Paper or Plastic?

That familiar refrain for choosing a grocery bag at the supermarket may be changing. As part of an effort to go green, more than 200 communities in 20 states have passed plastic bag regulations.

"These laws make a huge difference," environmental attorney Jennie Romer told CNBC's "On The Money" in a recent interview.

The regulations range from complete bans in cities like Seattle and Austin, to bag-use fees. They range from 5 cents in Washington D.C., all the way up to 20 cents per bag in Aspen, Colorado.

Romer worked on the San Francisco law, which was the first in the nation, that initially began as a ban on plastic bags. She also served as a pro bono counsel to the New York City Council, which last month passed its own law requiring supermarkets to charge 5 cents a bag, beginning October 1st.

"I helped rewrite that to make it be a ban on thin plastic bags, and a charge for paper bags and the thicker plastic bags that qualify as reusable," she said.

"That's where we really saw a huge change in consumer behavior," said Romer, who is founder and director of plasticbaglaws.org.

Since that bag law was passed in San Francisco in 2007, the city reported a 75 percent decrease in bag usage.

"Plastic bags are a particularly problematic form of waste, and cities are the ones that pay to clean up bag litter," Romer explained. "Plastic bags clog recycling machinery and make it harder to recycle the things that are actually really useful to recycle like bottles and cans."

She added the best alternative for consumers is to "bring a reusable bag in and use that bag over and over again."

Todd Myers, author of "Eco-Fads: How the Rise of Trendy Environmentalism Is Harming the Environment," described the bag laws as "sound-bite, feel-good solutions."

However, "when you look at the science and the environment, they end up doing more damage," he told CNBC. Myers acknowledged the environmental impact of plastic bags. "I'm not saying there's zero impact, [but] a plastic bag ban simply moves people to something else."

Myers, who is also environmental director of the Washington Policy Center in Seattle, added that "what people switch to" is more harmful "for water quality and energy."

He says the manufacture of "a plastic bag uses a lot less energy, about one-fifth the energy of paper bags." A substitute, such as a reusable cotton bag that has become popular with shoppers, "uses 200 times the energy" of the plastic film bags, Myers said.

In addition, Myers pointed out potential health hazards with reusable bags. In 1992, a small outbreak of E. coli and bacteria was linked to contaminated reusable bags.

"The reason," he says," is with reusable bags you have to wash them. That's another environmental impact. You use more detergent, you use more water. Those are trade-offs we have to think of."

Plasticbaglaws' Romer, who is, says the intention of these rules is reducing plastic bag use by changing people's behavior.

"The goal isn't to have people switch to a different type of bag," she said. "It's to have people think about it when they're at the register."

She said the bag fees, even a little as 5 cents work because, "people just hate the idea of having to pay something for a plastic bag."

On the Money airs on CNBC Saturday at 5:30 am ET, or check listings for air times in local markets.