clues to climate change

7/30/2019 Clues to Climate Change

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Clues to Climate Change

Grades: 5-8

Curriculum Connections: Science

Standards Connections: National Academies of Science, National Science

Education Standards

Content Standard D: Earth and Space Science/Structure of the EarthSystem-Global patterns of atmospheric movement influence local weather

Required Software: Microsoft Word version 2002; Microsoft PowerPoint version

2002, the Office XP presentation solution; Microsoft Internet Explorer 5/5.5; Microsoft

Excel version 2002; Microsoft Paint

What's in this Lesson:

Teacher Guide (including How to Begin)

Resources

Student Activity, Step-by-Step:

o Step A: From One Extreme to the Other

o Step B: Global Patterns, Local Effects

o Step C (Optional): Mine the Data

o Step D: Join the Debate!

Teacher Guide

Summary: Global warming is big in the news, but it can seem too "academic" and

abstract to be relevant to your students. This lesson "brings it home" by framing the

global warming debate in terms of local weather and online data that your students

can analyze and interpret themselves. It captures their interest with a look at extreme

winter weather in their home state (as well as in the other 49) and expands to raise

larger questions about the political, economic, and environmental causes and effects

of global climate change.

Objectives:

To stimulate student interest in topics related to global weather patterns andtheir local effects.

To encourage students to look at data as clues that can be analyzed toanswer questions and support hypotheses.

To provide an opportunity for students to hone research and presentationskills using online resources and research


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Prerequisite Skills:

Ability to navigate and search the Web using Internet Explorer

Previous experience using PowerPoint to create simple presentations

Basic Microsoft Word skills

Introduction to Excel (more experience required for optional Step C)

Time Allotted:

Three to four class periods

How to Begin:

1. Preview the Web sites listed under Resources. Add the resources you likebest to your Favorites so that students will have easy access.

2. As part of this activity, your students will create a PowerPoint presentation.Create a template for them to use, and post it where they can all access it.This will save them time and make sure that all presentations have aconsistent look.

3. Your students will need Adobe Acrobat Reader to view PDF files that theydownload in Step A. Make sure that Acrobat Reader is installed on everystudent computer before you begin this activity. You can download AcrobatReader at http://www.adobe.com/products/acrobat/readstep2.html

4. In Step B, you must assign each of your student teams a different city tostudy. The cities you can choose from are displayed on a map (seehttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.html). Be sure to

assign only cities displayed in blue. They have complete temperaturehistories that your students need to complete the activity.

5. There are several optional steps in this activity: the last step in Step A and theentire Step C. The option in Step A requires no exceptional skills orexperience. Step C requires skill with Excel beyond that which is required forthe rest of the activity. Before you begin this activity, review the optional stepscarefully and consider which are appropriate for your students.

6. Copy and hand out the Student Activity pages, and set your class to work!

RESOURCES

National Climatic Data Center/National Oceanic and Atmospheric

Administration

http://www.ncdc.noaa.gov/

"The World's Largest Archive of Weather Data," including historical analysis.
http://www.adobe.com/products/acrobat/readstep2.htmlhttp://www.adobe.com/products/acrobat/readstep2.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://www.ncdc.noaa.gov/http://www.ncdc.noaa.gov/http://www.ncdc.noaa.gov/http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://www.adobe.com/products/acrobat/readstep2.html


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Global Warming Sites

http://lwf.ncdc.noaa.gov/oa/climate/globalwarming.html

A good place to start your research.

http://www.epa.gov/globalwarming/

Another government perspective.

http://www.climatehotmap.org/index.html

An environmentalist perspective.

http://www.globalwarming.org/

A business perspective.

NCDC/NOAA-U.S. Cities Analysis

http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.html

Over 100 years of temperature and precipitation records for nearly 40 U.S. cities.
http://lwf.ncdc.noaa.gov/oa/climate/globalwarming.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/globalwarming.htmlhttp://www.epa.gov/globalwarming/http://www.epa.gov/globalwarming/http://www.climatehotmap.org/index.htmlhttp://www.climatehotmap.org/index.htmlhttp://www.globalwarming.org/http://www.globalwarming.org/http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://www.globalwarming.org/http://www.climatehotmap.org/index.htmlhttp://www.epa.gov/globalwarming/http://lwf.ncdc.noaa.gov/oa/climate/globalwarming.html


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NCDC/NOAA-Storm Events

http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Storms

Historical database of major U.S. storm events that you can search by state.

NCDC/NOAA-Temperature Extremes and Drought

http://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.html

Tables, maps, and graphs documenting extreme weather events in the United

States, including record high and record low temperatures by state.

USA Today Weather

http://www.usatoday.com/weather/wfront.htm

Archived weather stories, temperatures around the country and the world, and more.

Weather.com/The Weather Channel

http://www.weather.com/

Everything from current forecasts to weird weather news.

The Weather Underground

http://www.wunderground.com/

Easy-access weather maps for every kind of data, plus forecasts and more.

Latitude Calculators

http://www.arrl.org/locate/locate.html

http://www.census.gov/cgi-bin/gazetteer

Enter the name of a city and instantly get the exact latitude and longitude.

Student Activity

Description: There's plenty of talk about global warming, but what does it really

mean? Does it mean that our winters are not as cold as they used to be? And how

does it affect the temperature variations from season to season and year to year?

You can answer some of these questions by studying weather information and

analysis available online. With the right data and the right tools, you can form your

own opinions about global warming and climate change-and back them up with cold,

hard numbers!
http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Stormshttp://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Stormshttp://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.htmlhttp://www.usatoday.com/weather/wfront.htmhttp://www.usatoday.com/weather/wfront.htmhttp://www.weather.com/http://www.weather.com/http://www.wunderground.com/http://www.wunderground.com/http://www.arrl.org/locate/locate.htmlhttp://www.arrl.org/locate/locate.htmlhttp://www.census.gov/cgi-bin/gazetteerhttp://www.census.gov/cgi-bin/gazetteerhttp://www.census.gov/cgi-bin/gazetteerhttp://www.arrl.org/locate/locate.htmlhttp://www.wunderground.com/http://www.weather.com/http://www.usatoday.com/weather/wfront.htmhttp://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.htmlhttp://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Storms


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Step A

From One Extreme to the Other

Software: Microsoft Excel 2002, Microsoft Word 2002, Microsoft PowerPoint 2002,

Microsoft Internet Explorer 5/5.5

What to do: What can temperature extremes tell you about global warming?

1. Global warming is the subject of "heated" debate among scientists,environmentalists, and policymakers throughout the world. Your teacher willlead a class discussion on the subject. What do you know about globalwarming? What are the causes and effects?

2. According to some experts, one sign of global warming is decreasingvariability in temperature extremes on a regional scale. After your classdiscussion, your teacher will divide your class into teams of three or four to

investigate record low temperatures in the United States over the pastcentury.

3. Go to the NCDC/NOAA Temperature Extremes and Drought page(http://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.html). Scrolldown to the All-Time Temperature Minimums by State heading, and right-clickthe Table (PDF) link beneath it to display the shortcut menu. Click SaveTarget As in the shortcut menu, and save the Mintemps.pdf file to yourdesktop.

4. Go to your desktop, and double-click the Mintemps.pdf file to open it withAdobe Acrobat Reader. This table lists the lowest temperatures ever recorded

(since about 1890) in every U.S. state. Find your state in the table. What isthe record low and when was it recorded? Where was it measured, and atwhat elevation? Does it ever get nearly that cold where you live? Why or whynot?

5. Looking at these extremely low temperatures, you might think a little warmingtrend wouldn't hurt. Is there any way to tell from these numbers if such a trendis actually occurring? Check the global warming sites listed in Resources formore information about the possible effects of global warming on extremetemperatures.

6. In Acrobat Reader, use the Text Select Tool to select the contents of the

Mintemps table, and then click Copy. Paste the contents into a new Worddocument, and then save the document to your desktop.

7. In the Word document, select the complete list of dates, and click Copy onthe Edit menu. Open Excel, click on cell A1, and then click the Paste button.The dates will fill column A from rows 1 to 50.

8. You need to "clean up" this data before Excel can work with it effectively. Forexample, you need to delete all the periods following the month abbreviationsbefore Excel will recognize them as date values. To do this quickly and easily:

a. Click Find on the Edit menu.

b. On the Replace tab, type a period (.) in the Find what box.
http://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/severeweather/temperatures.html


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c. Leave the Replace with box empty.

d. Click Replace All.

You'll also need to delete asterisks next to some of the dates.

9. Select column A and click the Sort Ascending button on the toolbar. Nowmanually move (that is, use the Cut and Paste commands) the dates prior to1900 to the top of the column.

10. Now that you have all the cold record dates (1893-1999) in order, it's easier tosee whether record low temperatures are evenly distributed over the years. Incolumn B on your spreadsheet, or on a separate sheet of paper, tally thenumber of record lows for each year in the list.

11. Compare the number of record lows in the first half of this period (1893-1946)to the number of record lows in the second half (1947-1999). Is thisconclusive proof for or against a warming trend? Why or why not?

12. Open the PowerPoint template created by your teacher. Personalize it byadding the names of your team members to the first slide. Create a new slide,titled "Minimum Temperatures and Global Warming." In bullet points, reportyour interpretation of the distribution of record lows determined in Step 11.

13. Optional: Repeat steps 1-10, using data from the All-Time TemperatureMaximums by State table on the NCDC Temperature Extremes and Droughtpage. See whether recorded maximums are evenly distributed over the years.

Record your findings and interpretations in a new PowerPoint slide, titled"Maximum Temperatures and Global Warming."


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Step B

Global Patterns, Local Effects

Software: Microsoft Excel 2002, Microsoft Paint, Microsoft PowerPoint 2002,

Microsoft Internet Explorer 5/5.5

What to do:Analyze temperature trends for individual cities.

1. Go to the NCDC/NOAA U.S. Cities Analysis page(http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.html). Click the citythat your teacher has assigned to your team. The Climate Summary page foryour city is displayed.

2. In the climate history compiler at the bottom of the page, your city ispreselected. Set the remaining options to the following values:

Data type: Mean Temperature

Period: Winter (Dec-Feb)

First Year to Display: 1895

Last Year to Display: 2001
http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.html


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Display Type: Line Chart

3. Click Submit, and study the resulting chart. Note the temperature trend(degrees F/decade).

4. Take a "snapshot" of the line chart that you generated in Step 2. While thechart is displayed on your screen, press ALT + PRINT SCREEN to copy thescreen image to the Clipboard. Now open Microsoft Paint, and click the Pastebutton. The screen capture appears in your Paint window. Save the image asa bitmap to your desktop.

5. Repeat Step 2 for each of the other three seasons, and for annual mediantemperatures. Save each of these charts as a bitmap as in Step 3.

6. Create six new slides in your PowerPoint presentation, titled "TemperatureTrends in [Your City]." Insert your screen captures on the first five slides. Onthe sixth slide, summarize the trend information and give your interpretations.Can you explain the annual trend in terms of the seasonal trends? Can long-term temperature trends for individual cities provide evidence of globalclimate change?


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Step C (OPTIONAL)

Mine the Data

Software: Microsoft Excel 2002, Microsoft PowerPoint 2002, Microsoft Internet

Explorer 5/5.5

What to do: Use statistical analysis to compare temperature variability over time

between U.S. cities.

1. As we discussed in Step A, global warming may affect temperature variability.The temperature trends you identified for your city in Step B don't indicateyear-to-year variability. To do that, we need to calculate standard deviationsfor the data. Calculating standard deviation and coefficient of variation alsoallows you to compare differences in variability between cities. (See Sidebarfor more information about standard deviation and coefficient of variation)

2. Return to the NCDC/NOAA U.S. Cities Analysis page(http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.html). Click the citythat your teacher has assigned to your group to go to the Climate Summarypage for that city.

3. In the climate history compiler at the bottom of the page, your city ispreselected. Set the remaining options to the following values:

Data type: Mean Temperature
http://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/cag3/city.html


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Period: Winter (Dec-Feb)

First Year to Display: 1895

Last Year to Display: 2001

Display Type: Table

4. Click Submit to generate the data table.

5. Select the contents of the table, and click Copy on the Edit menu. Open theExcel worksheet that you created in Step A, and click on the Sheet 2 tab atthe bottom of the window to open an empty spreadsheet. Select the A1 cell,and click the Paste button. The table's contents will flow into columns Athrough D of the spreadsheet. Delete the ranking data from columns C and D;you won't be using it.

6. Before Excel can perform the necessary calculations, you need to delete the

"deg F" labels from the temperature data. To do this quickly and easily: a.Click Find on the Edit menu. b. On the Replace tab, type deg F in the Findwhat box. c. Leave the Replace with box empty. d. Click Replace All.

7. Format cells in column B, below the temperature data, to perform thecalculations. First create labels for these calculations in the adjacent cells incolumn A. In four empty cells below the column of dates, type (top cell tobottom):

a. 1895-2001

b. Mean

c. Standard Deviation

d. Coefficient of Variation

8. Select the cell in column B next to the "Mean" label, and type this formula inthe formula bar:

=AVERAGE(BX:BY)

where X is the number of the first row of temperature data and Y is thenumber of the last row of temperature data. This formula will calculate thearithmetic mean for your entire dataset. Or click Function on the Insert menuto format this cell.

9. Select the cell in column B next to the "Standard Deviation" label, and typethis formula in the formula bar:

=STDEVP(BX:BY)

where X is the number of the first row of temperature data and Y is thenumber of the last row of temperature data. This formula will calculate the


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standard deviation for your entire dataset. Or click Function on the Insertmenu to format this cell.

10. Select the cell in column B next to the "Coefficient of Variation" label, andtype this formula in the formula bar:

=BN/B(N+1)

where BN is the cell that contains your standard deviation calculation, andB(N+1) is the cell that contains your mean. This formula will calculate yourcoefficient of variation (percent error of the mean).

11. The standard deviation and coefficient of variation for the entire dataset alonedon't tell you much. However, comparing the standard deviations of the firsthalf of your data versus the second half can reveal a change in variability overthe course of the century.

Repeat Steps 6 through 9 for the temperature data from 18951948 andagain for 19492001. Format cells below your existing statistics to hold yournew calculations-don't overwrite your previous work. Be sure to make thefollowing adjustments:

. Use the same labels as before, except for the different date ranges.

a. Use =STDEV(BX:BY) for your standard deviation formula (becausethese date ranges are subsets of the entire data population).

b. Remember to use X and Y values that correspond to the date ranges

you are evaluating.


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12. Compare the standard deviations for the first and second halves of your datarange. Do your results support an interpretation of decreasing variability due

to global warming? Create a new slide in your PowerPoint presentation, titled"Standard Deviation over Time," and include your calculations andinterpretations.

13. Share your data and calculations with the other teams in your class. Comparetheir standard deviations and coefficients of variation with yours. Can youdraw any conclusions about the variability of winter temperatures in differentcities? Add another slide to your PowerPoint presentation, titled "StandardDeviation-Comparing Cities." Make sure your bullet points address thefollowing issues:

. What are the possible explanations for differences in variability

between cities? Consider the effects of altitude, latitude, and proximityof large bodies of water. Consult a map if necessary.

a. Explain the importance of the coefficient of variation when comparingthe standard deviation of your data with that of cities that have verydifferent mean temperatures.

Standard Deviation

Standard deviation quantifies the variation in a group of numbers. It's the average of

the deviations of each number from the mean (average). Standard deviation allowsyou to compare the variability of different datasets.


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The standard deviation formula in Microsoft Excel comes in many flavors. For the

purpose of this activity, we are interested in only two:

STDEV is used when the data being evaluated is only a partial sampling ofthe whole population of values.

STDEVP is used when the data being evaluated is the entire population(hence the P) of values.

You can find more information about standard deviation, including the specific

formulas that Excel uses, in your Microsoft Excel Help.

Coefficient of Variation

The coefficient of variation (also known as the percent error of the mean) allows you

to compare standard deviations of datasets that have very different means. It

represents the relative variation in the data by expressing the standard deviation as a

percentage of the mean. The formula is:

coefficient of variation = standard deviation / meanStep D

Join the Debate!

Software: Microsoft PowerPoint 2002

What to do: Take a stand on global warming. Defend your position in your

PowerPoint presentation, and cite your sources!

1. Your teacher will mediate an open-class debate on global warming. But first,you'll have time to add one or more slides to your PowerPoint presentation,summarizing your team's position on global warming. Be sure to cite evidencesupporting your position, including your findings already documented onprevious slides, and any new information you can find in the time allotted.

Start with the Web sites listed on the Resources page, but feel free to expandyour research. Remember to cite your sources.


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2. In the first stage of the debate, teams will present their PowerPointpresentations to the class. Can you persuade other teams to accept yourposition on global warming?

3. After the PowerPoint presentations, let the debate begin! Think about how

you would answer the following questions:

a. What is global warming, and how is it related to the greenhouseeffect?

b. What is the evidence that global warming is actually taking place?

c. How does global warming affect precipitation and temperatureextremes and variability?

d. Should we be concerned about the long-term effects of globalwarming? If so, why? If not, why not?

e. Is global warming caused by human activity? What is the evidence?

f. Is there anything we can do to reduce global warming, and shouldwe?

g. What are the political and economic issues surrounding the globalwarming debate?

4. After the debate, discuss the process as a class. Are there any clear answersto the questions about global warming? What kind of evidence would it take todefinitely prove that global warming is taking place? And if we wait for thatevidence... will it be too late? Did this activity change your ideas about globalwarming?

clues to climate change

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