Carbon dioxide theory science projects introduce students to the greenhouse effect, the carbon cycle and the effects of CO2-induced climate change. Students can investigate and compare man-made sources for dangerous levels of CO2 in the atmosphere as well as how excess CO2 in seawater may affect life in the oceans. These projects increase a student’s awareness of global warming and the need to reduce humanity’s dependence on fossil fuels.
Easy: Compare CO2 Emissions of Cars
Write down the mileage from your family car’s odometer after the tank has been filled with gas. Repeat this procedure the next time your family car’s gas tank needs filling. Subtract the first mileage reading from the second one. Divide the number of gallons of fuel required to fill the car’s tank to obtain number of miles per gallon of gas. Record your data in a table. Continue to record your family car’s gas intake and mileage for at least three more fill-ups. Divide 23.6 lb. CO2 per gallon by your car’s average mpg to calculate the CO2e, or the greenhouse gas emissions of your family car. Research the average fuel efficiency of a plug-in hybrid car. Calculate the CO2e for the hybrid and compare it to your car.
Easy: Probe the Greenhouse Effect
Gather four 1-inch by 6-inch by 20-inch wood boards, eight 2-inch-long nails, a sheet of 24-inch by 24-inch by 1/4-inch clear plastic and a thermometer. Have an adult hammer the boards together to construct a frame. Place the frame on soil where it can remain exposed to sun. Put a thermometer inside the frame. Cover it with the plastic sheet so that no air can pass through gaps. Put the second thermometer outside of the plastic. Record the temperatures inside and outside of the frame in three identical intervals over a 24-hour period for seven days. Create a graph with time of day on the x-axis and temperature on the y-axis, noting the heat differential between an environment with and without an atmosphere.
Moderate: Investigate the Acidification of the Sea
Consider what happens if the sea absorbs excess CO2. Gather a pH meter, 6 oz. of mussel shells, plastic baggies, a scale, a camera, a paper towel roll, six pint-size jars, a marker, labels, white vinegar, an eye dropper and a sieve. Purchase some Instant Ocean salt. Stir the salt and water to make seawater according to the manufacturer’s instructions. Mix enough solution to fill six jars. Use the pH meter to record the seawater’s pH, which should be about 8.1. Weigh an ounce of shells. Place them in a baggie, crush them and weigh them again. Photograph the fragments. Put the shell bits into a jar. Pour seawater up to the jar’s rim and seal. Label the jar with the pH, date and the shells’ weight. Repeat the procedure to fill two more jars. Repeat the procedure for the remaining three jars; however, use the eyedropper to squeeze three drops of vinegar into the solution, stir and measure the pH. Check to see if the pH is 7.5, or the expected pH of ocean water by 2100. Seal the jars and label. Open the jars after a month and pour their contents through a sieve. Rinse the shells with filtered water. Dry with towels and then weigh. Record the appearance of the shells in normal water versus acidified seawater. Calculate the percentage change in the shells’ weight.
Challenging: Compare CO2 Levels in Different Gases
Gather five test tubes, four different-colored balloons, four twist ties, household ammonia, bromothymol blue indicator solution, vinegar, baking soda, a funnel straw, a bottle, a graduated cylinder and modeling clay. Have an adult, who should wear thick gloves and goggles, slip a balloon over the nose of the funnel, and then place the funnel over the tailpipe of a running vehicle. Overinflate the balloon. Release gas until the the balloon’s diameter is about 7.5 cm. Use a twist tie to seal the balloon. Pour 15 ml of water and 10 drops of indicator solution into each test tube. Label the test tubes A, B, C, D and Control. Use a tire pump to inflate balloon A, which will fill with ambient air. Blow up balloon B with your breath. Use the exhaust-filled balloon for sample C. Pour 100 ml of vinegar into the bottle. Funnel in 5 ml of baking soda, and allow the mixture to roil for three seconds. Slip balloon D over the bottle’s mouth, inflate to 7.5 cm in diameter and seal. Mold clay around a straw tip to form an airtight collar. Plug balloon A’s neck into the collar. Put the straw’s other end into test tube A’s indicator solution. Allow the gas from the balloon to bubble through the solution. Repeat the last three steps for the rest of the balloons. Record which bromothymol blue solutions turned yellow, signaling the presence of carbonic acid, a CO2 byproduct. Observe how the solution did not react when mixed with your breath but reacted strongly with vehicle exhaust. Consider the impact of CO2-rich exhaust on the Earth’s atmosphere.