In recent years the interaction between international trade and environmental protection has generated much debate, but little consensus. The international community is in theory committed both to trade liberalization, through the Uruguay Round extension of the General Agreement on Tariffs and Trade (GATT) and the creation of the World Trade Organization (WTO), and to environmentally sustainable development, through the agreements signed at the UN Conference on Environment and Development, the 'Earth Summit' of 1992. Given modern systems of economic activity, however, trade can also harm the environment. Trade and environmental policies are therefore inextricably interlinked. Conflict between trade liberalization and environmental protection has already erupted in a number of instances as regulations drawn up in pursuit of the objective of environmental sustainability have been challenged as erecting barriers to trade. Over the next few years, the depletion of the Earth's stratospheric ozone layer as a result of emissions of industrial chemicals will reach its peak.