Through a lifecycle energy analysis, plastic is the better bag.
At current recycling rates two plastic bags use less energy and produce less solid, atmospheric, and waterborne waste than a single paper bag. Moreover future improvements only increase preference in plastic bags. Increasing recycling rates and reducing the 2-to-1 ratio through proper bagging techniques would further the energy preference for plastic bags.
ENERGY TO PRODUCE BAG (BTUs)
Safeway Plastic Bags: 594 BTUs
Safeway Paper Bags: 2511 BTUs
(Source: 1989 Plastic Recycling Directory, Society of Plastics Industry.)
Paper bags generate 70% more air pollution 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
The making of paper can waste thousands of gallons of water, as can the recycling of paper. The human and mechanical efforts and costs are very high, not forgetting the physical cost to loggers and those who work around the numerous chemicals. Also, it is proven that manufacturing paper produces a significantly higher amount of pollution than plastic. Plastic is, by comparison, efficient and low energy to produce, and, easily and efficiently recycled. Plastic reduces, recycles marvelously, and in that, is reused.
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.
Sources:
http://www.epa.gov/ne/communities/shopbags.html
http://www.greenfeet.net/newsletter/debate.shtml
http://www.ilea.org/lcas/franklin1990.html
