Greg McPherson’s Tree Carbon Calculator

You might know that trees help take carbon dioxide out of the atmosphere. But you probably don’t know how much carbon a particular tree in your front yard is storing in its roots and branches. Greg McPherson tells EarthSky how to find out.

You might know that trees help take carbon dioxide out of the atmosphere. But do you know how much carbon that tree in your front yard is storing in its roots and branches? Greg McPherson says that’s a question for the Tree Carbon Calculator.

Greg McPherson: The Tree Carbon Calculator is helpful because it takes all science that’s gone into estimating the amount of carbon sequestration, measurements on thousands and thousands of trees. It puts all of that kind of behind the scenes, and makes it very simple and easy for you to quantify the carbon benefit of a tree.

McPherson, director of the Center for Urban Forest Research in Davis, California, helped develop the Tree Carbon Calculator. It’s an online tool that asks you to plug in just three pieces of information about your tree.

Greg McPherson: The climate region in which you live, the species of tree, and either its size or its age.

The calculator then estimates how much carbon dioxide has been stored in the tree over the past year, and its entire lifetime.

Greg McPherson: A big, large oak tree, for example, stores thousands of pounds. A small crab apple tree will not store anywhere near that amount.

McPherson said the Tree Carbon Calculator tool was originally conceived to certify the value of tree planting projects, for the purpose of selling carbon offsets.

Greg McPherson: This was a tool that would simplify quantification of the carbon benefits that are associated with greenhouse gas tree projects. But it can be used by people who are just interested in planting a tree and estimating what would be the benefits associated with different types of trees, planted at different locations around a building.

He said there are many factors to consider in determining how much carbon a tree can store.

Greg McPherson: It’s highly variable, depending on the type of tree, how healthy it is, which influences how fast it’s growing, how large it will grow to, and how long it will live.

If the tree shades and cools your house, a few more pieces of information could tell you how much energy your tree is saving you. McPherson said these savings mean fewer greenhouse gas emissions from power plants, more money for you, and benefits for Earth’s atmosphere. You can learn more about urban forests and carbon sequestration here. Download the Tree Carbon Calculator on Windows XP here.

Our thanks to Greg McPherson

Lindsay Patterson