The core behind this diagram is that biogas is a better solution for cooking fuel in India. First of all, human and the environment are closely coupled together. Before introduced to biogas. Women and children have to gather fuel wood from the forest, in which deplete trees, causes soil erosion and make the land more vulnerable to natural disasters ultimately. This create a positive feedback loop with negative effects. More woods gathered enable to feed more people, in which more forests got cut down. Women and children spending time gathering fuel, children don’t have enough time for their breakfast and school work, in which result in a worse health condition and education level. Women will be impacted with dirt and smoke created while cooking. Using biogas requires no wood, children get better education and people would be healthier. Comparing to the system diagram from Marten “what is human ecology,” both diagrams have main category as social system and ecosystem. Two-direction arrows suggest that these two are coupled to each other. Change in one would affect the other. The difference is that in my diagram, a new technology of biogas is introduced to the system. Thus changed some factors in both categories. For example, kids have more time studying and less trees are cut down. By comparing both diagrams, my diagram doesn’t show the effect of biogas generator clearly. In Marten’s graph, reduced impacts are shown with dotted lines.