Disruption of the global nitrogen cycle: A grand challenge for the twenty-first century This article belongs to Ambio's 50th Anniversary Collection. Theme: Eutrophication

Disruption of the global nitrogen cycle by humans results primarily from activities associated with food and energy production. Since the middle of the twentieth century, human activities have more than doubled inputs of nitrogen to the Earth's ecosystems. This new nitrogen is in chemically and biologically active forms (reactive N) and moves through the environment causing an array of health and environmental problems. Research published in Ambio for the past three decades has been documenting this major global-scale problem and has catalyzed the formation of a science-led initiative, the International Nitrogen Initiative (INI), which has informed policies to manage the global nitrogen cycle. Currently, gaps and opportunities in nitrogen pollution policies still exist and require new interdisciplinary science to help to place the nitrogen management challenge in the context of the other environmental grand challenges of our time including climate change and biodiversity loss because their solutions will be interconnected.

Automated summary

Human disruptions to the global nitrogen cycle, primarily from food and energy production, have led to various health and environmental issues. The International Nitrogen Initiative has played a crucial role in informing global nitrogen management policies, but gaps and opportunities in nitrogen pollution policies still exist. Interdisciplinary science is needed to address the nitrogen management challenge in the broader context of other environmental challenges like climate change and biodiversity loss.