A widely touted effort to clean up the embattled carbon-offset market has been met with disappointment among experts.

The new guidelines from the Integrity Council for the Voluntary Carbon Market, released Thursday following three years of work, present incremental improvements to a system that allows corporations and individuals to pay for credits that compensate for their climate damage.

"Twenty years ago this kind of effort might have been a good idea,” said Danny Cullenward, a research fellow at American University. "Now it feels like far too little, too late.”