Living in a Carbon World
Introduction: A Carbon Journey
Consider the image of a terrestrial and ocean carbon cycle below. Can you identify where carbon exists in these two carbon cycles? Can carbon move back and forth between the terrestrial and ocean carbon cycle? How? What if a change happens in one part of the carbon cycle? How will other parts of the terrestrial and ocean carbon cycle change? These are a few of the important questions you will explore as you work your way through this module.
Because understanding the carbon cycle is key to understanding climate change, many scientists are trying to understand how carbon moves through the carbon cycle. Throughout the module, you will have multiple opportunities to observe scientists doing their research and will have the opportunity to conduct your own research.
You can begin your carbon journey by watching the NASA video Keeping Up with Carbon.
- Before you begin, make a list of what you think you already know about carbon and the carbon cycle.
- As you watch the video, make a list of where on Earth carbon can be found, its relationship to life, climate change and any other carbon fact that interests you.
Share your list of carbon facts from the NASA video with your classmates. How do your "pre- and post-viewing" lists compare? What three items on the list do you think are the most important to understand about living in a carbon world? Explain why you chose them.
In Part A, you will trace the pathway of carbon from the atmosphere into plants and then into food webs and soil. Next, you carry out a controlled two-week hydroponic plant growth experiment that lets you model the role of trees in storing carbon (also called sequestering carbon) and the environmental factors that might limit that process.
In Part B, you will learn about carbon as an element. Using a ball-and-stick carbon molecule kit and 3-D structures of carbon compounds, you will demonstrate how carbon can bond with other atoms and create many different types of carbon compounds.
After completing this investigation, you should be able to:
- explain why carbon atoms can form the basis of millions of different types of carbon compound molecules.
- describe how the carbon atoms in CO2 absorbed via plant photosynthesis provide the carbon atoms for all of the new carbon compounds a plant produces and uses to build its cells and tissues and to burn for energy.
- explain how carbon compounds are transformed in five chemical reactions that are critical to the carbon cycle: photosynthesis, cell respiration, decomposition, biosynthesis and combustion.
- answer whether trees and other plants can absorb ever-increasing amounts of carbon dioxide from the air or are limited by environmental factors.
Keeping Track of What You LearnThroughout these labs, you will find two kinds of questions.
- Checking In questions are intended to keep you engaged and focused on key concepts and to allow you to periodically check if the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
- Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills you should be learning from the lab activities and readings.