## 6 Discussion
Promising research has addressed the potential of POME to generate biohydrogen and biomethane (or a mixture of these: biohythane) for energy purposes [111]. These alternative POME utilizations could dramatically reduce the GHG footprint during the production phase. The second-largest GHG emission source identified in this study is transport (marine and road), accounting for 61 kg CO\({}_{2}\) eq; it is important to mention that this footprint could be reduced if agricultural production areas are located closer to refining facilities and to marine ports. In addition, N\({}_{2}\)O contributes 42 kg CO\({}_{2}\) eq; this GHG is commonly derived from the use of nitrogen-based fertilization and was estimated as a function of applied N, as mentioned. It is important to mention that by-products of palm oil production can also be used for fertilization: the use of 300 kg of empty FFB could be equivalent to 4.8 kg of potassium chloride (KCL), 0.25 kg diammonium hydrogen phosphate (DAP), and 10 g of borate per plant [112]. In the case of WCO, the higher contributor to GWP (91% of the total) is the use of electricity from the Galapagos electricity grid which, as mentioned, is heavily reliant on fossil fuels. This footprint could be reduced if more renewable energy is integrated into the system. The second GHG source is road and marine transportation. Regarding RPO-based electricity acidification potential, the main contributor with 1.6 kg SO\({}_{2}\) eq is ammonia emissions derived from N fertilizer application during the agricultural production of FFB. Thus, it is important to stress the environmental benefits related to the reduction of chemical nitrogenated fertilization. The second contributor, with 20%, is NOx emission derived from the use of fossil fuels in transport and energy generation during the production process. Regarding WCO-based electricity, the main source of acidification in this study came from SO\({}_{2}\) and NOx from the combustion of fossil fuels during electricity generation in the Galapagos grid; these impacts are relevant in sensible ecosystems such as islands. According to [PERSON] (2018) [113], if CO\({}_{2}\) emissions are not reduced,ocean warming and acidification are projected to drastically reduce or eliminate coral reefs from the Galapagos between the years of 2026 and 2035. In RPO electricity production, chemical oxygen demand (COD) contributes 62% of the total eutrophication potential (PO\({}_{4}\) eq); this process is linked to the high amount of oxidizable pollutants found in the wastewater from the extraction phase. In terms of abiotic depletion (ADP), 56% of the total antimony (Sb) equivalent is attributed to the use of fossil fuels in RPO production, including fuels used for input production and materials. Considering the rich and sensible marine ecosystem of the Galapagos, the main contributor to marine ecotoxicity is wastewater from WCO cleaning with 80.6 1,4 Dichlorobenzene equivalent (1,4-DB eq). In this regard, adequate final disposal of the wastewater in this process is crucial to reducing this environmental impact. Some of the unanswered questions and future research derived from this study are to (i) study the willingness of business owners to provide WCO in Galapagos or other islands; (ii) conduct emissions testing in conditions similar to those of the electric group located on Floreana Island; (iii) analyze the environmental impacts of WCO disposed in the sewage system in Galapagos; (iv) determine the impact of the potential energy usage of other by-products not exploited in the production cycle, such as palm kernel residues and sludges from the extraction phase; and (v) analyze the land-use change impact of productive zones with high carbon content, such as the Amazonian region.