We also have some clover, which supposedly keeps weeds at bay, but it isn't working.
How can we maintain our lawn and gardens without using gasoline powered equipment or environment damaging chemicals?
Personally, I think that keeping my gasoline-powered lawn mower than must consume a grand total of 5L per year (I'm in the UK so the grass basically stops growing from about now until March, and although I have a large garden for local standards it's not half an acre...) makes me emit less than throwing it away and replacing it with a new battery-powered electric one. Mileage may vary, of course.
It is said that for nature the best thing to do is actually to get rid of lawns, as least some of them, and to replace them with richer ecosystems. So perhaps one option, since you seem to have space, would be to reduce the size of the lawn (which obviously makes mowing it easier) and to plant a meadow and whatever other plants.
Investing in all of those tools using gasoline just seems antiquated. But you're probably right, the individual footprint is tiny in the grand scheme of things.
OK, so I'm being a little tongue-in-cheek... Another answer is: Get rid of the lawn. Sheet mulch and plant food-producing trees for a food-forest.
It's still a lot of work though, so we just paved over it. Maybe next time I'll try artificial grass that does need maintenance.
There are plenty of examples on YouTube to learn technique from.