Simplify the following text for a Grade 6 native English-speaking person.
Original: The Chairperson of the IPCC is Rajendra K. Pachauri , elected in May 2002 ; before that Robert Watson headed the IPCC .
Simplified: The Chair of the IPCC is Rajendra K. Pachauri , elected in May 2002 ; previously Robert Watson headed the IPCC .