Tuesday, January 10, 2012

The Environment

Having examined the three parties to the commercial transaction, I thought we’d take a little time to talk about a few more “interested parties” in corporate commuting, even though they perhaps are a little more, er, abstract. With that in mind, the next “participant” in the Meet Rideshare series is the environment.
Gasoline emits any number of pollutants, which can broadly be broken down into two categories. Local Pollutants are pollutants which linger in the immediate (i.e. same city) area in which they are emitted. The levels of these pollutants in a given city is therefore highly correlated to how much of them is emitted by that city. And so, therefore, actions to reduce emissions of these pollutants benefits primarily the city which has reduced them. Local pollutants include Volatile Organic Compounds, formaldehyde, nitrous oxides, hydrocarbons, carbon monoxide, and particulate matter, and produce such things as smog and soot. They contribute to lung and heart disease as well as just general blight on the horizon.
Global pollutants spread out beyond the immediate area in which they are emitted. The best known global pollutant is probably carbon dioxide, which pools in the upper atmosphere of the planet. Carbon emissions anywhere on the planet are therefore a reflection of carbon emissions throughout the planet, and so are somewhat harder to take action against, since reducing one’s own emissions of carbon does no good if everyone else does not simultaneously reduce theirs. Other Global pollutants include methane, sulfur dioxide, and mercury, which all tend to pool at either the nationwide or regional level.

For the reasons explained, Rideshare’s primary benefit to the environment will be the reduction of Local Pollutants. While Rideshare will also reduce emissions of Global Pollutants, such reductions are not large enough to alter the global balance of these pollutants, since in terms of global emissions one city’s rush hour transportation emissions are a drop in the bucket. A city’s rush hour transportation emissions do however constitute a substantial portion of the city’s own Local Pollutants, and so Rideshare’s ability to reduce such emissions will provide noticeable benefits to the citizens of Los Angeles; even the ones who never use our service.

Putting numbers on these benefits is a little harder. In the U.S., a total of 238 billion vehicle miles were traveled in December 2009. Los Angeles contains about 3% of the U.S. population, so our local vehicle miles traveled would probably equal about 8.1 billion VMT per month, assuming Los Angeles is somewhere close to the average U.S. number. Los Angeles corporate commuters represent, according to our prior calculations, about  4 billion VMT per month(20 miles per trip x 5 million commuters x 2 trips per day x 20 days per commuter per month). So corporate commuting represents close to half of L.A. vehicle miles travelled. We can maybe quibble over these numbers a little bit, but they’re almost certainly not grossly off the mark. According to the E.P.A., automotive emissions account for about half of nitrous oxide emissions and hydrocarbon emissions, and a staggering 95% of carbon monoxide emissions. So if half of L.A.’s corporate commuters join Rideshare, at a one to one Driver to Passenger ratio, total vehicle miles traveled will be reduced by an eighth. This means that CO emissions will be reduced by 12%, and NOx and HC emissions by about 6%.

While that may not sound like much, it is important to remember that environmental pollutants operate on a synergistic basis. That is, each additional pound of pollution does far more damage than the one before it. Reducing pollution by 6-12% reduces the damaging health effects of pollution by a far greater proportion. In fact, the EPA has set a goal of reducing the emissions in the Los Angeles area by half(this is what is required to earn the EPA’s designation of Los Angeles as an “attainment area”), since that is all that is required to eliminate the detrimental effects of the pollutants. Remove half the pollutants, and the other half become harmless. So while Rideshare will not do the whole job, it can make a big dent.

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