Carbon releaf

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The U.S. Forest Service has launched the first government program whereby individuals can pay to have some of the pollution created by our modern lifestyles removed.

Burning fossil fuels, like coal and oil, to produce electricity and to power cars releases carbon dioxide (C[O.sub.2]). The average plugged-in, on-the-road American family of four directly generates between 19 and 30 metric tons of this heat-trapping greenhouse gas annually. All that pollution adds to global warming, or an increase of Earth's average temperature.

The easiest way to cut down on C[O.sub.2] emissions is by reducing your family's fossil fuel use. But the U.S. Forest Service now has another way to help beat the heat: personal carbon credits. Purchasing a $6 credit pays to offset one metric ton of C[O.sub.2] your family produces. The money goes toward planting and tending trees in our national forests.

How can trees reduce C[O.sub.2]? They remove this greenhouse gas from the atmosphere during photosynthesis. This process uses sunlight to convert C[O.sub.2] and water into sugar, which the trees use for energy and new wood growth. "A tree's dry wood is about one-half carbon, so trees very effectively store large amounts of carbon that would otherwise be in the atmosphere," explains plant biologist Jeffrey Coker of North Carolina's Elon University.

U.S. forests currently absorb around 10 to 15 percent of C[O.sub.2] emissions. Expanding forests will help absorb even more C[O.sub.2] and sustain one of our country's natural resources.

RATE OF CARBON UPTAKE BY THREE TREE SPECIES

Trees grow at different rates depending on their species and the soil and climate in which they grow. That affects the amount of C[O.sub.2] the trees remove from the atmosphere. In the graph below, which tree species absorbs the most carbon after 35 years?

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