FIFO or GIGO?
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When the plastic ban was first imposed in 2007, the SF Chronicle was ecstatic over the city’s pioneering action.
Fifty years ago, plastic bags -- starting first with the sandwich bag -- were seen in the United States as a more sanitary and environmentally friendly alternative to the deforesting paper bag. Now an estimated 180 million plastic bags are distributed to shoppers each year in San Francisco. Made of filmy plastic, they are hard to recycle and easily blow into trees and waterways, where they are blamed for killing marine life. They also occupy much-needed landfill space.
Mirkarimi's legislation is one in a string of environmentally sensitive measures -- such as outlawing Styrofoam food containers and encouraging clean-fuel construction vehicles at city job sites -- adopted by the city in recent months.
"It's really exciting," Jared Blumenfeld, director of the city's Department of the Environment, said after the vote on Tuesday. "We're thrilled. It's been a long time in the making."
Blumenfeld said it takes 430,000 gallons of oil to manufacture 100 million bags. Compostable bags can be recycled in the city's green garbage bins and will make it more convenient for residents to recycle food scraps, he said.
So much bullshit, so few compost piles. Leaving sanitation aside for the moment, here’s a neutral look at paper vs plastic
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: 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: reusablebags.com].
Consumes water: 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 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: Lilienfield].
Biodegrading difficulties: Surprisingly, the EPA has stated that in landfills, paper doesn't degrade all that much faster than plastics [source: Lilienfield].
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: 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: 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: 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.
Ah, but what about those “reuse bags”?
Here’s a liberal’s comparison of plastic vs reusable.
I felt really good about myself, until I saw a report published earlier this year by Denmark’s Ministry of Environment and Food that said that plastic bags are better for the environment than organic cotton tote bags. In fact, of all the shopping bags the study looked at — from paper to recycled plastic — cotton tote bags fared the worst: they need to be reused thousands of times to have the same environmental footprint as a lightweight plastic bag, according to the report. A study published in 2011 by the UK Environment Agency reached similar conclusions. So, was my decision to ditch plastic bags bad for the environment?
The answer is not that easy. First of all, these studies — called “life cycle assessments” — have to be taken with a grain of salt. The research looks at different types of shopping bags through all of their life cycles: from the extraction of the raw material needed to make the bag to the way the bags are used and then discarded. It then determines how “environmentally friendly” each bag is based on several impact categories, such as climate change, toxicity, and water use.
“Here’s the rub: it’s basically impossible for one bag to score better than all other bags in each impact category, says David Tyler, a professor in the Department of Chemistry and Biochemistry at the University of Oregon. “So you have to decide, when you talk about the impact on the environment, what environmental impacts am I most interested in mitigating?” Tyler says.
I decided to give up plastic bags because I wanted to do something about the scourge of plastic pollution in our oceans. Scientists estimate that around 8 million metric tons of plastic trash enters the oceans every year. That plastic doesn’t degrade, and it poses a threat to wildlife, including corals. Sea turtles that eat plastic bags thinking they’re food can choke. Just last month, a dead whale in Spain was found to have more than 60 pounds of plastic waste in its stomach, including bags. Several cities in the US, like Austin, Los Angeles, and Seattle, banned single-use plastic bags to address the litter problem. Last month, New York governor Andrew Cuomo proposed a bill to nix plastic bags in New York state for that same reason.
Still, in all these life cycles assessment studies, plastic bags do seem to be “more green” than cotton tote bags. That’s because cotton requires lots of land, water, and fertilizers to grow; then, it needs to be harvested, processed, and brought to market. “Cotton is a very thirsty crop,” Tyler says. One study done by the Australian government in 2007 found that plastic bags also have a lower carbon footprint than paper bags. Making paper from trees sends a lot of waste to the landfill, Tyler says. In comparison, “petroleum is generally considered so valuable that there’s very little waste,” he says. Plus, transporting 1,000 paper bags across the country with a truck consumes much more fuel than transporting 1,000 thin plastic bags, Wagner says. “A lot of the carbon production is the function of the weight of the bag,” he says. “That’s why it’s tricky when you start comparing them.”
At the end of the day, it’s all a matter of what you care about the most. If marine litter is your biggest concern, paper bags are better because paper degrades and doesn’t stick around for years. In New York City, the Department of Sanitation spends more than $12 million a year to dispose more than 10 billion single-use plastic bags, so that’s why the city has tried (unsuccessfully) to impose a 5-cent fee on them. In Africa, the concern is that discarded plastic bags also pool water that can breed disease-causing mosquitoes.
So, what should you do if you want to limit your environmental footprint? Many of the experts I talked to say that using reusable plastic bags — whether made of recycled plastic, nylon, or woven polypropylene — is best. “You can use them hundreds of times. The ones I’m using, they’re showing some wear and tear, but I’ve had them for a couple years, and they’re in good shape,” Tyler says. “When you can use a bag so many times, eventually you reach a break-even point.” These bags are durable and can easily be cleaned if, for example, meat juices spill out.
Turns out, there is no break-even point, because to be properly cleaned, reusable bags must be run through a washing machine, and they wear out in 6-8 cycles, not the “hundreds” needed to equal single-use bags. Conclusion: you want to (pretend to) save the whales, go cotton. If the safety of your family takes priority then I have one word for you, just one word: plastics.
UPDATE: From October 15, 2015, Reason, “Plastic Bags Are Good For You
Debunks each and every favorable claim made for reusables, including the purported litter, whale killing, energy-consuming, and landfill-filling arguments, using EPA’s own figures, Greenpeace “plastic bags aren’t killing whales, fishing nets are the problem”, and so on.
