Implementing Domestic Tradeable Permits : Recent Developments and Future Challenges Tradeable or transferable permits (TPs) are increasingly perceived as a cost effective and flexible policy instrument for pollution control and natural resources management. Initially they were considered a policy tool whose applications were limited to only certain sectors such as air pollution management and fisheries. However over the last few years there have been significant developments in the use of domestic TPs across a broader range of environmental issues. TPs now face a double challenge: could they become a key instrument for curbing greenhouse gas emissions in light of the Kyot