Environmental benefit of biofuels is overestimated, new study reveals

Jun 08, 2012

Two scientists are challenging the currently accepted norms of biofuel production. A commentary published today in GCB Bioenergy reveals that calculations of greenhouse gas (GHGs) emissions from bioenergy production are neglecting crucial information that has led to the overestimation of the benefits of biofuels compared to fossil fuels.

The critique extends to the Life Cycle Analysis models of production. Life Cycle Analysis (LCA) is a technique used to measure and compile all factors relating to the production, usage, and disposal of a fuel or product. The authors conclude that LCAs are overestimating the positive aspects of use versus fossil fuel use by omitting the emission of CO2 by vehicles that use ethanol and biodiesel even when there is no valid justification.

Proponents of bioenergy argue that analyses should always ignore this CO2 because plants grown for biofuel absorb and therefore offset the same amount of carbon that is emitted by refining and combusting the fuel. The commentary critiques this method by arguing that doing so double counts the carbon absorbed by plants when the bioenergy crops are grown on land already used for crop production or already growing other plants because the bioenergy does not necessarily result in additional . Biofuels can only reduce if they result in additional plant growth, or if they in effect generate additional useable biomass by capturing that would otherwise decompose anyway.

The overestimation of bioenergy LCAs becomes increasingly magnified when the omission of CO2 is combined with the underestimation of nitrogen emissions from fertilizer application. According to lead author Dr. Keith Smith, from the University of Edinburgh, "Emissions of N2O from the soil make a large contribution to the global warming associated with crop production because each kilogram of N2O emitted to the atmosphere has about the same effect as 300kg of CO2." He notes that several current LCAs underestimate the percentage of nitrogen that is actually emitted to the atmosphere as a GHG. The authors claim that the observed increase in atmospheric shows that this percentage is in reality nearly double the values used in the LCAs, which greatly changes their outcome.

Since results of the LCAs have been widely utilized, Searchinger and Smith conclude that the overall development and research of alternative fuels has been heading in the wrong direction. "The best opportunity to make beneficial biofuels is to use waste material or to focus on relatively wet but highly degraded land," notes Dr. Smith. If bioenergy crops are produced on degraded land, less GHGs will be emitted and more will be stored. There are additional benefits: this method will not compete with crop production for food, textiles, and other products.

This paper is published in GCB Bioenergy.

Explore further: Next-generation nuclear reactors that use radioactive waste materials as fuel

More information: Smith, K, Searchinger, T. (2012), Crop-based biofuels and associated environmental concerns. GCB Bioenergy. doi: 10.1111/j.1757-1707.2012.01182.x

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User comments : 13

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mtc123
2 / 5 (8) Jun 08, 2012
Truth! Perhaps sanity is being restored to environmentalism. Probably not. The Algoreans have added these scientists to the smear list.
NotAsleep
4 / 5 (5) Jun 08, 2012
Proponents of bioenergy argue that analyses should always ignore this CO2 because plants grown for biofuel absorb and therefore offset the same amount of carbon that is emitted by refining and combusting the fuel.

I thought we'd actually stopped thinking along those lines a long time ago... was this article written years ago and just finally published?

Correct me if I'm wrong but I think algae-based biofuels are the last bastion for naturally harvested gasoline-equivalent fuels, and this only because it can be done in desert environments where we wouldn't otherwise be growing crops
NotParker
1.6 / 5 (14) Jun 08, 2012
"omitting the emission of CO2 by vehicles that use ethanol and biodiesel even when there is no valid justification."

Translation: The AGW Cult Lies.
Origin
1.4 / 5 (11) Jun 08, 2012
AGW has nothing to do with environmental benefit of biofuels (or whatever else fuels). For me it's just another way, how to evade the investments into cold fusion research and the environmental benefit of biofuels is actually negative from long-term perspective. It would be great to cover the Sahara with biofuel crops, but you'll need the energy for desalination of water first. Without it we'll make a Sahara from existing tropical forests instead. These connections were known a long time before the biofuel industry has established - it was just an evasion for easy access to the remainders of the wood and soil supplies covered with tropical forests.
NotParker
2.1 / 5 (10) Jun 08, 2012
There is no environmental benefit to biofuels. The could be an economic benefit in terms of balance of payments, make work projects etc.

But it traditionally diverts food crops and thereby increases food costs.

And ethanol is not necessarily a good fuel and it can do damage to engines.
antialias_physorg
5 / 5 (5) Jun 08, 2012
I have a question: Would we grow food if we weren't be growing biofuel-plants? I mean aren't we producing food for the available demand. If we don't produce biofuels demand for food doesn't just suddenly increase so we have to use these fields for food crops, does it?

Biofuels don't reduce greenhouse gases, they just prevent more to be added (by replacing the use of fossil fuels).

Adding NO2 is a valid point. We should be moving away from burning stuff, anyhow. That's just not...elegant technology

Terriva
2 / 5 (6) Jun 08, 2012
Would we grow food if we weren't be growing biofuel-plants?
We wouldn't destroy rainforrests for it so we wouldn't experience droughts and another climate extremes so frequently. We could say demagogically, the cheap bioethanol from Panama had come at the high price for Texans - but these extremes are increasing the cost of food production over the whole world. Of course, I do realize, you as a formally thinking member of PO forum cannot account to these distributed sources of added costs, until they cannot be expressed in money directly. We could say, the physicists who spend their life in observations of Universe with transverse waves are blind to distributed phenomena mediated with longitudinal waves.
Sanescience
5 / 5 (1) Jun 08, 2012
I find this to be somewhat in the camp of paralysis of action because no perfect solution that is all things to all people is available. The default is to then fall back to status quo.

Just because step one of not adding more CO2 doesn't accomplish the goal of removing CO2 from the atmosphere, doesn't mean it isn't worth doing.

As for food vs fuel, yes there is some concern there, but GM grass grown on land unsutable for farming might be part of the solution. See these:

http://phys.org/n...ose.html

http://arstechnic...iofuels/
jerryd
5 / 5 (1) Jun 08, 2012
What a bunch of Bull. Of course biofuels don't make new CO2 and even if it did if you do a full account of gasoline, diesel you'll find it far worse.

For instance just the 3kw of electricity to refine a gal of gasoline my EV's go 30 and 60 miles. Add all those energy leaks, drilling, production, transport, cleaning, refining, sulfur removal, etc and oil is not good.

Vs biofuels like which can be made without inputs from other energy either on the farm or the plant. Also one needs to count the byproducts like in ethanol the corn oil, dried mash/DDG's, stalks/cobs have enough value the corn feedstock is almost free.

Likely you'll find links to big oil if you check the study financing because it's obviously biased.

Big oil is getting scared as they are going to have to pay the full cost instead of putting it off onto the US taxpayer.

Just why do we protect international oil companies and oil dictators for free? For 50% of that we could be energy independent in 5 yrs

Feldagast
1 / 5 (2) Jun 09, 2012
Until the power plants that use coal, natural gas, nuclear shut down and then you EV's go no where.
hagger
3 / 5 (2) Jun 09, 2012
turning food producing land into feilds of bio fuel just so the americans can continue to use huge engined cars and consume subsidised petrol is nothing short of insanity..shall i eat or drive to the mall to buy food that will soon be rationed as all the arable land is used for growing fuel..a fuel that can never replace oil..the US oil boom has peaked..it now imports oil..why do you think they are in the middle east..oil..not democracy..oil production has peaked world wide..we had it good..god help our kids..
NotParker
1.8 / 5 (5) Jun 09, 2012
turning food producing land into feilds of bio fuel just so the americans can continue to use huge engined cars and consume subsidised petrol is nothing short of insanity..shall i eat or drive to the mall to buy food that will soon be rationed as all the arable land is used for growing fuel..a fuel that can never replace oil..the US oil boom has peaked..it now imports oil..why do you think they are in the middle east..oil..not democracy..oil production has peaked world wide..we had it good..god help our kids..


The Russians have discovered an oil shale field similar to the Bakken that has 4,000 years of oil in total. And probably 100 years of easily recoverable oil.

"enough oil to satisfy all of current global demand for 64 years, or to do 5 million bpd for more than 1,000 years"

http://www.forbes...ale-oil/
wwqq
5 / 5 (1) Jun 12, 2012
The Russians have discovered an oil shale field similar to the Bakken that has 4,000 years of oil in total. And probably 100 years of easily recoverable oil.


What a pity then that we shall have to leave nearly all of it in the ground.