One synonym for "tradable smoking pollution permits" is "emissions trading permits." These permits allow companies to purchase and sell permits that allow them to emit a certain amount of pollution. Another possible synonym is "carbon credits." This term refers to a similar system in which companies can purchase credits that allow them to emit a certain amount of carbon. Both emissions trading permits and carbon credits are designed to reduce pollution by creating a market-based incentive for companies to reduce their emissions. However, critics argue that these systems are often complex, prone to fraud, and ultimately ineffective at reducing pollution.