What is Green Transportation? The negative effects of our transportation system is large and the "greening" of the transportation system is very important. Unfortunately the phrase "Green _____" is widely used for many different things, but doesn't have a very precise meaning. Obviously "Green" is meant to have a meaning other than the color, but it appears that different people have different meanings for this phrase. As of this writing I hold the title Green Transportation Examiner with examiner.com and write news articles about the greening of transportation. The following is my personal outline of what I think Green Transportation is.

In my mind since 'green' is so poorly defined I like to substitute the word 'sustainable'. That word has a better definition even though its usage is also problematic. Basically sustainable means something that can survive for a very very long time. For example sustainable farming practices would produce a farm which can produce food for several generations preferably without applying external inputs like fertilizers.

Sustainable transportation isn't so clearly definable because obviously the machines we use today for transportation are built of metals that are mined, are in use for the lifetime of the vehicle, and after 10 or so years are probably too rusty to be reused in another vehicle. Further the fuels are mined, refined, toxins are released at every step of the process, used once (burned), and the smoke produced from burning the fuel pollutes the air with poisons. In other words transportation as currently practiced relies on resources with finite supply and which cause damage to the environment around us. Obviously this is nonsustainable.

Sustainable forms of transportation predates the modern era with things like horse drawn carts made of wood. That sort of model is very sustainable because it's easy to grow new horses and tree and hay to keep the system going. But I rather doubt the people in our modern society would willingly go back horses and buggies. Further use of horses carried its own consequences like diseases, smells, maintenance, animal cruelty, etc.

At the moment the best I hope for is transportation that's less bad than the current model. The current model has a number of bad negative effects, and what I'm interested in is anything which can decrease them. Some of the negative effects are:-

• Release of toxic chemicals at essentially every step of producing, using and disposing of transportation machines
• Greenhouse gas increases are massively impacted by transportation
• Limited supply of oil and potential for society wide chaos when oil production capacity begins to decrease
• The majority of remaining oil supplies are located in unfriendly countries, making for a geopolitical nightmare
• Biofuels (an alternative) require massive amounts of land & diverts agriculture resources from food to fuel production
• Modern agriculture relies on fertilizers made from petroleum.. making for a strange situation in a few years when oil production capacity declines and the idea of using biofuels to replace fossil oil means more agriculture which depends on petroleum which would be in short supply
• Oil extraction from tar sands, oil shales, etc, are a horror story and give a very low energy return on investment