The Quick Facts: Photosynthesis is a mechanism that we all learn about in elementary school but many people don’t realize the benefits of planting trees and other vegetation on the environment. Plants can be used in urban spaces to improve local air quality and, on a global scale, to reduce the impacts of climate change through carbon sequestration. Plant a tree, flowers, or garden today to reduce your impact and help clean the air.
How Plants Clean the Air
The cycle of how plants make energy is called photosynthesis. Greatly simplified, it is when the sun, water, minerals, and carbon dioxide are all absorbed by a plant and then used to make food, glucose/sugar, for the plant. Oxygen is produced as a by-product of this process and released into the air by leaves.
The process of photosynthesis results in the production of oxygen as well as the removal of carbon dioxide (CO2), a greenhouse gas, and contaminants from the air. In one year, an average tree inhales 26 pounds of CO2 and exhales enough oxygen for a family of four to breathe for a year. In addition, trees help trap and hold pollutants by absorbing them through the pores in the leaf surface and trapping them. The tree then filters pollutants through its leaves, stems, and twigs, and pollutants are then washed to the ground by rainfall instead of remaining in the air.
Urban Spaces
Urban spaces can greatly benefit from the planting of trees or leafy vegetation. Trees and vegetation provide aesthetic benefits, improve our air (as discussed above), protect our water, and reduce noise pollution, among other things. Trees reduce urban runoff (often polluted) and erosion by storing water and breaking the force of rain as it falls. The U.S. Department of Agriculture (USDA) reports that 100 mature trees can reduce runoff caused by rainfall by up to 100,000 gallons. The New Jersey Forest Service reports that a well-planted group of trees can reduce noise pollution by up to 10 decibels.
If planted in areas where air pollutant concentrations are high and where relatively high planting densities can be achieved, the health of urban dwellers can be improved. In New York City, a 10 percent increase in urban canopy (e.g., more trees) translated to a reduction of peak ozone levels by around 4 parts per billion. (Source: Luley, Christopher J.; Nowak, David J. 2004. Help Clear the Smog with Your Urban Forest: What You and Your Urban Forest Can Do About Ozone.)
Global Impacts and Carbon Sequestration
Trees and leafy plants are not only good for our local environment but our global environment as well. Another benefit of photosynthesis is carbon storage or sequestration. This occurs when carbon is stored in forests and soils. As discussed above, trees and leafy vegetation take carbon dioxide (CO2) in through tiny openings in leaves and that carbon gets incorporated into the woody biomass of trees and agricultural crops. Roughly half of this biomass is carbon. Over time, the carbon can make its way into soils when vegetation, natural forest litter and roots decay. However, carbon in forests and soils can be returned to the atmosphere as CO2 when the soil is disrupted by agricultural practices or when trees decay and/or are burned. Depending on the management of forests and use of agricultural soils, they can act as either a net carbon sink or source. The movement of carbon in and out of trees and soils is part of the Earth’s global carbon cycle.
Approximately 20% of the world’s annual carbon dioxide (CO2) emissions result from land-use changes, primarily deforestation in the tropical regions of Central and South America, Africa, and Asia. According to the UN statistics, we lose 49,421 acres of forest every day; this adds-up to 18 million acres per year.
What You Can Do
- Plant a Tree. Join the Arbor Foundation for as little as $10 dollars and get 10 free tress from 6-12 inches that are appropriate for your hardiness zone and will arrive at the best time of year for planting. See http://www.arborday.org/shopping/memberships/memberships.cfm?membership=trees for more on how to join.
- Make lifestyle changes like using tree-free paper or 100% recycled paper.
- Switch to a diet that does not require deforestation or a change in land-use (i.e., drink coffee designated as grown while protecting rainforests).
Information used in this article was found at the following sources, which you can visit if you want to find out more about this topic:
http://www.arborday.org/trees/benefits.cfm (Arbor Day Foundation’s mission is to inspire people to plant, nurture, and celebrate trees)
http://planetgreen.discovery.com/home-garden/reasons-hug-tree.html?campaign=daylife-article (Planet Green is the first and only 24-hour eco-lifestyle television network with a robust online presence and community)
http://www.epa.gov/sequestration/science.html (U.S. Environmental Protection Agency information on carbon sequestration)
http://www.rainforest-alliance.org/agriculture.cfm?id=coffee (Rainforest Alliance works to conserve biodiversity and ensure sustainable livelihoods by transforming land-use practices, business practices and consumer behavior)
Tags: carbon sequestration, clean the air, environment, improve local air quality, photosynthesis, planting trees, reduce the impacts of climate change, reduce your impact
