Analysts Question Carbon-Credit Benefits

Carbon credits have ballooned to a $22 billion market. But does the ecological investment really make sense? Fiona Harvey, environmental correspondent for the Financial Times, and John Coequyt, energy policy analyst for Greenpeace, warned "Street Signs" viewers that some of the credits "are much more valuable than others."

Carbon credits -- the trading of excess greenhouse gas emissions -- are bought and sold on the Chicago Climate Exchange and on London and European exchanges. But Ben Lieberman of the Heritage Foundation told CNBC's Erin Burnett that the trade is creating an "artificial market, and an artificial scarcity" that will drive up energy prices -- without limiting fossil-fuel use.

As to the environmental benefits, Coequyt is doubtful. He said the system "could" work if the credits are bought from "the right companies" -- but will be a failure if they only allow the bigger polluters to "buy indulgences."

Harvey agreed, saying the credits may constitute a "get out of jail free card" for carbon-emissions creators -- and said some of the credits "are much more valuable than others." But the Financial Times reporter said investors may find "very reputable companies" -- with both environmental and financial value -- by doing a little research.