A Breakdown of Life Cycle Analysis

Here is a more detailed portrait from the EPA of life cycle analysis, a concept that analyzes energy or product investment based on its total cradle-to-grave costs of production (including production of sub-products or materials), refinement, distribution, and consumption.

What is very telling about these charts is the degree to which highly-touted alternative fuels - corn-based ethanol, for example, have been promoted without much regard to whether they are significantly "greener" than conventional petroleum gasoline. This is a great example of how production itself becomes politicized in our society, with various interest groups lobbying federal and state legislatures on behalf of energy sources for which there may be little, if any, environmental benefit. Others argue that any displacement of petroleum gasoline itself is an environmental benefit, regardless of whether using the alternative fuels truly reduces overall greenhouse gas emissions.

Chicago to Follow NYC in Embracing "Green" Practices for Taxi Cabs

The oldest and largest cab fleet in North America, Yellow Cab Chicago, has recently announced a 10-year contract with Clean Energy Fuels to provide two compressed natural gas (CNG) filling stations in the city to power its taxi cabs. These filling stations will also be available to the public. 


Chicago is not the first American city to use CNG taxi cabs, but it is by far the largest and most influential to do so. The timing of this partnership comes as a result of a $1.5 million dollar grant package from the City of Chicago and the US Department of Energy (through the Clean Cities Coalition program). 


The City of Chicago is convinced that the CNG taxi cab program will both reduce greenhouse gas emissions and save cab operators money, according to a story posted to Inhabitat:

CNG isn’t a zero emission technology, but according to the Environmental Protection Agency, it emits 80 percent fewer ozone precursors and over 95 percent fewer particulates than conventional gasoline-powered vehicles. In addition to being cleaner, compressed natural gas is also 30 to 40 percent cheaper than gasoline or diesel on a mileage basis.

Although these estimates of emissions and cost reductions may be accurate, it is important to analyze new investments in alternative fuel technology from a life cycle analysis perspective. In short, this new CNG taxi cab partnership should be assessed based on whether its total aggregate emissions from every stage of its operations - construction of the filling stations, station maintenance, fuel production, procurement, and logistics, purchase of new CNG-compatible cabs, and the increased distances cabs must travel to fuel up - constitute a significant reduction from conventional petroleum fuel emissions. The City of Seattle recently suspended its own 1992 experiment with CNG vehicles for this very reason: the predicted emissions reductions did not materialize when the life cycle costs were factored in.

New Cab-Sharing Program in NYC Helps to Reduce Emissions and Encourage Carpooling

According to a post at the great urban design blog Inhabitat, the NYC Taxi & Limousine Commission just announced they are launching a taxi sharing program where riders will be able to pay a flat fare to be picked up and dropped off at designated taxi share stops. PlaNYC used GIS  data from individual cabs to determine the most heavily-trafficked cab routes in Manhattan. The pilot project is designed to reduce carbon emissions from single-passenger cab trips. There is a great incentive for cab riders to save money with this service because of the flat rate of $3-4 along the proposed cab-share routes. Cab drivers are more likely to drive along these cab-share routes because they stand to earn more money from multiple passengers than single riders. The routes are as follows:

 W. 57th St. and Eighth Ave. with drop-offs allowed on Park Ave. between 57th St. until 42nd St.; W.72nd St. and Columbus Ave. with drop-offs on Park Ave. from 72nd St. to 42nd St.; E. 72nd St. and Third Ave. with drop-offs on Park Avenue from 72nd St. to 42nd St. To start, all stops will be active during morning rush hour only and pick-up sites will be marked with signs.  

Now here's the ultimate test of social capital: Do New Yorkers trust each other enough to regularly share a cab with a complete stranger?