2019-2020年高中英语Unit4Globalwarming--Backgroundination.doc

2019-2020年高中英语Unit4Globalwarming-BackgroundinformationPart Two: Teaching ResourcesSection 2: Background information on THE EARTH ISBEING WARMERBUT DOES IT MATTER?I. What is global warming?Global warming is the name of the theory (idea) that the worlds atmosphere (air) has bee hotter over the last two hundred years. It is also used as the name of this event (an event is sth. that happens). Some people say that global warming is a very serious problem for the world, that it causes floods for example. Others say that there is nothing for the world to worry about.It is a fact that the atmosphere of the world is in general about a half of a degree Celsius hotter than it was two hundred years ago. But many people disagree about whether this is caused by mans pollution (from cars and factories for example), or a natural change.II. What is greenhouse effect?The greenhouse effect is a way that the suns rays make sth. warmer.A greenhouse is a glass or plastic building where people raise plants. The rays of the sun shine into the greenhouse and bee warmth. The glass or plastic holds the warmth inside the greenhouse.We can also see the greenhouse effect when the sun makes the inside of a car hot.Many people are very interested in the greenhouse effect in the atmosphere of the Earth. Factories, farms, and other things that human beings do make many different gases that go into the Earths atmosphere. The gases carbon dioxide, methane, and chlorofluorocarbons make the atmosphere hold more of the suns heat, so the Earth might get warmer. If the Earth does get warmer, this could cause many serious problems. Different parts of the Earth could bee warmer or colder, wetter or drier. The ice at the north and south poles could melt, which would make the sea level higher, and flood many cities that are close to the sea.Scientists, politicians, and ordinary people disagree about what is happening and what might happen. Scientists think that weather has been especially warm the last few years, but they disagree about whether this warming is caused by the things that human beings are doing or is happening naturally.III. What is Earth Care International? Earth Care builds the awareness, knowledge, and mitment in youth necessary to create a healthy, sustainable future. Our approach is based on the recognition that sustainability can only be achieved by linking issues of economics, social justice, and the environment infused with a multicultural awareness.We develop young visionary leaders capable of creating an abundant and sustainable world. These visionary leaders will make choices that will improve their relationship to the environment, one another and ultimately the world. We educate youth to understand the local and global connections between human and natural systems. “A movement thats courageous and visionary on the environment but cowardly and ignorant about the social issues, will fail. And on the other side, a movement that is visionary and passionate on the social side but is ignorant and indifferent on the ecological side will also fail. Theres a light at the crossroads. Hope is at the crossroads.”IV. Celebrate Earth Days 35th Anniversary! “地球日”三十五周年纪念！On April 22, 1970, 20 million people across America celebrated the first Earth Day. It was a time when cities were buried under their own smog and polluted rivers caught fire. Now 35 years later, Earth Day is being celebrated around the globe. Through the bined efforts of the U.S. government, grassroots organizations, and citizens like you, what started as a day of national environmental recognition has evolved into a world-wide campaign to protect our global environment. V. Earth Day background informationOur planet is a plex system of land, air, and water. Living things depend on each other and this system for existence. Over the thousands of years since life has existed on the earth, it has undergone some changes. The following are some of these changes:Many species became extinct before mankind made its appearance, however, since humans have existed on the earth, the extinction rate has risen dramatically. More than 4,000 species are currently considered threatened. Plant and animal life bee endangered for many reasons. Forest depletion, hunting, and pollution are the most obvious factors. When an animal bees endangered, dozens of other species can also bee endangered. For example, elephants disappeared from southern Africa about 80 years ago because of hunters. Elephants continue to be hunted, mainly for their costly ivory tusks. The endangerment of elephants also has endangered such animals in their area as wildebeest and antelope who live off of the open-grassland which elephants create by eating their way through a jungle.Oxygen-producing trees and plants are being cut down for the purpose of growing foods, grazing livestock, making paper products, etc. The cutting down of forests puts forest wildlife at risk and decreases the oxygen in the air. It also defaces the natural beauty of the planet. Tropical rain forests are often cleared for farming. The soil in these forests are poor in nutrients, and within a few years the crops fail and the land is abandoned. New forests are cleared. Pollution has bee more and more a problem, especially in the past century with the drastic increase in technology. Garbage, sewage, chemicals, and oil are being dumped into the ocean. As human population grows, people are looking to the ocean more for resources. Landfills and littering have polluted the land. Dangerous levels of chemical emissions from cars, planes, factories, aerosol cans, etc., enter the air without end. Plants and animals are dying because of pollution.Ozone is a form of oxygen that has collected in a layer about 30 km above the earths surface. This ozone layer protects us from most of the dangerous ultraviolet radiation from the sun. Without this layer, living things could not thrive on the earth. Satellites have detected in the last ten or so years damage done to the ozone. The damage is often referred to as a hole in the ozone. This damage has been caused by certain chemicals being emitted into the atmosphere that react with the ozone. One major chemical is called chlorofluorocarbons (CFCs), which are monly used in such products as solvents used for cleaning electronics such as television and puter circuit boards, cooling fluid in automobile air conditioners, aerosol spray cans, etc. Ozone depletion has effected the temperature of the earth. Some scientists say that if CFCs were not in existence, the earth would be cooler now than it presently is. This global warming is often called the greenhouse effect. Environmentalists have been actively aware of these issues, and are doing their best to promote awareness. In the late sixties, Senator Gaylord Nelson of Wisconsin first suggested the idea of an Earth Day to bring people to the realization that Earth has some problems, and we as humans need to do something about it. The first Earth Day celebration took place on April 22, 1970. It was a nationwide focus. Twenty-million Americans joined in to proclaim the message, “Give Earth a Chance.” A series of events took place on a munity level, most of which were organized by student groups. Since then, Earth Day has expanded. The tenth anniversary of the celebration in 1980 was sponsored partly by The United States Environmental Protection Agency. The twentieth anniversary in 1990 was sponsored by hundreds of environmental organizations across the nation. Every year on April 22, all Americans are asked to celebrate Earth, to take a look at what is being done to help our ecosystem, and to ask ourselves, “What am I doing to help?” Many people use the day to plant flowers or trees, clean up munities, promote recycling, forest and wildlife protection, etc., and look to the future of the earth.