The nation’s first Air Pollution Control District formed in Los Angeles more than 75 years ago.
Air pollution, such as seen here in Los Angeles circa 1972, contains greenhouse gases which cause the climate to change. Gene Daniels / National Archives / Wikimedia Commons Public Domain
On July 26, 1943, an eerie cloud engulfed the city of Los Angeles. The LA Times described the cloud as a “gas attack,” and attributed it to the war with Japan. But of course—notwithstanding the fierce fighting several thousand miles off the California coastline—there was no attack on Los Angeles. The “hellish cloud,” as a city government report described it, was a relatively new phenomenon known as “smog.”
That smog attack set California on its path to lead the nation in efforts to control air pollution. In 1947, Los Angeles County created its own Air Pollution Control District, the first such government agency in the United States. And once climate change—which is caused largely by air pollution—became an acknowledged threat, California stepped up to combat that menace as well.
Here are seven of the significant and groundbreaking measures California has taken to lead the country’s fight against air pollution and climate change.
Human society has been concerned about the quality of the air we breathe since the days of antiquity. Sometime in the fourth or fifth century B.C., the Greek physician Hippocrates authored On Airs, Waters, and Places, in which he proposed the theory that “bad air” caused various “pestilences.” It wasn’t until the 20th century, however, that scientists started to figure out exactly what air pollution was—and that it was caused largely by industry. And by cars.
California was the first state to realize that it would take concerted government action to bring air pollution under control. In 1955 the state created the Bureau of Air Sanitation, an agency within the Department of Public Health, followed by the California Motor Vehicle Pollution Control Board in 1960. The two agencies merged in 1967 to create a single, statewide air pollution regulatory body. Today, the California Air Resources Board has a $1.5 billion budget and 1,550 employees and is the one state agency whose mission is to set air quality standards, as well as to find ways to reduce greenhouse gas emissions.
The fact that scientists can identify pollutants that come out of cars at all goes back to research conducted by California. In 1965, scientists working for the state came up with a set of tests that consisted of driving seven different vehicles of varying makes, models and model years and drove them in 12-mile loops around downtown Los Angeles, following highly specific patterns of acceleration and idling. The idea was to create tests that could be duplicated on stationary machines, allowing the emissions to be more easily captured and measured. Those tests, while they’ve evolved over time, are essentially the same ones used in smog tests required for most cars in California today.
The tests resulted in the country’s first emissions standards for cars, focusing mainly on emissions of hydrocarbons and carbon monoxide. When the federal government adopted its own national emission standards in 1968, they were identical to the California rules.
The federal government sets standards for vehicle emissions, but due to its huge number of cars coupled with its geography (lots of mountain ranges to trap air pollutants—Los Angeles in particular), California has always received a waiver allowing it to impose the strictest emissions regulations in the country. The waiver was also granted in part because California was first state with emissions regulations and had them in place before Congress passed the Clear Air Act in 1970.
The waiver remained in place until 2019, when the Trump administration revoked it, citing a supposed need for uniform nationwide emissions standards. California’s ambitious goals for putting the brakes on climate change—goals that ran in the opposite direction to Trump’s, who made rolling back climate change regulations a major focus of his administration—were probably the real reason.
When in 2019 California struck an agreement with automakers Ford, Honda, BMW and Volkswagen for those automakers to adopt California’s standards on greenhouse gas emissions, Trump became so outraged that he ordered the Department of Justice to launch an antitrust investigation of the companies.
In March of 2022, the Biden administration EPA reversed Trump’s revocations of California’s waiver and Section 177.
In 1975, much to the consternation of the auto industry, the EPA as well as California began requiring that all new cars include a device known as a catalytic converter, a device that traps gases from a vehicle’s exhaust before they can be blown out the tailpipe and into the atmosphere.
The catalytic converter has been described as “one of the greatest technical successes of chemical work, ever.” The Washington Post once called the device “the nation’s most powerful weapon against urban smog.” But ever since 2009, if you own a car in California, you don’t just need a catalytic converter, you need a CARB-compliant catalytic converter.
What’s the difference? As anyone familiar with California’s strictest-in-the-nation emissions standards might guess, the CARB-compliant kind pulls even more gases out of vehicle exhaust than catalysts in other states. Since California adopted the CARB-complaint regulations on January 1, 2009, only three other states have followed suit. New York and Colorado require CARB-compliant catalytic converters for all models of vehicle. Maine requires them for any vehicle sold in 2001 or later.
Lead is a highly toxic substance, especially for children. Its harmful, even deadly effects were already known when lead—in the form of tetraethyl lead—was first added to gasoline in the United States in 1922. The substance absorbs easily into the human body and penetrates the “blood-brain barrier,” entering the brain and nervous system where it causes a wide range of neurological and behavioral disorders.
But gasoline with added tetraethyl lead did indeed make combustion engines run more smoothly. Perhaps not surprisingly, then, the auto industry funded “scientific” studies supposedly demonstrating that leaded gasoline had no detrimental health effects. The federal government began phasing out leaded gas in 1975—but not due to its toxicity to humans. The reason was that leaded gas causes damage to catalytic converters, which were required in new cars starting that year.
It wasn’t until 1991 that one state banned leaded gas altogether, prohibiting gas stations from selling it for cars made in any year. That state, of course, was California. At the time, about 1.5 million of 22 million cars on the road in California ran on leaded gas. The federal government did not ban leaded gas nationwide until 1996.
In 2006 the California legislature passed a landmark law to directly attack the causes of climate change, the Global Warming Solutions Act. The law passed on an almost completely partisan vote. Only one Republican in the Assembly and none in the Senate voted for it. Two Democrats opposed the bill in the Assembly but in the Senate Democrats were unanimous. Nonetheless, Republican Gov. Arnold Schwarzenegger signed the bill into law on Sept. 27.
The Natural Resources Defense Council, a leading environmental advocacy group, called AB32 a “turning point in international efforts to solve the world’s most pressing environmental problem.” The law put the burden on CARB to make sure that greenhouse gas emissions in the state were reduced to the level they were at before 1990. The deadline for that goal: 2020. The law set the most ambitious climate change goals in the United States.
The state met that goal—with four years to go. But that wasn’t good enough. On Sept. 8, 2016, Schwarzenegger’s successor, Gov. Jerry Brown, signed SB32, an update to the sweeping climate law. Under the new law, CARB was authorized to impose rules and regulations that would bring greenhouse gas emissions to 40 percent below the 1990 levels, by 2030.
“This is big,” Brown said when he signed the bill. “I hope it sends a message across the country.”
Banning leaded gas was nothing. In 2022, Gov. Gavin Newsom handed down an executive order requiring that all new cars sold in California must be “zero-emissions,” starting in 2035. Of course, the current best way to power a car that produces no emissions is to use electricity.
The order made California, once again, first in the nation on a major climate-change or air pollution problem. No other state banned gas-powered cars, in effect requiring all new cars sold in the state to be electric. Within a year, six other states had invoked the above-mentioned Section 177 and adopted the new California rule, known as the Advanced Clean Cars II Rule.
The rule will not take all gasoline-powered cars off the road. Even in 2035 anyone owning a gasoline vehicle can keep it, and they can also be sold as used cars. The new rule will be phased in over a decade leading up to 2035. Starting in 2026, 35 percent of all new cars sold in the state must be electric vehicles (EVs), with a 51 percent EV quota in 2028, 68 percent in 2030—ending with 100 percent in 2035.
