By: Jackie Harrigan

Climate change, deforestation and biodiversity loss – the top three huge threats to the planet – are now being joined by nitrogen pollution. According to Fred Pearce, writing for the Yale Environment 360 online magazine, experts from around the world are drawing up plans to start measuring and then reducing the nitrogen pollution on our nearly N-soaked planet.

Meeting as part of the International Nitrogen Management System, a five year US$60 million research project under the United Nations Environment Programme, experts concluded the amount of N dumped into the environment must halve by 2050 or “our ecosystems will face epidemics of toxic tides, lifeless rivers, and dead oceans”.

Synthetic nitrogen fertiliser, the cheap, easy-to-source, go to crop and pasture fertiliser, has combined with fossil fuel burning and increasing levels of sewage and livestock waste to double nitrogen flows over the past 50 years.

Pearce says half the world’s crops today are grown with the aid of fertiliser made by capturing inert nitrogen from the air, (twice the amount of N than from natural sources) and while that has served agriculture well in feeding the world, the environmental fallout is coming home to roost in algal blooms, toxic tides and oceanic dead zones.

While nitrogen use efficiency (NUE) has been improving in developed countries, developing agricultural industries are pouring more and more cheap N fertiliser on to crops to lift yields with rapidly decreasing efficiency.

A suite of solutions is being considered – and many discounted for reasons of economic disparity – pushing up fertiliser prices, N-footprint monitoring, rearranging where crops are grown, precision agriculture and a world agreement on N use much like the climate change targets.

Recommendations to aid in fixing the N-pollution problem could also include increased recycling of nutrients in livestock manure and human waste, reductions in food waste and encouraging changes to human diets.

Read the full report: