Relating Land Use and Select Environmental Impacts to U.S. Consumption with a Focus on Agricultural Products

Approximately 29 percent (%) of the Earth’s surface is used to support humanity. Demand for land use is expected to increase by an additional 33% over the next 100 years. Land suitable for crop cultivation is limited, as are pasturelands, both critical for food production. How we use these lands and all land results in environmental impacts. Environmental impacts associated with land use and land use change are many and various. Land use change can cause runoff and sedimentation of soil, contamination of waterbodies with fertilizers and pesticides and release of carbon to the atmosphere. Paving of surfaces causes changes to the hydrology of an area and can create heat island effects. All of these land uses disrupt habitat for other species. This thesis addresses the following main research questions: What types and how much land occupied by industry and agriculture, in this thesis defined as land in production, are used to meet demands for consumption in the U.S.? What commodities use the most land? How much land is traded between the U.S. and the rest of the world (ROW)? Are there particular categories of land use that dominate supply chains across sectors? How is land use connected to environmental impacts? First, land in the United States is related to domestic final demand, including land embodied in U.S. exports. To do this an inventory of land with respect to economic sectors is created. Environmentally Extended Input-Output Analysis (EE-IOA) is used to define connections between land in production and consumed goods and services. It is found that agricultural land use is significant in the majority of economic sectors. Next, the EE-IOA is expanded to include an additional region representative of the rest of world. This enables estimation of the land embodied in U.S. imports. In many land use studies only agricultural products are considered. Through extending this analysis to include the total supply chain land use embodied in the production of good and services it is shown that land use associated with manufactured goods is significant. Finally, two analyses are executed to demonstrate the connections between land use and environmental impacts. First, Monte Carlo Analysis is employed to approximate the nitrate output within the Mississippi/Atchafalaya River Basin as a result of increased demand for biofuels in the U.S. Nitrate output is related to the formation of hypoxia in the northern Gulf of Mexico. Results indicate that with or without biofuels, our current land use and land use management practices are inadequate. Each year a hypoxic zone forms in the northern Gulf of Mexico the additional land in cultivation will exacerbate this situation. Next, the connection between greenhouse gas (GHG) emissions and land use was explored, again using EE-IOA methods.