Too Much of Nitrogen is Bad for the Planet

Nitrogen makes up about 78% of the Earth’s atmosphere, but it mainly exists as inert molecular nitrogen (N2), a form not usable by most living organisms, including plants. However, several natural processes can convert this inert nitrogen into reactive forms crucial for life.

Specialised bacteria in the root nodules of specific plants, the effects of lightning, and various bacteria in water and soil all play significant roles in these transformations. Additionally, industrial processes can also convert nitrogen into reactive forms.

Since the onset of the Industrial Revolution, human activities have dramatically increased the conversion of atmospheric nitrogen into these reactive forms, and this transformation occurs at unprecedented rates.

Key contributors to this phenomenon include the combustion of fossil fuels, which generates nitrogen oxides (NOx) as pollutants; the production of fertilisers that synthesise ammonia (NH3); and agricultural practices that include the cultivation of legumes that naturally fix nitrogen.

Unfortunately, a significant portion of the anthropogenic reactive nitrogen enters the environment. When this happens, it can have dire implications for both human health and the integrity of ecological systems.

According to the United Nations Environment Programme (UNEP), approximately 80% of the 200 million tonnes of reactive nitrogen pollution lost to the environment annually results in increasingly severe environmental issues. One of the drivers of nitrogen pollution is applying nitrogen-based fertilisers in vast quantities to enhance crop productivity. This practice has drastically disrupted the natural nitrogen balance within the biosphere.

Reports indicate that human activities have led to the production of reactive nitrogen at rates surpassing what occurs via natural processes, effectively doubling the global rates of nitrogen fixation.

The UNEP article articulates how nitrogen pollution is intertwined with what is described as the triple planetary crisis, which encompasses climate change, biodiversity loss, and pollution.

It identifies the primary drivers of nitrogen pollution and discusses its various environmental and health-related consequences. Furthermore, the article outlines the numerous benefits of reducing nitrogen pollution, emphasising the need for concerted efforts to address this pressing issue.

For further information, click the link to the UNEP’s full feature on nitrogen pollution: What is nitrogen pollution?