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More corn ethanol = Bigger Gulf dead zone

By Joe Romm on March 18, 2008 at 7:58 am

"More corn ethanol = Bigger Gulf dead zone"


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As if we didn’t have enough reasons to dislike corn ethanol (and here).

Some aquatic dead zones are primarily due to global warming, and some are due to fertilizer runoff. In the future the two will combine with acidification to wipe out most ocean life if we don’t change course soon. Now a new study says U.S. corn ethanol policy will aggravate the New Jersey-size (!) area of hypoxia in the Gulf of Mexico.


As Scientific American explains:

The water in brooks, streams and creeks from Michigan to Puerto Rico carries a heavy load of pollutants, particularly nitrates from fertilizers. These nitrogen and oxygen molecules that crops need to grow eventually make their way into rivers, lakes and oceans, fertilizing blooms of algae that deplete oxygen and leave vast “dead zones” in their wake. There, no fish or typical sea life can survive. And scientists warn that a federal mandate to produce more biofuel may make the situation even worse.

That scientific warning, “Corn-based ethanol production compromises goal of reducing nitrogen export by the Mississippi River,” was published in Proceedings of the National Journal of Sciences (subs. req’d). Here is the abstract:

Corn cultivation in the United States is expected to increase to meet demand for ethanol. Nitrogen leaching from fertilized corn fields to the Mississippi–Atchafalaya River system is a primary cause of the bottom-water hypoxia that develops on the continental shelf of the northern Gulf of Mexico each summer. In this study, we combine agricultural land use scenarios with physically based models of terrestrial and aquatic nitrogen to examine the effect of present and future expansion of corn-based ethanol production on nitrogen export by the Mississippi and Atchafalaya Rivers to the Gulf of Mexico. The results show that the increase in corn cultivation required to meet the goal of 15–36 billion gallons of renewable fuels by the year 2022 suggested by a recent U.S. Senate energy policy would increase the annual average flux of dissolved inorganic nitrogen (DIN) export by the Mississippi and Atchafalaya Rivers by 10–34%. Generating 15 billion gallons of corn-based ethanol by the year 2022 will increase the odds that annual DIN export exceeds the target set for reducing hypoxia in the Gulf of Mexico to >95%. Examination of extreme mitigation options shows that expanding corn-based ethanol production would make the already difficult challenges of reducing nitrogen export to the Gulf of Mexico and the extent of hypoxia practically impossible without large shifts in food production and agricultural management.


Hansen (et al) must read: Get back to 350 ppm or risk an ice-free planet

On Gas Prices, Bush And McCain Acknowledge Their Own Cluelessness

12 Responses to More corn ethanol = Bigger Gulf dead zone

  1. Beefeater says:

    We should just replace the use of oil altogether as America’s fuel of choice. This doesn’t mean singing the praises of ethanol, and hoping that it finds its way into our fuel supply on its own. It means taking some serious steps now to put a national bio-fuel infrastructure into place. Already some cars on the road have flexible fuel tanks necessary for them to run on E85, which is a cheaper, cleaner blend of 85 percent ethanol and 15 percent gasoline. But millions upon millions of cars still don’t have these tanks. So its time for auto-makers to install those tanks in every single car that they make and the government can help cover this small cost which currently runs at just around $100 per car. It’s also time to start making E85 fueling stations more available to the American public.

  2. PGosselin says:

    Now I wonder what hysteria led to this ethanol craze?
    Answer: Global warming hysteria

    Instead of saving the world, you Luddites are going to bring it down like communism did. “The road to hell is paved with good intentions”.

  3. PGosselin says:

    We warned you all!

  4. Joe says:

    Corn ethanol was pushed not by the climate crowd — check the votes in Congress. I don’t know any climate activist who thought corn ethanol was a good idea, especially at the volumes we’re now at.

  5. HighSchoolStudentJD says:

    I don’t think we should use any form of bio-fuel. Anything biological is made from carbon and, as everyone knows, things made of carbon that burn release carbon. Now, bio-fuels may reduce CO2 emissions, but they will still be there and really just delay the more extreme effects of global warming until later on. Since the United States emits 25% (no kidding) of the world’s CO2 emissions, it should really not focus on any carbon-burning fuel.
    I believe the best way to go is probably with hydrogen fuel cells or, even better, air (yes, there is an air-powered car). With hydrogen, for one thing, it’s abundant, the most common element in the universe. Second, the only biproduct of it is water, which can actually be used to fuel a stage of the fuel cell opperations. Air would probably be the best choice because, well, it’s relatively infinite. There are no CO2, CO, CH4, etc. emissions from pure air and the creators of this revolutionary idea have developed a prototype egine that recycles the air used back into the tank, essentially refueling itself and never needing to be refilled. So, yeah, air as a fuel is probably the best choice for the United States, and the world for that matter, if we really wish to live on this planet.

    By the way, scientists have calculated that if greenhouse gas production continues at its current rate that in a hundred years or so Earth will closely resemble Venus…we can’t live on Venus.

  6. Steve Howell says:

    Look at the bright side! Those dead zones are anoxic, drastically slowing degradation of sinking organic material. It’s the original geological method of carbon sequestration.

  7. PGosselin says:

    No biofuels,
    No nuclear,
    No coal,
    No oil,
    No gas,
    No hydro…
    Err…we get the picture.

  8. Joe says:

    Who said I’m against (cellulosic) biofuels? Who said I’m against nuclear? Who said I’m against coal with CCS? Who said I’m against gas? Or hydro?

    You get nothing.

  9. David B. Benson says:

    HighSchoolStudentJD stated “By the way, scientists have calculated that if greenhouse gas production continues at its current rate that in a hundred years or so Earth will closely resemble Venus…we can’t live on Venus.” I doubt this. Adding 2 ppm per year for one hundred years gives 385 + 200 = 585 ppm, which in the short term increases the temperature another 3+ K and in the long term maybe 7 K. Far from Venus conditions. Nonetheless, looks to me to be quite deadly for most, if not all, humans.

    Some use of certain biofeuls is certainly a good idea. You can learn more about the advantages and disadvantages here


    and also here


  10. HighSchoolStudentJD says:

    Hey, don’t shoot the messenger. The thing about Venus was something I read in a science journal a year or two back. However, I do suggest they should probably switch to something else, but if they do continue with ethanol, they should take a step toward improving the areodynamicy of modern vehicles before they start putting it everywhere. With the two combined, it would be relatively more efficient, if only slightly.

  11. Peter Foley says:

    Hey Joe what’s up with deleting my posts? Too much real science for you?

  12. TheSUBWAY.com says:

    We found an interesting article about the problems with Ethanol on ConsumerReports.org:


    “But there are some problems with increasing ethanol blends. Ethanol contains less energy than gasoline, so increasing the amount of ethanol in gasoline will likely result in lower fuel economy. Increasing standard fuel blends from zero to 10 percent ethanol, as is happening today, has little or no impact on fuel economy. In tests, the differences occur within the margin of error, about 0.5 percent. Further increasing ethanol levels to 20 percent reduces fuel economy between 1 and 3 percent, according to testing by the DOE and General Motors. Evaluations are underway to determine if E20 will burn effectively in today’s engines without impacting reliability and longevity, and also assessing potential impact on fuel economy.”

    TheSUBWAY.com would like to invite readers to post their own views and ideas in TheSUBWAY.com’s Investor Forum: