The palm oil industry experienced significant improvement in its production level from 2002 to 2009 from the established companies, medium scale mills (MSM), small scale and other private holdings (SS and OPH) groups. However, the same cannot be said for treatment of the palm oil mill effluent (POME) produced. The quantity of crude palm oil (CPO) produced in Ghana from 2002 to 2009 and IPCC guidelines for National Greenhouse Gas Inventories, specifically on industrial wastewater were used in this study. During this period about 10 million cubic metres of POME was produced translating into biomethane potential of 38.5 million m(3) with equivalent of 388.29 GW h of energy. A linear growth model developed to predict the equivalent carbon dioxide (CO2) emissions indicates that if the biomethane is not harnessed then by 2015 the untreated POME could produce 0.58 million tCO(2)-eq and is expected to increase to 0.70 million tCO(2)-eq by 2020. (C) 2012 Elsevier Ltd. All rights reserved.