California’s air quality began deteriorating in the 1930s and 1940s. In 1943, L.A. experienced its first smog day, with visibility down to three feet in some areas. By 1947, L.A. County established its first air quality board to battle the deteriorating air situation.

California air quality hit a low in the 1970s. This was due, in large part, to automobiles. Los Angeles has a lot of cars and many miles of road. All those cars driving all those miles created an emissions problem that led to a peak of 184 smog alert days in 1976.

Effect of Emissions Controls

California emissions standards have made enormous improvements in L.A.’s air quality. Angelenos drive twice as many miles as in the 1970s, but the number of smog alert days has dropped anywhere from zero to a few per year.

The growth in electric vehicle sales has given California residents hope that the smog levels could drop even more. A federal proposal could mandate that all new car and light truck sales have zero emissions by 2035. In 2017, total new vehicle sales surpassed $1 trillion. This means the auto industry is in for a major shift over the next 14 years.

Limits of Emissions Controls

However, emissions controls, by themselves, probably will not solve L.A.’s pollution problems. Although cars are a major driver of California’s smog, there are many other vehicles that burn fossil fuels and produce emissions. L.A. is a major transportation center with freeways and major seaports, rail centers, and airports.

The proposal for zero-emissions does not include ships, trains, airplanes, or trucks. These sources of transportation will continue to pollute the air around Los Angeles. Southern California also has some of the largest farming operations in the U.S. and farm equipment, like tractors and combines, would not be included in the zero-emissions mandate.

The proposal for zero-emissions also will not affect stationary sources of air pollution. Factories, electric power plants, oil refineries, chemical plants, farms (farm animals and fertilizers emit pollution), landfills (decomposing garbage produces air pollution), and residential fireplaces can all contribute to air pollution.

As a result, the drop in emissions from zero-emissions passenger vehicles cannot drop below the level produced by the other sources and L.A. could still have a smog problem.

Effect of Wildfires

But the most concerning source of air pollution for many reasons is California’s wildfires. Years of drought due to climate change have made California wildfires an annual disaster. Wildfire season contributes about half of the air pollution in California. Even when passenger vehicles drop to zero emissions, wildfires could more than replace their contribution to L.A.’s smog problem.

Other Responses to L.A.’s Air Problems

Addressing L.A.’s air problems will require more than strict auto emissions requirements. Instead, it will require a multipronged approach. Some of the ways California could reduce air pollution include:

• A shift to smaller, more efficient vehicles. Electric vehicles still need charging from power plants. Smaller vehicles and motorcycles use less electricy than larger vehicles. This shift is already occurring. The number of on-road motorcycles registered in the U.S. doubled from 4.2 million
• Tighten emission standards on other sources. Trucks, ships, airplanes, and power plants will take over as the largest sources of air pollution when passenger vehicles go to zero emissions.
• Continue to expand recycling. Landfills produce a lot of methane and release other chemicals into the air. But recycling efforts can reduce these emissions. Over 87% of Americans have access to curbside or drop-off paper recycling programs, and this will help.

Although zero-emissions vehicles will not solve all of L.A.’s air problems, it will be a move in the right direction. By coupling this proposal with other actions, L.A. could have air quality it has not seen in over 100 years.