SACRAMENTO, CA - Last Saturday, Earth Day, President Bush toured the California Fuel Cell Partnership in West Sacramento, where he told an audience of about 150, including reporters, that after five years of his administration, "America's air is cleaner, our water purer and the land is better cared for." That invites a look at the delicate subject of air quality in California.

The last three years have seen the nation's lowest levels of ozone smog since monitoring began in the early 1970s. In 2004, ozone levels were the lowest in U.S. history. In 2005, a hot summer caused more exceedences of the Clean Air Act standard than were experienced in 2004. Ozone levels, however, remained below those of previous summers with above-average temperatures, especially 1988 and 1998.

As the media noted, Houston and the San Joaquin valley experienced "exceptionally clean air." While that made Los Angeles look bad by comparison, California's largest city did well on its own terms, with fewer exceedences of the ozone standard in 2005 than in 2004, part of a long-term trend.

In 1975 Los Angeles experienced 192 exceedences of the one-hour ozone standard. That number fell to only 27 last year. Exceedences of the tougher eight-hour standard fell from 201 in 1975 to 75 last year. These trends understate actual conditions.

There are dozens of ozone monitors in the Los Angeles air basin. But an exceedence at only one, according the rules of the Environmental Protection Agency (EPA), applies to the entire airshed. In large areas of the LA air basin there have been no exceedences of the ozone standard at all for the last several years. The EPA is taking note of this fact with changes to its reporting language.

The California Air Resource Board (CARB) shows that hydrocarbons, the main component of volatile organic compounds or VOCs, has fallen 99.3 percent since the 1960s. Similar trends follow for tailpipe emissions, down 96 percent since the 1960s. These emission rates per mile apply to all makes and models uniformly.

According to the EPA, VOCs from cars and trucks have declined by 73.8 percent since 1970 and carbon monoxide emissions from cars are down 64 percent. During this time the total number of cars and trucks in the United States more than doubled, and the total miles driven increased 181 percent.

Both the California Air Resources Board and the EPA forecast that emissions from autos will fall another 75 to 80 percent from current levels. In 1980, emissions from cars and trucks accounted for a third or more of total VOC emissions. CARB estimates that by 2020, mobile source emissions will onlyaccount for five percent of total VOC emissions.

Reductions in VOC emissions from mobile sources account for a full two thirds of the total reduction in VOC emissions achieved so far. Automobile emissions have fallen so far that in 2005 it was announced that the 2.5 million dairy cattle in California's Central Valley are now a larger source of VOCs than cars.

California's central valley is also home to more than 100 wineries, now coming to the attention of regulators as another source of volatile organic compounds. The lesson here is that regulators are moving to more diffuse and small-scale sources of emissions as the large technological fixes have begun to run their course. That is, the fixes are working. No single administration in Sacramento or Washington can take credit for it, but California's air is much cleaner than cleaner it was on the first Earth Day in 1970. Problems remain, but the picture on water and land is similarly optimistic.

Those who hold the default position that everything is getting worse should check out the new version of PRI's Index of Leading Environmental Indicators. There will always be room for improvement, which recalls the reason for President Bush's visit to the California Fuel Cell Partnership, a collaboration of 31 companies working to promote the commercialization of hydrogen fuel cell vehicles. These could help, as the president said, liberate the United State from dependence on fossil fuels from "unstable parts of the world."

State legislators should strive to keep such ventures in California by lowering taxes and promoting a business-friendly climate. Here too there is much room for improvement.

K. Lloyd Billingsley is Editorial Director at the Pacific Research Institute. He can be reached via email at
klbillingsley@pacificresearch.org.