Next Generation Biospheres

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Originally appears in the Winter 2020 issue.

By Jimmy Karlan and Hannah Root

“What do you think would happen if we put a large number of crickets into your biosphere today?” After carefully constructing and sealing their biospheres and then monitoring them closely for three weeks, the 7th- and 8th-graders were bursting with predictions and questions. “They would have babies and then their babies would have babies and they would use up all of the resources!” “They would eat all of the plants, which would stop oxygen from being produced, and they would all die!” “They would breathe out so much carbon dioxide, which the plants would like for a little bit, but maybe it would be too much?” This group of thoughtful students at the Surry Village Charter School in Keene, New Hampshire, USA completed the Biosphere Challenge this fall as part of the lead author’s full-year program called Wild Treasures: Climate Change.1 The biospheres that students built are working models of the world around us, with active natural processes and cycles happening in the small confines of 10-gallon terrariums. Arranged along two sunny classroom windows, they are playgrounds where students explore concepts like systems, cycles, and resiliency. The Biosphere Challenge is an iterative cycle that begins with the introduction of a new challenge, and then leads students to test out their ideas, monitor the results, and learn from the outcomes. Over the course of a month and a half, the students build on their ideas week-to-week and come away with a concrete understanding of how our Earth’s systems work and the consequences that can happen when they get out of balance.

In teaching about climate change, it can be overwhelming to take this global-scale problem and turn it into an observable phenomenon in the classroom. How do we capture the complexities of the issue, while making it relevant and engaging for middle and high school students? And how do we present it in a way that empowers students instead of filling them with dread? The answer is not only simple and accessible, but it can fit into a 10-gallon tank on your classroom windowsill.

The Biosphere Challenge is an inquiry-based curriculum that was first designed as part of Professor Jimmy Karlan’s doctoral thesis to elicit students’ understanding of ecological concepts and theories about what has to happen to sustain life.2 “Create whatever you think has to happen so that multiple generations of life can live inside a sealed 10-gallon container for as long as possible” is the challenge that has engaged students since 1995. But the next generation of this hands-on, minds-on inquiry is more relevant today as a climate change education tool than ever before. With the aid of carbon dioxide monitors and a compelling series of challenges, students use their biospheres to experience core scientific concepts of climate change firsthand. Identified by the authors with input from a variety of experts including Bill McKibben, Tom Wessels, and Michael Simpson, five simple scientific concepts make the complex global phenomenon of climate change accessible to budding middle and high school scientists. Play along with us as we walk through challenges for three of the five core concepts of climate change in detail: systems, cycles, and resilience. You can find lessons for the other two core concepts, feedback loops and exponential growth, and much more at https://wildtreasuresclimatechange.weebly.com.

Systems

“The biospheres were in an enclosed space, so we had to make sure that there was oxygen for the animals to live. So, we learned about systems because we had to have water, plants, and animals. We had to have plants to give out oxygen, animals to give out carbon, so it all balances out.”

– Chloe, Surry Village Charter School 7th-grader

On the first day of the Biosphere Challenge, students create a system that sustains life. Understanding systems is critical for understanding climate change. A system is when the whole of something is greater than the sum of its parts. A pile of dirt, plants, and rocks laying on the ground is not a system. When the parts are assembled into a biosphere that can sustain multiple generations of crickets, spiders, or millipedes, then the biosphere is greater than the sum of its parts. The smaller components in the students’ biospheres — like the plants, insects, and soil — are smaller systems nested in the larger system of their biosphere.

The climate change problem centers on the fact that humans are making changes to smaller systems — through deforestation or burning fossil fuels, for example — which changes the larger earth system in ways that humans have never done before.
When a smaller system changes, it may not cause an immediate change in the larger systems that it is a part of, but those changes can add up and eventually have larger impacts. Most systems in nature tend to stay balanced, but because everything is connected, seemingly small changes can add up to cause larger changes. In a sealed 10-gallon terrarium, small changes can have big consequences.

Cycles

“I didn’t know a lot about cycles before. I didn’t really think about how things would pan out and, I guess, the long-term effect of things.”

– Joslin, Surry Village Charter School 8th-grader

Carbon is the backbone of life on Earth; however, it is exceedingly difficult in the classroom to represent the different ways it moves through our Earth system. To address this, we challenge students to illustrate the small-scale water and carbon cycles happening in their mini-biospheres. Students each create desk-sized cut-out illustrations revealing their understanding of the cycles occurring in their biospheres, and then superimpose their understanding directly onto the exterior glass walls. To close their day of playing with the notion of cycles, students are invited to make one change to help either the carbon and/or water cycle in their biospheres and then track its success over the following week using the CO2 meter.

When cycles are balanced, matter doesn’t build up in one part of the Earth system because it is cycled out just as quickly as it is put in. However, dramatic change in one part of a cycle can put the whole cycle out of balance. This is the dilemma with burning fossil fuels and releasing unprecedented amounts of carbon dioxide into the atmosphere. Although fossil fuels are not burning in students’ biospheres, they soon observe that their CO2 levels are much higher than the 400ppm in the atmosphere. Why?

The answer lies beneath the surface of the soil. Some scientists estimate that there are more than a million microorganisms in a teaspoon of soil. In our Earth system, the CO2 respired by these organisms is photosynthesized by the plethora of plant life, so the cycle remains balanced. However, in our tiny biosphere systems, this cycle is likely to be out of balance due to its small size and the unnaturally large soil microorganisms-to-plants ratio.3 To see this first-hand, students can be invited to use a smart phone with a magnifying feature (flash on), allowing them to observe a far greater number and diversity of creatures than what students will ever see on just the surface of their biospheres. Healthy biosphere soils can reveal a maze of interconnected tunnels and passageways made and used by millipedes, roundworms, mites, beetles, and bacteria — and that’s just what’s revealed in the soil resting directly against the glass wall. This magnifying tool can open a window into the extraordinary numbers, diversity, and activity of creatures that live beneath our feet.

Resilience

“I didn’t realize how much climate change affected. It helped me learn that parts of the world may be slowly being affected and [that] over time the whole world might be affected. It’s slower because it’s such a big area. And so, in the biospheres, we saw that over a week they were almost completely destroyed unless they were resilient.”

– Thomas, Surry Village Charter School 7th-grader

A system that is resilient is able to absorb stress, recover from it, and prevent further changes from spiraling out of control. During the resilience challenge, students randomly pick a “fate card” (See Appendix A.), each of which describes a major disturbance that will be imposed on their biospheres at the end of the class period. Within moments, students are outside gathering materials to prepare for disturbances ranging from heatwaves to rainstorms to deforestation. At the end of the week, after collecting post-disturbance data, student pairs make an argument for why or why not their system was resilient in the face of their chosen disturbance.

A resilient system can adapt to the impacts of climate change. We can learn about resiliency from natural systems and apply what we learn to human-made systems, making sure that everything we build has the ability to absorb the stress of climate change and recover from it.

For our students participating in Wild Treasures: Climate Change, they turn their attention to applying these core ideas to designing original research about their school’s resiliency, so that by the end of the year they can take measurable actions to enhance their school’s preparedness for the local effects of climate change. Some may choose to localize their food system by starting a school garden and composting system, some may design a series of purchasing criteria to encourage their school to reduce the carbon footprint of their school purchases, and some may add to their school emergency procedures to account for more frequent and severe weather events. Across the board, students are able to experience the empowerment that comes from taking action in the face of great challenges. In the words of Greta Thunberg, Swedish teen activist on climate change, “When we start to act, hope is everywhere. So instead of looking for hope, look for action. Then the hope will come.”

Effective communication
Of equal importance to the core concepts of climate change is the social experience of engaging in the Biosphere Challenge in class. One 5th/6th-grade teacher who used this challenge in her Massachusetts classroom shared,

“…this is an activity that brings everyone together. SIP [Social Intervention Program] kids who were deathly afraid of outdoors were cared for by the kids that were all over finding the insects and let themselves be directed by them. A Level 1 ELL [English Language Learner] was paired with a non-Spanish speaker and they communicated just fine.”

– Kristin McLaughlin, 2019

The Biosphere Challenge is engaging for all kinds of learners. It encourages collaboration and effective communication in the problem-solving process. It gives students an opportunity to be and feel successful in solving a problem with another person. In recent years, it has become clear that being able to communicate and collaborate across differences of all kinds (including identity, opinions, and biases) are as important as having a basic understanding of climate change science. The Biosphere Challenge is a curriculum that promotes the development of these skills in a fun and supportive environment.
Depending on where you are located and what kind of background your students come from, the climate change knowledge in your classroom might vary quite dramatically. We encourage you to jump into the challenge of teaching climate change head-on, bolstered by the simplicity and integrity of the five core concepts of climate change and the intrinsically-motivating structure of the Biosphere Challenge. The stakes are high with this particular scientific dilemma, and no one will experience the consequences more acutely than our students and future generations. As educators, we have an opportunity to equip our students with effective communication skills and the best available climate science in order to enhance their collaborative problem-solving.

Practical Information for teachers
Materials for each pair of students:

• 10-gallon glass terrarium (or any other container with transparent sides and an air-tight lid)
• Glass lid (We have the hardware store cut glass to the exact dimensions of the inside lip of our terrariums, then cover the sharp edges with electrical tape.)
• Suction cup (to open and close the biosphere top)
• Trowel
• Access to natural materials (dirt, moss, plants, rotting wood, insects, water, etc.)
• Assorted containers (used for catching bugs and transporting water or other materials)

CO2 monitor purchasing information and tips

• We use the XT-10 CO2 Monitor, which has an easy-to-read display that gives CO2 readings in real time and is rechargeable with a USB cable.
• https://www.co2meter.com/products/rechargeable-co2-monitor-data-logger is the website for purchasing (also on Amazon for slightly lower cost).
• Make sure automatic calibration is OFF; automatic calibration takes the lowest CO2 reading and uses it as 400PPM outdoor air. Using the CO2 meter in a biosphere will cause readings to artificially increase. If you bring your CO2 meter outdoors and it is outside the 350–450PPM range, then it should be manually recalibrated. See the instructions manual for how to turn off automatic calibration and manually recalibrate.

Biosphere Observations (See Appendix B.)

• We welcome you to use or adapt this chart for student biosphere data collection.

Jimmy Karlan, Ed.D., excels in crafting science curricula that engage and empower middle and high school students. Jimmy directs the Science Teacher Certification Concentration in the Environmental Studies department at Antioch University New England. Hannah Root is pursuing her Masters of Environmental Studies along with her Science Teacher Certification at Antioch University New England. She studied environmental writing at Middlebury College for her undergraduate and worked with Bill McKibben on a creative thesis exploring place-based education in public elementary schools in Vermont.

Endnotes:

1. All Wild Treasures: Climate Change curriculum is available for free at www.wildtreasuresclimatechange.weebly.com
2. Karlan, J.W. (1995) Children’s Ecological Concepts & Theories: 5th & 8th Graders’ Ideas About the Nature of Nature, Harvard University.
3. Dr. Rachel Thiet is a soil ecologist and Director of Conservation Biology at Antioch University New England. Personal conversation (September 29, 2018).