Americans’ love affair with lawns has consequences. The United States has over 63,000 square miles of lawn, an area over three times larger than any single irrigated crop (there’s a map as well). Each week, 54 million homeowners mow their lawn, producing pollution and using fossil fuels. Lawns also require water and fertilizer, and many Americans also use pesticides to kill weeds and insects.
1. Air Pollution: The mowers, leaf blowers, and trimmers Americans use on their lawns are a major source of air pollution, including volatile organic compounds (VOCs), particulate matter (PM), nitrogen oxides (NOx), and carbon monoxide (CO) (EPA National Emissions from Lawn and Garden Equipment). In fact, the air pollution produced from mowing for an hour is about the same as driving 100 miles in a car! These pollutants can cause asthma attacks, lung damage, heart conditions, and premature births.
2. Water Use: Americans use 200 gallons of potable, or drinking-quality, water per person per day to maintain lawns — between 30 percent and 60 percent of municipal water supplies.
3. Climate Change: While lawns photosynthesize, a recent study has shown that due to heavy maintenance, such as mowing, leaf blowing, watering, and fertilizing, lawns actually produce more carbon than they sequester.
4. Water Pollution: Homeowners use 10 times more chemicals per acre than farmers, and these chemicals can run off into surface waters. Fertilizers contain nitrogen and phosphorus, which can cause algae blooms, and ultimately result in dead zones when the decaying algae consumes the dissolved oxygen in the water. In addition, many pesticides used in lawn care are toxic to aquatic organisms – from invertebrates to fish.
5. Biodiversity Loss: Earth is in the midst of the Sixth Mass Extinction, caused mostly by habitat loss. Humans alter ecosystems for many reasons, but the biggest is agriculture – more than 40 percent of Earth’s land is used to grow food. Our gardens provide little habitat value, and the result is that many organisms don’t have a place to live. In addition, pesticides kill many invertebrates, including beneficial ones such as pollinators and predators, and can disrupt food chains by leaving predatory consumers with little to eat. Pesticides also kill over 70 million birds each year, and are potentially a main driver in the global amphibian decline.
6. Invasive Organisms: Gardeners and ecologists use the word “invasive” differently. In ecological terms, an invasive species is one that is introduced to an area in which it is not native, and that causes widespread environmental and/or economic harm. Not every introduced organism will become invasive. Most invasive species tolerate a wide range of environmental conditions, reproduce quickly, and lack the controls that kept their population in check in their native ecosystem, such as predators, competitors, parasites, or diseases. Many of our most destructive invasive species were introduced for horticultural reasons. Some, such as the ornamentals Japanese knotweed and burning bush, were introduced purposely. Others, such as the chestnut blight, which hitchhiked on the introduced Japanese chestnut, were introduced accidentally. This devastating fungus killed off the American chestnut, which was once the most common and important tree in the forests of the eastern United States.
7. Noise Pollution: Lawn mowers and leaf blowers are loud! Most lawn equipment produces levels of 90 – 115 decibels. Sounds above 85 decibels can cause hearing loss, but noise pollution can also result in stress, high blood pressure, sleep loss, and headaches.
8. Flash Flooding: Urban and suburban areas have large amounts of impermeable surfaces, such as concrete and asphalt, and lawns. Due to their short root systems, lawns aren’t able to capture water as efficiently as a prairie or forest ecosystem, resulting in urban flash flooding during heavy rains.
9. Time and Money: Lawns are high maintenance! Americans spend $36.9 billion a year on lawn and garden care, and the average homeowner spends about 70 hours a year on lawn and garden care (American Time Use Survey through link).