Will Banning Plastic Bags Help the Environment?

I am all for this ban. Its ridiculously easy to bring reusable bags to the grocery store or have a few in the trunk. A lot of the trash I see around is plastic bags.

Since every other person in San Francisco has a doggie and grocery bags are a convenient, economical way to dispose of dog "refuse", I suspect we've gotten considerably poopier run-off since the ban came into play in SF -- although, gratefully, most the runoff here goes through the sewage treatment plant. Also, shouldn't they just penalize people for improperly disposing of the bags like any other litter? I do definitely agree that there are far to many of these things blowing about.

"Help the environment" is a broad term. I'm actually getting my MBA in Sustainable Business at SF State and studied sustainability at UCSD. If you're talking about the North Pacific Gyre aka Great Pacific Garbage Patch, then banning plastic bags most likely "helps the environment" by reducing the amount of plastic that ends up in the ocean. If the plastic didn't end up the ocean, it would end up in the landfill. Now, this issue is pretty hard to study scientifically, but a lot of smart people have analyzed this popular issue and the consensus is that it does help reduce plastic from littering the environment and also reduces that amount of petroleum that is used to make the plastic.

On the flip side to that is that bags then either have to be reusable or made out of paper, which of course has its own set of environmental issues (deforestation, more energy intensive processes, etc). The only scientific method to really know what is more "environmentally friendly", is called Life Cycle Analysis or LCA , which has very specific parameters. It's very expensive and takes a long time to do and the results do not apply to everything. In fact, it usually only applies to the question being asked. In this case, the question is: what is better for the City of San Jose - paper, cloth, or plastic bags? The city of San Jose would then quantify all the inputs and outputs of each bag and try to determine the net result.

Anyways, I could go on forever about this stuff, but the bottom line is that plastic is gnarly shit and try to limit the amount of plastic you use in your life.

PS: Fun fact: Take any bottle of water. Fill it up 1/3 of oil and that's how much oil is used to make the bottle. Every single bottle. Around the world.