Archive for July 25, 2010
“Acid rain” is a broad term used to describe several ways that acids fall out of the atmosphere. A more precise term is acid deposition, which has two parts: wet and dry.
Wet deposition refers to acidic rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals. The strength of the effects depend on many factors, including how acidic the water is, the chemistry and buffering capacity of the soils involved, and the types of fish, trees, and other living things that rely on the water.
Dry deposition refers to acidic gases and particles. About half of the acidity in the atmosphere falls back to earth through dry deposition. The wind blows these acidic particles and gases onto buildings, cars, homes, and trees. Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone.
Prevailing winds blow the compounds that cause both wet and dry acid deposition across state and national borders, and sometimes over hundreds of miles. Scientists discovered, and have confirmed, that sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain. In the US, About 2/3 of all SO2 and 1/4 of all NOx comes from electric power generation that relies on burning fossil fuels like coal.
Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. Sunlight increases the rate of most of these reactions. The result is a mild solution of sulfuric acid and nitric acid.
How Do We Measure Acid Rain?
Acid rain is measured using a scale called “pH.” The lower a substance’s pH, the more acidic it is. Pure water has a pH of 7.0. Normal rain is slightly acidic because carbon dioxide dissolves into it, so it has a pH of about 5.5. As of the year 2000, the most acidic rain falling in the US has a pH of about 4.3.
Acid rain’s pH, and the chemicals that cause acid rain, are monitored by two networks, both supported by EPA. The National Atmospheric Deposition Program measures wet deposition, and its Web site features maps of rainfall pH (follow the link to the isopleth maps) and other important precipitation chemistry measurements.
The Clean Air Status and Trends Network (CASTNET) measures dry deposition. Its web site features information about the data it collects, the measuring sites, and the kinds of equipment it uses.
Effects of Acid Rain
Acid rain causes acidification of lakes and streams and contributes to damage of trees at high elevations (for example, red spruce trees above 2,000 feet) and many sensitive forest soils. In addition, acid rain accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation’s cultural heritage. Prior to falling to the earth, SO2 and NOx gases and their particulate matter derivatives, sulfates and nitrates, contribute to visibility degradation and harm public health.
Have a look around – what do you see? There’s a haze in the sky, some dusty rubbish clogs a drain, trees are curling and dropping their leaves, a constant hum fills the air. It rises and falls with the flow of traffic. A sea bird is yanking at a piece of discarded fishing line that’s wrapped around its neck. A beetle hitches a ride on a piece of rubbish that drifts across the harbour. What a mess! It’s all ours and it’s called POLLUTION.
FACTS
The responsibility for pollution rests with us all. As individuals we are responsible. The faceless multinational corporations who pollute Australia every day are responsible. Our government who allow them to set up their polluting factories, smelters and power stations with the promise of cheap water and cheap power are responsible. We are all responsible.
Air Pollution
- Air pollution is a nasty little beast. It’s almost impossible to see, it moves on the wind and can travel great distances. It knows no borders and respects no countries. It settles on the land and water, causing massive problems for our environment and us. Some types of air pollution get more attention than others. And so they should. Carbon Dioxide and Methane are two seriously nasty pollutants that are directly attributing to global warming and climate change.
Water Pollution
- Our water is also in a bit of strife. Activities that we do on land can affect the quality of our water. Our waste often gets washed into our waterways and coasts without any treatment. This waste might be the big bits that you can see like plastic bags, dead animals and ciggie butts. But it’s also the tiny, microscopic nasties that we can’t see. They build up and pollute our water to such an extent that waterways become unliveable for native plants, fish and animals. Not only are we running low on water we somehow reckon it’s a good idea to pollute the good stuff we have.
Land Pollution
- As for our land, well the story doesn’t improve much. By 1991, 30% of Victoria’s agricultural land was considered ‘severely degraded.’ Rising salinity (due to over irrigation and loss of native vegetation) costs Victoria $50 million in lost agricultural production every year and the direct costs of salinity are expected to reach $77–166 million by 2050.
The bad news is that just about everything we do can cause pollution. The good news is that in most cases, there are easy ways to reduce or even stop the pollution.
We send more and more rubbish ‘away’ to landfill every year. There is no away, everything ends up somewhere and we are all responsible.
pokok mati dalam kawasan rumah anda???? jangan buang dan bakar… ada sesuatu yang boleh anda lakukan dengannya. daripada dibakar dan menambahkan gas rumah hijau….. projek nie boleh anda lakukan untuk landskap taman dan hiasan di sudut rumah anda sebagai background, dan landskap kejur..
1. kerat dahan pokok tersebut kepada bongkah2 seperti rajah di atas… potong banyak2 dan pelbagai saiz lagi cun… lebar pemotongan yang dicadangkan adalah 5cm… bergantung kepada ketinggian pagaran anda.. jika terlalu nipis, bimbang binaan anda tidak kukuh..
2. siapkan rangka empat segi mengikut kelebaran dahan yang dipotong dan susun seperti rajah di atas… pastikan ruang2 kosong diletakkan dengan dahan yang kecil untuk lebih cun…
3. pagaran yang telah siap akan kelihatan seperti ini… penggunaan pelbagai jenis potogan kayu, penggunaan pelbagai jenis warna kayu menambahkan lagi seri pagaran anda…. p/s, untuk potongan dahan bersaiz kecil ( diameter 10sm – 15 sm ) lebar (3sm) luas bingkai lebih kurang 2kaki x 1 kaki boleh digantung pada dinding sebagai hiasan dinding… selamat mencuba…
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You can help to reduce the demand for fossil fuels, which in turn reduces global warming, by using energy more wisely. Here are 10 simple actions you can take to help reduce global warming.
1. Reduce, Reuse, Recycle
Do 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 newspaper, Plastic, paper, glass and aluminum cans. If there isn’t a recyching program 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 Conditioning
Adding 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 you’re 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. Change a Light Bulb
Wherever practical, replace regular light bulbs with compact fluorescent light (CFL) bulbs. Replacing just one 60-watt incandescent light bulb with a CFL will save you $30 over the life of the bulb. CFLs also last 10 times longer than incandescent bulbs, use two-thirds less energy, and give off 70 percent less heat.
If every U.S. family replaced one regular light bulb with a CFL, it would eliminate 90 billion pounds of greenhouse gases, the same as taking 7.5 million cars off the road.
4. Drive Less and Drive Smart
Less driving means fewer emissions. Besides saving gasoline, walking and biking are great forms of exercise. Explore your community’s 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.
5. Buy Energy-Efficient Products
When it’s 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 can’t be recycled. If you reduce your household garbage by 10 percent, you can save 1,200 pounds of carbon dioxide annually.
6. Use Less Hot Water
Set your water heater at 120 degrees to save energy, and wrap it in an insulating blanket if it is more than 5 years old. Buy low-flow showerheads to save hot water and about 350 pounds of carbon dioxide yearly. Wash your clothes in warm or cold water to reduce your use of hot water and the energy required to produce it. That change alone can save at least 500 pounds of carbon dioxide annually in most households. Use the energy-saving settings on your dishwasher and let the dishes air-dry.
7. Use the “Off” Switch
Save electricity and reduce global warming by turning off lights when you leave a room, and using only as much light as you need. And remember to turn off your television, video player, stereo and computer when you’re not using them.
It’s also a good idea to turn off the water when you’re not using it. While brushing your teeth, shampooing the dog or washing your car, turn off the water until you actually need it for rinsing. You’ll reduce your water bill and help to conserve a vital resource.
8. Plant a Tree
If you have the means to plant a tree, start digging. During photosynthesis, trees and other plants absorb carbon dioxide and give off oxygen. 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.
9. Get a Report Card From Your Utility Company
Many utility companies provide free home energy audits to help consumers identify areas in their homes that may not be energy efficient. In addition, many utility companies offer rebate programs to help pay for the cost of energy-efficient upgrades.
10. Encourage Others to Conserve
Share information about recycling and energy conservation with your friends, neighbors and co-workers, and take opportunities to encourage public officials to establish programs and policies that are good for the environment.
These 10 steps will take you a long way toward reducing your energy use and your monthly budget. And less energy use means less dependence on the fossil fuels that create greenhouse gases and contribute to global warming.
