In June 2012, government leaders from around the world came together in Rio de Janeiro, Brazil, for the first United Nations Conference on Sustainable Development (UNCSD). This so called Rio+20 conference took place 20 years after the United Nations Conference on Environment and Development (UNCED), which forms an international milestone on the way to the integration of economic, social and environmental dimensions of development. Important results of the Rio "Earth Summit" in 1992 were the Rio Declaration on Environment and Development, the Agenda 21 as a guideline for the implementation of sustainable development, the UN Framework Convention on Climate Change (UNFCCC), the UN Convention on Biological Diversity (CBD) as well as the start of negotiations on the UN Convention to Combat Desertification (UNCCD). The aim of the Rio +20 conference was to measure the progress that had been made during the last two decades and to renew the international commitment to sustainable development. As part of this special, the German Development Institute / Deutsches Institut für Entwicklungspolitik (DIE) and experts from academia, politics and business reflect background information, events and publications on the topic, such as those published by 13 high-level experts in July 2011.