This chapter examines the part played by considerations of justice and fairness in the European acid rain talks that commenced in the mid-1970s and that culminated in the 1994 Oslo Protocol. A fundamental basis and engine of negotiations over acid rain and other environmental issues are the principle of 'no harm'. 'Acid rain' has come to refer to transboundary air pollution generally. Several kinds of air pollutants can travel over long distances in the atmosphere, before they are deposited on the earth's surface. The chief ones are sulphur dioxide (S0₂), nitrogen oxides (NO_x), volatile organic compounds (VOCs) and ammonia (NH₃). The chapter focuses on the Helsinki Protocol and the Oslo Protocol. Soon after the signing of the Convention on Long Range Transboundary Air Pollution (LRTAP) Convention, the Scandinavian countries continued their efforts to secure actual cuts in SO₂ emissions. The 1985 the Helsinki Protocol and its shortcomings triggered in due course renewed talks on the reduction of SO₂ emissions.