By signing a memorandum of understanding (MOU) the two parties hope to give more transparency to markets and improve investor confidence by providing in-depth analysis of each project and trade.

"Demand for independent evaluation of the risk of carbon offset projects is growing rapidly around the world," says Vickie Tillman, senior vice-president of sustainability business development at McGraw-Hill, S&P's parent company.

The move is likely to be welcomed by participants of the carbon market