National governments are ill-equipped for tackling transnational environmental problems, from ozone depletion to soaring trade in commodities like timber and shrimp. As these issues climb higher on the political agenda, industrial and developing countries are on a collision course over climate change and water shortages. Goods, money, microbes, pollution, people and ideas are crossing global boundaries evermore frequently. The implications for our future and for the health of the planet are profound. This text describes what we need to do to cope with the challenge.