It seems that everyone knows what we have to do to reduce greenhouse gas (GHG) emissions --- Get out of our cars and into transit --- and move from our suburban detached houses to high-rise condominiums in the core. That is the basis of California Attorney General Jerry Brown’s intervention in the San Diego (SANDAG) regional planning process. This “back to the cave” mentality (or at least back to 1920 mentality) is both unnecessary and could lead to substantially less economic growth and higher levels of poverty.
There is no doubt that transit produces less in greenhouse gas emissions than cars in some applications and some corridors. The San Diego Trolley is a good example. However, trolleys cannot be built everywhere, not just because they cost so much, but also because the travel demand is simply not there. Local transit officials have built the trolley lines where demand is the greatest and the potential for reducing GHG emissions is the greatest. But there are serious limits to transit expansion.
The Attorney General may not be aware that cars are often more GHG friendly than transit. Outside New York, transit GHG emissions per passenger mile were virtually the same as cars in urban operation, based upon an analysis of 2005 US Department of Transportation and US Department of Energy data. Excluding the Trolley, transit services in the San Diego area emit more GHGs per passenger mile than cars.
The proposed federal 35 mile per gallon standard will reduce car GHG’s per passenger mile by 30 percent from present levels. Even more effective technology is on the way. Hybrid diesel cars entering the market in Europe next year will drop GHG’s per passenger mile a further 50 percent. The way forward is technological progress, not substantial life style changes.
Anyone who believes that people are going to abandon their cars for transit service that does take them where they are going or takes too long simply does not understand human behavior. Despite its substantial investment in transit, San Diego has the fourth worst traffic congestion in the nation, and things are only getting worse.
Moreover, the mobility that the car affords is crucial to the economy. International research demonstrates that metropolitan areas create more jobs and income where travel time is minimized. People use transit where it makes sense, but not where it doesn’t. University of California research suggests that a principal barrier to reducing minority unemployment is to make cars available. To keep traffic congestion under control, it will be necessary to continue investing in additional roadway capacity. This is also good for the environment, since air pollution and GHG emissions are far more intense where traffic becomes “stop and start.”
Then there is the matter of housing. It is not at all clear that single-family attached housing is produces more GHGs per capita than high-rise condominiums. Research in Sydney, Australia finds the opposite --- that GHG emissions per capita are substantially higher from high-rise condominium buildings than from single-family detached housing. The reason is the huge energy burden of common areas, shared services (such as central heating and air conditioning) and elevators, none of which are included from in US Department of Energy data for energy use by housing type.
There are those who believe that if we stop building additional highway capacity and traffic congestion gets bad enough, people will switch to transit. That is naïve. If traffic becomes bad enough, people and businesses will leave the area.
And, indeed, local smart growth policies are already driving people away from San Diego. The excessive regulations and land rationing of smart growth have driven housing prices to more than three times the level relative to incomes that occurs in markets with less severe regulation. San Diego County’s outward migration since 2000 is at or above the rate of Rust Belt Pittsburgh, Buffalo, Cleveland and Detroit.
The reality is that GHG emissions can be reduced substantially without seriously altering the way we live. What is needed is fact based strategies, not the tired ideology that has already done so much to increase traffic congestion and housing prices in San Diego (and to drive people away).