Tuesday, December 18, 2007

A Black Mark For Green

At the weekend, I discussed the coming oil crunch and how alternative energy sources might stack up to replace fossil fuels.

Specifically, when it comes to corn ethanol, there's a negative energy impact in converting from fossil fuels: it takes a lot of energy to produce one gallon of corn ethanol, more energy than is derived.

A lot of that energy comes from the petroleum-based fertilizers that corn needs in order to grow efficiently enough to create a supply of ethanol.

There's also a downside to using that much fertilizer:
The nation's corn crop is fertilized with millions of pounds of nitrogen-based fertilizer. And when that nitrogen runs off fields in Corn Belt states, it makes its way to the Mississippi River and eventually pours into the Gulf, where it contributes to a growing "dead zone" — a 7,900-square-mile patch so depleted of oxygen that fish, crabs and shrimp suffocate.

The dead zone was discovered in 1985 and has grown fairly steadily since then, forcing fishermen to venture farther and farther out to sea to find their catch. For decades, fertilizer has been considered the prime cause of the lifeless spot.

With demand for corn booming, some researchers fear the dead zone will expand rapidly, with devastating consequences.
In short, you kill off the Louisiana shrimp farmers, which is a critical link in the economic recovery of the region.

Corn prices have doubled in the past five years, from $2 a bushel to $4. That makes corn a very tempting crop to plant for any farmer. It also makes it impossible for environmentalists to ask farmers to cut back on production, or to create environmental buffer zones so that run-off is less of a problem (i.e. plant nitorgen-fixing crops like alfalfa that will thrive in a fertilizer rich environment).

The dilemna can be summed up this way:
Farmers realize the connection between their crop and problems downstream, but with the price of corn soaring, it doesn't make sense to grow anything else. And growing corn isn't profitable without nitrogen-based fertilizer.
The flip side of this problem (and isn't there always?) is that, with a dead zone of over-nitrogenated water taking over more and more of the Gulf, there's less and less chance of having carbon scrubbed out of the atmosphere and back into the life cycle on the reefs and other offshore ecosystems. Algae bloom into overpopulation, die off en masse, and then suck all the oxygen out of the water as they drop to the bottom of the ocean, decaying.

There's nothing left at the surface to exchange carbon dioxide for oxygen until the algae levels balance out again. Plus, the oxygen at the bottom is taken away, meaning shellfish (who can't outswim the depletion) die off.

This happens on an annual basis now, but the dead zone season has been extending each year, forcing shrimpers to go further and further off-shore, endangering fragile ecosystems that include larger pelagic fish and mammals.

And as the dead zone grows larger and stays longer, it may actually trap many fish and mammals within its confines, where even the fastest swimmers won't be able to outrace their deaths.

In other words, dolphins, whales and sharks are dying off because of shrimpers due to the unintended consequences of corn ethanol research.

Which was supposed to help save them and their fragile environments.