Fat guys with power tools

Running down by the towpath on Delaware & Raritan canal at Carnegie Lake, I saw the state of America as if etched in amber. Over by some sort of bunkerish water treatment facility, about four obese municipal workers were cutting overgrowth with chain saws, then throwing the overgrowth into a big chipper they left running. Think about the externalities of this, all these two-stroke and other large engines left running to reduce the aggregate carbon sink, and how much it costs to manage the health of these fat guys: the disability and health insurance.

What about the good old axe? And hasn't anybody developed a pedal-powered chipper? That's obviously the ticket here.