As a tree grows, it removes carbon from the atmosphere, stores it as wood, bark, roots and leaves, and gives off oxygen in return. This process of photosynthesis reduces the temperature locally and helps counteract global warming.
On average, the temperature under a tree canopy is 12 degrees cooler than out in the open. A single large tree has the same cooling effect as 10 room-sized air conditioners. Well-located trees around the home can reduce energy costs nearly 30 percent on average. Each healthy, large tree in our lawns and forests produces enough oxygen in one season to supply all the oxygen necessary for two people for an entire year.
The road surface on a tree-lined roadway lasts on average three to five years longer than that on an exposed roadway. This is because increased temperatures degrade the chemicals in asphalt at a faster rate.
Excess carbon in the atmosphere is thought to contribute to global warming, so trees combat global warming when they take up carbon and act as "carbon sinks," removing this source of greenhouse gas from the atmosphere.
The shading effect of leaves and the removal of carbon from the atmosphere help cool our communities. It is estimated that all of the trees in our cities and suburban areas remove about 30 percent of the carbon we produce on a yearly basis. If each family planted one tree, it would counterbalance 5 percent of the carbon produced by human activity each year.
Nature Notes for 7/18/2010