Modeling and Quantitative Analysis in the Energy–Food–Water–Waste Nexus (EF2W): Case Study in Cameroon

In order to achieve the Sustainable Development Goals (SDGs), it is necessary to quantitatively examine the interactions in the EF2W nexus in more detail. The main objective of this work is to model and quantify the EF2W nexus. The approach and model (input–output model) used from the literature is applied to the case of Cameroon. This model has some advantages that make it special, namely the possibility of establishing quantitative relationships on a local, national, regional, or global scale. The results indicate that the method presented in this study is sufficiently relevant to achieve a quantitative framework for modeling the sixteen (16) relationships intertwining the EF2W. Moreover, the analyses carried out on the EF2W interactions for the three decades (1990–2020) show that the energy sector is strongly impacted by biomass, water, and petroleum products with very low impact of waste; the proportion of energy for electricity generation is, on average, 67.528%; the contribution of water (surface and groundwater, water use per ton of food) for agriculture is estimated to be 0.16%, on average, for 17.44 m 3 /t feed; the energy sector contributed during the three decades 0.42% for 0.88 toe/kt of energy produced. As for the waste (agricultural and animal waste), their use in the agricultural sector is, on average, 97.80%. These results have a significant impact on the energy mix in the management and distribution of production sources and its uses in the different sectors considered. A new optimal approach should be considered.