There has been growing interests to reduce the environmental impact caused by greenhouse gas emissions from process plants through various energy conservation strategies. CO2 emissions are closely linked to energy generation, conversion, transmission and utilisation. Various studies on the design of energy-efficient processes, optimal mix of renewable energy and hybrid power system are driven to reduce reliance on fossil fuel as well as CO2 emissions reduction. This paper presents a systematic technique in the form of graphical visualisation tool for cost-effective CO2 emission reduction strategies in industry. The methodology is performed in four steps. The first step involves calculating the energy consumption of a process plant. This is followed by identification of potential strategies to reduce CO2 emissions using the CO2 management hierarchy as a guide. In the third step, the development of “Investment” versus “CO2 Reduction” (ICO2) plot is constructed to measure the optimal CO2 emission reductions achieved from the implementation of possible CO2 reduction strategies. The Systematic Hierarchical Approach for Resilient Process Screening (Wan Alwi and Manan in AIChE J 11:3981–3988, 2006) method is used in the fourth step via substitution or partial implementation of the various CO2 reduction options in order to meet the cost-effective emission reduction within the desired investment limit or payback period (PP). An illustrative case study on a palm oil refinery plant has been used to demonstrate the implementation of the method in reduction of CO2 emissions. The developed graphical tool provides an insight-based approach for systematic CO2 emission reduction in the palm oil refinery considering both heat and power energy sources. Result shows that 31.2 % reduction in CO2 emissions can be achieved with an investment of USD 38,212 and PP of 10 months based on the present energy prices in Malaysia.