This document summarizes key concepts and terms related to greenhouse gas emissions regulations. It discusses concepts like baselines, targets, plans, reporting, reductions, intensity vs absolute emissions, offsets, and compliance vs enforcement. It provides examples of regulations in places like Alberta, Canada, and at the international level. Key policies and approaches are outlined, such as cap and trade systems, carbon taxes, and command and control styles of regulation. International frameworks like the UNFCCC and agreements like the Copenhagen Accord are briefly touched on. Contact information is provided for the Environmental Law Centre.