International audienceThe creation of carbon markets is one of the solutions currently envisaged to meet the widely recognized challenge of global warming. The contributions in this special section of Accounting, Organizations and Society show that many controversies nevertheless exist on the ways in which these markets are organized, the calculative tools that are devised to equip them, and the role that they are supposed to play, especially in relation to other types of intervention which favour political measures or technological research. In light of these controversies, the article considers carbon markets as on-going collective experiments. It is argued that carbon trading is an exceptional site for identifying the stakes involved in ...