Plastic bags are cheap, hygenic and functional products that are often reused. Provided they do not end up as litter, they have very little effect on the environment. Carbon that was stored in gas deposits ends up being stored in landfill sites.
Issue 1: Energy and natural resources
It takes more than four times as much energy to manufacture a paper bag as it does to manufacture a plastic bag.
ENERGY TO PRODUCE BAG ORIGINALLY (BTUs)
Safeway Plastic Bags: 594 BTUs
Safeway Paper Bags: 2511 BTUs
(Source: 1989 Plastic Recycling Directory, Society of Plastics Industry.)
Issue 2: Pollution
The majority of kraft paper is made by heating wood chips under pressure at high temperatures in a chemical solution. The use of these toxic chemicals contributes to both air pollution, such as acid rain, and water pollution. Millions of gallons of these chemicals pour into our waterways each year; the toxicity of the chemicals is long-term and settles into the sediments, working its way through the food chain. Further toxicity is generated as both plastic and paper bags degrade.
POLLUTANTS PAPER V.S. PLASTIC
Paper sacks generate 70% more air and 50 times more water pollutants than plastic bags.
Source: "Comparison of the Effects on the Environment of Polyethylene and Paper Carrier Bags," Federal Office of the Environment, August 1988
Issue 3: Recycling
It takes 91% less energy to recycle a pound of plastic than it takes to recycle a pound of paper. In Australia most plastic shopping bag are reused as bin linners.
ENERGY TO RECYCLE PACKAGE ONCE (BTUs)
Safeway Plastic Bags: 17 BTUs
Safeway Paper Bags: 1444 BTUs
Source: 1989 Plastic Recycling Directory, Society of Plastics Industry.
Although paper bags have a higher recycling rate than plastic, each new paper grocery bag you use is made from mostly virgin pulp for better strength and elasticity.
Issue 4: Degradability
Current research demonstrates that paper in today's landfills does not degrade or break down at a substantially faster rate than plastic does. In fact, nothing completely degrades in modern landfills because of the lack of water, light, oxygen and other important elements that are necessary for the degradation process to be completed. A paper bags takes up more space than a plastic bag in a landfill, but because paper is recycled at a higher rate, saving space in landfills is less of an issue
Much of the above information was sourced from www.reusablebags.com.