The impact of Antarctica on the global environment is extremely farreaching, whether in terms of energy exchange through the atmosphere and oceans, its role in the hydrologic cycle, or its influence on the biota of the Southern Ocean. In terms of its ecology, the continent is quite unique. Perhaps the most crucial aspect of the environment of this all‐important continent is the delicate equilibrium existing between the flora, fauna, and the physical environment, an equilibrium which is extremely vulnerable to uncontrolled exploitation. Starting with the signing of the Antarctic Treaty in December 1959, the authors trace the sequence of measures taken by the international community to safeguard the delicately balanced antarctic environment. They conclude that the signing of the Protocol on the Protection of the Environment in Madrid in 1991, which established a 50‐year moratorium on mineral exploration or development, has made Antarctica the largest nature reserve in the world.