Many people are increasingly conscious of their "carbon footprint," and are interested in taking actions to reduce their contribution to greenhouse gases. Atmospheric carbon dioxide is considered a greenhouse gas and a key contributor to climate change. While it's difficult to calculate your total carbon footprint, there are ways to evaluate the impacts of particular actions, such as mowing a lawn. The U.S. Environmental Protection Agency estimates that, hour-for-hour, gas-powered lawn mowers produce 11 times as much pollution as a new car. That adds up, considering the average house owner mows their lawn 22 times a year.
What Is A Carbon Footprint?
"Carbon footprint" can refer to one of several metrics for how much carbon pollution an individual, a nation or other entity is producing. A carbon footprint can be measured as the direct quantity of carbon emitted or as the area of land it would take to absorb the carbon released. For our purposes, carbon footprint will be defined as the amount of carbon produced, measured in pounds, per year. In 2010, the average person in the United States produced 19.4 tons of carbon over the course of the year. The carbon footprint of your lawn mower depends on how big your lawn is and what type of mower you use.
Push Reel Lawn Mower
The lowest carbon option for mowing your lawn is an old-fashioned push reel mower, since the only power needed is the human power you provide. Of course, no energy source is completely carbon free. To calculate the carbon footprint, first calculate how many calories you burn while mowing: Calories = (hours mowing the lawn) x (number of times you mow per year) x (298 calories burned per hour mowing) Your carbon footprint can then be calculated as: Footprint = (calories burned) x (0.0034 pounds of carbon per calorie) For example: 1 hour x 22 mowings per year x 298 calories = 6556 calories per year Footprint: 6556 calories x 0.0034 pounds of carbon per calorie = 22 pounds of carbon per year
Electric Lawn Mower
The next lowest carbon option is an electric mower. You can find the power rating for your lawn mower either on the machine or in the owner’s manual. Use that to calculate the electricity, in kilowatt-hours, used mowing the lawn: Electricity = (hours mowing the lawn) x (number of times you mow per year) x (lawn mower power rating in kilowatts) Your carbon footprint can then be calculated as: Footprint = (kilowatt-hours) x (1 pound carbon per kilowatt-hour) For example: 1 hour x 22 mowings per year x 1.44 kilowatts = 31.68 kilowatt-hours Footprint: 31.68 kilowatt-hours x 1 pound per kilowatt-hour = 31.68 pounds of carbon per year
Gas Lawn Mower
The lawn mowing option with the highest carbon output is the gas-powered mower. To calculate the footprint of your gas mower, you will first need to know how much gas you consume per hour of mowing. You can calculate this by putting a measured amount of gas in your mower and seeing how long it lasts, or check online for information specific to your model. To measure how much gas you use in a year: Gas used = (hours mowing the lawn) x (number of times you mow per year) x (gas used per hour) Your carbon footprint can then be calculated as: Footprint = (gas used) x (17.7 pounds of carbon per gallon) For example: 1 hour x 22 mowings x 0.5 gallons of gas = 11 gallons Footprint: 11 gallons of gas x 17.7 pounds of carbon per gallon = 194 pounds of carbon per year
About the Author
Based in Wenatchee, Wash., Andrea Becker specializes in biology, ecology and environmental sciences. She has written peer-reviewed articles in the "Journal of Wildlife Management," policy documents,and educational materials. She holds a Master of Science in wildlife management from Iowa State University. She was once charged by a grizzly bear while on the job.