SunCorp

Paper or plastic grocery bags - which are better for the environment?

You probably think you know the answer. And you're probably wrong.

Paper bags are not necessarily better for the environment than plastic - despite many consumers' long-standing assumption that paper beats out plastic hands down when it comes to eco-friendliness.

"There definitely was a period of time when the message was, 'Choose paper over plastic,' " said Jenny Powers, a spokeswoman for the Natural Resources Defense Council. "That's not the way to view it."

Powers and other environmental experts now say the best choice is neither paper nor plastic - it's reusable shopping bags made of substances like cotton, hemp, nylon or durable mesh-like plastic.

"The ideal option is bring your own bag," Powers said. "Second choice is to ask for the type of bag that you know will be reused - plastic if you'll use it for holding trash, or paper if you will recycle it."

The question of the relative merits of various kinds of grocery bags sounds simple.

But in fact, scientists spend large amounts of time trying to nail down the environmental impacts of creating, transporting and disposing of products such as grocery bags - a process known as life cycle analysis.

The final answer depends on numerous details, including:

-- Whether the bags are made from recycled or virgin materials.

-- How far the raw ingredients and finished bags must travel before reaching consumers.

-- How much energy and water are used in the manufacturing process.

-- Whether bags that are labeled "recyclable" or "compostable" actually end up being recycled and composted, or just get dumped in the trash.

The stakes are high. Ninety percent of today's grocery bags are plastic. Californians alone use 19 billion plastic bags each year - 600 bags every second - according to the California Integrated Waste Management Board.

And fewer than 5 percent of plastic bags historically have been recycled, compared with 21 percent of paper bags.

Plastic bags are a particular problem in coastal regions like the Bay Area, where they often end up in rivers and oceans - poisoning or strangling marine life. Sixty to 80 percent of ocean debris is plastic, according to the Algalita Marine Research Foundation. And while plastic may gradually shred into smaller pieces, those fragments will persist and threaten sea life for up to 1,000 years.

But paper bags have other negative effects on the environment.

"If you're comparing a paper bag made from virgin timber with a plastic bag made with natural gas, the paper bag causes more global warming pollution, more biodiversity impacts and more water impacts," said Allen Hershkowitz, a senior scientist with NRDC who has worked on life cycle analyses for two decades. "If the paper bag is not recycled, it will generate greater carbon emissions during incineration than plastic would, or greater methane emissions if it is landfilled."

One thing is clear in every study that has been done: Reusable bags beat both paper and plastic on virtually all environmental criteria.

For instance, a 2002 Australian study concluded that someone using plastic grocery bags for a year would go through 520 bags and generate 6.08 kilograms of greenhouse gases, which contribute to global warming. Someone using paper bags would also go through 520 bags to generate 11.8 kilograms of greenhouse gases.

But a year's worth of reusable polypropylene bags - estimated at four bags, used twice a week - would generate less than 2 kilograms of greenhouse gases.

"The best thing is for people to be encouraged to take reusable bags," said Hershkowitz. "That's a truism everyone can agree upon."

 

 

Hong Kong shoppers will be paying a levy on plastic bags by the year 2009 following the approval of a new bill aimed at helping the environment.

The bill, published yesterday, will impose a levy of HK$0.50 (US$0.06) on every plastic bag taken home from supermarkets, convenience stores and cosmetics shops.

The introduction of the levy follows years of debate on the issue and comes just one month after supermarket chain Park 'N' Shop abandoned a similar scheme charging HK$0.20 per bag following public uproar.

The scheme has also come under fire by plastic bag manufacturers, many of whom are based in Hong Kong but have factories in China, who argue that many of the alternatives to plastic bags are even less environmentally friendly.

According to government statistics, Hong Kong uses 23 million plastic bags -- more than three bags per person -- every day.

With the Product Eco-responsibility bill, the tax will be imposed in phases, with the first phase affecting supermarkets and larger chain stores expected to be in place by the beginning of 2009.

Secretary for the Environment Edward Yau said he expected the levy to bring in HK$100 million in its first year. However, he stressed the aim was to change public behavior and its success would be measured by less money being generated, not more.

The spectre of an earth devastated by climate change marked the Sanctuary Wildlife Awards on Friday night; the function also saw 11 individuals being honoured as Earth Heroes for their efforts in the field of conservation.

Several local heroes were also honoured for being anonymous warriors in the battle to save the environment. They included students who helped bust a ring selling tiger claws and other products; the Save Rani Baug Committee, which is seeking to stop the zoo from becoming a Rs 400-crore entertainment park; and a Sanjay Gandhi National Park forester who documented and helped shift encroachers and others.

Forest ranger Sasi Kumar has won many an accolade for tracking down the purveyors of animal products—a regular menace in the forests of Wayanad, Kerala. From chasing leopard killers to tusk smugglers, this winner of the Wildlife Service Award has displayed his sharp investigative skills on all fronts.

He co-heads a design company in Mumbai, and at 31, has traversed the length and breadth of India on self-organised survey tours and photography adventures. Sachin Rai’s photograph of a male Wards Trogon Harpactes, a rare bird found in the jungles of Arunachal Pradesh, has won him the first prize in the Sanctuary Wildlife photography awards this year.
He is a teacher by profession, but his lessons are not confined to the four walls of a classroom. Sukumar Paira of Bali, an island near the Sunderbans in West Bengal, won the Sanctuary Green Teacher Award. He has extended his work to renew the bond between children and tigers by opening 26 nature clubs.

Winner of a Lifetime Service Award, researcher and zoologist Dr Ulhas Karanth has been active in tiger conservation surveys and measures at the Nagarhole and Bhadra reserves. He has maintained a reliable record of the tiger population in India through the camera-capturerecapture method. Karanth is also director of the US-based Wildlife Conservation Society’s India programme.

The Sanctuary Wildlife Awards ceremony in Mumbai showcased prize-winning photographs shot in the jungles of India. With a humour-laced commentary interspersed with warnings on global warming, green warrior Bittu Sahgal unveiled images that vibrantly captured fauna in habitats that have to kept alive.