Carbon Sequestration

jun 17 2011

Source: NYSCI

Summary Information

Keywords:

carbon dioxide, greenhouse gas, climate change, global warming, carbon cycle, tree, sequestration, carbon sink, biomass

Topic:

Algebra

Earth Science

Measurement

Biology

Chemistry

Target Grade (Ages):

Grade 7 (Ages 12-13)

Estimated Time Required:

2-3 hours

Diversity Indicators:

This lesson requires students to go outside and measure trees at a height of 4.5 feet off the ground which may be challenging for students with limited mobility.

Watch this Lesson in Practice

Introduction

Lesson

Reflection

Tab Wrapper

LESSON

Goals and Prerequisites

Goals:

To introduce students to the concept of carbon sequestration
To encourgage students to think critically about the management of forests for carbon sequestration

Prerequisites:

Students should:

Be familiar with the carbon cycle
Identify carbon dioxide as a major greenhouse gas
Understand the greenhouse effect
Understand how human carbon emissions contribute to global climate change.

Instructional Objective(s)

Calculate the biomass of a tree
Relate a tree's species and biomass to the amount of carbon it can store
Explain how trees contribute to carbon sequestration
Calculate roughly the number of trees needed to offset students’carbon output.

Instructional Resources

Background:

To start, you may want to view the What is STEM Education video below.

What is STEM Education

Humans are contributing to global climate change by emitting large quantities of greenhouses gases into the atmosphere. Carbon dioxide is one of these major greenhouse gases. Carbon dioxide, however, also plays an important role in many natural processes such as photsynthesis and respiration. It is when we release too much carbon dioxide that it causes environmental problems.

Carbon sequestration is the process of capturing and storing carbon. Carbon can be stored in trees, soil, and even in the ocean. Carbon sequestration can happen naturally like when carbon is stored in trees as part of photosynthesis, but engineers can also create opportunities for carbon sequestration by purposefully planting trees in certain areas or researching and creating manmade ways of storing carbon such as pumping carbon into the ground.

Trees are one of the most promising ways of sequestering carbon to help mitigate climate change. Climate change mitigation is an attempt to reduce the sources of climate change,whereas adaptation is the process of getting ready for the effects of climate change in order to lessen the impact. In this activity, students will investigate a tree's ability to store carbon and make conclusions about using trees to sequester carbon.

Before completing this lesson, students should already have an understanding about the mechanisms of climate change. For example, aperson's carbon footprint is the amount of greenhouse gases that individual is responsible for emitting. This includes carbon produced by activities such as travel, food choices, and energy use– activities that can contribute to climage change.

This lesson also requires students to go outside and measure the circumference of trees. If you are in an area with lots of trees, have students measure different types of trees. If you are in an urban area, you could visit a park, playground, or even trees on the sidewalk and have students measure the same trees if necessary. You can also measure common shrubs.

For more background information about carbon sequestration, please visit the U.S. Environmental Protection Agency web site.

What is STEM Education (FLV)

Materials:

Measuring tape
Calculator
Carbon Sequestration Student Worksheet

Biomass paramaters table
Pen/pencil
Paper

Procedure:

Once you are outside, have students select a tree. They will have to identify the tree species, so encourage them to select trees with distinct features that may be easier to identify.
Have students measure the circumference at breast height in cm. This is the circumference of the tree at about 4.5 feet off the ground. Students can record this on their Carbon Sequestion Student Worksheet. Use this number to find the diameter at breast height (dbh).
Carbon Sequestration Student Worksheet
Once they have recorded their measurements, students should return to the classroom, and using books or the internet, have them identify the species of the tree (or trees) they measured.
Using their research and their measurement, students will be able to use a standard equation to measure the biomass of their tree. (See worksheet.)
Now that they have the biomass, they can determine the amount of carbon stored in their tree. (See worksheet.)
Once students have discovered how much carbon is stored by their tree, have students research how much carbon is emitted each day. This carbon counter can help them.
Students should then complete a carbon footprint quiz to see how much carbon they are responsible for. There are many different quizzes available online. Some look just at greenhouse gas emissions, such as the one at Cool the World.com and this number can easily be related to the amount of carbon stored by the trees the students measured. Other quizzes look at more than just carbon, such as the one at Global Footprint Network. This site tells students how much land is needed to support their lifestyle and also includes a ratio for converting their result to tons of carbon (691,895 global acres per ton of carbon dioxide per year).
Using their research, ask students to create a report on the potential for using trees for carbon sequestration. The report should address the following questions:

How many trees/acres would they need to plant to offset their carbon emissions?
How about the whole class' carbon emissions?
Is this number of trees/amount of land needed to plant the trees feasible? Why or why not?
Would using trees for sequestration work better in different parts of the world?
What factors would they need to take in to account?
What species would they plant?

To get them started, you could present them with information from Slate.com andthe Federation of American Scientists.

Extensions

Students could research man-made processes for carbon sequestration and present their findings. They could also use their research to create their own design for a carbon sequestration strategy.

Students could research other methods of calculating the carbon content of trees and compare them. Are the results the same for each method?

Assessments and Rubrics

If you are interested in learning how to make your own rubric for this or other lessons, you may be interested in watching the How to Make a Rubric video below.

How to Make a Rubric

Or, you can choose to use or customize the one created for this lesson plan below.

Carbon Sequestration Rubric (XLS)

Carbon Sequestration Rubric (PDF)

A basic understanding of climate change is a prerequisite for this lesson, and you could use a pre-activity discussion to ensure that students actually have a strong grasp on this topic.
You could use the students' completed worksheets to assess their calculations and their lab practices.
See the attached rubric for criteria to assess students' final reports.

External Resources

Resources related to tree identification

Arbor Day Foundation: Tree identification books to purchase
Virginia Tech, Department of Forest Resources and Environmental Conservation: Basics of tree identifcation

Resources providing more information about carbon sequestration science and techniques