The Intergovernmental Panel on Climate Change or IPCC is an international body that assesses and reports about climate change. Specifically, it reports on the current knowledge about climate change and its possible impacts. The IPCC does not conduct research or monitor climate related data, rather it reviews current knowledge. Originally, it was established in 1988 by the United Nations Environment Program and the World Meteorological Organization. The IPCC's work is guided by a specific set of principles and procedures.
The IPCC is composed of thousands of scientists worldwide that contribute on a voluntary basis to review information. A vast number of scientists are consulted as the IPCC aims to reflect a wide range of views. Additionally, since the IPCC is an intergovernmental body under control of the UN, all member countries of the UN are open to join. There are currently 195 member countries in the IPCC. Governments of these countries participate in the review process and plenary sessions wherein decisions about the IPCC are discussed and reports are accepted. Members of the IPCC Bureau are also elected during these sections.
The IPCC is currently structured with three Working Groups and a Task Force supported by Technical Support Units. Each working group deals with a different topic, and these topics are: "The Physical Science Basis of Climate Change", "Climate Change Impacts, Adaptation and Vulnerability" , and "Mitigation of Climate Change". These working groups meet in the plenary sessions alongside government representatives. The Task Force's goal is to develop and refine a method for calculating and reporting national greenhouse gas emissions and removals.
For more information on the IPCC and what they do, see their homepage here.