Simplify the following text for a Grade 14 native English-speaking person.
Original: The panel was first established in 1988 by the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , two organizations of the United Nations -- an action confirmed on 6 December 1988 by the United Nations General Assembly through Resolution 43\/53 .
Simplified: The group was established in 1988 by the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , two organizations of the United Nations .