A Collaborative Classroom Investigation of Climate Change on the Antarctic Peninsula

Developed by Juanita Constible, Miami University, Oxford, Ohio; Luke Sandro,

Springboro High School, Springboro, Ohio; and Richard Lee, Miami University, Oxford, Ohio

TEACHER SECTION OVERVIEW: Increasing air temperatures in the last 50 years have dramatically altered the Antarctic Peninsula ecosystem. In this across-the-curriculum inquiry, learners use a cooperative approach to investigate changes in the living and nonliving resources of the Peninsula. The activity stresses the importance of evidence in the formulation of scientific explanations. CORRELATIONS WITH NATIONAL SCIENCE EDUCATION STANDARDS: Content Standard A: Science as Inquiry

Formulate and revise scientific explanations and models using logic and evidence (p. 175) Recognize and analyze alternative explanations and models (p. 175) Communicate and defend a scientific argument (p. 176) Understandings about scientific inquiry (p. 176)

Content Standard C: Life Science

Biological evolution (p. 185) The interdependence of organisms (p. 186)

Content Standard E: Science and Technology

Understandings about science and technology (p. 192) Content Standard G: History and Nature of Science

Science as a human endeavor (p. 200-201) Nature of scientific knowledge (p. 201)

BACKGROUND INFORMATION

The popular media commonly paints science as a solitary endeavor, but nothing could be further from the truth. Science is a highly social process, requiring constant communication with colleagues, students, funding agencies, and the general public. Some phenomena, such as climate change, even necessitate a multi-disciplinary and international approach. This chapter describes a high school-level investigation

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into climate change on the Antarctic Peninsula that simulates the cooperative nature of climate research. In this cooperative learning lesson, every student within a group must be an active and equal participant for the rest of the group to succeed.

Warming Climate, Waning Sea Ice

Temperature data from the western Antarctic Peninsula indicate that the region has experienced rapid warming of 4-5° C during the winter. The relatively short-term record (<60 years) is only from a few research stations; nevertheless, several other indirect lines of evidence confirm the trend and suggest that it is not a “natural” climate cycle. The most striking of these proxies is a shift in penguin communities. Adélie penguins, which are dependent on sea ice for their survival, are rapidly declining on the western Antarctic Peninsula despite a 600-year colonization history. In contrast, chinstrap penguins, which require open water, are increasing dramatically. These shifts in penguin populations appear to be primarily the result of a decrease in the amount, timing, and duration of sea ice (Figure 1).

Figure 1. Relationships between direct and indirect signals of climate

change in the western Antarctic Peninsula.

Why is sea ice so important to Adélie penguins? First, sea ice provides winter food resources to krill, which are the primary prey of Adélies on the Peninsula. Second, Adélies can’t swim quickly enough to effectively search large stretches of open water for krill; rather, they primarily hunt on the underside of the sea ice where krill are found in large aggregations. (In contrast, chinstrap penguins can’t hold their breath long enough to hunt under the ice but are very fast swimmers.) Third, Adélies are indirectly affected by the climatic consequences of a reduction in sea ice. Declining sea ice results in an increase in ocean evaporation and cloud condensation nuclei, meaning more snow in the winter. The extra snow melts too late in the year for nesting Adélies, suffocating their eggs. Finally, there is a positive feedback between sea ice extent and air temperature; in other words, increasing air temperatures are amplified by the temperature-related melting of sea ice (Figure 2; see Chapter 3 for a discussion of positive feedback loops).

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Figure 2. Feedback between air temperature and sea ice extent.

This inquiry uses the cooperative learning technique called a ‘jigsaw’. Students are originally

organized into ‘Home Groups’ composed of five different specialists each (Figure 3). Specialists from each Home Group then meet with ‘Specialist Groups’ that contain only one type of scientist (e.g., Group 1 includes all of the Ornithologists, Group 2 includes all of the Oceanographers, etc.). Each Specialist Group receives a piece of the flowchart in Figure 1, in the form of a data table. With only a few facts to guide them, the Specialist Groups create graphs from the data tables, brainstorm explanations for patterns in their data, and report results back to their Home Groups. Finally, Home Groups use the expertise of each specialist to reconstruct the entire flowchart (Figure 1). TEACHING NOTES Prior to the Inquiry

Before the activity, students should know these facts: - (1) Antarctica is in the southern hemisphere, so the timing of the seasons is the opposite of what we experience in North America. (2) Because most of the Antarctic continent is covered by a permanent ice sheet, terrestrial habitat for sea birds is limited to the coastline and small islands. (3) The western Antarctic Peninsula has a maritime climate, and therefore is warmer on average than the rest of the Antarctic continent. Materials

1. Specialist Fact Sheet (1 for each student) 2. Temperature data set for the teacher (Figure 4) 3. Data sets for each Specialist Group (Adélie Penguin, Sea Ice, Snowfall, Chinstrap Penguin, and

Krill) 4. Specialist Group Report Sheets (1 for each student) 5. Sheets of graph paper (1 for each student), or computers or graphing calculators that are hooked

up to a printer (1 for each Specialist Group) 6. Blank sheets of paper for constructing flow charts (1 for each Home Group) 7. Sets of 6 flowchart cards labeled according to the boxes in Figure 1 (1 complete set for each

Home Group) 8. Tape and markers 9. Classroom space in which seating can be rearranged and wall space can be used for posters is

desirable

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Procedure Minimum Time: 2 class periods (2-3 hours) Class Period 1:

1. Split the class into Home Groups of five students each. Assign the name of a different real-life research agency to each group (e.g., Palmer Long-Term Ecological Research Network).

2. Instruct students to read the Specialist Fact Sheets. Each student in the group should assume the identity of a different scientist from the list.

3. Introduce yourself as follows: “Welcome! I am a climatologist with the Intergovernmental Panel on Climate Change in Geneva, Switzerland. In other words, I study long-term patterns in climate. My colleagues and I have studied changes in air temperatures on the Antarctic Peninsula since 1947. We have observed that although air temperatures on the Peninsula cycle up and down, they have increased overall [show Figure 4]. We think this is occurring because carbon dioxide emissions have enhanced the Earth’s natural greenhouse effect. Carbon dioxide and other greenhouse gases trap some of the sun’s heat and reflect it back to the earth, rather than releasing it back to space. We are interested in the effects that recent warming has had on the Antarctic ecosystem. This is where you come in. It is your job to describe the interconnected effects of warming on Antarctica’s living and nonliving systems.”

Figure 4. CLIMATOLOGISTS: Air Temperature Data Set (Flowchart Card 1)

4. Direct the specialists to meet with their respective Specialist Groups. Specialist Groups should

not interact with each other! 5. Distribute the data sets and Specialist Group Report Sheets to each Specialist Group. The

specialists should choose an appropriate way to graph, and then interpret their data set.

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Class Period 2: 6. Hand out a complete set of flowchart cards to the reconvened Home Groups. Each specialist

should make a brief presentation to his or her Home Group that approximates the format on the Specialist Group Report Sheet. Home Groups should then construct their own flowchart with the poster paper and all of the flowchart cards. Remind the scientists throughout this process that the weight of evidence should be used to construct the flowcharts.

7. When the flow charts are completed, have each Home Group do a brief presentation on their major findings and conclusions.

8. Consider these discussion questions at the end of the period as a class, by Home Group, or as homework for each student:

a. How has the ecosystem of the Antarctic Peninsula changed in the last 50 years? What are the most likely explanations for these changes?

b. Are you convinced by the evidence for these explanations? Why or why not? What further questions are left unanswered?

c. Did your Specialist Group come up with any explanations that you think are not very likely (or not even possible!), based on the complete story presented by your Home Group?

d. What are some common features of all the data sets? Assessment

We used a simple score sheet to assess student understanding (Figure 11) that focuses on group work and the nature of science. Depending on the unit of study in which this inquiry is used, however, a variety of specific content standards may also be assessed. For example, in an ecology unit, you may wish to determine student knowledge of interactions among populations and environments; in an earth studies unit, students could be assessed on their understandings about the dramatic effects of small fluctuations in global temperature. Modifications Some students may have difficulties with the construction and interpretation of flowcharts. It may be constructive to have students label each arrow with a verb. For instance:

There are several ways to shorten this lesson:

• Start immediately with Specialist Groups, rather than with Home Groups. • Provide graphs of the data for interpretation rather than having each Specialist Group create

their own graph. • Omit the Home Group presentations.

Alternatively, the activity could be extended by: • Encouraging the role play aspect of this inquiry (e.g., use costumes). • Assigning individual research projects on topics such as comparisons/contrasts to other

ecosystems impacted by global warming.

WINTER SNOWFALL causes

SEA ICE EXTENT

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• Hosting a class debate on measures that should be taken nationally and internationally to address changes in climate.

• Hosting a mini career day, in which students are provided with materials on careers in science or possibly are allowed to interact with guest speakers.

Figure 11. Rubric STUDENT NAME: Criteria SELF TEACHER

Comments

Active participation in group process. (5 points)

Appropriate graph is used to display data. All required elements (labels, titles, etc.) are present. Data are graphed accurately. (5)

Data and interpretations from Specialist Groups are clearly communicated to Home Groups by individual specialists. (10 points)

Alternative explanations are weighed based on available evidence and prior scientific knowledge. (10 points)

Conclusions are clearly and logically communicated. (10)

Report sheet is complete. (5 points) TOTAL (out of 45)

BIBLIOGRAPHY Numerical Data Sea ice, Palmer Station LTER Grid and air temperature, Faraday/Vernadsky Station: Palmer LTER Data

Archive (http://pal.lternet.edu/cgi-bin/ucmbo-cgi/studycatalog.cgi), supported by Office of Polar Programs, NSF Grant #OPP-96-32763.

Penguins (all species), Arthur Harbor: Smith, R. C., W. R. Fraser, S. E. Stammerjohn, and M. Vernet. 2003. Palmer Long-Term Ecological Research on the Antarctic marine ecosystem. Pp. 131-144 in Antarctic Peninsula Climate Variability: Historical and Paleoenvironmental Perspectives, E. Domack, A. Leventer, A. Burnett, R. Bindschadler, P. Convey, M. Kirby, eds. Washington, D.C.: American Geophysical Union.

Krill, Southern Ocean: Atkinson, A., V. Siegel, E. Pakhomov and P. Rothery. 2004. Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature 432: 100-103.

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Winter snow, Faraday/Vernadsky Station: Antarctic Meteorology Online, British Antarctic Survey (http://www.antarctica.ac.uk/met/metlog/).

Background Information and Facts on Data Sheets Ainley, D. G. 2002. The Adélie Penguin: Bellwether of Climate Change. New York: Columbia

University Press. Atkinson, A., V. Siegel, E. Pakhomov and P. Rothery. 2004. Long-term decline in krill stock and

increase in salps within the Southern Ocean. Nature 432: 100-103. Carlini, A. R. N. R. Coria, M. M. Santos, and S. M. Buján. 2005. The effect of chinstrap penguins on the

breeding performance of Adélie penguins. Folia Zoologica 54: 147-158. Chappell, M. A., V. H. Shoemaker, D. N. Janes, S. K. Maloney, and T. L. Bucher. 1993. Energetics of foraging in breeding Adélie penguins. Ecology 74: 2450-2461. Colburn, A. 2003. The Lingo of Learning: 88 Education Terms Every Science Teacher Should Know.

Arlington, VA: NSTA Press. Daniels, C., and E. Kingsley. 2005. Reel science. Times Educational Supplement. Available online:

http://www.tes.co.uk/section/story/?story_id=380415&window_type=print [accessed 03 March 2005].

Emslie, S. D., W. Fraser, R. C. Smith, and W. Walker. 1998. Abandoned penguin colonies and environmental changes in the Palmer Station area, Anvers Island, Antarctic Peninsula. Antarctic Science 10: 257-268.

Fraser, W. R., and D. L. Patterson. 1997. Human disturbance and long-term changes in Adélie penguin populations: a natural experiment at Palmer Station, Antarctic Peninsula. Pp. 445-452 in: Antarctic Communities: Species, Structure and Survival, B. Battaglia, J. Valencia, and D. W. H. Walton, eds. Cambridge, UK: Cambridge University Press.

Fraser, W. R., W. Z. Trivelpiece, D. G. Ainly, and S. G. Trivelpiece. 1992. Increases in Antarctic penguin populations: reduced competition with whales or a loss of sea ice due to environmental warming? Polar Biology 11:525-531.

Fraser, W. R. and W. Z. Trivelpiece. 1996. Factors controlling the distribution of seabirds: winter- summer heterogeneity in the distribution of Adelie penguin populations. Pp. 257-272 in: Foundations for Ecological Research West of the Antarctic Peninsula, R. M. Ross, E. E. Hofmann, and L. Quetin, eds. Washington, DC: American Geophysical Union.

King, J. C. and S. A. Harangozo. 1998. Climate change in the western Antarctic Peninsula since 1945: observations and possible causes. Annals of Glaciology 27: 571-575.

Lynnes, A. S., K. Reid, J. P. Croxall, and P. N. Trathan. 2002. Conflict or co-existence? Foraging distribution and competition for prey between Adélie and chinstrap penguins. Marine Biology 141: 1165-1174.

National Research Council (NRC). 1996. National Science Education Standards. Washington, D.C.: National Academy Press. Newman, S. J., S. Nicol, D. Ritz, and H. Marchant. 1999. Susceptibility of Antarctic krill (Euphausia

superba Dana) to ultraviolet radiation. Polar Biology 22: 50-55. Patterson, D. L., A. L. Easter-Pilcher, and W. R. Fraser. 2003. The effects of human activity and

environmental variability on long-term changes in Adélie penguin populations at Palmer Station,

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Antarctica. Pp. 301-307 in: Antarctic Biology in a Global Context, A. H. L. Huiskes, W. W. C. Gieskes, J. Rozema, R. M. L. Schorno, S. M. van der Vies, and W. J. Wolff, eds. Leiden, The Netherlands: Backhuys Publishers.

Smith, R. C., D. Ainley, K. Baker, E. Domack, S. Emslie, B. Fraser, J. Kennett, A. Leventer, E. Mosley- Thompson, S. Stammerjohn, M. Vernet. 1999. Marine ecosystem sensitivity to climate change. Bioscience 49: 393-405.

Smith, R. C., W. R. Fraser, and S. E. Stammerjohn. 2003. Climate variability and ecological response of the marine ecosystem in the Western Antarctic Peninsula (WAP) region. Pp. 158-173 in: Climate Variability and Ecosystem Response at Long-Term Ecological Research (LTER) Sites, D. Greenland, D. Goodin, and R. C. Smith, eds. New York: Oxford Press.

Turner, J., S. R. Colwell, and S. Harangozo. 1997. Variability of precipitation over the coastal western Antarctic Peninsula from synoptic observations. Journal of Geophysical Research 102: 13999- 14007.

Turner, J., T. A. Lachlan-Cope, J. P. Thomas, and S. R. Colwell. 1995. The synoptic origins of precipitation over the Antarctic Peninsula. Antarctic Science 7: 327-337.

Vaughan, D. G., G. J. Marshall, W. M. Connolley, C. Parkinson, R. Mulvaney, D. A. Hodgson, J. C. King, C. J. Pudsey, and J. Turner. 2003. Recent rapid regional climate warming on the Antarctic Peninsula. Climate Change 60: 243-274.

Wadhams, P. 2000. Ice in the Ocean. The Netherlands: Gordon and Breach Science Publishers. Weingart, P., C. Muhl, and P. Pansegrau. 2003. Of power maniacs and unethical geniuses: science and

scientists in fiction film. Public Understanding of Science 12: 279-287. ACKNOWLEDGEMENTS We thank Dr. William Fraser for providing valuable information about Adélie penguins and constructive criticism on a previous version of this project. Thanks to everyone at Palmer Station for background information related to this activity. Marianne Kaput and an anonymous reviewer provided constructive criticism on previous drafts of this activity. This project was supported by NSF grants OPP-0337656 and IOB-0416720.

STUDENT PAGES SPECIALIST FACT SHEET Each Home Group contains five different specialists that spend part of the year in the Antarctic collecting data, and part of the year analyzing data and writing reports at home base.

1. Ornithologist: A scientist that studies birds. Uses visual surveys (from ship or on land), diet analysis, and satellite tracking to collect data on penguins.

2. Oceanographer: A scientist that studies the ocean. Uses satellite imagery, underwater sensors, and manual measurements of sea ice thickness to collect data on sea ice conditions and ocean temperature.

3. Meteorologist: A scientist that studies the weather. Uses automatic weather stations and visual observations of the skies to collect data on precipitation, temperature, and cloud cover.

4. Marine Ecologist: A scientist that studies the relationship between organisms and their environment. Uses the same data collection techniques as the ornithologist.

5. Fisheries Biologist: A scientist that studies fish and their prey. Uses research vessel cruises to collect data on krill.

ORNITHOLOGISTS: Adélie Penguin Data Set (Flowchart Card 2) - Adélie penguins spend their summers on land, where they breed, and winters on the outer extent of

the sea ice surrounding Antarctica, where they molt their feathers and fatten up. - Adélies are visual predators, meaning they need enough light to see their prey. Near the outer part

of the pack ice, there are only a few hours of daylight in the middle of the winter. There is less sunlight as you go further south.

- On the western Antarctic Peninsula, Adélie penguins eat mostly krill, a shrimp-like crustacean. - Japan, Russia, and other countries have been harvesting krill since the mid-1960s. - Adélie penguins need dry, snow-free, pebbly places to lay their eggs. The same nest sites are used

year after year and at about the same time every year. - Female Adélies usually lay two eggs, and on average, only one of those eggs result in a fledged

chick (fledged chicks have a good chance of maturing into adults). The two most common causes of death of eggs and chicks are abandonment by the parents (if they can’t find enough food) and predation by skuas (a hawk-like bird).

- In the water, Adélies are eaten mostly by leopard seals, but also by killer whales. - Adélies can look for food under sea ice because they can hold their breath for a long time. They’re

not as good at foraging in the open ocean, because they can’t swim very fast. - Adélie penguins have lived in the western Antarctic Peninsula for at least 644 years.

Year # Breeding Pairs of Adélie Penguins

1975 15,202

1979 13,788

1983 13,515

1986 13,180

1987 10,150

1989 12,983

1990 11,554

1991 12,359

1992 12,055

1993 11,964

1994 11,052

1995 11,052

1996 9,228

1997 8,817

1998 8,315

1999 7,707

2000 7,160

2001 6,887

2002 4,059

OCEANOGRAPHERS: Sea Ice Data Set (Flowchart Card 3) - In the winter (August), sea ice covers over 18 x 106 km2, or 40%, of the Southern Ocean. This is an

area larger than Europe. In the summer (February), only 3 x 106 km2 of the ocean is covered by sea ice.

- Sea ice keeps the air of the Antarctic region cool by reflecting most of the solar radiation that hits it. On the other hand, sea ice keeps the ocean relatively warm by acting as an insulator.

- Sea ice reduces evaporation of the ocean, thus reducing the amount of moisture that is released to the atmosphere.

- As sea ice melts, bacteria and other particles are released into the atmosphere. These particles form condensation nuclei, which serve as starting points for cloud droplets, and freezing nuclei, that allow cloud droplets to grow into rain or snow droplets.

- Rain helps to stabilize the sea ice by freezing on the surface. - Sea ice can be broken up by strong winds that last a week or more. - An icebreaker is a ship with a reinforced bow to break up ice and keep channels open for navigation.

Icebreakers were first used in the Antarctic in 1947, and have been commonly used to support scientific research in the last 25 years.

Year Area of Sea Ice Extending from the Antarctic Peninsula (km2)

1980 146,298 1981 136,511 1982 118,676 1983 88,229 1984 85,686 1985 78,792 1986 118,333 1987 142,480 1988 90,310 1989 44,082 1990 79,391 1991 111,959 1992 110,471 1993 94,374 1994 103,485 1995 95,544 1996 86,398 1997 100,748 1998 73,598 1999 79,223 2000 79,200 2001 69,914

METEOROLOGISTS: Winter Snow Data Set (Flowchart Card 4) - In the winter, most of the precipitation in the western Antarctic Peninsula occurs as snow. There is

an even mix of snow and rain the rest of the year. - It is very difficult to accurately measure the amount of snowfall in the Antarctic because strong

winds blow the snow around. - Antarctica is the world’s driest desert. However, the Antarctic Peninsula has a warmer, more

maritime climate, so gets more rain and snow than the rest of the continent. - Most of the rain and snow in the western Antarctic Peninsula is generated by cyclones from outside

the Southern Ocean. Cyclones are areas of low atmospheric pressure and rotating winds. - Sea ice reduces evaporation of the ocean, thus reducing the amount of moisture that is released to

the atmosphere. - As sea ice melts, bacteria and other particles are released into the atmosphere. These particles form

condensation nuclei, which serve as starting points for cloud droplets, and freezing nuclei, that allow cloud droplets to grow into ice crystals (snow).

Year % of Precipitation Events that are Snow

1982 49 1983 67 1984 72 1985 67 1986 81 1987 80 1988 69 1989 69 1990 68 1991 72 1992 70 1993 70 1994 83 1995 77 1996 74 1997 81 1998 81 1999 83 2000 77 2001 90 2002 82 2003 76

MARINE ECOLOGISTS: Chinstrap Penguin Data Set (Flowchart Card 5) - Chinstrap penguins breed on land in the spring and summer and spend the rest of the year in open

water north of the sea ice. The number of chinstraps that successfully breed is much lower in years when the sea ice remains late in the spring.

- Chinstraps eat mostly krill, a shrimp-like crustacean. - Whalers and sealers overhunted seals and whales, which also eat krill, until the late 1930s. - Chinstraps need to forage in mostly open water, because they can’t hold their breath for very long. - The main predators of chinstraps and gentoos are skuas (a hawk-like bird), leopard seals, and killer

whales. - Chinstraps will aggressively displace Adélie penguins from nest sites in order to start their own

nests and may compete with Adélies for feeding areas. - Although chinstrap penguins have occupied the western Antarctic Peninsula for over 600 years, they

have become numerous near Palmer Station only in the last 35 years.

Year # Breeding Pairs of Chinstrap Penguins

1976 10 1977 42 1983 100 1984 109 1985 150 1989 205 1990 223 1991 164 1992 180 1993 216 1994 205 1995 255 1996 234 1997 250 1998 186 1999 220 2000 325 2001 325 2002 250

FISHERIES BIOLOGISTS: Krill Data Set (Flowchart Card 6) - Krill are a keystone species, meaning they are one of the most important links in the Antarctic food

web. All the animals in the Antarctic (penguins, whales, seals, fish, etc.) either eat krill or another animal that eats krill.

- Krill eat mostly algae. In the winter, the only place algae can grow is on the underside of sea ice. - Japan, Russia, and other countries have been harvesting krill since the mid-1960s. - Ultraviolet radiation is harmful to krill, and can even kill them. - Salps, which are small, marine animals that look like blobs of jelly, compete with krill for food

resources.

Year

Density of Krill in the Southern Ocean (no./m2)

1982 91 1984 50 1985 41 1987 36 1988 57 1989 15 1990 8 1992 7 1993 22 1994 6 1995 9 1996 31 1997 53 1998 46 1999 4 2000 8 2001 31 2002 8 2003 3

SPECIALIST GROUP REPORT SHEET NAME: SPECIALIST GROUP: In your own words, summarize the general trend or pattern of your data. Attach a graph of your data to the back of this sheet. List possible explanations for the patterns you are seeing. With the help of the facts at the top of each data sheet, choose the explanation that you think is most likely. Why do you think that explanation is most likely?