5 Elements of Sustainable Transportation

Transport is responsible for around a seventh of greenhouse gas emissions globally. Of these emissions almost two thirds are the result of passenger travel while the rest is due to freight.

So passenger travel is a big deal for climate.

In the chart above, which comes from our new eBook Emit This, we compare carbon intensity of different types of passenger transport on a per passenger kilometer basis. Using it we can explain some elements important to the development of a sustainable transport system.
1) Fuel Economy

Our chart today compares the carbon intensity of different transport modes, per passenger kilometer. The better fuel economy gets the lower emissions go. If you just look at the cars you’ll see the large car (15 MPG) has emissions almost three times that of the hybrid car (45 MPG).

By improving fuel economy we can get the same mileage while generating fewer emissions. Something that is achieved by making engines more efficient, vehicles lighter and bodies more aerodynamic. But even then combustion engines remain relatively inefficient and produce emissions at the tailpipe, so improving them is really just a stop-gap en-route to sustainable transport.
2) Occupancy

The cheapest and simplest way to lower the carbon intensity of a passenger kilometer is to stick more people in the vehicle. In each of the figures above car occupancy is assumed to be an average of 1.6 passengers (including the driver). But most cars are designed for 5 people.
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