Geography Reference
In-Depth Information
Climate change in response to increasing atmospheric carbon dioxide is chal-
lenging life as we know it. In the carbon-enriched air, not only are tempera-
tures rising, but also seas are acidifying, diseases are spreading, and the timing
of basic biological events, such as bird migrations, are getting out of synch with
the natural products, such as fruits and insects, that they depend upon. Curb-
ing our combustion of fossil fuels is essential if we are to minimize these im-
pending disasters. As we cut back on the use of fossil carbon, we can also follow
Steve Humphrey's lead and convert some of the turl ands of subirdia into na-
tive forests, or where forests do not naturally grow, into natural shrublands and
grasslands. These plants are nature's carbon dioxide scrubbers.
It is a foggy autumn morning, and the upper canopy of my i r, hemlock, and
cedar forest is barely visible. I take pride in knowing that the shrouded, thick
foliage is helping i ght climate change. It is a remarkable battle, technically
called “photosynthesis,” that my trees are waging against carbon dioxide. Dur-
ing the day, using the power from sunlight, chloroplasts deep in their needles
drink in carbon dioxide and water and convert them to glucose and oxygen.
Glucose is a sugar that plants use to fuel their life processes; extra glucose that
trees don't use is converted into wood. The oxygen is released back into the
atmosphere to be breathed by us and other animals.
It takes a lot of trees to have a meaningful ef ect on atmospheric carbon diox-
ide. In the United States, for example, our vast national forests store about 16
percent of the carbon we annually produce. All the street trees in U.S. cities to-
gether store only less than 1 percent of our carbon emissions. Still, the 360 metric
tons of carbon that street trees store won't warm our climate. What if we con-
verted half of subirdia's lawns to trees? How much carbon could they pull out of
the air? I i gured my backyard was a good place to start answering this question,
and I knew just the person to help me determine the carbon capacity of my trees.
Dr. Dave Peterson is an ecologist with a passion for forests and their nem-
eses: i re, bugs, and climate change. As a member of the Intergovernmental
