California Diesel Regs Cut Black Carbon Soot in Half, Shows the World How to Reap Big Benefits for Health and Climate

Washington, D.C., December 15, 2010 – Cleaner air and significant climate benefits are the result of California laws implemented two decades ago to reduce soot pollution from diesel trucks, according to a new paper published yesterday in Atmospheric Environment. Dirty diesel-burning vehicles are normally guilty of polluting the air with black carbon soot, dark-colored particles that kill and cripple, and cause climate change.

“A leading cause of respiratory diseases, soot is responsible for some 1.9 million deaths a year,” notes paper co-author, Professor V. Ramanathan, in a recent opinion piece published in the New York Times. California’s regulations have cut black carbon emissions from the state in half, providing a direct positive effect on local and regional air quality.

Black carbon is a formidable climate warming agent, estimated to be the second or third greatest contributor to global warming.  While in the atmosphere, the dark particles absorb heat and contribute to global temperature rise.  After a few days to a few weeks, the dark particles fall out of the atmosphere and can settle on snow and ice where they darken the surface and absorb more heat, leading to accelerated melting.

“As this study shows, the technology already exists to solve the black carbon problem,” said Durwood Zaelke, President of the Institute for Governance & Sustainable Development. “Because black carbon is short-lived in the atmosphere, reducing it provides fast benefits for public health and climate change.”

In addition to improving diesel vehicles, cleaner burning cook stoves can reduce black carbon in countries such as India, China, and much of Africa. Prof. Ramanathan, along with his daughter, Nithya Ramanathan, both at the Scripps Institution of Oceanography at the University of California, San Diego, launched Project Surya several years ago to bring improved cookstoves to Indian villages. The Project Surya team works with local women to collect data on black carbon by providing them with cell phones to take photos of black carbon filters.

“We know how to cut black carbon; we have the solutions,” added Zaelke. “Getting rid of black carbon can avoid millions of deaths and incapacitating injuries a year.  Whether you view the issue from a public health or climate change perspective – we need to take fast action now to cut black carbon.”

For more information, see:

Bahadur, R., Feng, Y., Russell, L.M., Ramanathan, V. Impact of California’s Air Pollution Laws on Black Carbon and their Implications for Direct Radiative Forcing, Atmospheric Environment (2010), doi: 10.1016/j.atmosenv.2010.10.054.


Contact Info: Alex Viets, IGSD: +1.213.321.0911, aviets@igsd.org