First thing we do, let's turn off all the leaf blowers

Into these perfect autumn afternoons, when light gleams on the red dogwood berries and the blue arrowwood berries and the purple beautyberries; on the last of the many-colored zinnias and the last of the yellow marigolds and the last of the white snakeroot flowers; on the shining hair of babies in strollers and the shining ponytails of young mothers and the tender, shining heads of old men walking dogs — into the midst of all this beauty, the kind of beauty that makes despair seem like only a figment of the midnight imagination, the monsters arrive.

They come in a deafening, surging swarm, blasting from lawn to lawn and filling the air with the stench of gasoline and death. I would call them mechanical locusts, descending upon every patch of gold in the neighborhood the way the grasshoppers of old would arrive, in numbers so great they darkened the sky, to lay bare a cornfield in minutes.

But that comparison is unfair to locusts. Grasshoppers belong here. Gasoline-powered leaf blowers are invaders, the most maddening of all the maddening, environment-destroying tools of the American lawn-care industry.

Nearly everything about how Americans "care" for their lawns is deadly. Pesticides prevent wildflower seeds from germinating and poison the insects that feed songbirds and other wildlife. Lawn mower blades, set too low, chop into bits the snakes and turtles and baby rabbits that can't get away in time. Mulch, piled too deep, smothers ground-nesting bees, and often the very plants that mulch is supposed to protect, as well.

But the gasoline-powered leaf blower exists in a category of environmental hell all its own, spewing pollutants — carbon monoxide, smog-forming nitrous oxides, carcinogenic hydrocarbons — into the atmosphere at a literally breathtaking rate.

This particular environmental catastrophe is not news. A 2011 study by Edmunds found that a two-stroke gasoline-powered leaf blower spewed out more pollution than a 6,200-pound Ford F-150 SVT Raptor pickup truck. Jason Kavanagh, the engineering editor at Edmunds at the time, noted that "hydrocarbon emissions from a half-hour of yard work with the two-stroke leaf blower are about the same as a 3,900-mile drive from Texas to Alaska in a Raptor."

The two-stroke engine found in most consumer gas-powered leaf blowers is an outmoded technology. Unlike larger, heavier engines, a two-stroke engine combines oil and gas in a single chamber, which gives the machine more power while remaining light enough to carry. That design also means that it is very loud, and that as much as a third of the fuel is spewed into the air as unburned aerosol.

How loud? "Some produce more than 100 decibels of low-frequency, wall-penetrating sound — or as much noise as a plane taking off — at levels that can cause tinnitus and hearing loss with long exposure," Monica Cardoza wrote for Audubon Magazine this year.

In his Oct. 2 newsletter, the writer James Fallows summarized the emissions problem this way: "Using a two-stroke engine is like heating your house with an open pit fire in the living room — and chopping down your trees to keep it going, and trying to whoosh away the fetid black smoke before your children are poisoned by it."

As Fallows's last point suggests, what's bad for the environment is bad for humans, too — most menacingly, of course, for the employees of landscape services, who are exposed to these dangers all day long.

The risks come not only from the noise and the chemical emissions that two-stroke engines produce, but also from the dust they stir up. "That dust can contain pollen, mold, animal feces, heavy metals and chemicals from herbicides and pesticides," notes Sara Peach of Yale Climate Connections. All this adds up to increased risk of lung cancer, asthma, cardiovascular disease, premature birth and other life-threatening conditions.

This month, Gov. Gavin Newsom of California signed a new law making his the first state with plans to ban gas-powered lawn equipment along with other machines, like generators and pressure washers, that use gasoline-powered engines.

Only the Environmental Protection Agency can set emission standards. But California, owing to its unique climate and geography, which allow airborne pollutants to coalesce and linger, is the exception to this federal limitation. Other states can opt to follow California's more stringent tailpipe emissions standards, as 12 states and the District of Columbia do. Thanks in part to those standards, the passenger vehicles on California's roads and highways collectively produce less pollution than off-road machinery does. Think about that for a minute: Lawn-care equipment creates more pollution in California than cars do.

More than 100 cities across the country have already passed regulations to ban or restrict gas-powered leaf blowers. For people committed to their manicured lawns, the good news is that powerful electric and battery-operated leaf blowers now exist, and they are quieter and greener and healthier than gasoline-powered blowers. Their market share is also growing rapidly; electric equipment now represents roughly 44% of lawn-care machinery sales.

But the trouble with leaf blowers isn't only their pollution-spewing health consequences. It's also the damage they do to biodiversity. Fallen leaves provide protection for overwintering insects and the egg sacs of others. Leaf blowers, whether electric or gasoline-powered, dislodge the leaf litter that is so essential to insect life — the insect life that in turn is so essential to birds and other wildlife.

The ideal fertilizer and mulch can't be found in your local garden center. They are available at no cost in the form of a tree's own leaves. The best thing to do with fallen leaves is to mulch them with a lawn mower if your lawn consists of entirely of unvariegated turf grass (which it should not, given that turf grass requires immense amounts of water and poison to maintain). Our yard is a mixture of grasses and clovers and wildflowers, so we can safely let our leaves lie. If a high wind carries them away, it's hard not to wail, "Wait! I was saving those!"

And the leaves that fall across every inch of this wild half acre of suburbia are so much prettier than any unnaturally green lawn beaten into submission by stench-spewing machinery. All those golden sugar maple leaves hold onto the light, and for weeks it looks as though our whole yard is on fire, even in the rain. Who could be troubled by a blanket made of light? A blanket keeping all the little creatures safe from the cold?

Margaret Renkl is the author of the books "Graceland, at Last: Notes on Hope and Heartache From the American South" and "Late Migrations: A Natural History of Love and Loss."