As a case in point, Michael Wara, who authored the Nature article, reveals that the largest volume of credits, almost 30 percent of the market, come from capturing and destroying HFC-23, one of six greenhouse gases listed under the Kyoto Protocol. The problem, according to Wara, is that HFC-23 is cheaper and easier to trap than carbon dioxide or methane, and polluters use that advantage to earn a disproportionate amount of money in CDM credits. For example, Wara writes, polluters have sold €4.7 billion in credits for collecting HFC-23, but if the buyers of those credits had invested directly in trapping HFC-23 in the developing world, they could have accomplished the same reductions with only €100 million. Therefore, Wara argued, the Kyoto agreement needs different protocols to regulate each greenhouse gas individually—carbon credits for carbon capture, methane credits for methane capture, and so on. He concludes that the global market is not enough to stem the impact of global warming. The open market, Wara wrote, will not push countries like the China and India to make serious investments in low-emissions economies; rather, more stringent regulation will be needed.

A few weeks later, Newsweek’s Emily Flynn picked up the CDM thread, highlighting a company in India called Gujarat Fluorochemical that made €27 million in three months during 2006, “thanks to carbon credits. That boost in profits will no doubt help fund its new plant for making Teflon and caustic soda, both pollutants.” Without really elaborating, or substantiating her allegations, which would have been appreciated, Flynn goes on to tackle the ETS market. Briefly, she reminds readers of the May 2006 discovery of a surplus of carbon credits in the European system, which triggered a market collapse. In November, the European Environment Agency announced that only the UK and Sweden were on track to meet their Kyoto targets.

But the compliance markets are not the only dysfunctional emissions-trading schemes around. The press has also sunk its teeth into the burgeoning demand for voluntary offsets in the U.S.

The knee-jerk criticism of “checkbook environmentalism,” as many pundits are calling the voluntary market, is that offsets do not force people to change their behavior. In February, former Vice President Al Gore caught flak when the Associated Press revealed that the star of “An Inconvenient Truth” uses ten times more electricity than the local average to power his home in Nashville. Yet, thanks to offsets, Gore claims to be “carbon neutral,” a catchphrase that was Oxford University Press’s 2006 Word of the Year. But the real problem, business reporters are finding, lies not with those who buy carbon offsets, but with those who sell them.

In the last few years, dozens of new operations have responded to the guilty cries from individuals, households, and small businesses. Some of the offsets they sell are as easy to purchase as soap. “Attention Shoppers: Carbon Offsets in Aisle 6,” read a headline in a March special section of the New York Times titled “The Business of Green.” Whole Foods, Dell, Travelocity, Hertz, Ikea, and many others now offer customers the opportunity to spend a few extra dollars to reduce the environmental impact of their shopping. The money is generally funneled to offset providers who plant trees, build wind turbines, trap industrial emissions, or engage in any number of activities designed to cancel out the deleterious effects of greenhouse gases. Outside of normal shopping hours, offsets can be purchased directly from a slew of new online providers that can, ostensibly, nix a ton of carbon for $5 to $25. There are even brokers for those who want to buy a lot of offsets at once.

But a number of articles have identified a high incidence of low-quality offsets on the market, which result from a variety of practices that range from negligent to duplicitous.

Curtis Brainard is the editor of The Observatory, CJR's online critique of science and environment reporting. Follow him on Twitter @cbrainard.