Chapter+4

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= = **Headings of Chapter Four** Wordle.net (http://www.wordle.net/show/wrdl/1653346/Science_Textbook_Headings)

Less than ¼ of Earth’s surface is not covered by water. Humans use this land for three things: development, agriculture and mining. Every year, five million hectares of former farmland is developed in the USA. Structures like houses, schools and bridges are developments, or permanent structures built by humans. Development destroys the habitats of the organisms that used to live in a given area. Barely 1/12 of Earth’s surface can be used for agriculture. New farmland is created by clearing forests, draining swamps, and irrigating deserts. While agriculture is important, the creation of new farmland disrupts the ecosystems of the area being converted. Farms grow fruits, vegetables and grains for humans, but also livestock. Farms must also grow food for their livestock, if they have any. Farms can also grow non-edible products, like cotton or tobacco. Mining is the removal of non-renewable resources. Strip mines are used when the resource is close to the surface. Soil is stripped off the ground until the resource is reachable. Sometimes, the soil is replaced when mining is completed. It can take years for the soil to return to its original state. The soil is loose, as a result of the mining, and thus more susceptible to erosion. Underground mining is used when the resource is further underground. The resource is mined, and then carried up a shaft.

Section 2-Landfills and Waste Every second, about 694 plastic water bottles are thrown away in the USA. Each person on Earth produces an average of two kg of waste every day. An average of more than seven rubber tires are thrown out every second. 38% of all the waste in landfills are paper and cardboard products, 16% does not fall into a general category, 13% is yardwaste like grass clippings or fallen branches, 10% is foodwaste, 9% is plastic 8% is metal 6% is glass At least 61% of the contents of landfills is recyclable. Only 27% of our waste does get recycled. Incineration makes up 17%. Landfills are the most "popular" destinations for waste, taking in 56%. Soil stores and filters water, nourishes plants, and is home to many different kinds of insects and bacteria. It takes thousands of years for soil to form. There are many different layers of soil, all of which are on the top layer of the earth: the crust.

-The top layer of soil is called “litter.” The litter is made up of rocks, dead animals and plant matter, decomposers and roots. -The next layer is the “topsoil.” The topsoil includes dead animals and plant matter, pebbles, nutrients, water, worms, insects, bugs, bacteria, and roots. -There are fewer plants or animals in the subsoil. There is not as much water, but more rocks. -The parent material is actually part of both the subsoil and the bedrock. This layer is mostly small rocks. -The last layer of soil is bedrock, the earth’s crust. The bedrock is made up of larger rocks.

Chapter 4, Section Five- Global Changes in the Atmosphere media type="youtube" key="qUfVMogIdr8" height="344" width="425"

The Ozone Layer is a thin layer of Ozone particles that sits in the upper atmosphere, 30 kilometers above the Earth's surface. Ozone particles are constantly being made and destroyed. They recycle each other. When sunlight strikes an Ozone particle, the energy is absorbed by the molecule, causing the molecule to break into an oxygen atom AND an oxygen molecule. The particles float until they crash into each other. This creates a new Ozone particle. However, even with this system still in effect, the Ozone layer is thinning, and a hole is forming.

This photo shows the hole forming. The blue represents the growing Ozone hole. By now, it covers much of southern South America and Antarctica. The Ozone hole was created by worldwide use of a chemical called chlorofluorocarbon (CFCs). Chlorofluorocarbons are a mixture of man-made gases that contain chlorine and fluorine. As a result of this hole, more direct sunlight and ultra-violet rays are reaching the earth. Scientists have been searching for a way to stop CFC output. However, because these were used in refrigerators and air conditioners, these products are now using less harmful substances. media type="custom" key="5380797" width="250" height="250"

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= Chapter 4 Section 2- Wasye Disposal and Recycling =

The Problems of Waste Disposal
"In their daily activities, people generate many types of waste, including used paper, empty packages, and food scraps. The waste materials produced in homes, businesses, school, and other places in the community are called municipal solid waste. Other sources of waste include construction debris and certain argiculural and industrail waste. Three methods of handling solid waste are burning, burying and recycling. Each method has advantages and disadvantages."-Science Explorer (p.123)

Landfills media type="youtube" key="z7EEC3ctQro" height="344" width="425"

Incineration media type="youtube" key="sdD1NjDsBUc" height="344" width="425" media type="youtube" key="fwikqijnftQ" height="344" width="425"

Hazardous Waste media type="youtube" key="nmqog6wEWCI" height="344" width="425"



Section 4- Air Pollution
Air pollution is caused by emissions, both natural and manmade. Like when you burn gas in your car, the emissions (or fumes) that come out of the tail pipe are air pollution, or when a volcano errupts, the material into the sky is also a form of air pollution. One kind of air pollution is smog. Smog is what happens when a temperature inversion happens. A temperature inversion happens when the cool air is trying to rise, and gets trapped by a layer of warm air, and brings the air and pollution closer to the Earth's surface. Snog is caused by toxic oxygen called ozone. Gases burned in a car release into the air, react to sunlight, and the ozone and smog are made. A picture of smog hanging over Kilaueu, Hawaii.

Another form of air pollution is acid rain. Acid rain is any kind of moisture from the sky, that is more acidic than normal. It's caused from power plants burning coal and gas, and releasing it into the air. These emissions release nitrogen and sulfer oxides, those mix with the water in the air, form nitric and sulfuric acid, than the acids return to Earth as any form of percipitation. Acid rain effects many things, such as fish, plants, and buildings. Acid rain changes the fish's habitat, and raises chances of eggs being infertile. When plants take acid rain in through the roots, it damages their leaves, stems, and the nutrients in the soil. It can also eat away at buildings and national monuments. It will cause decoloration in some areas, rough areas in the stone, and this damage is not reversable. Discovery Channel video about how acid rain eats away monuments in Washington, D.C. Did you know that the air in your homes can be polluted? Well, it can be. There is inside air pollution that is very dangerous and there are many causes. Some of the causes are dust,pet hair,toxic chemicals, and smokes. Also, if there are incompletely burned wood,coal,oils,or gases they can build up and can be very deadly. There is also things called radon which is radio active that is colorless and odorless formed by rocks underground which is in indoor air and can cause lung cancer after many years of takeing them in. There are only a few ways that you can reduce the air pollution. The most easiest way is to reduce energey. Such as car pulling will help. Air pollution is very dangrous and needs to be reduced.