A traditional lawn mower uses gasoline. A single gallon of E10 gas can produce 18.95 pounds of carbon dioxide when combusted*. By comparison, an automower uses no gasoline. If attached to a solar panel, the automower produces no carbon dioxide. However, most people have their mowers running off of the same electricity that powers their house. Is it still greener then? Yes! An automower uses at most 30 kWh of energy each month, and the largest model mows up to 1.25 acres of grass. According to the EPA, one kWh produces approximately .998 pounds of carbon dioxide**. That’s about 30 pounds in an entire month, whereas a single acre of grass can take one to two gallons per mow (assuming the use of a mid-sized zero turn lawn mower).
On top of the direct reduction of carbon dioxide from switching mowers, automowers constantly cut, so the clippings are more easily absorbed by your lawn. This means that you can use less fertilizers, which are bad for our natural water systems and produce many gases that contribute to climate change***.
*Learn the facts: Fuel consumption and CO2. (2014). Retrieved June 24, 2019, from https://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/oee/pdf/transportation/fuel-efficient-technologies/autosmart_factsheet_6_e.pdf
**Greenhouse Gases Equivalencies Calculator – Calculations and References. (2018, December 18). Retrieved June 24, 2019, from https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references
*** Johnston, I. (2015, January 17). Keep off the grass: Research confirms that highly manicured lawns. Retrieved June 24, 2019, from https://www.independent.co.uk/environment/climate-change/keep-off-the-grass-research-confirms-that-highly-manicured-lawns-produce-more-greenhouse-gases-than-9985720.html