Now that the California Air Resources Board has released its draft targets for greenhouse gas emissions reduction under SB 375, it's time to do some math. What follows is nerdy and a little dense, but it's important – and planners need to be able to follow the bouncing ball on 375. 

The bottom line is that the math doesn't yet add up – and that's because what AB 32 calls for and what California's regional planning agencies think is realistic don't line up with each other.

In the so-called "Scoping Plan" (CP&DR Blog Oct. 2008) – the master plan for reducing emissions under AB 32 – released at the end of 2008, ARB concluded that the state would have to reduce emissions by 100 million metric tons of CO2 equivalent between 2010 and 2020 – from about 520 million metric tons to 420 million, or about a 20 percent cut. That would bring the state down to the same level of GHG emissions as 1990, which is the target set in AB 32 for the year 2020.

But ARB also concluded that, if no action were taken, GHG emissions would increase by 2020 to 590 million metric tons – meaning the state must cut 170 million metric tons from what otherwise would be emitted, given population and economic growth during that period. Thus, ARB concluded, to meet AB 32, the state would have to cut emissions by almost 30 percent from the "business as usual" scenario.

In the Scoping Plan, ARB also set a goal for the implementation of SB 375's probable land use and transportation reforms. Recognizing that these will create mostly long-term benefits, ARB said SB 375 should deliver about 5 million metric tons of savings from the "business as usual scenario". That's only about 3 percent of the overall savings. And it's a lot less than the reductions required by other key moves in the transportation sector, including the low-carbon fuel standards (16 million metric tons) and the increased gas efficiency standards (28 million metric tons). To put it another way, ARB is expecting to get almost 15 metric tons of savings out of technological improvements for every 1 metric ton of savings that comes out of a different land use pattern.

So, despite considerable carping on the part of local officials who are fearful that they can't meet the standard, that would seem to be a pretty modest goal – "aggressive but achievable," (CP&DR Blog May 2010) as the SB 375 wonks keep saying. (Environmentalists wanted a target that would be double or triple that amount.)

But will the targets released the other day hit the goal? Let's do more math.

After an enormous amount of wrangling at the Regional Targets Advisory Committee – and endless input by the regional planning agencies – the ARB staff has proposed a per-capita target of 5-10  percent by 2020 for the "Big 4" regional planning agencies – Sacramento, the Bay Area, Southern California, and San Diego. That means that emissions attributable to land use changes should go down 5-10 percent per person – not 5-10 percent overall. The targets for the Central Valley regional planning agencies were even smaller – between 1-7 percent.

Remember, under SB 375, emissions reductions pretty much equals reductions in vehicle miles traveled. So think about what this means: a 5-10 percent reduction in per-capita VMT over the next decade – in a state where per-capita VMT is already among the lowest in the nation.

Hard enough on its own terms. But don't forget that California's population keeps growing. The Department of Finance Demographics Research Unit projects that our state's population will grow from 39 million today to 44 million by 2020 – an increase of about 13 percent.

So, summing things up …

SB 375 is supposed to cut emissions by 5 million metric tons. ARB is saying the per-capita target for the vast majority of the state should be 5-10 percent. But the population is going up 13 percent. 

If you're wondering how the heck that works out to a net reduction in emissions, you're not alone. It doesn't. But it does reflect what the regional planning agencies in California think is realistic. 

Here's how Steve Heminger, the widely respected head of the Metropolitan Transportation Commission in the Bay Area, summarized his agency's situation in a communication to ARB: "Given that our RTP financially constrained expenditures for maintenance and operations will likely continue in the 80 percent range, the region will likely not be able to depend on massive infrastructure improvements to support GHG emission reductions. We can expect some modest reductions as a result of strategic expansion through priced Express Lanes and select transit corridors, and operational improvements that squeeze more capacity out of our existing transportation system."

Most of the other major regional planning agencies had similar conclusions based on a variety of model runs and scenarios. Indeed, the lower targets for the Central Valley communities – where a lot of the car-oriented growth is likely to occur – will put more pressure on the coastal metros (plus Sacramento and the Inland Empire) – to reduce emissions.

And the current recession has actually made it more difficult to reduce GHG emissions, even though growth has slowed considerably. That may sound counterintuitive, but there's a difference between slower emissions growth and actually reversing the trend so that emissions go down. A recession will slow emissions growth, because recessions always slow VMT growth. But recessions also reduce the overall amount of change in the built environment. New TOD projects won't get built. New transit lines won't get built. And so there will be fewer changes that can give people alternatives to driving – or shorten trips.

So the bottom line is this: There's no way California's getting anything like 5 million metric tons of savings out of these targets. 

But does this mean we should give up? Probably not, for two reasons.

First, it should be obvious to everyone that emissions reduction under AB 32 is a zero-sum game. Every metric ton that you can't get out of land use is a metric ton that has to come from somewhere else – most likely from somewhere else in the economy where powerful lobbyists (Insight Vol. 22 No. 09 Sep 2007) are at work.

And second, as Hasan Ikhrata of the Southern California Association of Governments often says, SB 375 isn't really a GHG reduction bill. It's a land use planning bill – a way to force us to think more aggressively and comprehensively about how to address longstanding problems in the way our built environment is organized. 

Ikhrata often makes this statement kind of ruefully – fearing, I think, that this reality gives the pavement crowd an excuse to push back against the planners. But he's right. Reducing GHG emissions isn't the only reason we should alter our built environment. But GHG emissions are a pretty good proxy for all kind of things. Fewer emissions means less energy consumed, which means less energy produced in environmentally destructive ways and less money going to purchase energy. It means less need for new highways, which are – again – not only environmentally destructive but also awfully blasted expensive for a state that's bankrupt. And so forth.

All this may be moot in November, if Proposition 23 passes and AB 32 is suspended (CP&DR Vol. 25, No. 7, April 1, 2010) – and/or if Meg Whitman is elected governor and decides to suspend AB 32 all on her own, as she's threatening to do. In the meantime, however, California's planners should keep trying to make the numbers add up – and figure out the "co-benefits" of SB 375.