Simplify the following text for a Grade 11 native English-speaking person.
Original: The principles of the IPCC operation are assigned by the relevant WMO Executive Council and UNEP Governing Council resolutions and decisions as well as on actions in support of the UN Framework Convention on Climate Change process .
Simplified: The IPCC activities are controlled by the WMO Executive Council and UNEP Governing Council to support the UN Framework Convention on Climate Change .