Public Smog is a conceptual work by artist Amy Balkin, which seeks to challenge the wisdom of carbon trading (and the trading of other pollutants such as sulphur dioxide). By purchasing these credits and presenting them as a public park in the air, Balkin confronts the economic notion of clean air as a public commons and the use of property rights to solve problems of air pollution. The work points to the difficulties inherent in communicating and addressing the issue of emissions reduction, and serves as a stimulating departure point for inter-disciplinary debate.