Inconvenient Truth- fact 2

Fact: Greenhouse gases keep in the sun's radiation waves in the Earth, warming the planet.



SOURCE 4: http://www.eia.doe.gov/bookshelf/brochures/greenhouse/Chapter1.htm

• The source is EIA (Energy Information Administration).
• The source's credentials are the US Government.
• This is a credible source because it gives the original source where it go the main information from and it is updated every year.
• The source says that the greenhouse gases allow sunlight to enter the atmosphere freely. When the sunlight hit the Earth's surface, it is re-radiated back towards space as infrared radiation. Greenhouse gases absorb this infrared radiation and trap the heat in the atmosphere.
• Yes, I believe the source because it is a credible source and it supports its explanations of the greenhouse gases.

SOURCE 5: http://www.umich.edu/~gs265/society/greenhouse.htm

• The source is the Greenhouse Gases And Society by Nick Hopwood and Jordan Cohen.
• The credentials are the World Book Encyclopedia, US Government of State, and the Global Environment.
• The source is sort of credible because it gives primary sources where it got some information from but it doesn't give the profession or where the author went to university.
• The source says that the shorter wavelength radiations from the sun passes through Earth's atmosphere, then it is absorbed by the Earth's surface, causing it to warm. Part of the absorbed energy is re-radiated back to the atmosphere as long wave infrared radiation. The greenhouse gases selectively transmit the infrared waves, trapping some and allowing some to pass through into space. The greenhouse gases absorb these waves and reemits the waves downward, causing the lower atmosphere to warm.
• I believe the source because it explains the process well.

SOURCE 6: http://www.epa.gov/climatechange/emissions/index.html

• The source is the US EPA (U.S. Environmental Protection Agency).
• Its credentials is the U.S. government.
• This source is credible because it is updated frequently by the US EPA.
• The source says the gases that trap heat in the atmosphere are often called greenhouse gases. Some gases like carbon dioxide happen naturally and are emitted to the atmosphere through natural processes and human activity. Other greenhouse gases like fluorinated gases are created and emitted solely through human activity.
• I believe the source because it makes sense on what it is explaining.