This report, the second of three, evaluates key findings for four plastic resins from the 2010 and 2020 series of life cycle assessments (LCAs) analyzing the potential environmental footprint of plastic resins and resin precursors. This report compares the CO2 emissions and total energy consumption of High Impact Polystyrene (HIPS), General Purpose Polystyrene (GPPS), and Acrylonitrile Butadiene Styrene (ABS) from 2010 to 2020, which demonstrates a clear trend of decreases in both impact categories ranging from 4 to 22% in CO2 and 7 to 16% in total energy consumption. The results highlighted in this report support the conclusion that the environmental footprint of manufacturing these plastics is being reduced where energy demand and greenhouse gas emissions (GHGs) are concerned.