Wal-Mart Watch, a group of Wal-Mart Stores critics, this week blasted the retail giant for lobbying against stricter carbon-offset marketing guidelines.

“Despite the company’s “green” initiatives, Wal-Mart is actively lobbying against the clarification of offset guidelines,” Tony Calero, an online communications assistant for the anti-Wal-Mart group, wrote in a blog post that called the opposition a “scandal.”

Wal-Mart has attracted plenty of attention for its environmental initiatives, including more energy-efficient lighting – the chain surpassed a goal to sell 100 million compact fluorescent light bulbs in 2007 – less packaging and a goal of removing nonrenewable energy from all its products, although an Environmental Leader report released in May found that most consumers didn’t identify the company as socially responsible, in spite of its significant green marketing.

The U.S. Federal Trade Commission has been working to update its environmental-marketing guidelines, also known as the Green Guides, since November (see Cleaning Up Greenwashing).

The guidelines haven’t been changed since 1998, and were scheduled for a review next year. But the FTC decided to move up the review in response to an increase in green marketing claims, and has held three workshops on different aspects of the guides.

Angela Beehler, senior director of energy regulation and legislation for Wal-Mart Stores, on Jan. 25 submitted written comments in response to the first workshop, on carbon offsets and renewable-energy credits, held Jan. 8.

She wrote that characteristics of carbon offsets and renewable-energy credits, “such as their less tangible nature and their flexibility,” provide opportunities for consumer participation and added that the markets and programs related to these offsets and credits have varying and sometimes conflicting requirements, all of which could change if new federal legislation is passed.

“Although some may urge otherwise, the commission should resist the temptation to define what constitutes an eligible offset or REC,” Beehler wrote. “Doing so would require the commission to resolve highly technical environmental debates that are beyond its expertise.”

Instead, she urged the commission to identify what the claims about offsets and credits are likely to mean to consumers and to establish how much evidence companies will need to show they have a “reasonable basis” to substantiate their claims.

“The fact that standards may differ from one seller to another simply reflects the fact that there is no consensus about what does, or should, constitute a carbon offset,” Beehler wrote. “Different authoritative and expert institutions have adopted different, but reasonable, approaches.

"Although the commission should insist that all carbon-offset claims are supported by a reasonable basis, FTC precedent provides no reason to choose one reasonable approach over another.”

In his blog post, Calero wrote that the comments are a sign that Wal-Mart is uninterested in enabling the transparency needed to ensure its environmental claims are legitimate.

“Wal-Mart’s attempt to keep offsets guidelines vague shows the company is more interested in marketing potential than actual environmental change,” he wrote. “Unspecific standards would allow the retailer to ‘commit’ to carbon neutrality, without providing much real documentation.”

Wal-Mart officials were unable to comment Thursday.

The idea behind carbon credits is to help customers eliminate their net carbon-dioxide emissions by “offsetting” their emissions with projects that reduce carbon by the same amount.

Renewable-energy credits are based on a similar concept. Companies sell carbon credits – stand-ins for the actual renewable energy – to make renewable-energy projects more economically viable, while others can buy credits instead of building their own projects.

But critics have compared carbon offsets to the Roman Catholic Church's sale of indulgences for worshippers' sins, saying they might not actually reduce overall carbon emissions or increase renewable energy (see New York Times stories here and here).

Because the offset and credit markets are voluntary in the United States, one problem has been a lack of standards that clearly define offsets and ensure they really are reducing emissions.

The FTC review of green marketing is one of the first attempts at a national definition.

A number of offset and REC providers, including the Carbon Offset Providers Coalition, Terrapass, NativeEnergy, Climate Clean and Juice Energy, weighed in on the guidelines (read the comments here).

Wal-Mart isn’t the only entity to urge the FTC toward a broad definition.

The Edison Electric Institute also warned the commission “to avoid being inappropriately prescriptive or narrow” and recommended that it “give marketers and advertisers wide latitude to substantiate the determination that a source of electricity is renewable.”

Meanwhile, other groups urged the commission to step in and help the industry come up with a clearer definition and standard.

The Pacific Gas & Electric Co. wrote that the commission is “uniquely positioned” to establish needed, consistent parameters for voluntary offset and credit programs through its Green Guides. Establishing guidelines and standards will help foster the legitimacy of the programs, according to the utility.

The Consumers Union, which publishes Consumer Reports, asked the FTC to come up with specific definitions and boundaries for carbon-offset and renewable-energy marketing claims and require disclosure about the type and quantity of offsets, the criteria considered when calculating the offsets and the relative impact in carbon reduction.

The potential for consumer confusion is great because companies’ parameters vary widely today, wrote Urvashi Rangan, a senior scientist and policy analyst at the Consumers Union.

Claims are already being made on products that are confusing, misleading and potentially deceptive,” he wrote. “Companies that are investing in alternative energies while generating carbon from their own production line are making marketing and product claims of carbon neutrality or negativity, such as Fiji bottled water being marketed as ‘carbon negative.’”