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Global Warming.

Hot, hot, hot! Earth's climate seems to get warmer every year. What's happening? And what can we do about global warming?

This past summer, a patch of ice one mile wide melted at the North Pole. Crops in Texas withered and died, fried by hot temperatures and a record-breaking eight weeks without rain. Severe drought allowed wildfires to burn millions of acres of forest across the West. Were these events caused by global warming?

Many scientists agree that global warming--the artificial heating of the atmosphere--is beginning to change the world's climate.

The National Aeronautics and Space Administration (NASA) reports that the average temperature on Earth's surface has risen by one degree in the past 100 years. The 10 warmest years of the 20th century occurred in the last 15 years--and 1998 was the warmest year on record.

Many scientists believe that unless people make efforts to reduce global warming, we may face harmful consequences. In addition to warmer temperatures, the ocean's sea level has risen between 4 and 10 inches in the past century. And the polar ice caps have been thinning at both the North and South poles.

Environmental Threat?

What causes global warming? Scientists explain that gases trapped in the atmosphere create a "greenhouse effect." These gases protect life on Earth much as a greenhouse protects plants in winter.

Some of the greenhouse effect is normal. Water vapor, carbon dioxide, and other gases trapped in the atmosphere help keep Earth warm enough to sustain life.

What worries experts is that Earth's temperature is rising abnormally--all because of a big increase in the amount of certain gases in the atmosphere.

Large amounts of carbon dioxide enter the atmosphere when fossil fuels such as oil and coal are burned. Because we are burning more and more fossil fuels, the amount of carbon dioxide in the air has been rising steadily. It is now 30 percent higher than it was when the Industrial Revolution began 200 years ago.

Cars and power plants are the leading sources of this added carbon dioxide. That means that every time you use the family car, run the dishwasher, or turn on the TV, more carbon dioxide is released into the air.

The United Nations, in a report dated October 26, said that if we stay on our current course, the average global temperature is likely to rise from 2.7 to 11 degrees in the next century. That may not sound like much, but during the last ice age, the average temperature was only 9 degrees cooler than today.

Hundreds of the world's most respected climate scientists worked to develop this report. They said that humans have contributed substantially to global warming.

Global Warming a Myth?

Not everyone agrees that global warming is real--or that an increase in carbon dioxide and other gases in the atmosphere causes global warming.

Recently, a group of scientists suggested that a possible cause of Earth's warmer temperatures could be an increase in the sun's heat. Other scientists blame warmer temperatures on natural fluctuations in Earth's weather patterns.

Pat Michaels, a University of Virginia scientist, told JS that temperatures vary naturally so much each year that scientists' predictions cannot be accurate.

Or Is Global Warming a Fact?

But a majority of scientists believe that global warming is a serious problem. How serious? Says NASA scientist James E. Hansen, "What you can say about global warming is that it is enough to affect the probability [chances] of having a warmer-than-normal season. But it is not enough to make every season warmer than it used to be 50 years ago."

What Has Been Done?

In 1997, delegates from 160 nations met in Kyoto, Japan, to work out a treaty to reduce global warming. The treaty set specific targets for reducing greenhouse-gas emissions. To meet the treaty's goals, the U.S. and many other countries would have to reduce their use of fossil fuels.

These countries would have to spend large amounts of money to develop new technology to meet those goals. So far, only eight countries have ratified the treaty. The U.S. is not one of them.

If global warming is not a real problem, then these countries would have spent money for nothing.

But if global warming is really happening, then there is no time to waste in taking action.

"There are a lot of actions you could take that make sense," says NASA'S Hansen. He says that building more fuel-efficient cars would reduce pollution, lessen health problems, and reduce U.S. dependence on foreign oil. "In effect," he said, "these steps don't cost anything. In many ways, they are economically beneficial."

Instead, more and more Americans are buying sport-utility vehicles (SUVs). These light trucks emit up to five times the amount of pollutants as cars.

What People Can Do

Can individuals do anything to cut down on global warming? There are many things that you can do--from lowering the temperature at home in winter to walking instead of driving.

The Environmental Protection Agency (EPA) recommends the following steps:

* When families buy new appliances, they should look for the Energy Star[TM] label. According to the EPA, a high-efficiency refrigerator alone can reduce carbon dioxide emissions by as much as 220 pounds a year.

* Compact fluorescent light bulbs save up to 40 percent more energy than regular light bulbs.

* A properly insulated home is a big step toward wasting less energy. It can reduce carbon dioxide emissions by more than 2,000 pounds a year.

* Recycling, and buying products that use recycled packaging, could help your family reduce carbon dioxide emissions by more than 1,000 pounds annually.

* One of the biggest causes of pollution is the family car. Anything you and your family can do to cut down on unnecessary car trips will help cut down on global warming.

The stakes are high. And time could be short.
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Author:Hanson-Harding, Alexandra
Publication:Junior Scholastic
Geographic Code:1USA
Date:Nov 27, 2000
Previous Article:Should Sport Stars Be Heroes?

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