Carbon debt: restoring the balance.

Did you know the trees you plant and care for help offset the carbon dioxide you put in the air? Use our Global ReLeaf climate change tree-planting guide to figure out your C[O.sub.2] total - then check out our suggestions for paying off that "debt."

By now we know that our fossil-fuel-burning society has been rapidly increasing the amount of carbon dioxide in the atmosphere. This is threatening to change our climate for the worse. The Summer issue of American Forests reported on the carbon build-up: why it's occurring, how the resulting climate change could alter the environment, and prospects for managing trees and forests to help slow its growth. We reported that by using the opportunities to maximize carbon storage we could offset 20 to 40 percent of our nation's current C[O.sub.2] emissions.

Along with energy conservation and alternative fuels, tree planting and care should be an important part of any overall national and global effort to mitigate climate change. Representatives from more than 100 countries, including the U.S., announced at a meeting in Geneva that they intend to endorse mandatory emissions reduction targets next year.

Since we all contribute to the build-up of carbon dioxide, we can all help. Some call this approach offsetting their personal [TABULAR DATA OMITTED] "carbon debt." "Balance," "debt," "diet" - however it's characterized, it's worth consideration.

What Can I Do?

Reducing energy consumption, using alternative fuels, working for improved public policies, buying "green," planting and caring for trees, recycling, and extending the useful life of wood products and materials "stored" in our homes and elsewhere are a few things each of us can do to help slow the build-up of carbon dioxide and other greenhouse gases in the atmosphere.

How Much C[O.sub.2] Do I Use?

The U.S. is responsible for emitting more than 5 billion tons of carbon dioxide a year, if you factor in all energy-consuming sectors of the economy: residential, commercial, transportation, and industrial. That works out to some 20 tons - 40,000 pounds - per person. Considering only the residential and transportation sectors cuts the per capital carbon dioxide emissions to 10 tons. Of course, your actual amount or that of your family will vary depending on personal circumstances and life style.

Use the simple worksheet at left to estimate your household's carbon dioxide emissions and to set conservation goals. Use the results to calculate how many trees you would need to plant to offset all or part of your carbon debt.

Get started

Before you begin calculating, have an idea of how much energy (electricity, oil, natural gas, etc.) is used in your home in a year, the number of miles you drive your vehicles and their average miles per gallon. You'll likely need a calculator or scratch pad for some simple math. Don't have the time or patience to determine your actual emissions? Make an estimate using the Calculation Shortcut below.

Calculation Shortcut

If you did not complete the worksheet, here's how to estimate your household emissions: Multiply the number of people in your household by 10 for an estimate of the total tons of carbon dioxide emitted.

Number of people in household _____ x 10 = _____ tons C[O.sub.2].

Plant a Tree, Cool the Globe

Once you've estimated your household's annual carbon dioxide emissions, it's easy to calculate the number of trees you would need to plant in a Global ReLeaf Forest project to offset those emissions.

Total household C[O.sub.2] emissions per year, in tons

(Enter number from worksheet or _____ tons C[O.sub.2]/Yr estimate above)

x 3

Total trees to plant _____ trees

For example, if an energy-conscious household emits 30 tons of carbon dioxide per year and wants to offset that, it could do so by planting 90 trees in Global ReLeaf projects. As the trees grow, over 40 years they will remove the amount of carbon dioxide the household generates this year.

Plant Those Trees

Now go out and plant some trees, or let us do it for you. There are four easy ways to have AMERICAN FORESTS plant your trees in a Global ReLeaf Forest for just $1 per tree:

1. Call in your credit-card order to 800/873-5323 (10-tree minimum, please).

2. Fax the information to us at 202/667-7751. (Include your credit card number and card expiration date.)

3. Send a check to Global ReLeaf 2000, P.O. Box 2000, Washington, DC 20013-2000.

4. Plant trees on-line. Visit us on the World Wide Web at: http://www.amfor.org. And we'll soon have our Global ReLeaf 2000 tally system ready to record the trees you plant yourself.

Remember the holidays and special occasions, too. AMERICAN FORESTS doesn't plant trees just to slow global warming. Thousands of people plant trees with us for gifts or remembrances, or to mark special occasions. For every 10 trees planted, we send a personalized certificate. And whatever your reason for doing so, the trees you have planted will help us reach our Global ReLeaf 2000 goal of 20 million trees by the year 2000.

The rate at which trees store carbon through photosynthesis varies widely depending on the type of tree and the particular site conditions. Unfortunately, not every tree planted survives to maturity - nature just doesn't work that way. We calculate our carbon storage not from theoretical models, but from seven years of on-the-ground experience planting millions of trees on dozens of project sites, combined with research on carbon storage in different forest ecosystems.

For every $3 you contribute (three trees), our projects offset one ton of carbon dioxide emissions over a 40-year period. These are carbon storage and sequestration rates that we can stand behind. We plan to bring more high-volume carbon projects online, but we never want to lose sight of the many other environmental and community benefits of our tree-planting projects, which are ecosystem-restoration projects first and carbon storage projects second (see "Trees for Tomorrow," page 14).

If you decide to plant your own trees and select larger ones for sites where they'll last for 40 years or more, reduce the number you plant by a factor of between two and four. Well-placed and well-cared-for oaks and maples, for example, will sequester well over a ton each in their lifetime.

Notes for Calculations

Home energy use: Check your utility bills or call consumer representatives at your utility companies to determine how much energy you use at home, including electricity, heating oil, and natural gas.

Automobiles: Multiply the total number of miles each car is driven by its miles-per-gallon performance to calculate the total gallons used in a year. Be sure to add in any oil and gas used in lawnmowers or other internal combustion engines.

Trash and recycling: Estimate the amount generated per year. Figure about seven pounds per paper grocery bag, 13 pounds for a 10-gallon trash bag, and 40 pounds for a large trash bag.

Sources and Resources

* For more on calculating carbon emissions for individuals: C[O.sub.2] Diet for a Greenhouse Planet: A Citizen's Guide for Slowing Global Warming, by John DeCicco, James Cook, Dorene Boize, and Jan Beyea (National Audubon Society, 1990). This thorough guide was most helpful for this artide. We used its C[O.sub.2] factors for several worksheet items.

* For more about trees and forests and carbon mitigation, see: Forests and Global Change, Volume 1: Opportunities for Increasing Forest Cover, R. Neil Sampson and Dwight Hair, editors (AMERICAN FORESTS, 1992), and Forests and Global Change, Volume 2: Forest Management Opportunities for Mitigating Carbon Emissions, R. Neil Sampson and Dwight Hair, editors (AMERICAN FORESTS, 1996).

* For middle- and high-school readers: Atmosphere by Mary Hoff and Mary M. Rodgers (Lerner Publications, Minneapolis, 1995), briefly explains atmospheric gases, how we've changed them, and what can be done to help. Good illustrations.

* Computer software is also available to conduct a detailed personal energy use audit. The most comprehensive version we've seen (see Are You an Eco-Titan?, September 1993) was developed and recently updated by Don Lotter, EarthAware: Personal Environmental Impact Assessment Software (from EnviroAccount Software, phone: [phone]; Web site: http://wheel.dcn.davis.ca.us/~dwlotter).

* The Global Cooling Action Center offers a free worksheet to estimate carbon emissions. Based on the information you send, they will calculate your emissions and the number of trees to offset those emissions. Fax them at 954/462-4423, or send email to: 71524.2372[at]compuserve.com

* For communities and cities of all sizes, CITYgreen is a computer software package designed by AMERICAN FORESTS to calculate the numerous benefits of urban trees, including carbon storage and sequestration, and energy efficiency. Contact: Urban Forest Center, 202/667-3300 ext. 227. CITYgreen and other AMERICAN FORESTS resources listed here are also on the World Wide Web at: http://www.amfor.org.

Dan Smith is AMERICAN FORESTS' vice president for communications. He wants to especially thank Forest Policy Center intern Dana Brancolini for her assistance in preparing this article.