Light vehicle emissions  

In Australia, the transport sector take around 16% of the Green house gas emission. The light vehicles, it contains about over half of the transport emission- which mean contains around 10 % of the GHG emission of Australia, there are really large scale in this sector. 

For the data from the Australian government, the light vehicles will still keep in high level of the GHG emission,the second large group will become the trucks.

For reduce the emission of GHG, the main method is to develop the mass public transport and encourage the citizen to use the public transport. By develop the better mass public transport system can reduce the number of the light vehicles. Moreover, the new technique can be reduce the GHG emission, for example the electric car or hybrid car. Those type of the cars have better function of car and release less GHG. The government can also provide the  subsidy on this type of cars so can encourage the buyer to use this type energy saving car. 

Refereence:

http://www.climatechangeauthority.gov.au/reviews/light-vehicle-emissions-standards-australia/opportunities-reduce-light-vehicle-emissions