IELTS作文——GLOBALWARMING.doc

GLOBAL WARMINGHow do humans contribute to the greenhouse effect?While the greenhouse effect is an essential environmental prerequisite for life on earth, there really can be too much of a good thing.The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.-Burning natural gas, coal and oil, including gasoline for automobile engines, raise the level of carbon dioxide in the atmosphere. -some farming practices and land-use changes increase the levels of methane and nitrous oxide.-many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and global warming that is currently under way.-deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.-population growth is another factor, because as more ppl use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new ppl, more greenhouse gases enter the atmosphere. What Can We Do?个人1. Reduce, Reuse, RecycleDo your part to reduce waste by choosing reusable products instead of disposables. Buying products with minimal packaging (including the economy size when that makes sense for you) will help to reduce waste. And whenever you can, recycle paper, plastic, newspaper, glass and aluminum cans. If there isnt a recycling program at your workplace, school, or in your community, ask about starting one. By recycling half of your household waste, you can save 2,400 pounds of carbon dioxide annually.2. Use Less Heat and Air ConditioningAdding insulation to your walls and attic, and installing weather stripping or caulking around doors and windows can lower your heating costs more than 25 percent, by reducing the amount of energy you need to heat and cool your home. Turn down the heat while youre sleeping at night or away during the day, and keep temperatures moderate at all times. Setting your thermostat just 2 degrees lower in winter and higher in summer could save about 2,000 pounds of carbon dioxide each year.3. Drive Less and Drive SmartLess driving means fewer emissions. Besides saving gasoline, walking and biking are great forms of exercise. Explore your community mass transit system, and check out options for carpooling to work or school. When you do drive, make sure your car is running efficiently. For example, keeping your tires properly inflated can improve your gas mileage by more than 3 percent. Every gallon of gas you save not only helps your budget, it also keeps 20 pounds of carbon dioxide out of the atmosphere.4. Buy Energy-Efficient ProductsWhen its time to buy a new car, choose one that offers good gas mileage. Home appliances now come in a range of energy-efficient models, and compact florescent bulbs are designed to provide more natural-looking light while using far less energy than standard light bulbs. Avoid products that come with excess packaging, especially molded plastic and other packaging that cant be recycled. If you reduce your household garbage by 10 percent, you can save 1,200 pounds of carbon dioxide annually.5. Plant a TreeIn addition to reducing the gases we emit to the atmosphere, we can also increase the amount of gases we take out of the atmosphere. Plants and trees absorb CO2 as they grow, sequestering carbon naturally. Increasing forestlands and making changes to the way we farm could increase the amount of carbon were storing.They are an integral part of the natural atmospheric exchange cycle here on Earth, but there are too few of them to fully counter the increases in carbon dioxide caused by automobile traffic, manufacturing and other human activities. A single tree will absorb approximately one ton of carbon dioxide during its lifetime. 公司There are many possible wedges, including improvements to energy efficiency and vehicle fuel economy (so less energy has to be produced), and increases in wind and solar power, hydrogen produced from renewable sources, biofuels (produced from crops), natural gas, and nuclear power. There is also the potential to capture the carbon dioxide emitted from fossil fuels and store it undergrounda process called carbon sequestration.Long-term changes in the business climateThe problem for the business world is that all of the incremental solutions we keep hearing about - use less electricity, drive a hybrid, buy recycled and organic products - dont exactly set entrepreneurs imaginations on fire. Sure, such efforts cut energy usage bit by bit, but global warming presents opportunities beyond dutiful belt-tightening.Saving the world and making a profit is not an either/or proposition, says Bob Willard, a former IBM (Research) executive and author of The Sustainability Advantage.What makes cashing in on climate change tricky is the fact that it could go in one of two radically different directions. Either the world will continue to heat up, or a complex series of climate changes could tip us over into a sudden new ice age - one so severe, suggests Peter Schwartz, co-founder of the Global Business Network consultancy, that the planets remaining arable land would only be able to support a mere two billion people. (Schwartzs 2003 report for the Pentagon said plainly that global warming would be a greater threat to national security in the 21st century than terrorism).But according to global warming scenarios from Australian insurer IAG, we wont see major changes in one direction or the other until at least 2040, long past the tenure of todays CEOs.These companies have taken the first step in fighting global warming by developing more climate friendly refrigeration. Now, however, is the true test of Coca-Cola, McDonalds and Unilevers commitment to confronting this issue; we urge them to implement this technology in North America, where its use is most important, as quickly as possible. GovernmentThe government made a law called The Clean Air Act so there is less air pollution. Global warming is making people get very bad illnesses that could make them disabled, very sick, and sometimes even die. The Clean Air Act is making many companies change their products to decrease these problems. Part of the law says that you may not put a certain amount of pollutants in the air. Making and using these products let out too much volatile organic compounds (VOCs), ozone-destroying chemicals (chlorofluorocarbons (CFCs), and related chemicals (such as CO2) into the air. Now, almost all of these products have a label on them telling people what this product can do to the environment and many people. By 2015 all products listed on the Clean Air Act will have this label on them: Almost all of the other chemicals that could be harmful will have this label on them hopefully by this time (2015) as well.The Clean Air Act has also made car companies change some of the things inside of the cars. Cars pollute a lot. While cars make more than half of the worlds smog (visible pollution in the air), many things that cars need to move and heat up make even more pollution. Some things that are inside of cars, buses, trucks, and motorcycles, like gasoline, pollute the air when the fuel is burned. It comes out as a chemical and when mixed in the air, forms smog. Smog is a kind of pollution that you see in the form of a cloud. If you have ever been to California you can see a lot of smog in some places. Sometimes the smog gets so bad that you cannot see at all! Smog forms when car exhaust, pollution from homes, and pollution from factories mixes in the air and has a chemical reaction. The suns heat and light add to the reaction.Cars, buses, and trucks are also responsible for over 50% of dangerous chemicals let into the air. Some of these chemicals can cause cancer, birth defects, trouble breathing, brain and nerve damage, lung injures, and burning eyes. Some of the pollutants are so harmful that they can even cause death.(以上也可以是公司如何如何)Even if we stopped emitting greenhouse gases (GHGs) today, the Earth would still warm by another degree Fahrenheit or so. But what we do from today forward makes a big difference. Depending on our choices, scientists predict that the Earth could eventually warm by as little as 2.5 degrees or as much as 10 degrees Fahrenheit.A commonly cited goal is to stabilize GHG concentrations around 450-550 parts per million (ppm), or about twice pre-industrial levels. This is the point at which many believe the most damaging impacts of climate change can be avoided. Current concentrations are about 380 ppm, which means there isnt much time to lose. According to the IPCC, wed have to reduce GHG emiss