Quote: ThirstyMan wrote in post #1

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By John DeCicco, University of Michigan | Oct. 5, 2016

Many scientists view biofuels as inherently carbon-neutral: They assume the carbon dioxide (CO2) plants absorb from the air as they grow completely offsets, or "neutralizes," the CO2 emitted when fuels made from plants burn. Many years of computer modeling based on this assumption, including work supported by the U.S. Department of Energy, concluded that using biofuels to replace gasoline significantly reduced CO2 emissions from transportation.

Our new study takes a fresh look at this question. We examined crop data to evaluate whether enough CO2 was absorbed on farmland to balance out the CO2 emitted when biofuels are burned. It turns out that once all the emissions associated with growing feedstock crops and manufacturing biofuel are factored in, biofuels actually increase CO2 emissions rather than reducing them.

Biofuel boom, climate blunder

Federal and state policies have subsidized corn ethanol since the 1970s, but biofuels gained support as a tool for promoting energy independence and reducing oil imports after the Sept. 11, 2001 attacks. In 2005, Congress enacted the Renewable Fuel Standard, which required fuel refiners to blend 7.5 billion gallons of ethanol into gasoline by 2012. (For comparison, in that year Americans used 133 billion gallons of gasoline.)
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Over the same period, however, CO2 emissions from fermenting and burning biofuels increased by 132 teragrams. Therefore, the greater carbon uptake associated with crop growth offset only 37 percent of biofuel-related CO2 emissions from 2005 through 2013. In other words, biofuels are far from inherently carbon-neutral.

Carbon flows and the 'climate bathtub'

This result contradicts most established work on biofuels. To understand why, it is helpful to think of the atmosphere as a bathtub that is filled with CO2 instead of water.

Many activities on Earth add CO2 to the atmosphere, like water flowing from a faucet into the tub. The largest source is respiration: Carbon is the fuel of life, and all living things "burn carbs" to power their metabolisms. Burning ethanol, gasoline or any other carbon-based fuel opens up the CO2 "faucet" further and adds carbon to the atmosphere faster than natural metabolic processes.

Nevertheless, expanding production of corn and soybeans for biofuels increased CO2 uptake only enough to offset 37 percent of the CO2 directly tied to biofuel use. Moreover, it was far from enough to offset other GHG emissions during biofuel production from sources including fertilizer use, farm operations and fuel refining. Additionally, when farmers convert grasslands, wetlands and other habitats that store large quantities of carbon into cropland, very large CO2 releases occur.

Mistaken modeling

Our new study has sparked controversy because it contradicts many prior analyses. These studies used an approach called lifecycle analysis, or LCA, in which analysts add up all of the GHG emissions associated with producing and using a product. The result is popularly called the product's "carbon footprint."

The LCA studies used to justify and administer renewable fuel policies evaluate only emissions – that is, the CO2 flowing into the air – and failed to assess whether biofuel production increased the rate at which croplands removed CO2 from the atmosphere. Instead, LCA simply assumes that because energy crops such as corn and soybeans can be regrown from one year to the next, they automatically remove as much carbon from the atmosphere as they release during biofuel combustion. This significant assumption is hard-coded into LCA computer models.

Unfortunately, LCA is the basis for the RFS as well as California's Low-Carbon Fuel Standard, a key element of that state's ambitious climate action plan. It is also used by other agencies, research institutions and businesses with an interest in transportation fuels.
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These approaches will help to protect biodiversity – another global sustainability challenge – instead of threatening it as biofuel production does. Our analysis also offers another insight: Once carbon has been removed from the air, it rarely makes sense to expend energy and emissions to process it into biofuels only to burn the carbon and re-release it into the atmosphere.

http://www.upi.com/Top_News/Opinion/2016.../3611475690695/

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Our new study has sparked controversy because it contradicts many prior analyses. These studies used an approach called lifecycle analysis, or LCA, in which analysts add up all of the GHG emissions associated with producing and using a product. The result is popularly called the product's "carbon footprint."

The LCA studies used to justify and administer renewable fuel policies evaluate only emissions – that is, the CO2 flowing into the air – and failed to assess whether biofuel production increased the rate at which croplands removed CO2 from the atmosphere. Instead, LCA simply assumes that because energy crops such as corn and soybeans can be regrown from one year to the next, they automatically remove as much carbon from the atmosphere as they release during biofuel combustion. This significant assumption is hard-coded into LCA computer models.

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There is an old joke in IT. If you do not like the output when testing your work, just change the input. This is exactly what the climate change/CO2 bad mongers have dome.

Quote: ThirstyMan wrote in post #4

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Did you mention, Climate Change CO2 Mongers?



Talk about a basketful of deplorables!

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