Since I already wrote my annual Bike to Work Week article and my 5 tips didn't exactly go viral, I thought I'd change it up today (Bike to Work Day) and point out that there are a few other commuting options that are potentially greener (with a few important caveats).
Bicycling is widely considered the most efficient mode of transportation on the planet, so you might be skeptical that you can commute to work in any greener way, but I'm pretty positive the options below are genuinely greener... when the stars are aligned right.
First, before jumping into those other options, here's a useful infographic that ranks various transportation modes by efficiency. The data are apparently from 2005, but not much has changed since then.
(Note: I believe there's an error in the infographic and "Plug-In Hybrid" should be "100% Electric Car." Also, the most efficient electric car in the US is now the 100% electric BMW i3, which gets 124 MPGe.)
Okay, so, what's greener than going 984 MPG to work on your bicycle?
1) Jumping on the bus, tram, or subway.
According to the infographic above, a bus only gets about 38 MPG and a passenger train gets about 72 MPG "per person." However, your transit options are going to be running anyway, with or without you. The fuel economy figures for those modes come from assumptions regarding ridership level in order to create a "per person" MPG rating. However, the small extra weight you add by stepping on board doesn't add very much at all to the energy the bus, tram, or subway requires. Unfortunately, I'm not actually sure how much extra energy each of those uses when you get on board, so it would be swell if any of you have done research in this field and could provide more detailed insight.
(Of course, this assumes that you have a transit line nearby that you can quickly/efficiently walk to.)
2) Jumping in your neighbor's car
That is, carpooling... but with the assumption that neither you nor your carpooling partner have to go very far to meet up (and especially that there's no need to drive more for any part of the carpooling trip). The rationale is the same as in #1. From what I've found, the MPG of that extra person is between about 1500 and 2000. (Of course, it depends a lot on the car itself.)
Again, however, just a couple of extra miles with the poor efficiency of a gasmobile puts bicycling back on top.
This is a rather obvious one for someone who already works from home. Telecommuting requires zeroa gallons of fuel. It's also been shown to benefit both the employee and the employer in many ways, so I think it's something many people could bring up with their boss, make the case for, and potentially explore.
However, there's also a caveat with this one. Basically, we need to exercise in order to be healthy. If your bike commute is your way of exercising, then you may as well write it off as a commuting option that requires zero gallons of fuel. If taking transit or telecommuting would make you start going to the gym or would make you join a sports club, then you may actually end up causing net environmental harm if you dropped bike commuting.
In the end, as with many things, it comes down to your unique situation. And there are also many non-environmental reasons to choose one commuting option over another. But since TreeHugger is all about being green, I figured it would be fun to tease out the potential green benefits of these other 3 (less glamorous) commuting options.