Nitrogen’s Turn

What is the nitrogen challenge?

Humanity’s very existence depends on nitrogen as an essential element of all forms of life, both in nitrogen’s pure form and in its reactive forms when combined with other elements such as oxygen, hydrogen or carbon.

Until a century ago, natural processes of “nitrification” (the formation of combined nitrogen elements) and “denitrification” (the restoration of nitrogen to its pure form) were fairly balanced. However, as humans learnt to harness nitrogen, by extracting it from their air and transforming it into various reactive forms (sometimes referred to as Nr), this balance was lost, due to an inability to denitrify leftover elements, leading to their accumulation

and subsequent environmental pollution.2 Although human cultivation of legumes, for example, expanded natural nitrification over thousands of years, reactive nitrogen pollution has increased and worsened following industrial nitrification.

Reactive forms of nitrogen are necessary for food production, representing a crucial nutrient for plants and a significant component of proteins, which all animals need to grow, reproduce, and survive. For thousands of years, reactive nitrogen compounds were available via legume crop rotations, manure and compost, until industrially manufactured fertilizers became the predominant source. Elsewhere, reactive nitrogen compounds are unwanted by-products of fuel combustion processes used to meet humans’ transport, industry, and energy needs.4 In short, although a balanced use of reactive forms of nitrogen is beneficial, the spillover and waste of these resources are resulting in severe harmful impacts.5



Nitrogen is an extremely abundant element in the Earth’s atmosphere, making up 3 almost 80 per cent of the air we breathe and is harmless in its pure form