Mmm Cupcakes: What's Their Life Cycle Impact?
Cupcakes are a favorite snack that are usually baked in paper liners that end up in landfills.Copyright 2008 Kim Siciliano, Wikimedia Commons CC BY-SA 2.0; 2009 Joyosity, Flickr CC BY-SA 2.0 https://commons.wikimedia.org/wiki/File:Chai_white_chocolate_cupcakes_(2).jpg
https://www.flickr.com/photos/joyosity/3412198095
Students learn about life-cycle assessment and how engineers use this technique to determine the environmental impact of everyday products and processes. As they examine what’s involved in making and consuming cupcakes, a snack enjoyed by millions of people every year, students learn about the production, use and disposal phases of an object’s life cycle. With the class organized into six teams, students calculate data for each phase of a cupcake’s life cycle—wet ingredients, dry ingredients, baking materials, oven baking, frosting, liner disposal—and calculate energy usage and greenhouse gases emitted from making one cupcake. They use ratios and fractions, and compare options for some of the life-cycle stages, such as different paper wrapper endings (disposal to landfills or composting) in order to make a life-cycle plan with a lower environmental impact. This activity opens students’ eyes to see the energy use in the cradle-to-grave lives of everyday products. Pre/post-quizzes, worksheets, activity cards, Excel® workbook and visual aids are provided.
Engineers use a tool called the life-cycle assessment (LCA) to determine the environmental impact of products and systems. They examine and assign costs to all the steps in the life cycle of an object—from raw material extraction, to manufacturing and distribution, to waste disposal. Life-cycle analysis reveals the environmental consequences of a product’s production, use and disposal methods and practices. LCA critiques inform redesign decisions to aid engineers in meeting the design objective to minimize the environmental burdens of products and systems, such as by reducing the amount of energy used and amount of greenhouse gases emitted.
After this activity, students should be able to:
- Define a product “life cycle.”
- Identify and differentiate parts of a life cycle.
- Identify and differentiate components of a life-cycle assessment.
- Describe the importance and value of the life-cycle assessment technique.
- Calculate the energy use and emissions for a specific life-cycle using dimensional analysis.