Global Climate Models (Part 2)
Lesson 5 of 11
Objective: SWBAT analyze data generated from a global climate model to make predictions about future climate.
This portion of the climate model activity will have students analyzing climate models to predict regional changes in temperature and snow/ice cover as greenhouse gasses continue to increase. The model uses two simulations, Modern-Predicted SST (mid-20th century climate prior to any major effects of human impacts on greenhouse gas increases) and IPCC (a scenario used for reports of the International Panel for Climate Change that displays what will likely happen if no changes are made in current human activity).
Begin this lesson by logging in to EzGCM and selecting week 4 assignment. I explain to students that this activity will use two simulations, Modern-Predicted SST and IPCC. I explain that the Modern-Predicted represents the climate prior to any major increase in greenhouse gases due to human activity. I than have students to read the brief introduction and have them explain how IPCC is different and why the Modern-Predicted is used as the control. Below is the introduction paragraph found on the EzGCM site.
In order to simulate a range of potential future climates the U.N. Intergovernmental Panel on Climate Change (IPCC) developed a set of four storylines that emphasize particular themes involving human socio-economic and technological actions, as well as the Earth’s physical responses to those actions. Each storyline is the basis for a family of scenarios, or projections, that illustrate how atmospheric greenhouse gas concentrations might change over the course of the 21st century. The A1 family of scenarios considers a world of strong economic growth, a population peak in mid-century, and the introduction of new and more efficient technologies. Specific A1 family scenarios explore the impacts of different energy sources (fossil fuels, non-fossil fuels, or a blend of both). Scenario A1FI is the most extreme of the IPCC scenarios, but is not necessarily an unlikely path if fossil fuel burning and population growth follow IPCC projections for the A1 family.
I recommend reading this aloud with students, along with the experiment description, to explain the vocab that students are unlikely to know. This is good practice for students and allows them to learn new words in context (I never let vocabulary stop me from having students read something, it just changes the amount of support I provide).
I strongly recommend working through the EzGCM Assignment 2 directions on your own prior to using them with students so you can determine the best use of time for your students. This part of the lesson focuses on what I want my students to recognize as they work to determine the potential changes the Earth might face in the scenario introduced in the introductory lesson.
Creating scientific visualization maps:
Begin by clicking the "run experiment" button and press the play button to plot the data. Once the data is complete, click the button marked "proceed to post processing" at the bottom of the screen. (I do this on my computer and project it from the LCD as my students do not have access to computers that can run this program).
Select the Modern-Predicted and IPCC simulations by clicking on each while holding Ctrl and then select last 5 and then click the average button to get the average data for these models for the final 5 years of the simulations (which will show in a new window and may take a few minutes to run, click close when it is done).
Now it is time to select the time and climate variables. Make sure that monthly, seasonal and annual are all checked for time periods. Deselect the following climate variables: ocean ice coverage, snow coverage, soil moisture, ocean mixed-layer temperature, and snowfall. When this is done, click the Extract button (again a new window will open, click close when it is done). You should now see two files listed in the Files Created column, click the Visualize button at the bottom of this column to open a new screen that shows a world map.
This may seem like steps you can take without students present to save time, however, then they do not gain any understanding on how the climate models work. I prefer for them to witness these steps and ask any questions they have about what we are doing.
In the section marked Filename, select both files by holding Ctrl and clicking each. Then select SurfAirTemp in the variables section and Annual as the time period. This will move 2 files into the Data File to Plot section. Select the "annual, SurfAirTemp, Modern-Predicted..." file and click the plot button at the top right of the page. This will display a colored map to appear. Change the scale (min,max) to "-45 to 35" and click set button. Then click the + button to add another map and select the IPCC map from the Data File to Plot. Again, change the scale to match the first map. These maps are found on the Surface Air Temperature Future Comparison Models handout for students (print in color) and they can use these handouts to answer the following questions:
- What areas of both maps are the warmest? Coolest?
- Describe how the two maps are alike and different, focus on the polar and equatorial regions.
- How would you describe the temperature of the United States on each map? How easy or hard is it to tell how much the temperature changed in the US between the Modern control and the increased CO2 experiment?
Students can write the answers to these questions or they can be part of a whole class discussion. As there are pros and cons to both, I like to have students first answer in small groups and then share answers to facilitate a discussion. Students will be able to answer these questions but they should find it difficult to see any big difference between the maps. The next step will have you create an anomaly map that displays the difference between the two maps and will be more helpful in helping students identify the impacts of warming trends in the US.
Creating anomaly map (page 13 step 5 in EzGCM Assignment 2):
Remove one of the maps using the - button. Select BOTH files in the Data Files to Plot section. In the Operations section, select the option that will allow you to subtract the Modern-Predicted FROM the IPCC (if IPCC is listed first in the Data Files to Plot, select Top-Bottom) and click Plot button. Click on the colorbar scale and choose "panoply_diff" and change the min/max scale to -7.0 and 7.0 and click the Plot button on the palette to get the setting to take effect. Click the title of the map to change the title to Surface Air Temperature Anomaly. Save the map using the save map button. The handout Surface Air Temp Anomaly (IPCC-Modern) can be provided to students as they answer the following questions:
- Explain what this map is showing.
- What regions show the greatest increase in temperature?
- Do any regions show a decrease in temperature?
- Why do you suppose the greatest temperature increases are over the continents rather than the oceans?
- Choose a location that interests you on the map. Describe the changes in the temperature anomaly at this location (how much did the temperature change). What do you think accounts for the differences it may have with nearby locations (why is this area different from other areas nearby)?
Again, this can be done individually, in small groups or as a class discussion.
To end this lesson, I have students make connections between what they learned during the climate modeling lessons and the larger purpose of this unit by asking them the following:
Based on what you learned from the maps generated during this lesson, can you answer any of the following questions that were generated during the lesson What Are We Coming Home To Part 2:
- What are the current temperatures throughout the United States?
- What effects have the altered climate had on human health?
- How has crop production been affected?
- How has the weather changed? Has there been an increase in the number and severity of extreme weather events? What is an extreme weather event?
- Do seasonal changes still occur?
- How have the ecosystems (land and water based) across the United States been impacted for both plant and animal life?
- Is there still usable soil for crop production? If so, where?
- What is the current state of air and water quality?
- What has been the impact of warming on the oceans in regard to current flow and direction? How has the increase in PH levels (acidifcation) altered that ecosystem?
- What has been the impact on energy production and consumption?
- What is the current state of our natural resources?
- What is permafrost and what could have been released as it melted?
Can you make any predictions on other ecosystem changes or impacts on crop production?