Nitrogen is second to plastics in ocean pollution

There is however another major ocean pollutant the magnitude of which is, coincidentally, quite close to plastics at around 13 million metric tonnes per year and that is nitrogen. This includes a combination of fertilizer (4) and manure (4) run-off to rivers, untreated sewage (1), and atmospheric deposition (4).  The dramatic increase in fertilizer production beginning in the 1950s led to the manufacture (using the Haber-Bosch process) of over 2 billion metric tonnes of reactive nitrogen and a 150 percent increase in the amount of nitrogen added annually to the environment, much of this reaching the ocean.  Based on recent fertilizer prices, the ‘value’ of this unrecovered nutrient “waste” is about $15 billion per year.

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