，难以完成联合国制定的在2015年之前消除全球一半饥饿人口的目标。The negative effects of ecosystem strain also include collapsing fisheries, coastal“dead zones” near sediment-heavy river mouths, shifting water quality, and un
12、predictable regional climate, the report says.报告还说，过度使用生态系统的负面影响还包括渔业的衰退，含有大量沉积物的河口周围近海“死亡区”的出现，水质的变化以及不可预测的区域性气候等。Deforestation and other radical ecosystem alterations also promote disease, such as malaria and cholera, as well as new strains of existing contagions.此外，森林的滥伐和其他生态系统的巨大改变也加剧了诸如疟疾、霍乱等疾病
13、的传播，并使已有传染病分化出新的类别。Changes to water systems may increase the frequency and severity of destructive floods. Over a hundred thousand people were killed in the 1990s by floods, which also caused destruction to the tune of 243 billion dollars (U.S.), according to the report.根据该报告，水资源体系的变化会增加毁灭性洪灾的爆发频率和程
14、度。在20世纪90年代，洪灾造成的死亡人数超过10万，损失约2,430亿美元。The regions facing the greatest environmental degradation are also among the worlds poorest: sub-Saharan Africa, Central Asia, and parts of Latin America, and South and Southeast Asia.目前，世界上环境破坏最严重的地区恰是全球最贫穷的地区：撒哈拉沙漠以南之中部非洲地区，亚洲中部，拉丁美洲的部分地区，以及亚洲的南部及东南部。Call for
15、 Radical Change呼吁彻底改变现状The report urges drastic policy changes to the ways in which natural resources are used.千年生态系统评估综合报告呼吁在自然资源利用方面对目前的政策进行大幅度的改变。From an economic perspective, the study suggests that many intact ecosystems should be regarded as more valuable than those altered for comical use.该研究
16、认为，从经济角度看，与那些被用于商业开发的生态系统相比，很多完整生态系统的价值更高。For example, citing wetland wildlife habitat, water pollution filtration, water storage and recreational value, the report appraised intact Thai mangroves at a thousand U.S. dollars per acre (0.4 hectare). The same mangroves were valued at only U.S. $200 an
17、acre after they had been cleared for fish and shellfish farming.例如，该报告通过对湿地野生动植物的生境、水污染过滤情况、水资源储存能力以及娱乐价值等方面的分析，估算出保护完整的泰国红树每英亩（0.4公顷）价值为1,000美元，而同样的红树，由于渔业及贝类养殖业的开发而遭到了破坏，其价值仅为每英亩200美元。“The overriding conclusion of this assessment is that it lies within the power of human societies to ease the stra
18、in we are putting on the nature services of the planet, while continuing to use them to bring better living standards to all,” the reports 45-person board of directors said in a statement.由45位成员组成的研究委员会在一份声明中指出，“这个评估报告最重要的结论是，如何在利用地球生态系统提升人类生活水平的同时，缓解我们对其所施加的压力，这完全取决于我们人类社会。”“Achieving this however
19、will require radical changes in the way nature is treated at every level of decision-making and new ways of cooperation between government, business and civil society,” the statement continued. “The warning signs are there for all of us to see. The future now lies in our hands.”该声明还指出：“但是，要达到上述目的，需要
20、彻底改变人们对待自然的方式，小到各级决策的制定，大到政府、商业和文明社会之间新的合作。警钟已经敲响，未来掌握在我们自己手里。”The board of the Millennium Ecosystem Assessment Synthesis Report was co-chaired by Robert Watson, chief scientist of the World Bank, and A. Hamid Zakri, director of the United Nations University Institute of Advanced Studies.担任千年生态系统评估综
21、合报告委员会主席的是世界银行的首席科学家罗伯特沃森和联合国大学高等研究所主任A.海米德扎卡雷。Unit 2 Energy SourcesThe Future of Alternative Energy替代能源的前景Residential energy use in the United States will increase 25 percent by the year 2025, according to U.S. Department of Energy (DOE) forecasts. A small but increasing share of that extra power w
22、ill trickle in from renewable sources like wind, sunlight, water and heat in the ground.据美国能源部预测，至2025年美国的家用耗电将增加百分之二十五，增加的电量中将有一小部分来源于再生能源（如风、阳光、水、地热），而且这部分还会不断增大。 Last year alternative energy sources provided 6 percent of the nations energy supply, according to the DOE.据美国能源部统计，去年替代能源占整个国家能源供给的百分之
23、六。“The future belongs to renewable energy,” said Brad Collins, the executive director of the American Solar Energy Society, a Boulder, Colorado-based nonprofit organization. “Scientist and industry experts may disagree over how long the worlds supply of oil and natural gas will last, but it will end
24、,” Collin said.美国太阳能协会（该协会是一个位于科罗拉多州博德市的非盈利性组织）的主管布拉德柯林斯说：“未来属于可再生能源。尽管就世界石油和天然气可以持续多久，科学家和工业专家可能有不同观点，但是油气资源终将耗尽。” While renewable energy is generally more expensive than conventionally produced supplies, alternative power helps to reduce pollution and to conserve fossil fuels. 尽管可再生能源通常比传统能源更昂贵，但是
25、替代能源有助于减少污染、保护矿物燃料。“People sometimes get caught up in cost-effectiveness,” said Paul Torcellini, a senior engineer at the DOEs National Renewable Energy Laboratory(NREL) in Golden, Colorado. “But it can be a question of values and what we spend our money on.”美国能源部国家再生能源实验室（位于科罗拉多州戈尔登市）的一位高级工程师保罗陶塞列尼
26、说：“有时人们考虑的只是节省成本的问题，但是这可能是一个价值观念的问题，一个我们把钱用于何处的问题。” Below, a look at some recent developments in renewable-energy technology:接下来我们一起了解关于可再生能源技术的新发展Solar Power太阳能 Photovoltaic, or solar-electric, systems capture light energy from the suns rays and convert it into electricity. Today these solar units
27、power everything from small homes to large office buildings.光电系统获取太阳光线的光能并将其转化成电。现在这些太阳能设备可以为各种建筑供电，小到家庭大到办公楼。Technological improvements have made solar-electric modules more cost-effective. In the 1980s the average price of energy captured with photovoltaic was 95 U.S. cents per kilowatt-hour. Toda
28、y that price has dropped to around 20 cents per kilowatt-hour, according to Collins, of the American Solar Energy Society.技术进步使得光电设备更加划算。20世纪80年代，光电系统供电的平均价格为每千瓦时95美分；而根据美国太阳能协会的统计，如今这一价格已降至每千瓦时20美分左右。 The cheaper rate is still more expensive than the average national price of electricity, which in
29、2003 was a little over 8 cents per kilowatt-hour, according to the U.S. Department of Energys Annual Energy Review.即使略微便宜的光电价格仍然高于全国电价的平均价格，据美国能源部发行的能源周刊统计，2003年每千瓦时的电价均价略高于8美分。Other recent advances include “thin film” photovoltaic technology, a high-tech coating that converts any surface covered wi
30、th the film into a solar-electric power source. Boats and RVs that use the film are now on the market.其他最新的发展包括薄膜光电技术，这种高科技的涂层能够将任何覆盖此类薄膜的表面转化成一种光电电源。使用这种薄膜技术的轮船和娱乐用车目前已上市销售。 Engineers have also developed a roofing material coated with electricity-producing film. “The guy who puts on the roof (on a
31、house now) puts on the solar panels at the same time,” Torcellini said. The roofing material withstands inclement weather and, on bright days, taps sunshine for electricity.工程师们也研究出一种涂有发电薄膜的屋顶材料。人们在搭建屋顶时，同时就可以放上这种太阳能嵌板，陶塞列尼说道。这种屋顶材料能耐极端天气，而且在阳光明媚的时候可以利用太阳光发电。 NREL researchers, meanwhile, are working
32、 to devise more efficient and cheaper solar-electric systems. Most traditional photovoltaic solar units on the market today convert between 11 and 13 percent of the suns light into energy. Engineers think they can improve on that.与此同时，美国可再生能源实验室的研究人员正在研发更为高效、价格更低的光电系统。目前市场上大多数传统光电设备可以将百分之十一至百分之十三的太阳
33、光转化成能量，工程师们认为这一比例还可以再提高。 Jeff Mazer, a Washington, D.C.-area photovoltaic engineer, notes that most thin-film photovoltaic systems today have a 7 to 11 percent efficiency rating. But he estimates that thin films could surpass that rating within three years. He also notes that some new traditional so
34、lar modules achieve 15 percent efficiency and believes that figure can climb to 17 percent in the near future.华盛顿地区的一位光电工程师杰夫梅泽说现在的多数薄膜光电系统的效能等级只有百分之七至百分之十一。然而，据他估计，薄膜光电系统在三年内可以超过这一等级。他还说一些新式传统太阳能设备可以实现百分之十五的效能，但他相信这一数字可以在不久的将来攀升到百分之十七。In the last two decades solar-thermal panels (units used to warm
35、 household hot water, pools and spas) have become highly efficient. “Energy costs have decreased from 60 cents to 8 cents per kilowatt-hour since the 1980s,” Collins said. 近20年中，光热板（用于为家庭热水、水池、泉水升温的设备）的效能大大提高。柯林斯说：“自20世纪80年代起，能源成本从每千瓦时60美分降至8美分。” Solar-powered water heaters are typically more expens
36、ive than conventional ones, but, as with other products that harness alternative energy, consumers benefit by knowing their energy costs up-front Torcellini said. “Otherwise, youre hedging your bets about the future cost of traditional energy sources by using standard appliances,” he said.太阳能热水器通常比常
37、规热水器更昂贵，但是像利用替代能源的其他产品一样，消费者可以预先知道其成本从而获益。陶塞利尼说：“否则，将难以抉择：是仍然使用普通热水器，还是致力于降低未来传统能源的成本。” Wind Power风能 Compare to other renewable energy sources, wind power competes with conventional energy at a price less than 4 cents per kilowatt-hour, according to Collinis.据柯林斯的说法，与其他可再生能源相比，风能更具有竞争力，其每千瓦时的价格比传统能源
38、低4美分。 Wind energy projects around the world now generate enough energy to power nine million typical U.S. homes, according to the American Wind Energy Association, a Washington, D.C.-based trade group.美国风能协会（一个总部位于华盛顿的贸易团体）称目前世界各地的风能项目发电足可以为九百万典型的美国家庭供电。 One of the newest trends in wind power is the
39、 construction of offshore wind farms, cluster of electricity-generating turbines erected in open-water areas with strong winds.利用风能的最新趋势之一就是建设离岸海上风力发电厂，在风力较大的空旷水域建造一组组的发电机组。 Europe now has 17 wind farms spinning offshore. The Arklow Bank Offshore Wind Park, 8 miles (13 kilometers) off the eastern co
40、ast of Ireland, is one such project. Its seven turbines generate enough electricity to power 16,000 homes. While few homes generate their own wind power in the U.S., many power companies allow consumers to opt for power generated at a wind plant or other renewable source.欧洲现在有17个海上风力发电厂在运转。距离爱尔兰东海岸8
41、英里（13公里）的阿克罗银行海上风力园就是这样的一个项目，它的七个涡轮机产生的电力足够为16000户家庭供电。尽管目前鲜有美国家庭利用风能自己发电，但是许多电力公司允许消费者选择风力供电或者其他可再生能源供电。 On Tuesday, Colorado voters will consider a ballot initiative that would requires power companies to provide 10 percent of their electricity from wind and other renewable sources by 2015.周二科罗拉多州
42、的选民将考虑举行一次公民投票，要求至2015年电力公司为他们提供的电力中的有10%是来自于可替代能源。 “If that passes, power companies will offer more rebates to homeowners to encourage renewable energy production,” said Sheila Hayter, an NREL senior engineer.美国可再生能源实验室的一位高级工程师希拉海特说：“如果该投票表决能够通过，电力公司将能够给房主提供更多折扣，鼓励他们使用可再生能源。” Ground Heat地热Tapping i
43、nto the ground offers another option to regulate household heating and cooling.开发地下能源为调节家庭供暖和降温提供了另一种选择。 In most areas of the United States, the ground below the frost line maintains an average temperature between 50 and 54 degrees Fahrenheit (10 to 12 degrees Celsius).在美国的大部分地区,冰冻线以下地面的平均温度保持在50至54
44、华氏度(10至12)。Ground-source heat pumps, also called geo-exchange systems, use this relatively constant temperature to keep homes at comfortable temperatures. The devices employ a series of underground, liquid-filled tubes or wells. Liquid flows through the pipes into the home, where a heat exchanger ei
45、ther adds or subtracts heat from indoor air, depending on the season. In winter, that means added warmth captured from the ground. “If you can (do that), your furnace doesnt have to work so hard,” Hayter said.地热泵系统，也称为地热交换系统，采用这种相对恒定的温度保证家中的室温维持在舒适的温度。这种装置使用一系列地下液体管或液体井。液体流经这个管道进入家中,通过一个热交换器根据季节增减室内
46、空气的热度。在冬天,这意味着增加了从地面获得的温度。海特说，“如果能够这样，家中的火炉就不必如此辛苦了”。A U.S. Environmental Protection Agency study found that geo-exchange systems can save up to 70 percent of home-heating costs.美国环保局的研究发现，地热交换系统可节省高达百分之七十的家庭供暖成本。Unit 3 Plants and AnimalsPlant Adaptation植物的适应性Like a human being or an animal, a plant
47、 must adapt to its environment in order to survive. Survival usually means struggle. It may be hard to think of a plant as “struggling,” yet that is often the case.像人类和动物一样，植物为了生存也必须适应周边的环境。生存就意味着竞争，我们很难想象植物之间的竞争。但也就那么回事。A plant, first, must compete with other plants for light, air, soil and water.
48、Second, it must contend with people and animals, who may eat it or make the environment unfit for it to live in. Third, the physical environment itself may be hostile or inadequate to a plants need. Is there enough light, water, air and soil? Is it warm and cool enough for a given plant species?首先，不同的植物之间会争夺阳光、空气、土壤和水分。其次，植物也会与那些吃它或者威胁到它生存环境的人类和动物竞争。再次，植物所处的环境也可能也是有敌对性的或者不利于其生长的。怎样才能有足够的阳光、水分、空气和土壤？气温的冷热就是植物生长的主要因素吗？ Light is vital to a plant, especially a green one. Green plants manufacture foodstuffs in sunlighta process known as photosynthesis. Light also affects the rate of water ab
