A couple weeks ago we wrote an article on gardening, recommending some “native” plants that would add beauty and diversity to your garden while attracting interesting pollinators, like butterflies and hummingbirds. We were rightly lambasted by many readers, as some of the species we listed are not native. We acknowledge that mistake and apologize to our readers.
So we are a bit sheepish as we take another venture into the backyard, this time to talk about lawn mowers.
According to sources, including Environment Canada, The Ontario Ministry of Environment, and the David Suzuki Foundation, lawn mowers with conventional two-stroke engines emit as much pollution in one hour of operation as a typical passenger car travelling 550 to 600 kilometres. Now we are not talking about CO2 emissions. Clearly driving this distance in a car uses much more fuel and will, in turn, emit much more CO2 to the atmosphere. However, that two-stroke engine will be spewing more carbon monoxide, particulate matter, hydrocarbons, and NOx into the atmosphere than a car’s engine running for the same period of time. This is because the two-stroke burns oil and gas simultaneously, and does so very inefficiently. The pollutants from these engines contribute significantly to urban smog, hence the frequent advisories and bans on use on those hazy, smoggy summer days.
So if they are so bad, why do we still use these two-stroke mowers? The engine, while inefficient, is lightweight and relatively cheap to manufacture. And, given the total quantity of gas burned, these mowers are still relatively cheap to run. Electric mowers have generally been seen as inconvenient (needing an extension cord), or too expensive and too heavy (those with battery packs).
However, if you are in the market for a lawn mower, this may be the time to consider more efficient options. Many of the larger and heavier mowers (with battery packs or more efficient four-stroke engines) now come in self-propelled models. Further, a quick survey of two of the major sellers of mowers in Canada (Rona and Home Depot) shows the gap narrowing in cost between gas mowers and electric mowers with battery packs.
As electric mowers have become more popular, they have also become much more affordable. Some retailers even offer rebate programs when you recycle your old, inefficient mower, eliminating the price gap between buying a new electric and a new two-stroke gas mower. Home Depot, for example, just wound down its annual lawn mower recycling program run in collaboration with the Clean Air Foundation to get conventional two-stroke gas engines off the street (or the lawn).
Obviously, running an electric mower is not carbon neutral. However, energy generated in power plants is much more efficient than energy generated by all those two-stroke engines out there. And many retailers are now selling inexpensive solar panels that can be used to recharge (or partially recharge) the battery packs.
On a final note, the tranquility you preserve with an electric mower may allow you to better enjoy your garden. You may not scare off those butterflies and hummingbirds visiting your actual native flowering plants.
Andrew Laursen is an assistant professor at Ryerson University, studying ecosystem ecology. Sophia Dore is an environmental scientist with Conestoga-Rovers & Associates, an environmental consulting company.