California has overestimated pollution levels by 340 percent in a scientific analysis used to determine the state’s clean-air standards, reports the San Francisco Chronicle. The results come after the California Air Resources Board (CARB) announced in April that it may have overestimated the amount of diesel emissions from backhoes tractors, trucks and other vehicles.
The truck and bus fuel emissions rule, written under AB 32, the 2006 law that addresses global warming, requires trucking fleets to acquire diesel particulate matter filters and upgrade their truck engines beginning in 2012, with the exception of small trucking businesses that will be exempt until 2014.
CARB told the newspaper that 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 vehicles in California. However, independent researchers attribute the huge overestimates in the air board’s work on diesel emissions to a faulty method of calculation, according to the article.
This follows the request of a member of the Air Board, who called for a review by independent researchers of the diesel emissions rules for trucks and buses after learning that a researcher whose work contributed to the pollution standards in December 2008 falsified his credentials.
As a result of the miscalculation, the air board and construction industry officials have announced a proposal that includes delaying the start of the requirements until 2014 and exempting more vehicles from the rule.
The setbacks and the proposed weakening of a landmark regulation raise questions about the performance of the agency as it implements the Global Warming Solutions Act of 2006 or AB32, which has come under political attack this year, according to the article.