Even biodegradable single-use bags score poorly in Green Cities' eco-assessment.
Tuesday, March 16, 2010
Bring your own bag.
That's the take-home message from a master environmental assessment of shopping bags released by Green Cities California, a coalition of 10 municipalities aiming to hurry up green policies.
Single-use bags all have environmental problems. The MEA finds paper and biodegradable bags are not much better than petroleum-based plastic.
- Single-use conventional plastic bags are most responsible for litter. Some 20 billion are used annually in California.
- But single-use biodegradable bags are more resource-intensive to make than plastic, constributing to more greenhouse gas emissions and water consumption. Although they degrade in composting facilities, they don't break down easily in the environment, and "have a similar impact on aesthetics and marine life" as plastic bags.
- Single-use paper bags are the most recycled, but their production causes significantly more greenhouse gas emissions, atmospheric acidification, water consumption and ozone production than plastic.
- Only reusable bags score well in the assessment, with significantly lower environmental impacts than any of the single-use alternatives, assuming they're used at least a few times.
Environmental groups. including Monterey's Sea Studios, have long targeted disposable plastic bags for littering land and sea. But a 2008 state law to ban plastic bags died in the Legislature. In fact, a state law prohibits fees on plastic bags.
The American Chemistry Council has sued numerous cities that have attempted plastic bag bans, arguing they need an environmental impact report first. Green Cities' assessment is intended to reduce the cost and time of cities' EIR preparations.
Locally, only the Old Monterey Farmers Market has banned plastic bags.