'An Inconvenient Truth' is a movie by former U.S. Vice President Al Gore. He has been talking about global warming for a long time. Here are some of the facts presented in the movie. Explanations are under the pictures.



  Most of the light from the Sun reflects off of the Earth, but carbon dioxide traps the Sun's rays and makes the air warm. Of course other things on the Earth are also heated by the Sun, but carbon dioxide absorbs more heat than the other gasses
  Every year the amount of carbon dioxide in the atmosphere decreases and then increases again because of summer and winter. In the summer, plants in the Northern Hemisphere absorb the carbon dioxide and in the fall and winter they give it off. Most land is in the Northern Hemisphere so there is a difference.
  The amount of carbon dioxide usually returns to about the same level, but recently it has been increasing year by year. By drilling ice in the North Pole, scientist can tell how much carbon dioxide was in the air as long as 650,000 years ago!



  Although the amount of carbon dioxide has naturally risen and fallen over time since long ago, the recent rise is more drastic than ever before. It has reached more than double its previous highest point and soon could reach triple. Looking at the graph, you can see the rise is not a natural variance. It is a much greater and sharper increase than that, especially in the last 50 years.
  You can also see that the average temperatures on the Earth increase along with the amount of carbon dioxide. They are obviously linked. In 2005 India hit 50 degree weather for the first time and 200 cities in the U.S. had the highest temperatures ever. 10 of the hottest years ever recorded have been within the last 14 years. This is not a coincidence.
 


  There are many other effects we can see on the Earth. For example the snows of Kilimanjaro are disappearing. The snow will be gone within 10 years.



 Many other mountains and glaciers are melting too. Glaciers are important because they give us drinking water. 40% of all the people in the world get drinking water from rivers fed more than half by melt water from glaciers. Within 50 years, 40% of the people in the world will face water shortages because the glaciers are disappearing.



 Perhaps the scariest part is that the polar caps are breaking up and melting. When the ice melts, it raises the level of the sea because the ice was floating. This is just like when a glass of ice water melts and overflows. This could be dangerous for many cities that are near the sea, for example Osaka! If Greenland or the North Pole melts, it will raise the sea level by 10 to 20 feet, enough to flood many cities.
  Another problem is that the ice melting causes the sea to warm. This is because ice is white so it reflects 90% of the Sun's heat, just like a mirror, but water is dark so it absorbs 90% of the heat. It's like if you leave something black near a window in the summer. When the ice melts there is more black and less white. This warms things up in the ocean.
 The polar ice has thinned 40% in the last 40 years and within 50 to 70 years it will disappear in the summer time if nothing is done to stop global warming.

 

  Because of sea currents, airflows, and dark water replacing white ice, the Poles heat up faster than the rest of the Earth. The sea flows all around the Earth so the sea is getting warmer all over.



  A warmer sea also causes changes in weather events. Flooding and droughts are increasing. A warmer ocean makes it rain harder and hotter weather dries the earth. Hotter weather means that more water is evaporated into the air both from the land and the sea.
   Extreme weather events like huge typhoons are also increasing. Japan had a record number of typhoons in 2004 and a storm like Katrina would never have been possible 50 years ago when the oceans were cooler. The reason Katrina was so strong is that it gained power over the Gulf of Mexico which is warmer than before. The future will see stronger storms for this reason.

  Population growth, energy use, and deforestation are the main causes for the increase in the carbon dioxide levels and the carbon dioxide is causing the global warming.  We can solve this problem but we need to act soon. What ways do you think will be effective?


Go to the BBS and answer these questions:
1) What things in our daily lives cause global warming?
2) How can we lessen carbon dioxide in the atmosphere?

If you like try this organization. It is typical for scientific essays.

Present Situation
   then
Problems
   then
Solutions