BLOGGER TEMPLATES AND TWITTER BACKGROUNDS

Monday, April 13, 2009

global change

Every day, millions of human and natural activities are altering the planet on which we live. Over the past century, through our ever-increasing population and mastery of technology, we have been changing the global environment at a pace unknown to natural history.
Greenhouse Effect
Some gases in the Earth's atmosphere act like a greenhouse. The gases let sunlight through and then traps some of it's heat. This natural greenhouse effect warms the Earth just enough for plants and animals to live.
Greenhouse gases such as methane and carbon dioxide trap heat near the Earths They are natural part of our atmosphere. People also make greenhouse gases when we burn coal and oil. For example, we make tons of carbon dioxide. These extra gases build up in the atmosphere. This traps more heat and makes the Earth warmer. This is called a global warming.
Global Warming
Global warming is the slow rise in the Earth's temperature. One cause of global warming is the greenhouse effect. If the world's average temperature rises just a little, conditions all over the world could change and cause problems for every living thing.
Some areas could turn into deserts, and others could become permanently flooded (watch the movie "Water World").
Global warming will not happen all of a sudden. We will not see it's effect in the next few months or years. Even though the most harmful effects may not happen in our lifetime, we should learn about global warming and try to stop it.

You can help stop global warming by cutting down on the use of fossil fuels. Walk or ride your bike if you can, instead of riding your car. When you do this, you can use less fuel and create less greenhouse gases. Planting a tree will also help. Trees remove carbon dioxide (see air pollution) from the air.
Shocking Facts
• Mountain Kilimanjaro has lost 75% of it's ice cap since 1912. This ice of Africa's tallest peak could vanish entirely within 15 years.
• Lake Baikal in eastern Siberia now freezes for the winter 11 days later than it did a century ago.
• Montana will lose all the glaciers in Glacier National Park by 2070 if their retreat continues at the current rate.
• Venezuelan mountains had six glaciers in 1972. Today only two remain.
• India's worst heat shock in 50 years killed more than 2,500 people in May 1998.
• Cherry Blossoms in Washington bloom seven days earlier in the spring than they did in 1970.
• Pacific Salmon populations fell sharply in 1997 and 1998, when local ocean temperatures rose 3*C.
• Polar Bears in Hudson Bay are having fewer cubs, possibly as a result of earlier spring ice breakup.
• Coral Reefs suffer from the loss of algae that color and nourish tem. The process, called bleaching, is caused by warmer oceans.
• Diseases like dengue fever are expanding their reach northward in the U.S.

0 comments: