According to the Government of Canada (One-Tone Challenge) a gasoline powered lawn mower emits about 48 kilograms (106 lbs) of greenhouse gas in one season.
There are about 8 million gasoline powered lawn mowers sold per year in North America and Europe. If a typical person keeps his lawn mower for 7 years, it would mean that there are 56 million lawn mowers in operation.
These lawn mowers produce around 3 million tones of greenhouse gas per year (106/2000 x 56 million).
If battery Mowers replaced all gasoline-powered lawn mowers, in one year, the equivalent pollution generated by 1.7 million cars driving 18,000 kms would be eliminated. The fuel contained in 2,800 tanker trucks would not be spilled and 3 million tons of greenhouse gasses would not be released into the atmosphere.