Green the Nutrient Economy and Reduce Ocean Hypoxia through a Policy, Regulatory and Economic Instruments that Promote Nutrient Efficiency and Recovery


Mankind has arguably perturbed the global cycle of nitrogen even more than that of carbon; a 2009 Nature Report, “A Safe Operating Space for Humanity”, determined that excess nitrogen in the environment was one of 3 of the 9 ‘planetary boundaries’ that had already been exceeded. Since the early 1900s with the invention of the “Haber-Bosch” process, and dramatically accelerating beginning in the 1950’s, humans have been converting atmospheric nitrogen gas into ‘reactive’ forms like ammonia and nitrate to produce fertilisers for agriculture, at current levels of about 100 million mt/year. This of course has generated substantial benefits in feeding a burgeoning global population through the ‘green revolution’ which featured massive increases in application of industrial fertilisers to agriculture and delivered dramatic increases in agricultural productivity. However, the massive increase in available reactive nitrogen over the last 50 years has led to a roughly three-fold increase in the amount of nitrogen – from agricultural runoff (fertiliser ~45% and manure ~45%) and wastewater (~10%) - reaching coasts and oceans from the continents.

Nitrogen (and phosphorus) are essential nutrients for growth of the ocean’s plankton, but excess amounts can create dead zones in which large numbers of decomposing plankton consume almost all available oxygen, seriously impacting coastal ecosystems and the livelihoods that depend on them. In recent decades, there has been an alarming increase in such hypoxic zones across the world’s bodies of water, such as in the Black Sea, Baltic Sea and Gulf of Mexico. While the emergence of modern wastewater collection and treatment systems in the late nineteenth century made enormous contributions to human health by reducing the incidence of water borne diseases in rapidly growing, dense urban environments, much of the world’s sewage remains poorly treated or not treated at all, which, combined with nutrient burdens from agricultural run-off (fertiliser, manure), has lead to continued growth in the occurrence of coastal hypoxic zones and economic damages approaching USD 100 billion per year in the EU alone.

At present, most of humanity – particularly in the industrialised world but increasingly in fast developing middle income countries - practices a ‘linear’ approach to managing nutrients involving: harvesting nitrogen from the air for conversion to fertiliser, applying to agricultural land (with often substantial losses to rivers and downstream coasts), growing and harvesting crops for human and livestock consumption, consuming food products and excreting human and livestock waste, collecting human excreta through wastewater systems, and releasing a sizeable fraction of these waste products, untreated, to the coastal zone. The urgency of the ocean hypoxia issue underscores the need to begin a transition to much more cyclic management of nutrients whereby efficiency of fertiliser use is increased and the majority of human and livestock ‘waste’ nutrients are recovered and reused for fertiliser and other needs. In parallel, some analyses project that available phosphorus reserves could run out as early as this century with unprecedented effects on global food security; whether it is this soon or somewhat longer doesn’t negate the fact that eventually, phosphorus recovery from the waste stream will need to become the norm, not the exception if long-term global food security is to be ensured.

Main objectives of the Proposal

1. Application of appropriate legal, regulatory and economic instruments should be scaled up to catalyse incremental transformation of the nutrient economy from linear to much more cyclic approaches over an appropriate time frame. Policy and regulatory instruments could include stricter regulation of nutrient removal from wastewater (and recycling of recovered nutrients into agriculture), mandatory nutrient management plans in agriculture, enhanced regulation of manure, and others. Economic instruments could include taxes on fertiliser and/ or agricultural and wastewater nutrient emissions, cap and trade frameworks on nutrient emissions and/or fertiliser production, and ‘good’ subsidies that encourage nutrient recovery and recycling.

2. Send clear regulatory and market signals to the agriculture, wastewater management and fertiliser industries of the urgent need to transition towards enhanced fertiliser use efficiency and sizeable recovery and reuse of nutrients from the human and livestock waste streams, and create new business partnerships between the agriculture, fertiliser, and wastewater management industries.

3. Catalyse innovation in fertiliser management and use efficiency and human and livestock waste nutrient recovery technologies, and create whole new sectors and associated jobs.

4. Fertiliser companies in countries with Emissions Trading Schemes that successfully partnered and innovated in waste nutrient recovery and fertiliser ‘remanufacture’ would also be able to sell carbon emissions reduction credits due to the sizeable reductions in their emissions of greenhouse gases as they transition away from energy intensive Haber-Bosch production.

Expected results

Gradual increase in the volume of fertiliser produced from recovered nitrogen (and phosphorus); this diversification of sources for fertiliser raw materials helps to moderate fertiliser prices and their volatility, enhancing global food security. Increased efficiency in agricultural use of both manufactured and recovered fertiliser in response to market and regulatory signals. Market and regulatory mechanisms help to catalyze the creation and dissemination of nutrient recovery technologies and supply chains, create sizeable numbers of new businesses and jobs, and are consistent with the Green Economy concept. Decreases over time in the loads of nitrogen and phosphorus entering coastal areas will reduce coastal hypoxia and restore associated ecosystems and livelihoods.

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