Dear EarthTalk: I’ve heard that gas-powered lawn mowers, despite their small engine size, actually pollute as much as cars. If this is true, is there a greener way to cut my grass?
—John Hoffman, Kent, WA
Reports about those noxious fumes emitted from gasoline lawn mowers are indeed true. A Swedish study conducted in 2001 concluded, “Air pollution from cutting grass for an hour with a gasoline powered lawn mower is about the same as that from a 100 mile automobile ride.” Meanwhile, the 54 million Americans mowing their lawns each weekend with gas-powered mowers may be contributing as much as five percent of the nation’s air pollution, according to the U.S. Environmental Protection Agency (EPA).
The problem is that small engines emit disproportionately large amounts of carbon monoxide, volatile organic compounds and nitrogen oxides that contribute to smog. The human health effects of smog-laden air are well known, and include inflammation and damage to lungs, increased risk of asthma attacks, and lowered levels of oxygen in the bloodstream, which can aggravate heart conditions.
Fortunately, the EPA is now phasing in new emissions standards for gas mower engines that will result in a 32 percent smog reduction for all models made starting in 2007. And with even more stringent standards slated to go into effect soon in California, environmental leaders are hoping that the old adage for automobile trends (“as goes California, so goes the nation”) will soon apply to lawn mowers too.
But even with such progress, gas power is not the only option. Eco-conscious consumers looking for a new mower should consider, among other options, any of the electric models now available. The easy part is the price, as many models cost less than $200. The trade-off is that they only work for small lawns and must be tethered to a power outlet during use. Also, going electric is not necessarily a way to reduce pollution overall. According to Consumer Reports, “Achieving a net environmental savings from switching to electric mowers depends on the efficiency of the power plant” from where the electricity originates.
If money is not an issue, the $2,500 solar-powered “auto mower” from Husqvarna can’t be beat for both eco-friendliness and convenience. It wanders unattended around any level lawn, its collision sensors carefully avoiding contact with anything but the grass itself. While it is currently not available directly in the U.S., some Husqvarna dealers are willing to special order it from Sweden where it is manufactured.
Another green option, and a much more affordable one, is the Solar Powered Mulching Mower from Gaiam, which is in essence a cordless electric Black & Decker mower modified with a small solar array to turn sunlight into power. The battery on the $795 mower can also be charged by simply plugging it in.
Of course, the greenest choice of all is the mower that runs on three square meals a day and a good exercise regimen: the venerable human-powered reel mower. The most popular choices are from American Lawn Mower, which makes nine models including a child-size. They can be found at retailers like Ace Hardware and Target (and at local hardware stores) and in catalogs like Real Goods and Smith & Hawken.