G O L B A L W A R M I N G

Global WarmingGlobal warming is the increase in the average temperature of Earth’s near-surface air and oceans.

A result of increasing concentrations of atmospheric aersols that block sunlight from reaching the surface , has partially countered the effects of warming induced by greenhouse gases.

WHAT CAUSES GLOBAL WARMING?

The atmosphere is a mixture of many gases. In the last 250 years, this mixture has been changing. The amounts of gases such as methane and carbon dioxide have been rising. These gases trap heat more effectively than other gases. It lets sunlight in, but it doesn’t let heat out. As a result, heat is building up close to the surface.

WHY IS THE ATMOSPHERE CHANGING?

•People are changing the atmosphere. The changes started hundreds of years ago when people began cutting down forests and burning the wood.• •The invention of cars and other machines greatly increased the amount of greenhouse gases into the atmosphere.• Such machines burn fuels like wood, coal, oil, and natural gas. When these fuels burn, they add carbon dioxide to the atmosphere. Methane comes from producing coal.

CAN GLOBAL WARMING BE STOPPED?•Burning less wood, coal, oil, and natural gas will help stop global warming.

•Scientists say trees can help prevent global warming. All growing plants take carbon dioxide out of the air. Trees do this especially well. They turn the carbon part of carbon dioxide into wood. They release the oxygen.

•In recent years, people have been cutting down forests all over the world. Scientists say vast new forests must be planted.

HOW CAN WE STOP POLLUTION?

•Chemicals that cause pollution are not easy to get rid of. They stay in the air and ground and water for a long time. The best way to fight pollution is to stop producing it in the first place. Governments can pass laws that forbid or limit the use of chemicals that cause pollution. Laws can stop factories from dumping poisonous chemicals in lakes, rivers, and the ocean. Factories and power plants can clean up the smoke that they give off.

•You can help cut down on the amount of garbage you make. You can recycle paper, plastic, glass bottles, and metal cans. Recycled material gets used over again. Recycling helps cut down on pollution.