Young Brunette Girl Posing On The Lawn

In the United States, ~50-70% of residential water is used for landscaping, most of it to water lawns.A 2005 NASA study showed that there are over 30 million acres of irrigated lawn in the US (128,000 km2 or 12,800,000 hectares), three times the area of irrigated corn.
“That means about 200 gallons of fresh, usually drinking-quality water per person per day would be required to keep up our nation's lawn surface area.”
In the United States lawn heights are generally maintained by gasoline-powered lawnmowers, which contribute to urban smog during the summer months. The U.S. Environmental Protection Agency found that in some urban areas, up to 5% of smog was due to pre-1997 small gasoline engines such as are typically used on lawnmowers. Since 1997, the EPA has mandated emissions controls on newer engines in an effort to reduce smog.
A 2010 study seemed to show that lawn care inputs were balanced by the carbon sequestration benefits of lawns, and they may not be detrimental in anthropogenic global warming.