(10-08) 04:00 PDT Sacramento – —
California grossly miscalculated pollution levels in a scientific analysis used to toughen the state’s clean-air standards, and scientists have spent the past several months revising data and planning a significant weakening of the landmark regulation, The Chronicle has found.
The pollution estimate in question was too high – by 340 percent, according to the California Air Resources Board, the state agency charged with researching and adopting air quality standards. The estimate was a key part in the creation of a regulation adopted by the Air Resources Board in 2007, a rule that forces businesses to cut diesel emissions by replacing or making costly upgrades to heavy-duty, diesel-fueled off-road vehicles used in construction and other industries.
The staff of the powerful and widely respected Air Resources Board said the overestimate is largely due to the board calculating emissions before the economy slumped, which halted the use of many of the 150,000 diesel-exhaust-spewing vehicles in California. Independent researchers, however, found huge overestimates in the air board’s work on diesel emissions and attributed the flawed work to a faulty method of calculation – not the economic downturn.
The overestimate, which comes after another bad calculation by the air board on diesel-related deaths that made headlines in 2009, prompted the board to suspend the regulation this year while officials decided whether to weaken the rule.
On Thursday, after months of work, the air board and construction industry officials announced a proposal that includes delaying the start of the requirements until 2014 and exempting more vehicles from the rule. It would be a major scaling back of the rule if the air board approves it in a vote scheduled for December. The announcement was made as The Chronicle was preparing to publish this report, which had been in the works for several weeks.
The setbacks in the air board’s research – and the proposed softening of a landmark regulation – raise questions about the performance of the agency as it is in the midst of implementing the Global Warming Solutions Act of 2006 – or AB32 as it is commonly called, one of the state’s and the nation’s most ambitious environmental policies to date.
AB32, which aims to reduce carbon emissions to 1990 levels by the year 2020, has come under intense political attack this year as the state prepares to elect a new governor. Critics cast the law as a jobs killer because of the expenses to industry and businesses in conforming to new pollution regulations. Supporters say it will reinvigorate the state’s economy and create thousands of new jobs in the emerging green sector.
Republican gubernatorial candidate Meg Whitman has promised to suspend the law for at least a year, while Democrat Jerry Brown supports the law. California voters, meanwhile, will vote on Proposition 23, a November initiative to suspend AB32 until the unemployment rate – now at 12.4 percent in California – falls to 5.5 percent or less for a year.
Mary Nichols, chairwoman of the California Air Resources Board, offered no explanation when The Chronicle questioned her about the diesel emissions miscalculation. She was recently asked why the air board estimate of a nitrous oxide source was off by at least a factor of two – air board scientists have since revised their numbers, and data show the estimate was off by 340 percent. Nichols’ response: “I can’t answer that for you.”
Nichols was emphatic, though, when asked whether she has concerns about other scientific calculations made by air board scientists.
“No, no, no, no, no, no, no and no,” she said.
Members of Nichols’ board don’t have an answer for the overestimate either, said Ron Roberts, an air board member who is a Republican supervisor in San Diego County and who voted in favor of the diesel regulation.
“One of the hardest things about being on the board is separating fact from political fancy,” Roberts said.