Air Quality & Emissions, California, SB 375

Air Resources Board proposes final regional targets for SB 375

Agency staff from the State Air Resources Board (ARB) has now proposed final targets for Senate Bill 375, which quantify each region’s target for reducing greenhouse gas emissions by the years 2020 and 2035.  The targets are the product of the “bottom-up” approach that ARB has adopted — the direct outgrowth of a collaborative process between ARB and California’s eighteen metropolitan planning organizations (MPOs).  The MPOs modeled different scenarios to estimate how much greenhouse gas reduction their regions could achieve, and then discussed and refined these results while consulting ARB.  At the end of June, ARB released draft target ranges, and the MPOs have since provided ARB with their potential target recommendations.

Following up on that process, ARB has now proposed more precise final targets for each region in California.  The Board will review the staff proposal and adopt final targets next month, as required by the legislation.  Having monitored the MPO analysis along the way, ARB’s proposals unsurprisingly track very closely the targets recommended by the MPOs.  These are the 2020 and 2035 targets that agency staff have proposed for the Board’s consideration:

Region (MPO) 2020 2035
Los Angeles/Southern California (SCAG) -8% -13%
San Francisco Bay Area (MTC/ABAG) -7% -15%
San Diego (SANDAG) -7% -13%
Sacramento (SACOG) -7% -16%
San Joaquin Valley (eight MPOs) -5% -10%
Monterey Bay (AMBAG) +13% +14%
Butte County (BCAG) +1% +1%
San Luis Obispo County (SLOCOG)
-8% -8%
Santa Barbara County (SBCAG) +6% +4%
Shasta County (SCRTPA) 0% 0%
Tahoe Basin (TMPO/TRPA) -7% +6%

All targets are expressed in terms of percent change in per capita emissions, as compared to a year 2005 baseline.

Small MPOs

Because the six small MPOs at the bottom of the above chart only account for five percent of California’s population and emissions — with no expectation of significant or disproportionately rapid growth — the proposed targets for these regions reflect expected emissions based on business-as-usual planning efforts.  These regions do not have the in-house technical expertise that other MPOs possess.  Rather than exert a large upfront effort to get these less populated, largely rural regions up to speed, ARB made a reasonable decision to concentrate on the Big Four MPOs and the San Joaquin Valley for now — that is, those regions that contribute the vast majority of the state’s transportation emissions and are expected to experience the most growth.  New targets for the six small MPOs will then be established in 2014.

San Joaquin Valley MPOs

The San Joaquin Valley continues to be particularly challenging.  Unlike the six small regions, the Valley is expected to grow significantly in the next quarter century — at over double the pace of the rest of California.  But the eight Valley MPOs do not yet possess the level of technical expertise needed to carry out necessary modeling.  SB 375 also contains a special provision for the Valley, which allows for a collaborative Sustainable Communities Strategy (SCS) prepared jointly by at least two Valley MPOs.  But it is not yet clear which, if any, of the MPOs will elect to do that, because the Valley regional transportation plans will not be updated again until 2014.

Given this extra time and the need to improve the models, ARB currently proposes placeholder targets of -5% in 2020 and -10% in 2035 for the San Joaquin Valley, with the understanding that these targets would be revisited and potentially replaced in 2012 by “provisional” targets for use in the RTPs.  By 2012, modeling capability will be improved, and the Valley MPOs should have decided amongst themselves whether any joint SCS will be prepared.

Big Four MPOs

The proposed targets for SCAG, MTC, SANDAG, and SACOG are generally in the ballpark of the draft targets.  The final targets proposed for 2020 are all within the -5 to -10% range identified in the draft targets.  Although the 2035 draft target ranges were not that well-defined in June, ARB’s proposed targets for 2035 have been narrowed to the -13 to -16% range.

In arriving at the 2035 targets, ARB matched the MPO recommendations for all regions except the SCAG region, which only recommended a meager -5 to -6%.  ARB ignored that suggestion and instead proposed -13% for SCAG, so that Southern California would be in the same ballpark as the other three major metropolitan regions.  Three months ago, in May, MTC had maintained that a -12% target for 2035 was the most ambitious possible Bay Area target.  But MTC ultimately recommended a -15% target by 2035, and ARB has included that more ambitious recommendation in its proposal.

The next post will examine whether these proposed targets are ambitious enough to achieve the level of emissions reduction required by Assembly Bill 32.


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