全球变暖演讲稿 800字左右
全球变暖可能造成的影响 全球变暖将给地球和人类带来复杂的潜在的影响，既有正面的，也有负面 的。
例如随着温度的升高，副极地地区也许将更适合人类居住；在适当的条件下， 较高的二氧化碳浓度能够促进光合作用，从而使植物具有更高的固碳速率，导致 植物生长的增加，即二氧化碳的增产效应，这是全球变暖的正面影响。
但是与正 面影响相比，全球变暖对人类活动的负面影响将更为巨大和深远。
今年8月份CCTV报道，由于气候变暖的影响，珠穆朗玛峰的顶峰下降了1.3米。
祁连山冰川缩减危及河西走廊：近年来，祁连山冰川融化比上个世纪70年代减少了大约10亿立方米，冰川局部地区的雪线正以年均2-2.6米的速度上升。
专家分析，冰川退缩，雪线上升除自然气候因素外，另一个主要原因是人口膨胀，超载超牧，过度开垦，乱砍滥伐，滥采地下水有关。
《中国环境报》2004-9-16 1、海平面上升的影响 过去的百年海平面上升了14．4cm,我国上升了11．5cm。
海平面升高的原因，主要是海水热膨胀，当海洋变暖时，海平面则升高。
全球升温会引起地球南北两极的冰山融化，这也是造成海平面上升的主要原因之一。
海平面上升的直接影响有以下几个方面： (1) 低地被淹： 英国加高堤坝应对气候变暖 全球变暖使海平面升高，暴风雨频率增加，这使英国人不得政治面目 加高防洪堤坝。
据英国官方近日公布的统计数据，在过去的20年中，由于泰晤士河的水位随全球变暖而升高，当地政府机构不得不先后88次加高防洪堤坝，以保障伦敦人的生命财产安全。
，据悉，人们现在平均每年4次加高其堤坝。
据估计，在2030年以前，其加高堤坝的频率会达到每年30次。
钟和 中国环境报2004-10-19 (2) 海岸被冲蚀 (3) 地表水和地下水盐分增加，影响城市供水。
（4）地下水位升高。
(5) 旅游业受到危害(海平面上升50米,大连、秦皇岛、青岛、北海、三亚滨海旅游区向后31-366料，沙滩损失24%，北戴河沙滩损失60%。
2002年中国国土资源公报报道，沿海旅游业已成为第一大产业，其产值为2503亿元，占海洋产业总产值的34.6%。
（6） 影响沿海和岛国居民的生活(占世界1／3的人口)，使之受到威胁。
如果极地冰冠融化，经济发达、人口稠密的沿海地区会被海水吞没，马尔代夫、塞舌尔等低洼岛国将从地面上消失，上海、威尼斯、香港、里约热内卢、东京、曼谷、纽约等海滨大城市以及孟加拉、荷兰、埃及等国也将难逃厄运。
2、对动植物的影响 气候是决定生物群落分布的主要因素，气候变化能改变一个地区不同物种的适应性并能改变生态系统内部不同种群的竟争力。
自然界的动植物，尤其是植物群落，可能因无法适应全球变暖的速度而做适应性转移，从而惨遭厄运。
以往的气候变化(如冰期)曾使许多物种消失，未来的气候将使一些地区的某些物种消 失，而人些物种则从气候变暖中得到益处，它们的栖息地可能增加，竞争对手和 天敌也可能减少。
比如说桔子，过去20世纪70年代，它的最北的边界线是在黄 山一线，宣城市也曾经试种过，但到冬天的一场大雪，树木就冻死了。
但现在我 们校园里的桔子树都长得很好。
又如，扬子鳄只生活在宣城、泾县和南陵这样狭 小的地带，如果北界线北移，扬子鳄可能会自然绝种。
这是从我省的局部地区来 讲。
从全国来讲，我国把冬季1月0度等温线作为副热带北界，目前这一界线处 于我国秦岭-淮河一带。
研究发现，气温升高会使这一界线北移至黄河以北，徐 州、郑州一带冬季气温将与现在的杭州、武汉相似。
3、对农业的影响 一年中温度和降水的分布是决定种植何种作物的主要因素，温度及由温度引起降水的变化将影响到粮食作物的产量和作物的分布类型。
气候的变化曾经导致生物带和生物群落空间(纬度)分布的重大变化。
如公元800-1200年北大西洋地区的平均温度比现在高1℃，使玉米在挪威种植成为可能，但到了公元1500-1800年，西欧出现小冰川期，平均气温也只比现在低1-2℃，就造成了挪威一半农场弃耕，冰岛的农业耕种活动则几乎全部停止。
除此之外，全球变暖还会使高温、热浪、热带风暴、龙卷风等自然灾害加重。
因此，全球气温升高后，世界粮食生产的稳定性和分布状况将会有很大变化。
4、对人类健康的影响 人类健康取决于良好的生态环境，全球变暖将成为下个世纪人类健康的一个 主要因素。
极端高温将成为下世纪人类健康困扰变得更加频繁、更加普遍，主要 体现为发病率和死亡率增加，尤其是疟疾、淋巴腺丝虫病、血吸虫病、钩虫病、 霍乱、脑膜炎、黑热病、登革热等传染病将危及热带地区和国家，某些目前主要 发生在热带地区的疾病可能随着气候变暖向中纬度地区传播。
关于全球气候变暖的演讲稿 3-5分钟左右。
影响全球变暖的主要原因1工业废气多(CO2),城市热岛效应2臭氧空洞变大，紫外线增强3树林的砍伐，破坏循环 提纲早对了，就这样着手回答
谢全球变暖演讲的顺序大概是什么
大概长三分钟的那种
谢谢
首先要阐述全球变暖的具体原因，然后是全球变暖给我们带来的影响以及危害（可从地理环境，人类活动，生物种类等多方面），最后是讲一些我们可以如何做来减缓全球变暖的速度，保护地球。
有关全球气候变暖的英语演讲稿
Global WarmingThere is little doubt that the planet is warming. Over the last century, the planets temperature has risen by around 1 degree fahrenheit (0.6 of a degree celsius). The warmest since the mid 1800’s was the 1990s. The hottest years recorded were 1997, 1998, 2001, 2002, 2003. The United Nations panel on climate change projects that the global temperatures will rise 3-10 degrees fahrenheit by the century’s end - enough to have the polar caps all but melted. If the ice caps melt, a vast majority of our countries borders will be under water. Monuments and great buildings, as well as homes and lives will be under water, including New York City.So now we know what some of the causes are for global warming, how can we as individuals do our part to help save the planet?The answer is simpler than you may think. You don’t have to go miles away from home to protest, or spend masses of money. If you try to follow the few simple steps that I shall now give you, you will have started to help us all.Firstly, plant a tree. This could be easier than it sounds. Join or help out a local wildlife group and ask to plant a tree. Trees, when fully grown, will help keep the planet cooler. On the same point, you could protest against the demolition of the rainforests. This is the same principle, we need the trees to cool our planet and yet they are chopping them down to create roads or homes.Something as simple as walking instead of taking the car will help reduce pollution. As well as stopping pollution, you are giving yourself exercise, something important for our bodies. So the next time you get into your car, or your motorbike, think - do I have to make this journey by vehicle or can I walk?When you are at home, and your getting a little cold. Put a jumper on and do not adjust the heating. The extra heat produced by our homes also affects the planet. So try wearing an extra layer in winter.If possible, buy your fruit and vegetables from local suppliers. And try to avoid imported goods. The more foreign food that we import the more pollution from aeroplanes and boats it will create.Keeping to the speed limit can also help the environment. The more you speed the more petrol you are going to use, making the pollution higher. Also, SUV’s make about six times their own weight in CO2 each year. A small efficient diesel car covering the same distance not only uses much less fuel; it makes two thirds less.If possible use solar energy, after all it is free; all you need to buy is the equipment. You can get much of your hot water and heating from the sun and even generate electricity. Reduce, reuse and recycle. Only buy what you need; don’t stock the cupboards with things you may or may not use. Reuse whatever you can, like containers and paper, and recycle what you cannot reuse. It really is as simple as that.Finally turning off unused sources of power such as televisions and heaters will help the environment, as well as save you money.If everybody stuck to these rules, we would be doing a great thing by protecting the earth. So please take into consideration what I have said, and try to do your part. After all, it will be our next generation that will feel the effects.
课前三分钟演讲
我想就今年（2011）的大雪为题材，联系一下当前的全球变暖情况呼吁大家保护环境，急
额- - 你就随便写写啦
3分钟英语演讲，关于环境污染的,求助高手
环境（Environment）Like all other living beings, humans have clearly changed their environment, but they have done so generally on a grander scale than have other species. Some of these changes-such as the destruction of the world's tropical rain forests to create grazing land for cattle or the drying up of almost three-quarters of the Aral Sea, once the world's fourth-largest freshwater lake, for irrigation purposes-have led to altered climate patterns, which in turn have changed the distribution of species of animals and plants.Scientists are working to understand the long-term consequences that human actions have on ecosystems, while environmentalists-professionals in various fields, as well as concerned citizens in the United States and other countries-are struggling to lessen the impact of human activity on the natural world.Population Growth（人口增长）Human population growth may be seen to be at the root of virtually all of the world's environmental problems. Increasingly large numbers of people are being added to the world every year. As the number of people increases, more pollution is generated, more habitats are destroyed, and more natural resources are used up. Even if new technological advances were able to cut in half the environmental impact that each person had, as soon as the world's population size doubled, the earth would be no better off than before.The Population Division of the United Nations predicts that the 5.63 billion humans alive in 1994 will increase to 6.23 billion in the year 2000, 8.47 billion in 2025, and 10.02 billion in 2050. The UN's estimate assumes that population will peak and stabilize at 11.6 billion in 2200.Although it is true that rates of population increase are now much slower in the developed world than in the developing world, it would be a mistake to assume that the population growth problem is primarily a problem of developing countries. In fact, because larger amounts of resources per person are used in the developed nations, each citizen from the developed world has a much greater environmental impact than does a citizen from a developing country.Evidence now exists suggesting that the most important factors necessary to lower population growth rates in the developing world are democracy and social justice. Studies show that population growth rates have fallen in areas where several social conditions have been met. In these areas, literacy rates have increased, and women are given economic status equal to that of men and thus are able to hold jobs and own property; also, birth control information is more widely available, and women are free to make their own reproductive decisions.Global Warming（全球变暖）Like the glass panes in a greenhouse, certain gases in the earth's atmosphere permit the sun's radiation to heat the earth but retard the escape into space of the infrared energy radiated back out by the earth. This process is referred to as the greenhouse effect. These gases, primarily carbon dioxide, methane, nitrous oxide, and water vapor, insulate the earth's surface, helping to maintain warm temperatures. If the concentration of these gases were higher, more heat would be trapped within the atmosphere, and worldwide temperatures would rise.Within the last century, the amount of carbon dioxide in the atmosphere has increased dramatically, largely because of the practice of burning fossil fuels-coal and petroleum and its derivatives. Atmospheric scientists have now concluded that at least half of that increase can be attributed to human activity, and they have predicted that unless dramatic action is taken, temperature will continue to rise by between 1° and 3.5° C over the next century. The consequences of such a modest increase in temperature may well be devastating. Sea levels will rise, completely inundating a number of low-lying island nations and flooding many coastal cities such as New York and Miami. Many plant and animal species will probably be driven into extinction, agricultural regions will be disrupted, and the frequency of severe hurricanes and droughts is likely to increase.Depletion of the ozone layer（臭氧层变薄）The ozone layer, a thin band in the stratosphere （a layer in the upper atmosphere）, serves to shield the earth from the sun's harmful ultraviolet rays. In the 1970s, scientists discovered that the layer was being attacked by chlorofluorocarbons （CFCs）, chemicals used in refrigeration, air-conditioning systems, cleaning solvents, and aerosol sprays.The consequences of the depletion of the ozone layer are dramatic. Increased ultraviolet radiation will lead to a growing number of skin cancers and cataracts and also reduce the ability of people's immune systems to respond to infection. Additionally, the growth rates of the world's oceanic plankton, the base of most marine food chains, will be negatively affected, perhaps leading to increased atmospheric carbon dioxide and thus to global warming.Predicting the rate of ozone depletion is difficult. Optimists claim that if international agreements for the phasing out of ozone-depleting chemicals agreed to in Montréal in 1987 are followed, ozone loss will peak in the year 2000. With many of the world's fastest growing countries in the process of industrializing and modernizing, there is reason to believe that destruction will continue to increase well beyond that year.Air pollution（空气污染）A significant portion of industry and transportation is based on the burning of fossil fuels, such as gasoline. As these fuels are burned, chemicals and particulate matter are released into the atmosphere. These chemicals interact with one another and with ultraviolet radiation in sunlight in various dangerous ways. Smog, usually found in urban areas with large numbers of automobiles, can cause serious health problems. Acid rain is a serious global problem because few species are capable of surviving in the face of such acidic conditions. Acid rain has made numerous lakes so acidic that they no longer support fish populations. Acid rain is also thought to be responsible for the decline of many forest ecosystems worldwide.Water pollution（水污染）Estimates suggest that nearly 1.5 billion people lack safe drinking water and that at least 5 million deaths per year can be attributed to waterborne diseases. Water pollution may come from point or nonpoint sources. Point sources discharge pollutants at specific locations-from, for example, factories, sewage treatment plants, or oil tankers. The technology exists for point sources of pollution to be monitored and regulated, although political factors may complicate matters. Nonpoint sources-runoff water containing pesticides and fertilizers from acres of agricultural land, for example-are much more difficult to control. Pollution arising from nonpoint sources accounts for a majority of the contaminants in streams and lakes.With almost 80 percent of the planet covered by oceans, people have long acted as if those bodies of water could serve as a limitless dumping ground for wastes. Raw sewage, garbage, and oil spills have begun to overwhelm the diluting capabilities of the oceans, and most coastal waters are now polluted. Beaches around the world are closed regularly, often because of high amounts of bacteria from sewage disposal, and marine wildlife is beginning to suffer.Groundwater pollution（地下水污染）Water that seeps through porous rocks and is stored beneath the ground is called groundwater. Although groundwater is a renewable resource, reserves are replenished relatively slowly. When groundwater is depleted in coastal regions, oceanic salt water commonly intrudes into freshwater supplies. Saltwater intrusion is threatening the drinking water of many areas along the Gulf and Atlantic coasts.The EPA has estimated that, on average, 25 percent of usable groundwater is contaminated, although in some areas as much as 75 percent is contaminated. Contamination arises from leaking underground storage tanks, poorly designed industrial waste ponds, and seepage from the deep-well injection of hazardous wastes into underground geologic formations. Because groundwater is recharged and flows so slowly, once polluted it will remain contaminated for extended periods.Habitat Destruction and Species Extinction（居住环境破坏与物种灭绝）It is difficult to estimate the rate at which humans are driving species extinct because scientists believe that only a small percentage of the earth's species have been described. What is clear is that species are dying out at an unprecedented rate; minimum estimates are at least 4000 species per year, although some scientists believe the number may be as high as 50,000 per year. The leading cause of extinction is habitat destruction, particularly of the world's richest ecosystems-tropical rain forests and coral reefs. At the current rate at which the world's rain forests are being cut down, they may completely disappear by the year 2030. If growing population size puts even more pressure on these habitats, they might well be destroyed sooner.This loss is critical from several perspectives. The economic value of species lost and of natural products and drugs that never will be discovered or produced is incalculable. Similarly, it is impossible to place either a moral or an aesthetic value on our growing list of extinct species. As habitats are destroyed and species lost, the world is increasingly losing threads from the interconnected fabric of life.Chemical Risks（化学成分污染）Pesticide residues on crops and mercury in fish are examples of toxic substances that may be encountered in daily life. Many industrially produced chemicals may cause cancer, birth defects, genetic mutations, or death. Although a growing list of chemicals has been found to pose serious health risks to humans, the vast majority of substances have never been fully tested.Environmental Racism（环境歧视）Studies have shown that not all individuals are equally exposed to pollution. Three of the five largest commercial hazardous waste landfills in America are in predominantly black or Hispanic neighborhoods, and three out of every five black and Hispanic Americans live in the vicinity of an uncontrolled toxic waste site. The fact that the wealth of a community is not nearly as good a predictor of hazardous-waste locations as is the ethnic background of the residents reinforces the conclusion that racism is involved in the selection of sites for hazardous-waste disposal.Environmental racism takes international forms as well. Dangerous chemicals banned in the United States often continue to be produced and shipped to developing countries. Additionally, the developed world has shipped large amounts of toxic waste to developing countries for less-than-safe disposal.Energy Production（能源问题）The world cannot continue to rely on the burning of fossil fuels for much of its industrial production and transportation. Fossil fuels are in limited supply; in addition, when burned they contribute to global warming, air pollution, and acid rain.Nuclear energy as an alternative is opposed by many because of the massive devastation an accident can cause. The accident at the Chernobyl' nuclear power plant in 1986 scattered radioactive contamination over a large part of Europe. Approximately 135,000 people were evacuated, and human health has been dramatically affected. The World Health Organization released a report in late 1995 attributing the explosive increase in childhood thyroid cancer in Belarus, Ukraine, and Russia directly to the accident.One reasonable solution is to combine conservation strategies with the increased use of solar energy. The price of solar energy relative to traditional fuels has been dropping steadily, and if environmental concerns were factored into the cost, solar power would already be significantly cheaper. Although it is desirable to have a wider range of energy options, other alternative sources of power （such as wind, geothermal, or hydroelectric） are not likely to provide large-scale solutions in the forseeable future.ConclusionGlobal environmental collapse is not inevitable. But the developed world must work with the developing world to ensure that new industrialized economies do not add to the world's environmental problems. Politicians must think of sustainable development rather than economic expansion. 帮你找了一些资料，仅供参考。
3分钟英语演讲
1.Television Addiction Television provides us with a wide range of information and entertainment. However, it's a pity that it may also have a bad influence on young minds. For instance, some TV shows have too much violence and crime. These programs may lead youngsters astray.It is easy for students to become addicted to the excitement of these programs and neglect their homework. Parents must, therefore, keep an eye on what their children watch. 电视给我们提供广泛的信息和娱乐。
不过, 遗憾的是, 它也会对年轻人的思想有不良的影响。
举例来说, 有些电视节目有太多的暴力和犯罪。
这样的节目可能使年轻人误入歧途。
学生很容易沉溺于这些刺激的节目中而忽视了他们的功课。
因此, 父母们应该留意孩子所看的电视节目。
2.Man's Best Friend The dog is man's best friend. He can do many things for us. He can protect our homes. He can guide the blind. He is loyal to his master and never asks for a pay raise. The dog has also made many contributions to English. For example, if there were no dogs, how could a husband tell his wife her cooking tastes like dog food? How could the weatherman say, It's raining cats and dogs? So the next time a dog lifts a leg to your bicycle, don't kick him. Bend down and say, Take your time. 狗是人类最好的朋友。
它可以为我们做许多事情。
它可以保护我们的家。
它可以引导盲人。
它对主人忠实而且从不要求加薪。
狗还对英文有许多的贡献。
举例来说, 如果没有狗的话, 做丈夫的如何告诉他太太她煮的菜吃起来像狗食
气象播报员又如何能用猫和狗来表示雨下得很大呢
因此下次有狗对你的自行车抬腿撒尿时, 可别踢它。
要弯下腰对它说：“慢慢来。
”3.Global Warming Have you noticed that it's getting warmer and warmer every year? To put it simply, that's because of air pollution. Scientists tell us that because of air pollution, the earth's heat cannot escape. This is known as global warming. If this situation is allowed to continue, it will just keep getting hotter and hotter. Then, can you imagine what will happen? We should all, therefore, do our part to stop polluting the air and help save the world. 你有没有注意到天气一年比一年变得还要暖和了呢
简言之, 那是因为空气污染的缘故。
科学家告诉我们由于空气污染, 地球的热气无法散出去。
这就是为人所知的全球变暖。
如果我们任由这种情形一直持续下去, 地球就会变得越来越热。
那么, 你能想象会发生什么事吗
因此, 我们全都应该尽一己之力来防止污染空气并拯救地球。
国旗下演讲稿（初中生的那种），关于环境的，2~3分钟，急急急急急急急急急急 23日下午5点之前要
柳丝轻拂是对春天的承诺；烈日当空是对夏日的承诺；落叶飘飞是对金秋的承诺；银装素裹是对严冬的承诺。
孔子有云；“人而无信，不知其可。
”面对匆匆易逝的生命，信守生活中的一个又一个承诺，人生将因此而光辉灿烂，耀眼夺目
诚信做人是对朋友的承诺。
据《庄子》记载，尾生与女友约定桥下相见，女友如期未至，尾生信守承诺，竟至山洪暴发，水淹桥下，仍旧不肯离去。
直至溺水身亡。
此情此信，为世人称道，至今仍传为美谈；陈健为英勇献身的战友金训华立下了守墓一辈子的誓言，36年如一日。
为此，他放弃了城市的繁华，放弃了无量的前途，只为了那句藏在心中都未明言的承诺。
一句承诺，感天动地，陈健因此而当选为感动中国十大人物；恩格斯承诺要在经济上支持马克思，于是他选择从事了自己并不喜欢的商业。
一句承诺，使他为马克思主义的创立建立了的卓著功勋。
奋斗不息，是对人生的承诺。
司马迁立志著书，许下了“通古今之变，究天人之际，成一家之言”的人生承诺，即便遭受腐刑，也从未放弃，十余载的含辛茹苦，使他完成了“史家之绝唱，无韵之《离骚》”；李白浪迹天涯，许下了“安能摧眉折腰事权贵，使我不得开心颜”的承诺，即便一生与青山流水做伴，也决不屈服权贵，出卖人格；李时珍嗜医为命，自小便承诺要编著一本准确、完成的药学巨著，27年间，他跋千山，涉万水，亲自试药，用勇敢和执著兑现了自己的承诺，最终写就了《本草纲目》。
鞠躬尽瘁是对祖国的承诺。
“路漫漫其修远兮，吾将上下而求索。
”自从屈原许下了振兴楚国的承诺后，便一直信守承诺。
无论前方的路多么艰险，无论自己受到怎样的迫害。
即使投江自尽，也决不违背承诺，与小人同流合污；林则徐忠君爱国，虎门销烟，即便被遣戍新疆，仍许下“苟利国家生死以，岂因祸福避趋之”的报国承诺，其忧民之心，忠君之意，令人敬畏；鲁迅弃医从文，立下“寄意寒星荃不察，我以我血荐轩辕”的人生誓词，面对“风雨如磐”的祖国，鲁迅将他那一腔爱国热忱托寒星传达，呼唤着中华民族的灵魂
信守承诺是对心灵的洗礼；信守承诺是对人格的升华；信守承诺是对品质的砥砺；信守承诺是对祖国的忠诚；信守你的承诺，无论这个承诺或大或小,或轻或重,或易或难.生命将在你的一个个承诺后闪烁灿烂夺目的光芒
