In a public career that dates back to the 1950s, S. David Freeman has made a habit of using local and regional government to push for far- reaching changes in national energy policy. He did it as chairman of the Tennessee Valley Authority in the 1970s, when he shut down most of the nuclear power plants that TVA had under development. He did it later as an advocate for conservation while running public utilities in New York, Los Angeles and Sacramento. Now, at the age of 80, he's doing it again. This time, though, it's from an unlikely perch.

Freeman is chairman of the Los Angeles Harbor Commission, which oversees the Port of Los Angeles. He was named to the post last year by Mayor Antonio Villaraigosa and given a mandate to clean things up. Literally.

The Port of Los Angeles--along with its next-door neighbor, the Port of Long Beach--is a huge player in the economy of the region. It is the leading container port in the nation, generates 260,000 jobs in Los Angeles County alone, and adds $52 billion to the area's economy every year; the entertainment industry, by comparison, clocks in at $34 billion.

The ports are also, however, profligate polluters. Ships, harbor craft, diesel-burning trucks, cargo-handling equipment and railroad engines all spew particulates into the air. According to the South Coast Air Quality Management District, the ports are the "single largest fixed source of air pollution in Southern California," responsible for more dirty air than all of the region's 6 million cars put together.

Prodded by a lawsuit and by intensifying opposition to its practices from neighboring communities, the Port of Los Angeles in recent years has reluctantly begun paying attention to environmental issues, agreeing to a plan aimed at keeping emissions at 2001 levels. When Freeman took over, however, the tone changed markedly. He has long had a reputation for speaking his mind no matter what the circumstances, and at his second commission meeting he lived up to it, effectively dressing down a Port executive for proposing minor cuts in some emissions. "Isn't this a drop in the bucket?" Freeman demanded. "Let's start acting like our lives depended on it. Our lives do depend on it."

Environmentalists loved it. "It's reassuring," says Julie Masters, a lawyer with the Natural Resources Defense Council who has litigated against the port. "We've never heard statements of this force and impact from any other board in the past."

In addition to his strategies for reducing emissions--through plugging container ships into electric power while in port, for instance, rather than running on their own fuels--Freeman has changed the rules for negotiating with shipping companies, giving terminal lease preference to those willing to find cleaner ways of operating. In what may be his most visionary idea of all, he is exploring maglev technology and monorails for moving cargo. "We're going to set an example," Freeman says, "and it's the critics who have their heads in the sand. The mayor is going to fire me if we're not the number one port in the nation, but he will also fire me if we don't get pollution under control. We can only grow if we grow green."