The Nitrogen Cascade

In the previous chapter, we explored how the Haber-Bosch process revolutionized nitrogen fixation and how human activity has introduced significant amounts of reactive nitrogen into the environment. These interventions have disrupted the natural nitrogen cycle, increasing the availability of reactive nitrogen far beyond preindustrial levels.

Now, we turn our focus to the nitrogen cascade—a sequence of environmental impacts triggered as reactive nitrogen moves through air, water, and soil. This chapter examines the pathways of reactive nitrogen, its cascading effects on ecosystems and human health. By understanding the pathways and consequences of reactive nitrogen, we can work toward minimizing its adverse effects on the environment.

• International Nitrogen Initiative (INI): Focuses on minimizing nitrogen's environmental impacts while optimizing its use in food production.
• Convention on Long-Range Transboundary Air Pollution (CLRTAP): Addresses transboundary nitrogen oxide and ammonia pollution through protocols like the Gothenburg Protocol.
• EU Nitrates Directive: Sets limits on agricultural nitrates to reduce water pollution.
• Global Programme of Action for the Protection of the Marine Environment: Aims to prevent nitrogen-driven eutrophication in coastal regions.

National Initiatives

• Germany’s Integrated Nitrogen Reduction Strategy: Implements cross-sectoral targets for reducing ammonia and nitrogen oxide emissions.
• Danish Nitrogen Action Plan: Combines nitrogen reduction efforts with climate goals, focusing on agriculture and water quality improvement.
  
• Germany’s Fertilizer Ordinance: Regulates nutrient application in agriculture to reduce nitrate pollution.