The Greenhouse Effect

Carbon dioxide is helping to warm the earth to the temperature we are used to having. But when too much carbon dioxide is released into the atmosphere it is dangerous. Before the heat from the sun would escape back out into space. But now the heat gets trapped in the atmosphere. Just like how that glass roofs and walls of a greenhouse let the sun's heat in but keeps the heated air from getting out. When there is to much pollution it lets too much much heat in. witch is what we call global warming. Scientist call that system the green house effect. Scientists say that because of the greenhouse effect the earth's weather will change in the next decade then it has in tens of thousands of years.

Global Warming is when the earth warms because there is too much pollution and it makes a big wall blocking the heat from the sun from getting out of the atmosphere. But it lets the heat come in so then the earth keeps heating up. With more carbon dioxide going into our atmosphere everyday it just keeps making the big wall bigger and bigger. Scientist believe that the change in the weather was just from growth of cities near weather stations. Pavement and roofs collect more heat then soils and plant leaves, that is why cities have warmer climates than remote places. Even oceans that were measured far away from cities had a rising heat. Climatologist still don't understand the earth's climate system completely. But they have decided that global warming will be most noticeable in the cold areas. Mostly in the Northern Hemisphere, because it has fewer oceans that absorb heat than the Southern Hemisphere. They predicted that places like Alaska, Canada, and Northern Russia would heat up more then the whole earth would together. That 's what is happening right now. In the twentieth century the earth's temperature rose one degrees Fahrenheit , Alaska's temperature rose five degrees in the last thirty years of that century. In large parts of Russia the temperature rose as much. Also a similar warming was going on over at the antarctic peninsula.

The Carbon Cycle

Carbon gets into the air through a process called the carbon cycle. Carbon is very common on the earth, like in some rocks there is carbon also in coral reefs. Huge amounts of carbon are stored for a time in soils, in ocean waters, and in sediments stored at the bottom of ocean floors. The scientist are still figuring out parts of of the carbon cycle and learning where all the carbon that is produced goes. When the carbon is freed from the rocks by erosion it mixes with other elements and makes carbon compounds like carbon dioxide. The green plants take carbon dioxide from the air. Inside the plant carbon dioxide is formed into leaves, wood, and other parts of plant like seeds, fruits, and leaves that people eat. People, animals, and the plants give off carbon dioxide when they metabolize (burn) their food, and while they decay after they die. Every time you breathe you release carbon dioxide into the air. The carbon dioxide might get picked up by a plant, soil, the ocean or some other piece of the carbon cycle. For over 420,000 years the carbon cycle has been keeping the amount- of carbon dioxide in the earth's atmosphere at less then 325 parts per million.

Swedish scientists said that if the amount of carbon dioxide doubled it would create enough heat to increase the earth's temperature by several degrees. Since people have started building factories and building big amounts of fossil fuels there was 25 percent increase in the amount of carbon dioxide in the earth's atmosphere. To figure that out scientists measure the carbon dioxide that got trapped inside glaciers hundreds of years ago. Then they compare the measurements to the measurements of todays air. Until recently half the carbon dioxide we produced was being absorbed by the plants and oceans. But now we are not just making more carbon dioxide the trees and oceans are absorbing less and less of it. This is happening because there are not as many trees as before. All over forests are being cut down because the farmers cut down trees to make more room for crops or to open more space to grow cattle or beef. 100 acres of the world's remaining forest are destroyed every minute everyday of the year. Burning wood adds carbon dioxide into the air. Scientists think that burning the rain forests in Brazil every year could be responsible for one tenth of the carbon dioxide added to the atmosphere each year. Because of Brazil's massive tree clearing efforts it is ranked third for carbon dioxide emissions in the world.

The Effects of Global Warming

Carbon dioxide is helping to warm the earth to the temperature we are used to having. But when too much carbon dioxide is released into the atmosphere it is dangerous. Before the heat from the sun would escape back out into space. But now the heat gets trapped in the atmosphere. Just like how the glass roofs and walls of a greenhouse let the sun's heat in but keeps the heated air from getting out. When there is to much pollution it lets too much much heat in. witch is what we call global warming. Scientist call that system the green house effect. Scientists say that because of the greenhouse effect the earth's weather will change in the next decade then it has in tens of thousands of years. The amount of salt will increase killing fresh water fish and contaminating our drinking water when the sea levels rise. Many ports and beaches will be flooded away. People on the coast of Louisiana, Texas, and Florida might have to move from their homes. The last ten years have been the hottest since record keeping started. All the people in the world create five and a half billion tons of carbon dioxide every year. Seventy-five percent of the carbon dioxide is produced by burning fossil fuels. Gases like methane and nitrous oxide have been in our atmosphere for a long time. We are producing them in much bigger amounts. Other gases called CFC are newer and are only made by factories and laboratories.

The release of carbon dioxide and other heat trapping gases from smokestacks, tail pipes, and burning forests, has raised the temperature of the earth’s surface by one degree since 1900. Gases like carbon dioxide and methane let the sun reach the earth and keep the heat from going back out into space, which heats the earth’s surface. As the amounts of carbon dioxide that is released increases, the atmosphere continues to get warmer. Since 1970, the temperature of the earth’s surface has gone up about three times the average in the twentieth century. By 2100 the sea levels are said to rise seven to three inches. As you can see, these changes will continue for centuries.