What about the worldwide millions of non smog checked garden tools, motorcycles, forklifts, construction equipment, golfcarts, etc., etc, all which would be clean on day one and day1000 if they were all electric and not gas, oil-gas mix or diesel from day one to dirty 1000.
The benefit from replacing gas trimmers with electric trimmers is massive; apparently those little tiny gas engines on lawn trimmers are horrendously inefficient and extremely polluting. There is no reason for anyone to use a gas trimmer any more; even if you have a huge amount of lawn to trim, it's more efficient to buy a few extra battery packs for your electric trimmer.
Which reminds me. I saw the city government using gas trimmers in the park. I need to go talk to someone about how they really ought to switch to electric.
Edit: topic about electric gardening tools, perhaps?