By Jeff McIntire-Strasburg

Six years ago, after my wife and I purchased our first house together, I went shopping for a lawn mower.

Our yard is small (we live in an urban neighborhood), so rather than buying a smog-belching gas mower, or even a much more efficient electric mower, I invested in a reel mower. Yep, one of those “old fashioned” lawn mowers you probably once saw at your grandparents’ house…which are now in vogue among the eco-conscious set.

My decision was based on the obvious lack of pollution created by the reel mower. But at the time, I didn’t realize just how significant the difference was.

A 2001 Swedish study published in the journal Environmental Science & Technology argued that cutting the grass for one hour with a gasoline-powered mower creates about as much air pollution as a 100-mile car ride: up to 4,000 micrograms per hour of potentially cancer-causing polycyclic aromatic hydrocarbons in the worst case.

The study didn’t address carbon emissions, but the EPA claims that a single gas-powered mower emits 80 pounds of CO2 a year. The Swedish study recommended catalytic converters on lawn mower engines; a new small-engine emissions standard from the U.S. Environmental Protection Agency will make that mandatory in 2011 or 2012.

I say: Beat the rush and avoid any emissions. If you’ve got a small or medium-sized yard, skip the engine altogether and use a reel mower.

In addition to keeping your yard presentable without any emissions, you’ll also receive a slight health benefit: You’ll burn between 400 and 500 calories per hour, versus the 250-350 you spend behind a power-assisted mower.

The opinions expressed in this article are the author's and do not represent those of The Nature Conservancy.

Nature picture credits (top to bottom, left to right): Photos © iStockphoto.com (reel mower); Courtesy Jeff McIntire-Strasburg (Jeff McIntire-Strasburg)