Estimating the opportunity costs of reducing carbon dioxide emissions via avoided deforestation, using integrated assessment modelling

•Integrated assessment modelling was used to study the opportunity costs of REDD.•The effects of protecting carbon rich lands were studied in various scenarios.•Land was endogenised by introducing a flexible land supply curve.•Results show different cost for different regions ranging from 0 to 60 USD.•A marginal opportunity cost curve for the world was constructed.