Classroom and Schoolyard Activities
The unit will start with consideration of potatoes. Each student will arrive to find a potato on their desk. Students will be asked to write down all the ways this potato has been used, or can be used for energy. The most obvious might be the chemical energy of calories. A second could be the gravitational potential energy in a potato held above the ground, and then the third might be kinetic energy if the potato is dropped or thrown. Several potatoes will have been sitting in a sunny windowsill, or atop the classroom radiator, and can be passed around to demonstrate thermal energy. We will consider where the potato might have been grown, and what sort of, and how much, energy was used to get it to our classroom. Some of these potatoes may have been grown in the school garden, and others with a less clear provenance, which can introduce the idea of food miles, fossil fuel use in the supply chain, and alternative agricultural practices.
Students will then be asked to brainstorm examples of each type of energy we haven’t yet covered but is listed – guided to focus on food and agriculture. A set of slides depicting each energy use and a connection to food and agriculture will follow.
This will lead to a more detailed discussion of where the chemical energy/calories come from. Students will hopefully recall some prior knowledge of photosynthesis and energy transfer through food chains/webs. Students will finish this lesson by completing a pre-test/prior knowledge review of these topics to assess gaps in understanding and specific areas requiring review.
Lessons two and three will be direct instruction overview of the climate crisis including the role of photosynthesis in the formation of the carbon in the fossils of fossil fuels, how the carbon cycle has been/could be in balance, and the many ways the carbon cycle has become “out of balance” with excess carbon dioxide, methane, and nitrous oxide as humans utilize long sequestered carbon, and/or deforest and degrade soils to prevent sufficient sequestration. This lesson will include several videos, graphic images including a playing and discussion of the temperature anomaly map referenced earlier.
Lesson four is a demonstration of how carbon captured through photosynthesis – i.e. carbohydrates – can be metabolized. This demonstration will include an interactive group lab to introduce students to the relationship between food and energy. A series of flasks will be filled with various plant material such as: grated potato (from lesson 1), chopped grass or clover, small pieces of wood, minced corn, or mashed peas. Yeast and warm water will be mixed with a small amount of sugar and added to each flask, one flask will have just yeast and water (no sugar). Students are asked to predict which container(s) will be more active, how will they know if they are more active etc. and offer reasons for their predictions. The flasks are then covered by a ballon. See figure below:
Figure 3 supplies and procedure for demonstrating metabolism of sugars
While students await balloons to be filled by carbon dioxide, they will work in small groups to observe yeast being fed sugar, becoming active (foaming), and measuring temperature increases due to this metabolic activity. Students will quantify the growth of the yeast, by measuring the height of the foam generated when yeast is given table sugar as a food source. Students will also be able to observe that the temperature of the water in which the yeast is growing will increase by between 1-3 ºF and graph this change over time. This one-hour lab requires only a vessel, water, sugar, and thermometer, to observe a key biologic process of liberating energy from carbohydrates created by photosynthesis. This process is also the foundation of brewing bioethanol, which will come up in another lab later in this unit.
As we progress through the unit activities, we will focus on hands-on projects that demonstrate and practice regenerative cycles, as we create, maintain and utilize renewable energy in our outdoor labs. Our focus will be to attempt school-scale strategies that would be similar enough in practice to be useful at larger scale. Students will participate in practical energy generation and use. First, by growing food, which is already a large part of our program, but hasn’t yet been framed explicitly as an “energy source,” and comparing our food growing practices to current commercial agricultural practices. Second, by taking food and garden residue and using a biodigester to convert this carbon rich resource into methane and fertilizer (reframing waste as a resource), and comparing this to the massive food waste/methane generation issue worldwide. Third, by using the gas from this biodigester to cook food. Fourth, by using what is left after bio digesting to fertilize crops on our “climate farming” regenerative food farm on the school property. We will also utilize food and garden residues (another reframing of waste) for creating compost, and the making of biochar, both of which when added to soil help sequester carbon, making these potent tools in a carbon farming toolkit. We will ferment and capture small amounts of bioethanol and attempt to make bioethanol from non-edible portions of plants (cellulosic bioethanol) to explore first-hand the challenges and opportunities inherent in using food crops and land that could grow food to grow fuel. We will make biodiesel from corn and soy oil – after hopefully making our own oil by grinding soybeans and corn kernels. In addition, we just purchased several small solar generators and a solar fan kit to demonstrate how we can use sunlight to power some practical on-farm needs, such as irrigation pump, shed ventilation, and creating a phone/computer charging station for our outdoor classroom.
We will review the food supply chain through a series of lessons that trace key commodities along their route from different sorts of farms to different sorts of markets. We will have several lessons on how animal agriculture impacts climate, and what it means when feed conversion ratios are the key tool to measure farm productivity. We will focus these lessons on where fossil fuel energy is used and what alternatives exist or could be imagined to replace GHG emitting practices. We will schedule field trips to local regenerative food producers and sustainable food processors to deepen and reinforce students’ understanding of all the intersecting parts within the global food supply chain. Each of these individual parts of this network who have been making contributions to greenhouse gasses emissions are an opportunity to learn how to shift to more sustainable/regenerative paths. Students will prepare for these field trips with advance research and guided notes which will be utilized before, during and after each trip and become a resource as they move towards their final projects.
Our students work in our garden weekly with school staff, with periodic technical assistance from the Pennsylvania Association of Sustainable Agriculture’s Climate Smart Farming and Marketing Program, to grow food and to engage in citizen community science to implement and monitor a variety of recommended urban farming practices in our growing spaces. These weekly “in the field projects” will be tracked in garden notebook guided notes and maintained in student binders.
Students who are learning about the ideas and practices of “climate farming” can explore the many ways that food growing, and natural resource management practices, can sequester carbon, contribute to renewable energy, and reduce the energy consumption and GHG emissions. These hands-on experiences will be supplemented by case studies and independent research so students can explore stories and data from the likes of seed producers who sell agronomic seeds can earn extra carbon credit for sequestering carbon in the soil; and farmers partnering with energy producers to co-locate biofuel production to utilize farm waste. This unit will tie into existing lessons from other units on regenerative farming, reducing food waste and composting. Students might choose to demonstrate their learning by doing an audit on an agriculture entity (farm, food processing facility etc.) to identify areas where energy/climate friendly practice related improvements could be made, or by teaching younger students the value of these practices during garden club.
The unit will also explore how to advocate, communicate, agitate, and educate about sustainable energy, sustainable food and farming practices, and other climate change solutions in our community. These lessons on “changemaking” will not explicitly be part of this unit but will be reviewed as applicable.
Figure 4 Our climate toolkit graphic and project choices for student capstone projects
Along with regular opportunities to demonstrate learning through assessments, projects and lab notes, students will each contribute to the Agriculture Can Reduce the Climate Crisis Toolkit by identifying an issue, a solution, and practical advice/details about implementation. These capstone projects will be combined into a shared slide deck, with links to each student’s work, organized by category: climate farming solutions; energy reduction solutions; innovations & policy. As a work in progress, this toolkit will be both a resource for current and future students and partners, and a repository for new ideas and emerging strategies.
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