Well it might be fine for the small home owner but those large estates it is going to be a problem.
Plus it is hard to believe a hand held blower operated an hour using only 1-2 quarts of fuel is polluting more than a car burning over 22 gallons of fuel.
If California want to clear up their pollution problem maybe they need to look into solving the vehicle traffic problems they have where a drive may sit in traffic with the engine running for 1-3 hours just trying to getting and from work.