Cutting transport greenhouse emissions

A recent report gave a list of initiatives aimed at reducing greenhouse emissions in the transport sector, said to be the third largest sector for emissions, and growing.

The report, written by transport expert Professor John Stanley (Sydney University), was presented to a local government conference in Melbourne on August 20. It identifies greater fuel efficiency in vehicles as the biggest source of reduction. This was followed by an increase in use of rail for freight - a reversal of the trend of recent decades.

Professor Stanley's full list of headline initiatives is:

1) Increasing vehicles' fuel efficiency by replacing older cars and introducing mandatory standards for car manufacturers.

2) Shifting freight from road to rail and encouraging the use of larger trucks to improve efficiency of freight movements;

3) Increasing car occupancy rates from an average of 1.4 to 1.6 people per vehicle (effectively, carpooling)

4) Doubling the proportion of trips taken by public transport, from about 7.5 per cent to 15 per cent nationally;

5) Increase the share of urban trips taken by walking or cycling from 16 per cent to 26 per cent;

6) Reducing demand for travel through better urban design to ensure people live closer to work, schools, shops etc.

Unfortunately, the Herald article (here) didn't give much more specifics than the above. One can only assume the particular figures plugged in (and the ensuing outcomes) were the results of a set of economic models put together by the Professor. Yet despite his expertise, those models must rely on input assumptions that are not beyond dispute, so the margins of error would have to be fairly healthy. So it's rather brave for the Herald to state in a rather incontrovertible tone, as it did, that car pooling would provide better outcomes than doubling public transport patronage. How do we know for example, that increasing car occupancy from 1.4 to 1.6 people per vehicle is the best, the most achieveable, or the most likely increment? And decoupling the items in the first point might be wise. The very process of replacing older model cars, as well as being very expensive would result in a substantial amount of gases released through the manufacturing process.

Still, governments need starting points for planning. The general points above, with the specifics stripped, would sound rather like motherhood statements, but it can't hurt to present the set of options and leave it to governments to choose how to tweak the factors of each initiative. It's plausible, too, that the relative viabilities of each option would vary on a regional basis.