For the battle over which is greener, neither paper nor plastic have it in the bag. iStockPhoto/Sean McBride

When you do get to choose between paper and plastic, don't let green guilt necessarily pull you toward paper. Consider that both materials have drawbacks for the environment.

­Before you brown bag it, consider these environmental disadvantages of paper:



Causes pollution : Paper production emits air pollution, specifically 70 percent more pollution than the production of plastic bags [source: : Paper production emits air pollution, specifically 70 percent more pollution than the production of plastic bags [source: Thompson ]. According to certain studies, manufacturing paper emits 80 percent more greenhouse gases [source: Lilienfield ]. And, consider that making paper uses trees that, instead, could be absorbing carbon dioxide. The paper bag making process also results in 50 times more water pollutants than making plastic bags [source: Thompson ].

Consumes energy : Even though petroleum goes into making plastic, it turns out that making a paper bag consumes four times as much energy as making a plastic bag, meaning making paper consumes a good deal of fuel [source: : Even though petroleum goes into making plastic, it turns out that making a paper bag consumes four times as much energy as making a plastic bag, meaning making paper consumes a good deal of fuel [source: reusablebags.com ].

Consumes water : The production of paper bags uses three times the amount of water it takes to make plastic bags [source: : The production of paper bags uses three times the amount of water it takes to make plastic bags [source: Lilienfield ].

Inefficient recycling : The process of : The process of recycling paper can be inefficient -- often consuming more fuel than it would take to make a new bag [source: Milstein ]. In addition, it takes about 91 percent more energy to recycle a pound of paper than a pound of plastic [source: reusablebags.com ].

Produces waste : According to some measures, paper bags generate 80 percent more solid waste [source: : According to some measures, paper bags generate 80 percent more solid waste [source: Lilienfield ].

Biodegrading difficulties: Surprisingly, the : Surprisingly, the EPA has stated that in landfills , paper doesn't degrade all that much faster than plastics [source: Lilienfield ].

However, plastic didn't get a bad reputation for nothing. Here are some environmental disadvantages of plastic:

" " Many stores offer bins for properly recycling old plastic bags. David McNew/ ­Getty Images

Litter : Littered plastic bags are everywhere toda­y -- blown around streets, stuck in fences and trees. And, aside from their use in the occasional art film (à la American Beauty) they can be ­an eyesore and a pain.

­Danger to wildlife : Plastic waste is deceptive for birds and other wildlife, who mistake it for food. And you can imagine how eating plastic messes with an animal's intestine. As a result, animals can die of starvation [source: : Plastic waste is deceptive for birds and other wildlife, who mistake it for food. And you can imagine how eating plastic messes with an animal's intestine. As a result, animals can die of starvation [source: Spivey ]. To prevent this, perhaps paper is the better choice, especially if you live on the coast, as your plastic waste is more likely to make its way to marine life and sea birds [source: Thompson ].

Long-term degrading : Light breaks plastic down so it photodegrades rather than biodegrades. Estimates say that this process can take up to 500 or even 1000 years in landfills [source: : Light breaks plastic down so it photodegrades rather than biodegrades. Estimates say that this process can take up to 500 or even 1000 years in landfills [source: Lapidos ]. Unfortunately, we don't really know, as plastic is a relatively new invention.

Recycling difficulties: Although for the most part, plastic takes less energy to recycle than paper, plastic bags are a frustrating recycling dilemma. The curbside recycling in many communities is not meant for plastic bags because they can screw up the plant's machines [source: : Although for the most part, plastic takes less energy to recycle than paper, plastic bags are a frustrating recycling dilemma. The curbside recycling in many communities is not meant for plastic bags because they can screw up the plant's machines [source: Milstein ]. Instead, some stores offer bins in which to properly recycle plastic bags.

These factors have made the question of which is greener mind-boggling. The EPA has admitted that not only is the question unresolved, but it doesn't consider the use of plastic bags a major issue [source: Spivey]. Most environmental groups say that it's best to avoid the choice altogether -- instead we should diligently reuse bags.

Papa's Got a Brand New Bag New developments in biodegradable plastic bags are making them stronger, and cities like San Francisco are hoping they will replace traditional plastic bags. However, reports show that even these new-and-improved versions have their downsides -- they generate more greenhouse gas emissions than disposable plastic bags [source: Lilienfield].

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Sources

Heredia, Christopher. "Lawsuit delays Oakland's plastic bag ban." SFGate.com. Jan. 29, 2008. (Aug. 8, 2008) http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/01/29/BAIDUNPN4.DTL

Lapidos, Juliet. "Will My Plastic Bag Still Be Here in 2507?" Slate. June 27, 2007. (Aug. 8, 2008) http://www.slate.com/id/2169287/nav/navoa/

Lilienfield, Robert. "Review of Life Cycle Data Relating to Disposable Compostable, Biodegradable, and Reusable Grocery Bags." The ULS Report. June 1, 2007. (Aug. 8, 2008) http://www.deq.state.mi.us/documents/deq-ess-p2-recycling-PaperPlasticSummary_2.pdf

Milsein, Michael. "Which bag is best: Paper or plastic?" The Oregonian. May, 17, 2007. (Aug. 8, 2008) http://www.oregonlive.com/environment/index.ssf/2007/05/paper_or_plastic_which_is_best.html

Reusablebags.com. "Paper Bags Are Better Than Plastic, Right?" Reusablebags.com. (Aug. 8, 2008) http://www.reusablebags.com/facts.php?id=7

Spiv­ey, Angela. "Plastic bags -- prolific problems - Recycling." Environmental Health Perspectives, April 2003. (Aug. 8, 2008) http://findarticles.com/p/articles/mi_m0CYP/is_4_111/ai_102102851

Thompson, Anne. "Paper or plastic -- what's the greener choice?" NBC News. Updated May 7, 2007. (Aug. 8, 2008) http://www.msnbc.msn.com/id/18538484/

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