Then I learned several things that changed my thinking both about leaf blowers and, up to a point, about politics.

One thing I learned has to do with the technology of leaf blowers. Their high volume, which I had long considered their most salient feature, is only their second-most-unusual aspect. The real marvel is the living-fossil nature of their technology. And because the technology is so crude and old, the level of pollution is off the charts.

When people encounter engines these days, they’re generally seeing the outcome of decades of intense work toward higher efficiency. The latest models of jet-turbine engines are up to 80 percent more fuel-efficient than their 1950s counterparts. While power plants burning natural gas obviously emit more carbon than wind or solar facilities, they emit about half as much as coal-fired plants. Today, the average car on America’s streets is almost 200 percent more efficient than in 1950, and smog-causing emissions from cars are about 99 percent lower.

The great outlier here is a piece of obsolete machinery Americans encounter mainly in lawn-care equipment: the humble “two-stroke engine.” It’s simpler, cheaper, and lighter than the four-stroke engines of most modern cars, and has a better power-to-weight ratio. But it is vastly dirtier and less fuel-efficient, because by design it sloshes together a mixture of gasoline and oil in the combustion chamber and then spews out as much as one-third of that fuel as an unburned aerosol. If you’ve seen a tuk‑tuk, one of the noisy tricycle-style taxis in places such as Bangkok and Jakarta, with purple smoke wafting out of its tailpipe, you’ve seen a two-stroke engine in action.

But you won’t see as many of them in those cities anymore, because governments in Asia and elsewhere have been banning and phasing out two-stroke engines on antipollution grounds. In 2014 a study published in Nature Communications found that VOC emissions (a variety of carbon gases that can produce smog and harm human beings) were on average 124 times higher from an idling two-stroke scooter than from a truck or a car. With respect to benzene, a carcinogenic pollutant, the group found that each cubic meter of exhaust from an idling two-stroke scooter contained 60,000 times the safe level of exposure. Two-stroke engines have largely disappeared from the scooter, moped, and trail-bike markets in America. Regulators around the world are pushing older two-stroke engines toward extinction.

Yet they remain the propulsive force behind the 200-mph winds coming out of many backpack leaf blowers. As a product category, this is a narrow one. But the impact of these little machines is significant. In 2017, the California Air Resources Board issued a warning that may seem incredible but has not been seriously challenged: By 2020, gas-powered leaf blowers, lawn mowers, and similar equipment in the state could produce more ozone pollution than all the millions of cars in California combined. Two-stroke engines are that dirty. Cars have become that clean.