Greenhouse gas (GHG) and nitrogen emissions from beef cattle production systems are receiving greater attention. Emissions of methane and nitrous oxide in grazing and confined feedlot systems are microbial-mediated, whether from the rumen (methane) or soil surfaces (methane and nitrous oxide). Additionally, emissions of ammonia are microbial-mediated as well as dependent on ammonium concentration. Factors that increase microbial activity, such as temperature and season, are positively correlated with emissions from soil surfaces, whereas enteric methane emissions are not affected by ambient temperature and therefore not affected by climate or season. Previous research illustrates that diet, season, and type of production system dramatically affect N emissions as ammonia. However, the effect of season, diet, and type of production system on nitrous oxide emissions from cattle production systems and soils are poorly understood. Additionally, methane emissions data from production systems are lacking and needed. Enteric methane emissions have received the greatest attention across a wide array of climates, season, and diets. Forage quality has been shown to have a large impact on methane emissions, with lower quality forage increasing methane per unit of energy intake. Likewise, feeding finishing diets results in less enteric methane per unit of energy intake compared with forages. However, both high quality forages, and finishing diets increase energy intake and thus absolute amount of methane produced per day. Expressing enteric emissions as amount per day will lead to different mitigation strategies compared with decreasing methane emissions per unit of energy intake or per unit of productive function (i.e., gain). Many benefits exist to utilize forages in beef production systems, thus converting existing forage-based systems to intensive (i.e., grain-based) beef production as a mitigation strategy for methane emissions is not logical. However, greater opportunity likely exists to mitigate methane emissions within forage-based production systems as compared with grain-based systems, which will require understanding microbial mediated processes to dramatically decrease enteric methane.