 Complete the following phrase:  The modern concept of sustainable development was a topic of discussion at the 1972 United Nations Conference on the Human Environment Stockholm Conference, and the driving force behind the 1983 World Commission on Environment and Development WCED, or Bruntland Commission. In 1992, the first UN Earth Summit resulted in the Rio Declaration, Principle 3 of which reads: The right to development must be fulfilled so as to equitably meet developmental and environmental needs of present and future generations. Sustainable development has been a core concept of international environmental discussion ever since, including at the 