An increasing number of people and companies want to offset the climate damaging greenhouse gases they emit. One example is offsetting of flight emissions, which travel agencies and airlines offer their customers directly during the booking process. However, no common procedures and no common binding standard for voluntary offsets exist by now. This can lead to fluctuating quality within a market that is confusingly complex for consumers. Against this backdrop, adelphi and sustainable conducted a study, commissioned by the Federal Environment Agency (UBA), which analyses the current state of the voluntary carbon market in Germany. To this aim, the supply and demand sides were surveyed about the patterns and preferences of market participants, and volumes, prices and characteristics of certificates traded. For a brief English summary, see pages 22-30.