There has been ongoing discussion about cutting the use of plastic bags in Singapore through various measures, in particular, charging for these bags.
While I agree with the overall need to reduce waste, we need to take a holistic approach towards sustainability.
The amount of waste is but one facet of the sustainability effort.
Also not to be neglected are carbon emissions and energy use, water use, health and safety issues of plastic bag use, where and how these bags are treated at the end of their life cycles, and the production, use and disposal of these plastic bags.
Many countries have engaged in life-cycle assessments of plastic bags and their alternatives.
Such assessments are important in the context of Singapore, and our results will likely differ from those in Britain and Australia, given our population density, imported energy, desalinated water, transport costs and demographics, among other factors.
Among various issues, it is important to understand if Singaporeans habitually reuse plastic bags as trash bags, or will purchase new plastic bags for their trash; whether eco-friendly reusable bags will be used more than the eight or more times needed to offset the environmental impact of plastic bags; whether there are health and safety repercussions of carrying fresh produce in these reused bags; and whether savings from plastic bags will be passed on to consumers (if so, then the idea of charging makes less sense).
A few years ago, people were advocating the use of paper bags, which they thought were more eco-friendly than plastic bags.
But life-cycle assessments found that a lot of resources were needed to grow trees, and for tree logging, paper making and transport.
They also found that paper bags were heavier than plastic bags, hence, generating more waste.
Today, it is generally accepted that "eco-unfriendly" plastic is better than paper from a holistic sustainability perspective.
Without fully understanding the status quo, the alternatives, and the impact of adopting those alternatives, one should not immediately adopt the more intuitively convenient assumption that waste can be reduced through charging for the use of plastic bags.