The humble lawnmower

Ah – Sunday morning. The sun is shining, the birds are singing – if you can hear them over the lawnmowers.
Noise pollution from mowers can be a serious issue. Even more serious is the air pollution that comes from a fossil-fuel burning piece of equipment.

Despite their small size, lawnmowers produce a great deal of harmful and carcinogenic emissions such as carbon monoxide, carbon dioxide, volatile organic compounds and nitrogen oxides.
Carbon dioxide is the familiar contributor to climate change. Mowers also produce methane, which adds significantly to global warming.

Mowers are also major contributors to local pollution through the production of pollutants including carbon monoxide (CO) and NOx (nitrous oxides). Both are directly harmful to health and the NOx mixes with other chemicals in the air to form acid rain, which in turn is destructive to waterways, trees and other vegetation.

The small size of mowers can make them seem relatively harmless, which is not at all the case. In fact, compared to vehicles, they present an even greater problem. Tests conducted at the University of Newcastle, with commonly used lawnmowers, showed they contribute 5.2% carbon monoxide (CO), and 11.6% of non-methane hydrocarbons (NMHC), compared to transport in the Newcastle region.

Of course, there are other garden tools using petrol, including line trimmers (whipper snippers), and chainsaws and leaf blowers. In California, the California Air Resources Board issued a 2020 report showing that emissions from this equipment were higher than emissions from California’s 14.4 million cars.

This massive contribution by lawnmowers and other garden equipment to local pollution is a clear cause for concern. Fortunately there are straightforward answers to the problem.

Electric and battery garden equipment has developed to the point where it can replace petrol-driven machines. The advantages of using this equipment go well beyond the reduction of pollution.

Battery-driven machines are lighter than their fossil-fuel equivalents. They are easier to use, making them ideal for non-professionals such as us. They are also far quieter, meaning they can be used in the community garden without disturbing other people working there.

Battery machines also get rid of the need to buy, transport, store and mix fuel. The non-petrol machines at the Sustainable Macleod Community Garden can be recharged from the off-grid solar power – a real win-win.

To date, Sustainable Macleod has an extensive tool library of battery-driven garden tools, including a hedge trimmer, leaf blower, whipper snipper and battery secateurs and branch loppers.

To replace the generously donated, but now old and difficult to start mower, Sustainable Macleod has applied for a grant from Banyule City Council for a battery-operated mower. This will be used to manage the grass immediately outside the Garden fence and to shred green waste. To deal with branches pruned from the fruit trees, the grant application includes a powerful electric chipper, running directly off the solar off-grid power.

Since Sustainable Macleod’s mission is to help in the transition to sustainable ways of living, it is important that the move away from fossil-fuel equipment is encouraged. Recognising the impact that the humble lawnmower has on the environment, it is clear we need to replace old petrol machinery as soon as possible.

Of course, there is another alternative – convert our lawns to gardens.

Written by Paul Gale-Baker

Emissions from in-use lawn-mowers in Australia: M.W. Priest a, D.J. Williams b, H.A. Bridgman
Emissions from petrol mowers: The toxic monster hiding in your shed