MVCC Effect of Greenhouse Gases on Global Warming Questions
fill in the documents and answer the questionsProcedurePart 1: Greenhouse Gases and Global WarmingIn Exercise 1, we observed that gases have different properties. In this section, we will further investigate gases and ask the question, “How are greenhouse gases related to global warming?”Conduct background research on global warming from reliable Internet sources such as NASA, USGS, IPCC, and major universities with current research on the topic such as U.C. Berkley, Yale, Stanford, etc.Note: The most acceptable websites to use for Internet sources end in “.gov” or “.edu.” Websites ending in “.com” or “.org” should be avoided since recognizing biased information may be difficult. Political, blogs, and news websites often have information that is biased and not based solely on scientific support. For this reason, these sites should also be avoided in investigating scientific topics. Temperature and Greenhouse GasesIn the next steps, you will model temperature changes in the Earth’s atmosphere by creating two models from large jars or glasses, each containing a thermometer. One jar will remain uncovered while the other jar will be covered with plastic wrap. Consider the following as you create each model:Plastic wrap is used in this experiment to model greenhouse gases in Earth’s atmosphere; however, it should be noted that greenhouse gases not only trap heat but also reflect heat into space, whereas the plastic wrap only traps heat.The two models will be placed in the same environment and exposed to direct sunlight. Since the models will be placed in the same environment, factors such as air pressure, ambient temperature, and light exposure will be consistent for the two models.Gather 2 thermometers, a clock or timer, measuring cup, spoon, clear plastic wrap, dish soap, 1 rubber band, and a sheet of white paper. Gather 2 large glasses (or jars) of the same size. The glasses should be large enough to fit the thermometers inside.Note: Jars or glasses with bottlenecks are NOT recommended for this experiment.Prepare a diluted dish soap solution as an anti-fog agent. When moisture is trapped in a container, by a lid or other covering, condensation can form on the inside of the container walls. If condensation forms on the inside of the jars or glasses used in this experiment, then it will be difficult to see the markings on the thermometer placed inside.Fill the measuring cup to the 1 cup mark with lukewarm tap water.Add 1 drop of dish soap to the water and gently stir with a spoon.Note: The solution should not form bubbles when stirred. If it does, then too much dish soap has been added and the solution needs to be re-made following step 7.Dip a paper towel into the solution and wipe the inside of the glasses (or jars). The glass should have a thin layer of solution, and there should be no pooling or beading of moisture.If the thermometers do not have a solid back, create backs from thick, white paper products, such as foam board, poster board, cardboard, or card stock. The backing will block direct sunlight, and prevent exaggerated temperature readings.Use scissors to cut a strip of paper for each thermometer. The strips should be slightly longer and wider than the thermometers.Attach each strip to the back of the thermometers with clear tape. Ensure that the numbers of the thermometer are still visible.Note: Do not use dark paper or brown cardboard as those materials absorb heat and will influence the temperature readings.Place a thermometer inside the first glass. See Figure 10. Tape the thermometer to the front of the glass ensuring that the markings are legible. This is Model #1, which represents the Earth if it had no greenhouse gases in the atmosphere.Figure 10. Placing the thermometer with a white foam backing into Model #1.Place the other thermometer inside the second glass, and tape the thermometer to the front of the glass.Use scissors to cut a square piece of plastic wrap that is large enough to cover the opening of the glass. Fit the plastic wrap over the opening of the second glass and secure it with a rubber band. This is Model #2, which represents the Earth plus its greenhouse gases.Set the two models on a sheet of white paper. This is how the experiment will be conducted when you are ready to begin.Remove the plastic wrap and rubber band from Model #2, and set them next to the glass. Model #2 will not be covered until the experiment begins.Consider what each model represents. Define the term “independent variable” and record the independent variable for this experiment in Data Table 2.Define the term “dependent variable” and record the dependent variable for this experiment in Data Table 2.Define the term “control group” and record which model acts as the control in Data Table 2.Formulate a hypothesis and record it in Data Table 2.Note: When formulating your hypothesis, think about how temperature will be affected in the two models (one covered and one uncovered). There is no “correct” answer for the hypothesis; however, it should be well-thought-out.Once the hypothesis has been recorded, the experiment may begin.You will record temperature data in Data Table 3 every 5 minutes during the experiment. Print or draw a copy of Data Table 3 if necessary.Transport the experimental setup to a sunny location, leaving Model #2 uncovered.Working quickly, place the two models on the sheet of white paper in direct sunlight. Turn the glasses so that the thermometers face the same direction, away from the sunlight.Note: Be sure to turn the jars so that the faces of the thermometers are not facing the sun.Place the plastic wrap and rubber band over the opening of Model #2, and immediately record the temperature of each model in Data Table 3. See Figure 11.Figure 11. Model #1 with no covering and Model #2 covered with clear plastic wrap secured by a rubber band.Continue to record the temperature every 5 minutes for an hour in Data Table 3.Record notes and observations as the experiment progresses. Describe in detail any changes inside of the models. Make note of changes in cloud coverage and light exposure in the comments section of Data Table 3 next to the time of the observation.Calculate the change in temperature for each model by subtracting the final temperature from the initial temperature. Record the change in temperature in Data Table 3.Note: If the thermometers measure in Fahrenheit, be sure to convert each reading to Celsius after the experiment is complete using the following equation:∘C=(∘F−32)×59∘C=(∘F−32)×59Create a line graph of temperature versus time, similar to Figure 12. Place time on the horizontal axis (x-axis) and temperature on the vertical axis (y-axis). The graph should have two lines total, representing Model #1 and Model #2.Figure 12. Example line graph of temperature versus time for three different models.Upload an image of the graph into Graph 1. Describe the trends in the graph. Indicate which model held more heat and which model had the greatest increase in temperature. Relate patterns in the graph to the observations recorded in Data Table 4.Indicate whether or not the hypothesis was supported or rejected, and explain why in Data Table 4.
