Human Alteration of the Nitrogen Cycle and Its Impact on the Environment

Abstract

Nitrogen(N) is a key element that controls the functions and dynamics of Earth's various ecosystems. In recent years, however, human activities, including the use of N fertilizers and the combustion of biomass and fossil fuels, have been injecting artificially transferred nitrogen into the atmosphere. Human alteration of the nitrogen cycle poses a threat to various aspects of the environment. Organisms in terrestrial and aquatic ecosystems used to lower nitrogen levels struggle with the new conditions; plant species richness and biodiversity are reduced due to excessive use of N fertilizers; reactive nitrogen in different forms negatively alter the ozone layer and exacerbate the greenhouse effect. Although most nitrogen inputs are serving human needs, the long-term environmental consequences are serious and should not be ignored.