Most rural people globally cook with firewood or other sources of biomass. When biomass that has more productive uses is instead burnt, it is a sign of household level energy insecurity. Burning crop residue and dung for fuel reduces the availability of fertilizer and fodder, as well as directly contributes to poor health outcomes. Ethiopia is largely deforested, and now many of Ethiopia's trees are on farms rather than in forests. The objective of this research is to investigate the relationship of on-farm trees to household-level energy security, rural livelihoods, and wellbeing. Using an econometric model with 20-year panel data from rural Ethiopia, we find on-farm trees contribute to building the household's most valuable asset: their home. By contributing to household-level energy security, we find on-farm trees increase crop residue availability for maintaining the rural household's second most valuable asset: their livestock. Large development efforts, including integrated water management projects and investment programs from the World Bank, are increasingly recognizing contributions of trees on farms, and environmental quality in general, as important contributing factors to meeting sustainable development outcomes. Asset creation related to on-farm trees and improved home biomass management provides a compelling pathway for building resilience, maintaining wellbeing, and reinforcing the foundation of rural livelihoods.Sustainability 2018, 10, 4716 2 of 24 been uneven, with urban residents enjoying a 90% rate of electricity access while rural areas estimate between 5% and 25% access, leaving approximately 90% of total energy needs met with biomass [1,8]. Household demands for biomass as fuel in rural Ethiopia results in less biomass available for other productive uses, such as fodder for animals or fertilizer to increase crop productivity [9]. Recent evidence from the Nile Basin of Ethiopia indicates that burning dung has measurable negative impacts on crop productivity, but this can be countered by increased availability of firewood from on-farm trees to replace dung as a household fuel that, instead, can be applied as fertilizer, thereby increasing yields [10].Indicators of physical access to modern energy sources are associated with the concept of an energy ladder where households will switch to electricity or fossil fuels as the most modern fuel available for purchase within their means [11]. Other quantitative energy poverty measures traditionally emphasize the concept of a deficit where a household's economic access to a sufficient amount of fuel for basic needs is calculated in a similar way and correlated with conventional consumption-based measures of poverty, such as the poverty line [12]. Instead, recent policy-relevant empirical studies of household fuel choice emphasize contextual factors that reveal a large role for cultural preferences in cooking methods and diverse reasons for using or stacking different fuel sources [13]. For example, Ruiz-Mercado found that an open fire used for cooking...