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Not so green: corn ethanol reduces the soil carbon, increasing emissions and possibly contributing to warming. This effect is worsened if the leaves are removed for biofuel production, as some have suggested.  (Source: Don Hamerman)

Professor DeLucia of the University of Illinois and his colleagues have completed a massive new study, showing just how bad for the environment corn, and especially sugarcane, ethanol may be. It also shows grass ethanol can be very beneficial to cutting carbon, on the other hand.  (Source: Don Hamerman)

Replanting corn and sugarcane land with biofuel grass can help undo the damage done by these crops, the study suggests.  (Source: Don Hamerman)
A new study shows that switching from corn ethanol to grass may have great benefits

The ethanol business is a booming market, buoyed by several years of high gas prices.  While hampered somewhat by falling petrol costs, the market is seeing support from big investors like GM and is producing millions of gallons fuel yearly, with pumps expanding across the country.

However, while most agree that moving away from reliance on insecure, depletable oil is a good thing, there are also significant downsides to corn ethanol production, the current primary form of ethanol produced.  As discussed previously at DailyTech, corn ethanol is cited for higher food costs.  Additionally, it may not be as green from a carbon perspective as people think.

Companies like Coskata are looking to use alternatives such as quick growing grasses or wood waste to fuel their ethanol production.  Now a new study shows that not only does such production help to normalize food prices, it also helps cut down on excess atmospheric carbon.

A study from the University of Illinois confirms that some sources of biofuels can actually increase emissions of carbon dioxide, while others can decrease them.  The key is what you grow and where you grow it. 

The study compiled soil carbon information from dozens of other studies in order to get the big picture.  What it observes is that the amount of carbon that exists in the soil is increased by letting decomposing plant matter sit and eventually be absorbed into the earth, while tilling and plowing decreases the carbon in the soil, releasing it into the atmosphere.

Explains Evan DeLucia, a professor of plant biology at Illinois, "From the time that John Deere invented the steel plow, which made it possible to break the prairie sod and begin farming this part of the world, the application of row crop agriculture to the Midwest has caused a reduction of soil carbon of about 50 percent  The biggest terrestrial pool of carbon is in the soil. The top meter of soil holds more than three times the amount of carbon stored in either vegetation or the atmosphere, so if you do little things to change the amount of carbon in the soil it has a huge impact on the atmosphere and thus global warming."

Corn ethanol increases emissions, according to the study, because corn must be constantly replanted, and replanting requires tilling the fields.  Switchgrass, Miscanthus, and other fast-growing grasses, however, require no tilling and can grow wild, greatly increasing the soil's carbon and decreasing emissions.

Furthermore, these sources have more carbon density than corn, so once cost-efficient ways are created to process them, cellulosic ethanol should require much less land to produce than corn ethanol.

The study is significant, says Professor DeLucia as currently 20 percent of the U.S.'s corn crop goes to ethanol.  He describes "so we began with the hypothesis that it might be good for soil carbon to put a perennial biofuel crop on the landscape instead of corn."

From there they delved into massive amounts of information on soil carbon levels on land growing corn, sugar cane, Miscanthus, switchgrass and native prairie grasses, taking into consideration many factors.

They found that sugarcane, used greatly by Brazil's ethanol industry, is the worst offender when it comes to biofuels.  Sugarcane planted on native land slashes the carbon content, releasing vast amounts of carbon into the air.  Whereas perennial grasses add to soil carbon's base level each year, sugarcane land would require a century just to recover to the base level.

Corn showed similar, but lesser problems.  These problems could be alleviated somewhat by leaving more of the corn stover (plant waste) on the field, but the carbon was still cut significantly.

Losses from the initial planting of Miscanthus, switchgrass or native perennial grasses by on converted corn or sugarcane land took very little time to be neutralized thanks to great yearly gains in soil carbon.  Professor DeLucia states, "Consistent with our hypothesis, the perennial feedstocks like Miscanthus and switchgrass start building soil carbon very, very early on.  From a purely carbon perspective, our research indicates that putting perennial biofuel crops on landscapes that are dominated by annual row crops will have a positive effect on soil carbon."

These conclusions, he says, walk the study unintentionally "seems to walk you right into the food for fuel debate".  But he says that it just makes sense to plant grasses as biofuel feedstocks, even from a purely carbon-conscious perspective.

The research will be featured in the journal Global Change Biology Bioenergy next month.



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RE: Subsidies distort the market
By dever on 12/8/2008 3:00:27 PM , Rating: 0
And, unfortunately, in a style typical for this author, this article completely neglected to point out why the scourge of corn-based ethanol is even an issue... government subsidies.

Scientific American and several others have pointed out the problem with corn ethanol years ago.

Without government interference this would be a non-issue. Yet, people continue to tout the benefit of "supporting" alternative fuels, which invariably means interfering with the market via the crippling hand of government.

When will we learn that flexibility that comes with freedom of consumer choice will allow problems like this to be resolved quickly and efficiently?


RE: Subsidies distort the market
By Fronzbot on 12/8/2008 6:42:30 PM , Rating: 3
Hmm, I could say that in a style atypical of the author he actually produces a piece that runs counter to what the "liberal" media portrays as "eco-friendly".

I expect you trolls to come out and flame for my strategic placement of quotations and my somewhat defense of Jason Mick, otherwise this wouldn't be a proper Environmental article on Daily Tech now would it?


RE: Subsidies distort the market
By Solandri on 12/8/2008 8:32:36 PM , Rating: 5
I should point out that the corn subsidies are well-intentioned (at least initially) and serve a useful purpose. The government subsidizes food production to insure an oversupply. Food is demand inelastic. If a crop fails thus decreasing supply, demand does not drop proportionately. Demand stays the same (everyone has to eat), so the short supply results in skyrocketing prices.

To protect against this, the government subsidizes food production to insure there's an oversupply. We could have a bad season or a partial crop failure, and there'd still be enough food for everyone to eat. Usually the excess was sold overseas, sold as livestock feed, used as humanitarian aid, or it just goes bad in storage and gets thrown away.

Someone got the bright idea of using it to produce ethanol. After all, if it was going to rot in a grain silo otherwise, might as well use it. Applied only to the excess corn, it's a good idea. Unfortunately, if the idea works, you no longer have an oversupply of corn anymore. It now starts impacting the market price of food, and the subsidy makes it look bad for all involved.

So the subsidies aren't quite as evil as people are making them out to be. If it were just food, they'd be a good thing. But now that we're mixing food (which people need to live) and energy (which we can get elsewhere), it's starting to have unintentional synergies.


RE: Subsidies distort the market
By Ringold on 12/8/2008 8:53:20 PM , Rating: 2
quote:
Usually the excess was sold overseas


Thus keeping global prices down, thus pricing out developing world farmers, thus helping to perpetuate deep poverty in the poorest parts of the globe. No surprise, then, that European and American ag trade barriers consistently derail global trade talks.

It's all cute, and maybe well intentioned (the lobbyists I'm sure are very well intentioned), but that doesn't mean it's good for world as a whole. Just farmers.


RE: Subsidies distort the market
By MamiyaOtaru on 12/8/2008 11:04:47 PM , Rating: 2
Well now the rest of the world can be super happy that food prices are going up. This will lift them out of their poverty somehow.


RE: Subsidies distort the market
By Ringold on 12/9/2008 4:23:54 AM , Rating: 1
They've been going down lately, but years of depressed prices followed by a massive short spike did nobody any good (except, of course, developed country farmers who managed to lock in prices). The net effect in the developing world was sending 100m or so people back in to poverty; at least, that was the last estimate I heard out of the IMF or WB. Particularly hard on the urban poor, who have to buy their food. No surprise, prices went up more than they should have in many markets, and will do so again in the future, because in the midst of the spike many countries erected quick barriers; a typical attempt at sticking ones head in the sand and wishing the real world away. Thats the kind of action that leads to massive famine, not actual supply shortages.

Food prices also dropped quick enough that I've read some farmers will lose money; they put more fertilizer and whatnot on their crop than the crops are now worth.

So, heading right back to the status quo. There's no replacement for free trade.


RE: Subsidies distort the market
By dever on 12/9/2008 12:16:51 PM , Rating: 1
Government policies are always "well-intentioned" aren't they? I'm sure every single action taken by force through government, had at least one fool behind it who thought "it's for their own good whether they no it or not."

"Well intentioned" doesn't matter. Effects do.


"So if you want to save the planet, feel free to drive your Hummer. Just avoid the drive thru line at McDonalds." -- Michael Asher














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