Food and energy production converts di-atomic N to reactive N species that cascade through environmental reservoirs and in the process impact human and ecosystem health. This talk will examine the magnitude and impact of this increased N mobilization on the global N cycle by contrasting reactive N creation and distribution in the late-19th century with that of the late-20th century. The presentation will illustrate that we have: • a good understanding of the amounts of reactive N created by humans, and the primary points of loss to the environment; • a poor to fair understanding of the degree of distribution, and of the resulting impacts on people and ecosystems; • a poor understanding of nitrogen's rate of accumulation in environmental reservoirs, which is problematic due to the cascading effects of N in the environment, including enhanced rates of atmospheric reactions, fertilization of terrestrial and aquatic ecosystems, loss of ecosystem biodiversity, and increased emission of greenhouse gases; • a good understanding, in general, of what must be done to reduce the amount of Nr created by human action. Given the likely increase in population and per-capita use of resources in the coming decades, a societal challenge is how to minimize reactive N creation while also maximizing food and energy production.