U.S. Corn-Based Ethanol Worse For The Climate Than Gasoline, Study Finds

 Source:

https://wattsupwiththat.com/2022/02/17/u-s-corn-based-ethanol-worse-for-the-climate-than-gasoline-study-finds/

New study published at PNAS.
https://www.pnas.org/content/119/9/e2101084119

"Biofuels are included in many proposed strategies to reduce anthropogenic greenhouse gas emissions and limit the magnitude of global warming.

The US Renewable Fuel Standard is the world’s largest existing biofuel program, yet despite its prominence, there has been limited empirical assessment of the program’s environmental outcomes.

Even without considering likely international land use effects, we find that the production of corn-based ethanol in the United States has failed to meet the policy’s own greenhouse gas emissions targets

and negatively affected water quality, the area of land used for conservation, and other ecosystem processes.

Our findings suggest that profound advances in technology and policy are still needed to achieve the intended environmental benefits of biofuel production and use.

    Abstract

    The Renewable Fuel Standard (RFS) specifies the use of biofuels in the United States and thereby guides nearly half of all global biofuel production, yet outcomes of this keystone climate and environmental regulation remain unclear.

Here we combine econometric analyses, land use observations, and biophysical models to estimate the realized effects of the RFS in aggregate and down to the scale of individual agricultural fields across the United States.

We find that the RFS increased corn prices by 30% and the prices of other crops by 20%, which, in turn, expanded US corn cultivation by 2.8 Mha (8.7%) and total cropland by 2.1 Mha (2.4%) in the years following policy enactment (2008 to 2016).

These changes increased annual nationwide fertilizer use by 3 to 8%, increased water quality degradants by 3 to 5%, and caused enough domestic land use change emissions such that the carbon intensity of corn ethanol produced under the RFS is no less than gasoline and likely at least 24% higher.

These tradeoffs must be weighed alongside the benefits of biofuels as decision-makers consider the future of renewable energy policies and the potential for fuels like corn ethanol to meet climate mitigation goals."

They also examine the effect of the RFS on food prices, something which became very apparent back in 2008

    We found that the RFS stimulated 20.8 billion L (5.5 Bgal) of additional annual ethanol production, which requires nearly 1.3 billion bushels of corn after accounting for coproducts that can be fed to animals.

This heightened demand led to persistent increases in corn prices of ∼31%, increasing soybean prices by 19%, and wheat by 20%

 The increase in corn prices relative to other crops increased the area planted to corn on existing cropland by an average of 2.8 Mha* per year, which is an 8.7% increase attributable to the RFS.

This additional area resulted from producers planting corn more frequently, including a 2.1 Mha increase in continuous corn production (i.e., sequential year cropping) and a 1.4 Mha increase in the area planted in rotation with other crops.

Collectively, corn area increased most markedly in North and South Dakota, western Minnesota, and the Mississippi Alluvial Plain—regions where the amount of corn increased 50 to 100% due to the RFS"