by vox_mundi » Sat 28 Mar 2015, 12:26:48
$this->bbcode_second_pass_quote('Tanada', '')$this->bbcode_second_pass_quote('Keith_McClary', '[')url=http://phys.org/news/2015-03-biofuel-policies-emissions-food.html]Do biofuel policies seek to cut emissions by cutting food?[/url]
$this->bbcode_second_pass_quote('', 'S')hrinking the amount of food that people and livestock eat decreases the amount of carbon dioxide that they breathe out or excrete as waste. The reduction in food available for consumption, rather than any inherent fuel efficiency, drives the decline in carbon dioxide emissions in government models, the researchers found.
I call BS on that claim. When you convert a grain to biological energy you get out water and CO2. When you ferment grain to get Ethanol you get out water, Ethanol and CO2. When you then burn that Ethanol in any way you get more water vapor and CO2. The chemistry has exactly the same result with much added complexity and energy input to ferment the grain and then transport the Ethanol that results, and most leftover mash from the process is then used as feed stock for animals. No water or CO2 output is prevented by fermentation, quite the opposite.
T - Your analysis is flawed.Grain converted to EtOH = H
2O + CO
2 (EtOH burns to H
2O + CO
2)
Grain converted to beef = H
2O + CO
2 +
Methane...Even if only 3% of the residual product is converted to Methane the GW effect would exceed that produced by CO2Mash is depleted of carbohydrates (sugars) and is used principally as a protein and fiber supplement.
From the original post ...
$this->bbcode_second_pass_quote('', 'T')he study looked at three models used by U.S. and European agencies, and found that all three estimate that some of the crops diverted from food to biofuels are not replaced by planting crops elsewhere. About 20 percent to 50 percent of the net calories diverted to make ethanol are not replaced through the planting of additional crops, the study found.
The result is that less food is available, and, according to the study, these missing calories are not simply extras enjoyed in resource-rich countries. Instead, when less food is available, prices go up. "The impacts on food consumption result not from a tailored tax on excess consumption but from broad global price increases that will disproportionately affect some of the world's poor," Searchinger said.
Both the models used by the U.S. Environmental Protection Agency and the California Air Resources Board indicate that ethanol made from corn and wheat generates modestly fewer emissions than gasoline. The fact that these lowered emissions come from reductions in food production is buried in the methodology and not explicitly stated, the study found.
The European Commission's model found an even greater reduction in emissions. It includes reductions in both quantity and overall food quality due to the replacement of oils and vegetables by corn and wheat, which are of lesser nutritional value.
"Without these reductions in food quantity and quality, the [European] model would estimate that wheat ethanol generates 46% higher emissions than gasoline and corn ethanol 68% higher emissions," Searching said.
by Keith_McClary » Sat 28 Mar 2015, 13:34:36
The article is a full copy from Princeton U
By Catherine Zandonella, Office of the Dean for Research (including "decreases the amount of carbon dioxide that they breathe out or excrete as waste", so I can't blame PhysOrg science journalism).
Author Tim Searchinger writes on
the WRI blog:
$this->bbcode_second_pass_quote('', 'S')tudies that find bioenergy reduces greenhouse gases incorrectly view plants as a carbon-free fuel and ignore the very real carbon emitted by burning them. The theory has been that the original growth of the plants absorbs enough carbon to offset the carbon released when they burn. But if those plants were going to grow and absorb carbon anyway – and typically they would – then diverting them to bioenergy does not remove any additional carbon from the atmosphere. Instead, bioenergy comes at the expense of some other uses of those plants. When the expense is food or agricultural land, the effect is poorer nutrition. When the expense is forests or woody savannas, the effect is less stored carbon.

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by Tanada » Sat 28 Mar 2015, 16:36:56
$this->bbcode_second_pass_quote('vox_mundi', '')$this->bbcode_second_pass_quote('Tanada', '')$this->bbcode_second_pass_quote('Keith_McClary', '[')url=http://phys.org/news/2015-03-biofuel-policies-emissions-food.html]Do biofuel policies seek to cut emissions by cutting food?[/url]
$this->bbcode_second_pass_quote('', 'S')hrinking the amount of food that people and livestock eat decreases the amount of carbon dioxide that they breathe out or excrete as waste. The reduction in food available for consumption, rather than any inherent fuel efficiency, drives the decline in carbon dioxide emissions in government models, the researchers found.
I call BS on that claim. When you convert a grain to biological energy you get out water and CO2. When you ferment grain to get Ethanol you get out water, Ethanol and CO2. When you then burn that Ethanol in any way you get more water vapor and CO2. The chemistry has exactly the same result with much added complexity and energy input to ferment the grain and then transport the Ethanol that results, and most leftover mash from the process is then used as feed stock for animals. No water or CO2 output is prevented by fermentation, quite the opposite.
T - Your analysis is flawed.Grain converted to EtOH = H
2O + CO
2 (EtOH burns to H
2O + CO
2)
Grain converted to beef = H
2O + CO
2 +
Methane...Even if only 3% of the residual product is converted to Methane the GW effect would exceed that produced by CO2Mash is depleted of carbohydrates (sugars) and is used principally as a protein and fiber supplement.
From the original post ...
$this->bbcode_second_pass_quote('', 'T')he study looked at three models used by U.S. and European agencies, and found that all three estimate that some of the crops diverted from food to biofuels are not replaced by planting crops elsewhere. About 20 percent to 50 percent of the net calories diverted to make ethanol are not replaced through the planting of additional crops, the study found.
The result is that less food is available, and, according to the study, these missing calories are not simply extras enjoyed in resource-rich countries. Instead, when less food is available, prices go up. "The impacts on food consumption result not from a tailored tax on excess consumption but from broad global price increases that will disproportionately affect some of the world's poor," Searchinger said.
Both the models used by the U.S. Environmental Protection Agency and the California Air Resources Board indicate that ethanol made from corn and wheat generates modestly fewer emissions than gasoline. The fact that these lowered emissions come from reductions in food production is buried in the methodology and not explicitly stated, the study found.
The European Commission's model found an even greater reduction in emissions. It includes reductions in both quantity and overall food quality due to the replacement of oils and vegetables by corn and wheat, which are of lesser nutritional value.
"Without these reductions in food quantity and quality, the [European] model would estimate that wheat ethanol generates 46% higher emissions than gasoline and corn ethanol 68% higher emissions," Searching said.