Jan. 28, 2008 -- California and nine other U.S. states have sent a letter to the Federal Trade Commission (FTC) requesting that the regulatory agency tighten its restrictions on carbon offset providers, claiming current guidelines leave too much room to "manipulate the system," Environment News Service reports.

"Currently, the market for these offsets is volatile, largely unregulated, and has serious potential for fraud," writes California Attorney General Edmund G. Brown, Jr. "The Federal Trade Commission must set clear guidelines for the sale of carbon offset credits," according to Brown, so that "consumers [can] feel confident that they actually get what they pay for -- real carbon reduction offsets."

Key concerns cited in the letter include the potential for double-selling carbon credits and for claiming credits for climate change mitigation activities that would have happened on their own. The states call for FTC to pursue "aggressive education and outreach" programs to ensure consumers recognize the potential for carbon-offset fraud.

The states also request that FTC offer a clearer definition of carbon offsets. For example, renewable energy certificates are often counted as carbon offsets despite the fact that the renewable energy generated may not have displaced energy generated from traditional sources.

In addition to California, the states signing the letter are Vermont, Arkansas, Delaware, Maine, Mississippi, Oklahoma, Illinois, Connecticut, and New Hampshire.

The FTC is currently revising its guidelines for the marketing carbon offsets.