Global Climate Change

Is Earth's Climate Changing?

• Earth's climate is always changing. In the past, Earth's climate has gone through warmer and cooler periods, each lasting thousands of years.

• Recent observations show that Earth's climate has been warming. Its average temperature has risen a little more than one degree Fahrenheit during the past 100 years or so. This amount may not seem like much. But small changes in Earth's average temperature can lead to big impacts.

The Greenhouse Effect - Experiment

Question - How does atmospheric CO² affect global temperature?

Materials

• two 500 ml beakers

• 30 ml graduated cylinder

• 10 ml water

• sand to coat the bottom of the beaker up to 2 cm

• plastic wrap to cover one 500 ml beaker

• light source

• ring stand

• 2 thermometers

1. Setup:

   • Pour sand into the bottom of each of the beakers.  Make sure that there is the same amount of sand in each.  

   • Pour 20 ml of water into the bottom of each beaker.  

   • Place a thermometer in each of the beakers so that it can easily be read without removing it.  Place the plastic wrap on only one of the beakers.  

   • Arrange the ring stand with light that is shining on each of the beakers.  

   • Record the temperature in each of the beakers. (they should be the same!)  This will be your starting temperature.  

   • Create a data table using Google Sheets.  You will turn on the light for two minutes and then turn it off for two minutes. 

2. Predict - How do you think the inclusion of the plastic wrap will affect the temperature in the beaker?  How do you know?

3. Experiment - Begin by turning on the lamp.  Collect your data for each of the beakers every two minutes.

4. Analyze - After 20 minutes take a final reading of the temperatures.  Use the data from your table to create a line graph using Google Sheets.

5. Explanation - Light from the sun (or a lamp) has a lot of energy.  When it hits the Earth's atmosphere during the day it is able to pass through easily to reach the ground.  Here it begins to heat up the land or water.  During the night a lot of that heat energy is radiated back out from the Earth but at this point it has much less energy.  Normally, enough of that energy can escape through the atmosphere to keep a perfect balance to sustain life on our planet.  However, when there is an excess of other Greenhouse Gases such as CO², the radiant heat is unable to pass through the atmosphere and is instead reflected back to the Earth where it heats things up a little more.

Back to Teams

• How does your graph compare to the graphs from other teams?

• What were the independent, dependent, and controlled variables in this experiment?

• What other experiments do you think you could perform using a similar setup?

Read the Following Articles

• Be prepared to share your answer to the question that the article is attempting to answer.

1. Does "global warming" mean it’s warming everywhere?

2. What are the impacts of Climate Change?

3. What is the difference between global warming and climate change?