Biofuel production vs. Aquatic ecosystems

Simon Donner writes about his new paper Corn-based ethanol production compromises goal of reducing nitrogen export by the Mississippi River (Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0708300105) on his weblog maribo:

A new paper by my colleague Chris Kucharik and I looks at the new US Energy Policy, will calls for growing more corn to produce ethanol, will affect the “Dead Zone” in the Gulf of Mexico. For a quick summary, see Reuters, the CBC or AFP.

The Mississippi dumps a massive amount of nitrogen, largely in the form of the soluble ion nitrate, into the Gulf each spring. It promotes the growth of a lot of algae, which eventually sinks to the bottom and decomposes. This consumes much of the oxygen in the bottom waters, making life tough for bottom-dwelling fish and creatures like shrimp. The Dead Zone has reached over 20,000 km2 in recent years.

The primary source of all that nitrogen is fertilizer applied to corn grown in the Midwest and Central US. Reducing the Dead Zone to less than 5000 km2 in size, as is suggested in US policy, will require up to a 55% decrease in nitrogen levels in the Mississippi.

The new US Energy Policy calls for 36 billion gallons of renewable fuels by the year 2022. Of that, 15 billion can be produced from corn starch. Our study found meeting those would cause a 10-34% increase in nitrogen loading to the Gulf of Mexico.

Meeting the hypoxia reduction goal was already a difficult challenge. If the US pursues this biofuels strategy, it will be impossible to shrink the Dead Zone without radically changing the US food production system. The one option would be to dramatically reduce the non-ethanol uses of corn. Since the majority of corn grain is used as animal feed, a trade-off between using corn to fuel animals and using corn to fuel cars could emerge.

2 thoughts on “Biofuel production vs. Aquatic ecosystems”

  1. Biofuels (and carbon capture) are a ‘catastrophe’ for future humankind

    The decisions being taken by governments around the world in the quest for sustainability are a catastrophe for humankind in the long-term. Two of these decisions at the forefront of news are biofuels, and carbon capture and storage.

    Biofuels — the fuel revolution that will supposedly help us:
    (1) Growing crops in the United States for biofuels requires around the same energy input for fertilisers and processing the crops as that saved by replacing petrol on the forecourt (Biofuels – A solution worse than the problem, Daily Telegraph).
    (2) By harvesting the peat bogs for biofuels, we release 30 times more carbon dioxide than will be recouped by burning the biofuel produced (Prof. Jack Riley, University of Nottingham).
    (3) Growing biofuels takes a lot of land and huge amounts of water — neither of which the world has to spare.
    (4) China and India risk famine if they proceed with their biofuels plans, because they don’t have enough water to grow both fuel and food (International Water Management Institute).
    (5) Biofuels are killing forests and leading to more global warming, besides taking land away from food crops (Global Forest Coalition).
    (6) The diversion of land meant for food crops to agrofuel production is a “crime against humanity” (Jean Ziegler, UN Special Rapporteur on the Right to Food).

    Carbon Capture — putting off today what others will have to solve tomorrow:

    (1) Carbon sequestration and storage (under our oceans and land) is an untried method of locking up carbon dioxide forever, but there is not a 100 per cent assurance that it will not escape. Possible escape routes include earthquakes, land shifts, terrorism (holding the world to ransom) or human disasters/accidents.
    (2) Sequestration and storage of carbon dioxide is not a solution, but a problem that humankind will have to face in the future — one that might eventually threaten the existence of human life itself on Earth, for nothing ever designed has lasted forever.
    (3) Governments, as usual, are only looking at solving problems today without any understanding of what this will bring in the future. They are attempting to lock up gases that are toxic to humans — leaving any problems for future generations to solve.
    (4) If there was a rupture in the storage vessel, the ramifications for the world would be immense, to say the very least. Therefore, carbon capture is a method of putting off today what others will have to fix tomorrow (if they can).

    Dr David Hill
    World Innovation Foundation Charity
    Bern, Switzerland

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