Oil refining is a highly energy intensive industry resulting in the generation of significant quantities of Green House Gases (GHGs).It is only since late seventies that the refining industry started focusing on the energy conservation, and very recently started focusing on the reduction in GHGs.This presentation focuses on the fundamentals of petroleum refining processes, including molecule management, and their relationships to GHG emissions.While GHG emission is mainly related to energy consumption, this presentation also identifies non-energy related issues impacting the GHG emissions based on refining processes globally.This presentation includes case studies for reducing GHG emissions in refineries and petrochemical complexes.The presentation also identifies solutions and provides paths forward for reducing GHGs.