In this lab, students are expected to go outside and measure the circumference of every tree on campus (or a given area-- modify however you want! the final calculation asks students to calculate the amount of CO2 sequestered per unit area). Using references (direct links in document), students are able to determine the amount of CO2 each tree sequesters annually based on their field measurements. THIS LAB IS A GREAT WAY TO QUANTIFY THE VALUE OF TREES ON CAMPUS, AND TO GENERATE POSITIVE PUBLICITY FOR YOUR SCHOOL! :) Lab easily modified to fit the needs of middle aged students.