Activity 2: Carbon Cycle and Greenhouse Gases Web- · PDF fileclimate is changing as a result...

Carbon Cycle and Greenhouse Gases Web-quest

Background

global climate changeMost scientists agree that our

climate is changing as a result of human activities, especially burning fossil fuels to produce energy. When you hear the phrase “climate change,” what do you think it means? Climate change includes long-term changes in temperature, precipitation, or wind. Climate change is the result of many factors, including human-produced greenhouse gases (U.S. EPA, 2007a).

Greenhouse gases trap heat in the Earth’s atmosphere. A certain amount of greenhouse gases are necessary to keep the Earth warm enough to sustain life. The temperature of Earth is maintained by heat radiation from the sun and heat loss into space. When greenhouse gases are added to the atmosphere, less heat is allowed to escape into space, and Earth’s

surface warms. This process is called global warming. Global warming is the gradual increase in the average global temperature (U.S. EPA, 2007a). Global warming contributes to additional and various changes in the overall climate.

Of all the greenhouse gases, carbon di-oxide (CO

2) levels have increased the most

in recent years. Carbon dioxide represents more than 80 percent of total greenhouse gas emissions in the U.S. (U.S. EPA, 2008). Energy generation and transporta-tion represent the largest sources of CO

2

emissions in the U.S. (Figure 1). Reducing

Section 1. Gathering Information

n suBjects

Science, Language Arts

n key Questions

1. What are the components of the carbon cycle?

2. How do human activities influence the carbon cycle and climate change?

3. What can be done to reduce greenhouse gas emissions?

n oBjectives

By the end of the activity, students will be able to do the following:1. Describe the basic

components of the carbon cycle (SC.912.E.7.1).

2. Explain how human activities influence the carbon cycle (SC.912.E.6.6; SC.912.L.17.16).

3. Explain the greenhouse effect and various causes of global climate change (SC.912.L.17.11; SC.912.E.7.7).

4. Synthesize information gathered by creating a poster and presenting this poster to the class (LA.1112.5.2.3).

n Materials

• Copies of Carbon Cycle and Greenhouse Gases Student Worksheet: Web-quest Exploration Guide for each student

• Computers with Internet access for each student or pair of students

• Headphones for each student for video/audio sections

n tiMe estiMate

1 hour

activity 2

suMMary

Students visit various Web sites and complete the Web-quest Exploration Guide to gather information and learn about the carbon cycle, greenhouse gases, and climate change. Students then create a carbon cycle poster and share with the class.

Climate change has different impacts to different locations on Earth. For example, some areas may have increased precipi-tation, while others may have decreased precipitation. Some areas may have warmer summers, while some areas may not notice any changes.

did you know??

Figure 1.

this graph depicts sources of co2 emissions in the u.s. (numbers are metric tons co2 emitted). GRAPH COURTESY OF U.S. EIA (2008)

27% 39%

34%

direct use of fossil fuels in:

Homes, commercial Buildings, and industry electric

Powersector

transportation

Should We uSe Wood for energy? • Section 1 – Activity 2: Carbon Cycle and Greenhouse Gases Web-quest 27

sunlight CO2 cycle

fossils & fossil fuels

photosynthesis

auto &factory emissions

animal & plantrespiration

organic carbon

ocean uptakedecay organisms

dead organisms& waste products

root respiration

Figure 2. carbon continuously cycles through living organisms, soils, oceans, and the atmosphere.

CO2 emissions is an important part of

slowing global climate change.

the carbon cycleCarbon is an element that continu-

ously moves through all plants, animals, soils, oceans, and the atmosphere. The movement of carbon is referred to as the carbon cycle (Figure 2). As you read the following paragraphs, refer to the figure above to visualize the movement of carbon through the cycle.

Carbon moves from the atmosphere to plants through photosynthesis—a process where green plants grow by harnessing energy from the sun. During photosynthesis, plants use sunlight, carbon dioxide (CO

2), and water to pro-

duce oxygen and glucose. The glucose (or sugar) is a form of chemical energy that is stored in the cells of plants.

Plants release energy in the form of carbon during plant respiration. The excess carbon that is not released during respiration is stored in tree trunks and

In 2005, about 21 percent of the world’s total energy-related carbon dioxide was emitted by the U.S.

(U.S. EIA, 2008c)

did you know??

Carbon is the building block of life! Carbon plays a major role in the makeup and function of all living organisms.

did you know??Greenhouse GasesGreenhouse gases emitted by the U.S. include the following:

• Carbondioxide(CO2)

• Methane(CH4)

• Nitrousoxide(N2O)

• Hydrofluorocarbons(HFCs)

• Perfluorocarbons(PFCs)

• Sulfurhexafluoride(SF6)

• Watervapor(H2O)

(U.S. EIA, 2008c)

28 Should We uSe Wood for energy? • Section 1 – Activity 2: Carbon Cycle and Greenhouse Gases Web-quest

trees store carbon as they grow, making them an important part of the carbon cycle.

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leaves as plants grow. This stored carbon is transferred to animals when plants are eaten. When animals breathe, CO

2 is

released into the atmosphere. If plants are burned, for example

in a forest fire or at a power plant, CO2

is released into the atmosphere. When plants and animals naturally decompose, carbon is released into the atmosphere and soil. Some of this carbon gets buried far beneath the Earth’s surface and will

form fossil fuels in millions of years.When fossil fuels are extracted from

the earth and burned for energy, CO2 is

released into the atmosphere. However, this carbon has not been part of the carbon cycle for millions of years. All of the CO

2 released by burning fossil fuels

cannot be absorbed back into the carbon cycle by land plants and oceans (Mat-thews & Robertson, 2005). Therefore, the overall amount of CO

2 in the atmosphere

increases when fossil fuels are burned.

the role of Woody Biomass in the carbon cycle

Unlike fossil fuels, woody biomass is a carbon-neutral energy source. This means using energy from woody biomass will not increase the overall amount of CO

2 in the atmosphere (Matthews

& Robertson, 2005). This may sound surprising to you: how can you burn something and not add CO

2 to the

atmosphere? As we learned, burning wood releases CO

2 into the atmosphere.

However, trees that are growing absorb and store carbon. Therefore, if trees are planted at the same rate they are har-vested and burned for energy, then the overall amount of CO

2 in the atmosphere

does not increase.

In the atmosphere, carbon combines with oxygen to form the gas carbon dioxide(CO2).

did you know??

Woody biomass is a carbon neutral source of energy.

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How is Wood CarbonNeutral?ThinkofCO2 in the atmosphere as a bathtub full of water. Burning wood rep-resents water entering the tub through the faucet, and growing trees represents the drain because combustion addsCO2 to the atmosphere and photosynthesis removes it. Woody biomass is carbon neutral as long as we do not burn wood (run the faucet) faster than we grow trees (drainthewater).Ontheother hand, because fossil fu-els are not part of the short-term carbon cycle, burning fossil fuels is like running the faucet without opening the drain. The water level rises and the tub overflows. The same thing happens when CO2 levels in the atmosphere increase: when atmospheric carbon rises, average global temperatures also rise.


Preparation1. Read the Background Information provided at the beginning of this activity and

make copies if you plan to assign reading before the activity. Additional, more detailed information is available in the Climate Change and Carbon fact sheets in the Supplemental Reading section.

2. Go through the Web-quest Exploration Guide on your own to familiarize yourself with the topic and activity.

3. Ensure that each Web site link is operational and that the video segments upload correctly.

Procedure1. When students are at computer stations, pass out copies of the Web-quest

Exploration Guide and provide them with the web address to open the PDF file from the program Web site (this will enable them to utilize active hyperlinks). Also, pass out headphones. Ask students to wear headphones during video/audio sections of the Web-quest or if headphones are unavailable, ask them to lower or mute the volume.

2. Review instructions with your class and make sure each student completes his or her own worksheet.

3. When students complete the Web-quest, initiate a class discussion using the Discussion Questions. If time is limited, you can do the discussion the following day or assign the questions as student homework.

4. After completing this Web-quest, ask students to create a poster depicting their own version of the carbon cycle. Encourage students to draw, use magazine clippings, or photos and to be as creative as possible. Their diagrams should not simply be a copy of a standard carbon cycle, but instead, have a unique or interesting component that shows a deeper understanding of the cycle. Have students share their posters with the class. Posters can be displayed around the classroom, lunchroom, or in school hallways.

AssessmentSuggestions

ObjeCTive1:Review student answers to the Web-quest Exploration Guide, part I. In addition, student understanding of carbon cycle processes can be assessed by reviewing student posters and the ability of students to answer questions about his or her poster.

ObjeCTive2:Review student answers to the Web-quest Exploration Guide, parts I and II.

ObjeCTive3:Review student answers to the Web-quest Exploration Guide,partsii–vi.

ObjeCTive4:Score student posters using the rubric on the following page.

teacher instructionsteacHer


Extensions

•Ask each student to calculate his or her individual emissions. Go to http://www.epa.gov/climatechange/wycd/calculator/ind_calculator.html for more information. This individual emissions calculator asks for detailed information, which students will need to gather on their own. Tell students to write a brief report on the data they entered and the results. Students can share their reports with the class and participate in a class discussion on ways to reduce individual emissions.

•Have students calculate their carbon footprints using a calculator available online. There are many versions of the carbon calculator; one is available at http://coolclimate.berkeley.edu/. Next,asaclass,comparecarbonfootprints and discuss reasons for differences in figures. Also, compare the national individual average to student averages and compute a class carbon footprint. Discuss ways to reduce your carbon footprint.

•Ask students to calculate the school’s carbon footprint. Go to http://www.epa.gov/climatechange/wycd/actionsteps.html for more information. As a class, write up a report for the principal identifying ways for your school to reduce its carbon emissions.

•As a class, participate in a climate change challenge and report results to your local newspaper. visithttp://www.carbonrally.com/ for more information.

•As a class, watch the movie An Inconvenient Truth and have a class discussion about what students learned and their own thoughts.

• KoshlandScienceMuseum:http://www.koshland-science-museum.org/exhibitgcc/• NASAEarthObservatory:http://earthobservatory.nasa.gov/Library/CarbonCycle/• U.S.EIA:http://www.eia.doe.gov• U.S.EPA:http://www.epa.gov/climatechange/emissions/index.html• WindowstotheUniverse:http://windows2universe.org/earth/Water/co2_cycle.html• WoodsHoleResearchCenter:http://www.whrc.org/resources/primer_home.html

Resources

n student Poster rubric: Carbon Cycle and Greenhouse Gases Web-quest

category 4 Above

Standards 3 Meets

Standards 2 Approaching

Standards 1 Below

Standards

graphics – originality

Several of the graphics used on the poster reflect an exceptional degree of student creativity in their creation and/or display.

Oneortwoof the graph-ics used on the poster re-flect student creativity in their creation and/or display.

The graphics are made by the student, but are based on the designs or ideas of others.

Nographicsmadeby the student are included.

content – accuracy

At least 7 ac-curate facts are displayed on the poster.

5-6 accurate facts are displayed on the poster.

3-4 accurate facts are dis-played on the poster.

Less than 3 accurate facts are displayed on the poster.

attractiveness The poster is exceptionally at-tractive in terms of design, layout, and neatness.

The poster is attractive in terms of design, layout, and neatness.

The poster is acceptably at-tractive though it may be a bit messy.

The poster is distract-ingly messy or very poorly designed. It is not attractive.

knowledgegained

Student can ac-curately answer all questions related to facts in the poster and processes used to create the poster.

Student can accurately answer most questions related to facts in the poster and processes used to create the poster.

Student can ac-curately answer about 75% of questions related to facts in the poster and pro-cesses used to create the poster.

Student appears to have insufficient knowledge about the facts or processes used in the poster.

grammar There are no grammatical mistakes on the poster.

There is 1 grammatical mistake on the poster.

There are 2 grammatical mistakes on the poster.

There are 3 or more grammatical mistakes on the poster.

teacHer


student (1 of 6)Web-quest exploration guidecarBon cycle and greenHouse gases

Carbon sinks, sources, and sequestration, greenhouse gas emissions, and climate change: what does this all mean, and how in the world are you part of the carbon cycle? This Web-quest Exploration Guide will direct you to numerous online resources related to the carbon cycle. Follow the instructions and complete the worksheet to turn in to your teacher.

i. tHe gloBal carBon cycle

Go to the �� Pearson/PrenticeHallBiologicalScienceWeb site: http://wps.prenhall.com/esm_freeman_biosci_1/0,6452,501436-,00.html

�� You may need to download a plug-in to view the video. Follow instructions to download the plug-in, and continue with the following steps.

Click on �� NaturalProduction.

Putyourheadphonesonormutethesound.��

Maximizethepageandwatchthevideodepictionofthecarboncycle.��

Describe two processes of the carbon cycle:��

�� Close the video window.

�� Click on HumanActivities on the original Web page.

�� Watch the video and answer the following questions:

1. What are two most significant ways that humans increase the amount of carbon in the atmosphere?

2. Since1950whathashappenedtoatmosphericCO2 concentrations recorded at a laboratory at MonaLoa?

___________________________________________________________________ _______________ ________________

NAMe DATE PeRiOd


ii. tHe greenHouse eFFect

Go to the �� NationalGeographicVideoWeb site: http://science.nationalgeographic.com/science/ environment/global-warming/gw-overview-interactive.html

�� Go through the animated depiction of the greenhouse effect (start and continue through each section by clicking on the green buttons).

Answer the following questions:��

1. What happens when the sun’s radiation reaches Earth’s atmosphere?

2. How does Earth stay warm enough to sustain life?

3. How do human activities intensify the warming effect?

4. Fill in the following chart about the major greenhouse gases (GHG) (Hint: click on the GHG inside the pie chart to retrieve more information on each GHG).

GHG % Contribution to increase in GHG emissions since 1700

Source(s)

carbon dioxide (co2)

nitrous oxide (n2o)

Methane (cH4)

other

studentCarbon Cycle and Greenhouse Gases Web-quest Exploration Guide (2 of 6)


iii. greenHouse gas MaPs

Go to the �� PurdueUniversityNewsroom Web site: http://www.purdue.edu/newsroom/

�� Type Vulcanin the SearchPurdueNews box.

Click on �� Revolutionary CO2mapszoominongreenhousegassources in the search results.

�� Answer the following questions:

1. Whatdothevulcanmapsdepict?

2. WhatpercentageofglobalCO2 emissions does the U.S. account for?

�� Click on Downloadimage under the map of Where CO2isbeingemitted (near the top of the article).


1. basedonthisimage,whatregionsoftheUnitedStatesemitthegreatestamountsofCO2?

2. WhydoyouthinktheseareasemitsuchlargeamountsofCO2?

iv. international co2 eMissions

Go to the�� InternationalEnergyAgencyDynamicMapsWeb site: http://www.iea.org/country/maps.asp

Click on �� GototheMap under MapEnergyIndicators.

Click on �� MapEnergyIndicatorsin the upper left corner and select CO2Emissions.

Click on �� NorthAmerica, click on the United States,andrecordCO2 emissions in the table below.

Click on �� Asia(includingChina), select China,andrecordCO2 emissions in the table below.

Click on �� OECD Europe,selectacountryofyourchoice,andrecordCO2 emissions in the table below.

Click on �� Africa, select Zimbabwe,andrecordCO2 emissions in the table below.

student Carbon Cycle and Greenhouse Gases Web-quest Exploration Guide (3 of 6)

Country CO2 emissions (Mt1 of CO2)

u.s.

china

european country:

Zimbabwe

1 Mt=Milliontonnes(1milliontonnes=2.05billionpounds)



1. HowdoCO2 emissions of the U.S. and China compare with the European country and Zimbabwe?

2. WhatmightbesomesimilaritiesanddifferencesthatcouldaccountforthedifferencesinCO2 emissions of these four countries?

v. WHat are tHe utility eMissions in My area?

Go to the U.S. �� EnvironmentalProtectionAgencyCleanEnergyWeb site: http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html

��Enter your five-digit zip code in the box.

��Select the utility company that provides your electricity.

��Review Graph 1: What is my fuel mix?

��Fill in the following chart:

vi. Fuel econoMy

Go to the �� U.S.DepartmentofEnergyFuelEconomy Web site: http://www.fueleconomy.gov/feg/whyshtml

List four reasons why fuel economy is important:��

1.

2.

3.

4.

Click on�� Find and Compare Cars at the top of the page.

Select the �� ModelYear of your personal car or your family car.

Select the �� Makeof your personal car or your family car.

Select the �� Model of your personal car or your family car.

Find the model from the list that matches the engine components in your personal car or family’s ��car (for example 4, 6, or 8 cylinder engine, automatic or manual transmission, etc.).

GHG Nitrogen Oxide Sulfur Dioxide Carbon Dioxide

your region’s utility emissions rate (lbs/MWh)

national average emissions rate (lbs/MWh)

Methane (cH4)

studentCarbon Cycle and Greenhouse Gases Web-quest Exploration Guide (4 of 6)


��Click Compare and fill in the table below with the information provided about your personal car or your family’s car.

vii. gloBal WarMing eFFects

Go to �� BenandJerry’sLickGlobalWarmingWeb site at: http://www.lickglobalwarming.org/map.cfm

Click on two of the icons to choose a category and then click on a dot on the map to learn more about a ��specific effect of global warming.

Record the information below: ��

category 1:

location:

effect:

category 2:

location:

effect:

viii. WHat can i do?

Go to the �� Union of Concerned Scientists Web site: http://www.ucsusa.org/global_warming/what_you_can_do/

�� Read WhatYouCanDoaboutGlobalWarming.

�� Record five things that you or your family can do:

1.

2.

3.

4.

5.

student Carbon Cycle and Greenhouse Gases Web-quest Exploration Guide (5 of 6)

year

Make

Model

city MPg

Hwy MPg

annual fuel cost ($)

annual petroleum consumption (barrels/year)

carbon footprint (tons co2 emitted/year)


Conclusion

Carbon cycles continuously through all plants, animals, soils, oceans, and the atmosphere. Carbon is the building block of life and is a major part of the makeup and function of all living or-ganisms. Humans get carbon fromfood.Plantsabsorbcarbon from the atmo-sphere during photosynthe-sis, and plants and animals store carbon as they grow and release carbon as they decompose. Some human actions, particularly burning fossil fuels to generate en-ergy, cause carbon dioxide to be released into the at-mosphere.Notalloftheseemissions can be absorbed into the carbon cycle by livingorganisms.Nowthatyou’ve learned about the carbon cycle and green-house emissions, review the following questions and be prepared to discuss your answers and thoughts with the rest of the class.

Discussion Questions

student

1 What agencies or organizations sponsored the Web sites you collected information from and what might their bias be?

2 Is the information presented on the Web sites balanced?

3 What are some of the reasons there is more carbon dioxide in the atmosphere now than ever before?

4 WhydoyouthinktheU.S.emitslargeamountsofCO2 and other greenhouse gases?

5 What can individuals and families do to reduce carbon emissions?

6 What can industries, communities, and federal governments do to reduce carbon emissions?

Carbon Cycle and Greenhouse Gases Web-quest Exploration Guide (6 of 6)


Activity 2: Carbon Cycle and Greenhouse Gases Web- · PDF fileclimate is changing as a result...

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