For the next 25 years all of Sydney’s non-recycled waste is headed for Woodlawn tip near Goulburn. It is an excellent site for land fill, especially as it is very well sealed and highly unlikely to leach any contaminants into the ground water system.
Land fills are smelly, unattractive places but Sydney is always going to need a land fill site. Every 20 to 25 years Sydney is going to have to change sites. If we dramatically reduce use of plastic bags (and perhaps other things!) we might be able to keep the Woodland tip running for another year or two before changing sites. This would make some people happy and others unhappy but there are no real environmental issues associated with this change of site.
In order to reduce our environmental footprint we should reduce our consumption and choose products that are less resource intensive to produce - informed environmentalists choose plastic over paper. The last paper mill proposed for Tasmania was rejected because even the best paper mill produces unacceptable amounts of polution.