When Greenpeace proposed for the first time that nuclear and chemical industries should stop taking ships out to sea to dump or burn their waste, these industries claimed that these environmental requirements were impossible to meet. Twenty years later, what Greenpeace proposed then has become international policy. The emergence of NGOs in international affairs is one of the novelties of the last couple of decades. But while intergovernmental fora where environmental issues are discussed have proliferated considerably in the last decade, NGOs still have limited resources. They cannot be present everywhere and at all times.