in a Blue World

The

environmental and socioeconomic

impacts of nutrient pollution are massive and occurring over wide areas globally. The occurrence of coastal hypoxic zones caused by eutrophication has increased exponentially in recent years, and nitrate pollution is one of the main groundwater contaminants in the developed and also increasingly in the developing world. Coastal hypoxia impacts fisheries, tourism and various ecosystem services provided by healthy coastal ecosystems. For the EU alone, the economic costs of damage to the aquatic environment from excess reactive nitrogen are estimated at up to € 320 billion per year.

Initial evidence from the

EU and US suggests that the overall benefits from improved nutrient management exceed costs and that this cost/benefit calculus occurs in other parts of the world.

A paradigm shift is needed in the way we produce, use and treat nutrients, from a dominantly ‘linear’ approach to a much more cyclic approach with substantial recovery of ‘waste’ nutrients. Without this change our oceans will continue to degrade through increased hypoxic zones with disastrous consequences to coastal communities dependent on marine resources for food and livelihoods. The ‘business as usual’ approach where we use sizeable fossil fuel energy resources to convert atmospheric nitrogen to fertiliser for production of food, and then use significant energy and infrastructure through conventional wastewater treatment to convert a portion of this reactive nitrogen back to atmospheric nitrogen, is highly wasteful. A move to a far more efficient and closed recycling approach to nutrients will not only protect the freshwater and ocean environment from pollution but will improve livelihoods through

creation of new business and job opportunities and reduce fossil fuel energy consumption and associated greenhouse gas emissions.

As part of the transition to a green economy, the massive global environmental externality from nutrient pollution needs to be internalized through use of a range of policy and regulatory tools and economic instruments at all geographic scales. Policy and regulatory instruments could include more strict regulation of nutrient removal from wastewater, mandatory nutrient management plans in agriculture, and enhanced regulation of manure. Economic instruments could include taxes on fertilizer and/or agriculture and wastewater emissions, cap and trade frameworks on nutrient emissions and/or fertilizer production, and subsidies that encourage nutrient recycling and efficient use of fertilizer.

Technology innovation, public-private partnerships, job creation and other benefits of a paradigm shift to a much more ‘cyclic’ nutrient economy would be catalysed by such actions. Furthermore, in the long run it will help to safeguard global food security by diversifying sources of nutrient raw materials to meet continued demand for fertilizer to feed a still growing world population. Many developing countries, for which wastewater collection and treatment and the ‘green revolution’ are still works in progress, present special opportunities to pilot and scale up new nutrient recovery and efficiency paradigms. Enhanced nutrient recovery and reuse would also help to ensure that phosphorus, with finite reserves, is increasingly recycled to maintain sufficient supplies to meet the long-term needs of human society.

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