
Viewing Assignment
Watch the Greenhouse Effect interactive presentation from National Geographic.
- Be sure to click on the individual gases at the end the presentation.
- Also, click on "Explore More" and read "More about the Causes of Global Warming" and take the "Global Warming Quiz."
Reading Assignment
Visit the Department of Energy website, Energy Explained (referred to in previous lessons).
- Read all pages under "Energy and the Environment."
The greenhouse effect is a natural and necessary process for maintaining the earth's temperature. It is the warming of the earth caused by gases in the atmosphere that absorb and then re-emit radiation from the sun. Increases in the concentration of the greenhouse gas carbon dioxide have contributed to an intensification of the greenhouse effect. Many natural processes serve as sources and sinks of carbon.
"A source is any process or activity through which a greenhouse gas is released into the atmosphere. Both natural processes and human activities release greenhouse gases. A sink is a reservoir that takes up a chemical element or compound from another part of its natural cycle." Source: Environmental Literacy Council)
Together, these geological and biological processes are called the "carbon cycle." The increases in carbon in our atmosphere are the result of imbalances in this system of sinks and sources, driven largely by human behavior.
Reading Assignment
Read The Carbon Cycle: What Goes Around Comes Around, from Visionlearning.Viewing Assignment
Watch the Six Decades of a Warming Earth from NASA. It's 14 amazing seconds!! Be wild, watch it twice.
Here's some important background (from NASA, link with video)...
This visualization shows how global temperatures have risen from 1950 through the end of 2013. At that point, "2013 tied for the seventh warmest of any year since 1880, continuing a long-term trend of rising global temperatures. With the exception of 1998, the 10 warmest years in the 133-year record all have occurred since 2000, with 2010 and 2005 ranking as the hottest years on record."
Jan 2015 Update: "The year 2014 ranks as Earth’s warmest since 1880, according to two separate analyses by NASA and National Oceanic and Atmospheric Administration (NOAA) scientists." (NASA)
Jan 2016 Update: "Earth’s 2015 surface temperatures were the warmest since modern record keeping began in 1880, according to independent analyses by NASA and the National Oceanic and Atmospheric Administration (NOAA)." (NASA)
Jan 2017 Update: "Earth’s 2016 surface temperatures were the warmest since modern recordkeeping began in 1880, according to independent analyses by NASA and the National Oceanic and Atmospheric Administration (NOAA)." (NASA)