Radiation and Climate
Lesson 7 of 9
Objective: Student will be able to explain how solar radiation interacts with gases in the atmosphere to impact earth's climate as demonstrated by taking notes, performing computer activities, and watching videos.
In this lesson students continue to learn about earth's atmosphere in terms of how solar radiation interacts with gases. In addition students learn about the carbon cycle and how there is an increase in greenhouse gases which effects climate change. This lesson incorporates some topics which I have not previously taught in my chemistry class, but I found that they fit well with this unit in terms of NGSS.
- This lesson aligns with the Next Generation Science Standards Performance Expectation LS 2-5: Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere. It does so because students learn about the carbon cycle.
This lesson also aligns with the Next Generation Science Standards Performance Expectation ESS2-4: Use a model to describe how variations in the heat flow of energy into and out of Earth’s systems result in changes in climate. It does so because students are presented with ideas related to greenhouse gases, radiation, and climate change.
This lesson also aligns with the Next Generation Science Standards Performance Expectation ESS1-1: Develop a model based on evidence to illustrate the life span of the sun and the role of nuclear fusion in the sun’s core to release energy that eventually reaches Earth in the form of radiation. It does so because students learn about solar radiation and the types of radiation that the sun emits to the earth.
- This lesson also aligns with the Next Generation Science Standards Practice 6: Constructing Explanations and Designing Solutions. It does so because students are challenged to try to explain why the different phenomenon occur in the experiments and activities in class.
For this lesson computers are needed for the computer activities as well as several resources needed for the class demonstration including:
- 5 empty and clean 2L soda bottles
- 5 thermometers that fit inside of the bottles
- baking soda
- beaker or graduated cylinder
To begin the lesson I show students the first slide of the PowerPoint and pose to them the following questions:
1. What is radiation?
2. What is a greenhouse gas?
I then give students time to discuss the questions with their groups. After about 3-4 minutes, or when I can tell that students are done talking I ask students to share out.
I get varied responses from students. Most students have heard of radiation in terms of a negative thing from bombs. Surprising many of my students did not know what greenhouse gases were, but simply thought of the place where you keep plants when they hear the word greenhouse.
This is a video of part of one group's discussion. This class had lots of ideas about radiation including how it is just energy, how it comes from the sun, how it comes from microwaves, and hot its both good and bad.
For this part of the lesson I set up a demonstration experiment with students. The goal of this experiment is to see if the temperature inside of a bottle changes when there is additional carbon dioxide present.
I chose to just measure everything myself, but I also could have had student volunteers set up the experiment for the class as well.
For the experiment I show students were they will be recording information on their activities paper as we continue the experiment but let them know we will come back to it throughout the lesson.
I let the bottles sit for about 10 minutes and then put outside. Here is a picture of the bottles outside. I found that it was easier if I put them in a box so they didn't blow over.
I then let the bottles sit outside for about 20-30 minutes and come back to them towards the end of the lesson.
Explain Part I
- I begin with explaining to students that we will be continuing to talk about gases in earth's atmosphere and how radiation interacts with gases.
- I present slides 3-6 and explain what radiation is and the types of radiation that come from the sun. This year I chose to just give students a very general picture of electromagnetic radiation and did not teach about wavelengths, frequency, etc.
- I then discuss how radiation affects earth's climate and about the Greenhouse effect on slides 7-8.
- At about this time I have students bring the bottles for the initial experiment outside (slide 9).
- I then teach students about the carbon cycle (slides 10-13). I talk about it generally, giving students enough details for them to understand how carbon is stored in different reservoirs.
- To help reinforce the idea of trees as a place where carbon is stored I show students the video Where do Trees come from?
- I like this video because it helps students better understand where the mass of trees come from which is a concept that a lot of people are confused about.
- This is an example of a student's filled in notes.
Elaborate Part I
To help reinforce students' understanding of the carbon cycle I have them play the carbon cycle game. I give students instructions for the activity on the 16th slide of the PowerPoint and have them fill in information about where they traveled and how they got there on the second page of their notes graphic organizer.
The game can be found on the Windows 2 the Universe website.
This game is nice because it allows students to act as a carbon atom and see where they travel.
Here is an example of one student's summary of their game experience. I like how they show the different places where they traveled and then in purple arrows explain how they got there.
This is a second example of a students summary of their game on the second page of their notes. This student explained in sentences how they got to each of their four destinations.
Explain Part II
After students have played the carbon game I synthesize what they have learned about carbon with greenhouse gases and radiation by talking about global climate change. I do this by showing them slides 17-22 of the PowerPoint while they finish their notes graphic organizer.
- I show students slides 17-18 of the PowerPoint and discuss global warming in terms of having additional Carbon Dioxide in the atmosphere which contributes to more greenhouse gases.
- I then show students slide 19 where we complete the lab activity that we started in the Explore section. I have students fill out information on the first page of their activities paper while we go over the final temperature of each bottle as a class. I then have students analyze the results of our data by making a claim and citing evidence from their data. Here are two examples of class results for this activity. Here is an example from my 2nd period (student period 2) where we got fairly good data in terms of seeing higher temperatures for the bottle that had more carbon dioxide. Here is an example from my 3rd period (student period 3) where we got mixed results.
- To reiterate the impact of carbon dioxide I show students a TED-ed lesson, Earth's Giant Game of Tetris
- I also show students the Keeling Curve and talk about how scientists have been measuring carbon dioxide levels.
Elaborate Part II
For the final part of this lesson I have students perform a computer simulation to better understand radiation, greenhouse gases, and the impact of both of them on earth's climate.
- Students perform the activity on the second part of their unit 7 lecture 5 activities paper.
- I have students go up to the class computers with their table groups.
- The Greenhouse Effect activity can be downloaded or done directly from the PhET website.
- In this activity students visualize how the radiation moves between the sun and earth as well as how greenhouse gases play a role in this. Additionally students are able to explore the climate of the ice age, 1750 (pre-industrial revolution) and today.
- I have students record data for each of the three time periods and then explain the relationship between greenhouses gases and the climate of the earth.
- My goal is for students to come to the conclusion that there is a direct relationship between the amount of greenhouse gases and climate.
- The way I have the activity written up I found that depending on when students record the final temperature during the simulation that they may not actually see this direct relationship.
- In this first example the student clearly writes down data that leads to the conclusion that I expect.
- However, in this second example the student records 14 degrees Celsius for both the present time and 1750 so would not have the relationship of more greenhouse gases with higher overall temperature.
- I do however make sure to walk to each group as they are working on the activity to ensure that they are able to articulate the effect of greenhouse gases on climate.