By Alec Rosenberg

The climate change debate most often focuses on environmental crises: What will happen to wildlife and water levels? But climate change also impacts human health, exacerbating asthma, aggravating allergies and contributing to premature deaths - with the biggest burdens potentially falling on the poor and people of color.

University of California scientists are studying these impacts in innovative ways, filling in pieces of the climate puzzle, assisting in public policy and offering solutions to improve public health.

"The most important message about climate change is it's going to affect our health, not just our environment," said Dr. John Balmes, UC Berkeley professor of environmental health sciences and UC San Francisco professor of medicine.

The impacts on human health are becoming more urgent, while Congress debates a climate change bill and the international community readies for the U.N. Climate Change Conference in December in Denmark.

California has addressed climate change with landmark legislation to reduce greenhouse gas emissions to the state's 1990 levels by 2020. The state has some of the nation's worst air quality, particularly in the Central Valley and the Los Angeles basin, where a stew of pollutants from cars, trucks, ships, power plants and other sources is trapped by topography. Climate change is expected to exacerbate air quality problems, with higher temperatures causing more heat waves and increasing pollutants such as ozone, a primary ingredient in smog that attacks lung tissue.

Already, in California the annual health ramifications of exceeding state standards for ozone and particulate matter include 6,500 premature deaths, 4,000 hospital admissions for respiratory disease, 3,000 for heart disease and 350,000 asthma attacks, according to the California Air Resources Board. Climate change could make that worse.

Balmes is studying the issue on two fronts: in the lab and in the field.

Balmes runs the Human Exposure Lab at San Francisco General Hospital. It features an 8 x 8 x 8-foot chamber, a modified cold storage room, where he exposes subjects to ozone and other pollutants. Balmes' group was the first to show that ozone can cause airway injury in humans.

In the field, Balmes has studied UC Berkeley freshmen (finding Southern Californians had lower lung function than Bay Area natives because of greater lifetime ozone exposure) and asthmatic children in Fresno (finding that early childhood exposure to air pollutants affects lung function).

Gov. Arnold Schwarzenegger appointed Balmes to the California Air Resources Board, which oversees the state's greenhouse gas emissions reduction law, AB 32. Balmes helped start a workgroup to address public health impacts of climate change mitigation efforts.

"It's an opportunity to put my scientific background to bear on policy issues," Balmes said. "I think I've had an impact on specific regulations."

Bridging the climate gap

One of Balmes' former officemates, UC Berkeley epidemiologist Rachel Morello-Frosch, is studying another aspect of global warming: the climate gap. The climate gap theory suggests that climate change will disproportionately affect communities of color and the poor. Her study, released in May, was the first to synthesize the public health and economic impacts of the climate gap, comparing the effects in some parts of U.S. cities to those of developing nations. For example, low-income African Americans living in Los Angeles are nearly twice as likely to die from a heat wave than other L.A. residents as they are less likely to have access to air conditioning or cars to allow them to escape the heat.

"If we focus our mitigation strategies on the most vulnerable, we are likely to do a much better job of protecting us all," said Morello-Frosch, an associate professor of public health and environmental science, policy and management.

Maximizing reductions in greenhouse gas emissions and toxic air pollution in neighborhoods with the dirtiest air can help close the climate gap, she said.

"If we're going to move forward and really address climate change, addressing the climate gap needs to be an integral part of that discussion," Morello-Frosch said.

Crunching data

Another key is having accurate data. "What we are doing to the climate is a very complex thing," said Anthony Wexler, who directs UC Davis' Air Quality Research Center. Colleague Michael Kleeman, a UC Davis professor of civil and environmental engineering, is looking at climate impacts on air quality in California. Crunching the numbers will take a year, with six months to go. Results will help to predict health impacts of climate change in California via changes to air quality.

"I think we're going to see pretty significant reductions in air pollution because of the climate change strategies that we are going to try to put in place," Kleeman said.

Where the rubber hits the road, so to speak, is near freeways. Air pollution particularly takes its toll on those living within 150 feet of freeways, said Michael Kleinman, a UC Irvine adjunct professor of community and environmental medicine.

Kleinman works with AirUCI, an organized research unit that expanded last year to advance understanding of air pollution and its impact on health. He is studying how pollutants interact in the surfaces of the lungs.

Kleinman also serves on the U.S. Environmental Protection Agency Scientific Advisory Board and California's Air Quality Advisory Committee.

"California has always been very progressive in terms of setting protective air quality standards," Kleinman said. "I think that climate change-driven regulations and some of the things that are being done to improve air quality are hand in glove."

Suppressing soot

Climate change is a global issue. And some solutions are difficult to deliver: building cleaner cars and power plants, implementing an emissions cap and trade system. UC scientists also are seeking a simpler, cost-effective solution: cleaner-burning stoves. Half the world's population burns wood and other solid fuel to cook, creating soot, or black carbon. Soot is one of the largest contributors to global warming along with carbon dioxide.

Balmes has found that giving Guatemalan highland villagers "planchas" - $200 stoves with metal chimneys to replace indoor open fires - reduces the risk of pneumonia in infants and improves mothers' respiratory systems.

Veerabhadran Ramanathan, distinguished professor of climate and atmospheric sciences at UC San Diego's Scripps Institution of Oceanography, is trying to attack the problem on a larger scale with Project Surya (Sanskrit for sun). Ramanathan has launched a pilot study of 500 homes in rural India, replacing traditional cooking with cleaner biomass, biogas and solar cookers costing $20 to $150. Results will be monitored outside with satellites and inside with cell phones with sensors in a partnership with a UCLA team.

Indoor air pollution, primarily from black carbon, causes 500,000 deaths in India alone, said Ramanathan, who grew up in India and remembers his grandmother coughing on the veranda after cooking with firewood and cow dung.

"I know how much she has suffered," Ramanathan said. "To me, it's one of the pleasures of Surya to see if I can make a change."

Ramanathan's pioneering work with unmanned aircraft to measure pollutants and their movement has led him to study air over Southern California and Beijing. But he also is working with economists and business students at UC San Diego to help expand Surya.

"The climate has gone into almost a crisis mode and we have to solve the problem," he said. "There are low-hanging fruits there, and they are amazingly simple and we should focus on these."

Alec Rosenberg is coordinator of health science communications at the UC Office of the President.