William Nazaroff

Civil and environmental engineering professor William Nazaroff says it's time to develop and deploy technologies that move beyond combustion. (Photo by Matt Beardsley)

Imagining a post-combustion world

It’s time to put out the fire. Burning fossil fuels for heat, cooking, electricity generation and transportation is an antiquated process still too reliant on dirty sources. To bolster household health in developing countries, improve global urban air quality and curb planetary climate disruptions, we must transition beyond combustion.

That’s the argument laid out in an editorial by civil and environmental engineering professor William Nazaroff in the journal Indoor Air, of which he is the editor-in-chief. Nazaroff is an expert on pollution dynamics in the built environment. In 2003, he created a new environmental engineering course, CE 107, called “Climate Change Mitigation.” Over the years, the course material has evolved, along with his thinking, resulting in the 2015 editorial. For Nazaroff, global climate change isn’t just an issue for science or policy or economics. It’s also an engineering challenge, which starts with figuring out how to decouple modern life from processes that rely on combustion. Or, as Nazaroff wrote, “The taming of fire and its application for beneficial purposes is a great achievement of humankind. And yet, fire is not fully tamed.”

From indoor air to climate science

Nazaroff studied physics as an undergraduate and then earned a master’s in electrical engineering and computer sciences from Berkeley in 1980. After a four-year stint working on radon research at Berkeley Lab, he decided to pursue a Ph.D. in environmental engineering at Caltech. “The most interesting project available was studying the soiling of works of art in museums caused by air pollution,” Nazaroff says. He set up studies in museums around Los Angeles, including the Getty and the Norton Simon museums, and he and his professor even once had a visit from the group restoring the Sistine Chapel.

He returned to Berkeley in the late 1980s as one of the college’s first air quality experts, against the backdrop of such foundational environmental policies of the 1970s and 1980s as the US Federal Clean Air Act, Clean Water Act and the Superfund program. “That context set the stage for a broader view about environmental quality,” Nazaroff says, “and the broad recognition that technology needed to be part of the story of environmental improvement.” The college’s civil engineering department was broadening at that time, expanding to encompass environmental engineering.  

Since then, Nazaroff has spent his career studying “the physical and chemical behavior, and more recently the microbial characteristics of the pollutants that we encounter, centered on what people are inhaling,” he says. “And then trying to understand what the important sources are, how the spaces we occupy influence levels of exposure and what can be done to control it, practically.”

Whether contamination from chlorinated solvents (used in a wide variety of hazardous materials such as thinners, resins and pesticides), environmental tobacco smoke, cleaning product chemistry or the air quality of aircraft cabins — all projects he has worked on — Nazaroff has followed a path dotted by interesting research challenges. “The indoor world is a small scholarly space,” he says, “but it’s big in terms of opportunities to work on really challenging and important problems. That’s what appealed to me.

“Lately, I’ve been studying microbiology in the built environment,” Nazaroff says. “We have been looking at how clothing might serve as a vector for exposure — specifically, how hospital-acquired infections may move throughout a hospital.”

Somewhere in the mix of three decades investigating the pollution dynamics of indoor built environments, Nazaroff became more attuned to climate change. He conceived of the idea for a climate change mitigation course following the terrorist attacks of September 11, 2001. “It was sort of odd to make this connection,” he says, “but when 9/11 happened, I thought, ‘I’m a full professor now, in the middle of my career. This is the opportunity to step back and do something really important, rather than just put one foot in front of the other.’”


Nazaroff’s climate change course revolves around one concept: “As society gets serious about counteracting anthropogenic climate change, we need to understand what role technology will play,” he says. “That leads us back to a discussion about energy. It turns out that half of the course is dedicated to energy, but not just the supply side. We don’t assume that we need so much energy; what we take as a given is that we desire the products and services that energy provides for us.”

That discussion in turn leads to questions about burning fossil fuels and what technologies can make energy production and use cleaner and more efficient. “One of the things I like about the post-combustion idea is that it’s an aspirational target. Mostly, we don’t burn because we really want to burn — that’s just the byproduct of figuring out how to transfer energy from one stored form into another, more active form. We don’t need to do nearly as much as we do, and maybe we should really think about not doing much at all.”

Nazaroff admits that right now a post-combustion world might seem like a lofty ambition, like the idea of a moon landing once was. Nevertheless, it’s a starting point. “If you can’t define a vision or an aspiration,” he says, “then you don’t have a sense of direction.”