Description
The United States emits roughly 6,483 million metric tons (MMT of CO2e) of greenhouse gas (GHG) into the atmosphere, every year. The U.S Department of Agriculture (USDA) suggests the U.S. food system is responsible for 18% of annual emissions, while U.S. Environmental Protection Agency (EPA) reports 10% of GHG totals are produced by the agricultural sector. Recently, numerous articles have been published discussing agricultural livestock, the meat industry, and excess meat consumption and their impact on climate change. The market for non-meat protein sources has exploded, encouraging food scientists to recommend micro-livestock (ML) i.e., edible insects as a suitable “meat alternative”. This thesis investigates GHG emissions produced by conventional livestock (CL), such as beef cattle, swine, and broiler chicken, either through direct emissions from the animal or through the entire supply chain, while simultaneously exploring pathways to incorporate ML into the U.S. food system. A systematic review isolated information from articles, published between 2000-2020, regarding GHG production and nutritional value of CL and ML and uncovered studies that offer empirical evidence of CO2, CH4, N2O emissions (kg of CO2e / FU) released via ML farming. The study also conducted a meta-analysis of all selected data sets and designed 4 theoretical models integrating ML, such as Acheta domesticus (AD), Tenebrio molitor (TM), and Locusta migratoria (LM) into particular stages of the U.S. food system. Utilizing published CO2e emission factors, the study quantified potential GHG emissions from a commingled system, which denoted a particular ratio of CL and ML inventory. The model #1 shows a 5.6% reduction from the 245 MMT of CO2e of livestock produced GHGs, when adopting a 90%-10% CL/ML commingled inventory with AD, TM, or LM, while model #2 indicates a 6.3% - 32.8% decrease from the estimated 1,173 MMT of CO2e released via U.S. food supply chain. Model #3 assessed U.S. dietary habits and estimates the U.S. would reduce GHG emissions by 73.9 – 384.4 MMT of CO2e by reducing meat-sourced protein and adopting a commingled CL/ML diet. The study also shows the nutritional benefit of consuming ML, which can provide 1.5x – 3x more protein, fiber, calcium, iron, and vitamin B12 compared to CL. Overall, this comparative analysis determined edible insects to be a sustainable and nutritious meat alternative.
