Reducing black carbon, carbon dioxide, particle pollution in California air

Diesel-smoke[1]The California Environmental Protection Agency Air Resources Board (ARB) in “Fact Sheet: California’s Plan to Reduce Diesel Particulate Matter Emissions,” notes, “In 1998, California identified diesel particulate matter (diesel PM) as a toxic air contaminant based on its potential to cause cancer and other adverse health effects.”

Added ARB in 2004: “Each year in California, diesel PM contributes to an estimated 2,900 premature deaths, 3,600 hospital admissions, 240,000 asthma attacks and respiratory symptoms and 600,000 lost workdays. Overall, diesel engine emissions are responsible for the majority of California’s potential airborne cancer risk from combustion sources.” 1

Meanwhile, back in 2000 the Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-fueled Engines and Vehicles was adopted by the state air board in September.  Plan goals are to reduce from baseline year 2000 amounts, diesel particulate matter 75 percent and 85 percent by 2010 and 2020, respectively, ARB specified.2

Black carbon being a key component of diesel PM, and as it relates, in a June 13, 2013 ARB news release, the air board mentions a study – “Black Carbon and Regional Climate of California” – and elaborating further, wrote: “The study, funded by the California Air Resources Board and led by Dr. Veerabhadran Ramanathan of the Scripps Institution of Oceanography at the University of California, San Diego, estimates that reductions in black carbon as a result of clean air regulations were equivalent to reducing carbon dioxide emissions in California by 21 million metric tons annually or taking more than 4 million cars off California roads every year.”

In fact, between 2012 and the time the ARB was established in 1967, black carbon emissions in the Golden State have been trimmed by around 90 percent, according to Lawrence Berkeley National Laboratory study co-author Dr. Tom Kirchstetter, the ARB noted. This level of reduction is largely attributable to regulations of diesel engine emissions by the state.

“The study took a conservative approach in examining the impact black carbon has on the Golden State. Researchers considered emissions only from diesel-powered trucks and buses, and off-road diesel equipment and vehicles to estimate the equivalent reduction of carbon dioxide,” the ARB pointed out in the release.

When taking into consideration black carbon-emissions releases via the combustion of diesel fuel from all sources, including, automated agricultural implements, construction gear, locomotives and water-borne craft, over the past two decades, the per-year reduction in carbon dioxide (CO2) can be as much as 50 million metric tons or the equivalent of a 13 percent decline in the per annum total of California CO2 emissions, according to ARB.

“As ARB’s current efforts to clean up trucks and buses moves forward, resulting in the continued cleanup and turnover of older heavy-duty diesel vehicles, California should continue to see declines in particulate matter emissions. Advanced engine emissions control systems and filters are expected to dramatically reduce emissions from all new diesel engines. Current diesel truck engines, for example, are over 90 percent cleaner than models from years when they were unregulated,” the agency further stated.

Further advances made in the emissions-reduction realm can only mean one thing: even greater air quality and quality-of-life gains.

For more on black carbon, carbon dioxide, diesel and particulate matter, see: “Black carbon and climate change: Research suggests link,” “Diesel consumption rises, black carbon concentrations drop in California” and “Black carbon a major air pollution culprit.”


  1. “Facts About: California’s Accomplishments in Reducing Diesel Particulate Matter Emissions,” California Environmental Protection Agency Air Resources Board (ARB), 2004, p. 1.
  2. Ibid.

Published by Alan Kandel