Comment Log Display

Below are comments on the recirculated draft EIS for the LCFS.
These comments are also attached in a zip file along with other
materials as attachments.


COMMENTS OF STEVE BERRY & TIM SEARCHINGER
ON RECIRCULATED DRAFT ENVIRONMENTAL IMPACT STATEMENT
FOR REVISIONS TO LOW CARBON FUEL STANDARD
(September 2024)


Steven Berry, David Swenson Professor of Economics, Yale University
(steven.berry@yale.edu) 
Timothy D. Searchinger, Senior Research Scholar, Princeton
University (tsearchi@princeton.edu)

 	We are an economist at Yale University and an environmental
scientist at Princeton University and have written papers analyzing
the emissions from biofuel use and global land use models. We have
previously submitted comments on the proposed revisions to the LCFS
and on the most recent 15-day rule amendments. These comments also
include a recent paper in which we analyze the GTAP model used by
CARB to estimate indirect land use change emissions from crop-based
biofuels. In these comments, and in this paper, we briefly explain
the compelling evidence that crop-based biofuels are contributing
heavily to global cropland expansion and tropical deforestation and
likely increase emissions relative to fossil emissions. We also
explain how the GTAP model lacks a credible empirical basis, how it
has built in structural biases and ungrounded assumptions that
guarantee the low ILUC estimates, and how it produces physically
impossible land use results by a large margin that are then
arbitrarily readjusted to conserve land. 

	We here resubmit these earlier comments and attachments and now
also include an annotated slide presentation that summarizes our
research findings. We also include comments submitted by
Searchinger and Professors Dan Kammen and Michael O'Hare of the
University of California at Berkeley to a panel of the National
Research Council that discusses these issues.	

	The GTAP model results provide the core justification in the
recirculated draft environmental impact statement of the findings
that the proposed LCFS revisions will reduce greenhouse gas
emissions. These findings of reduced emissions are implicitly or
explicitly mentioned in much of the document and set forth
quantitatively on pages 59-60. In fact, the best evidence is that
at least the elements of the rule that assign reductions in
greenhouse gas fuel intensity to crop-based biofuels in general,
and vegetable oil-based biofuels in particular, will likely result
in large increases in global greenhouse gas emissions over the
30-year period that CARB uses to evaluate the effects of biofuels.
These increased emissions are particularly significant if CARB does
not cap crop-based biofuels. Because the GTAP model lacks a
credible empirical basis for the reasons set forth in our paper,
the findings of greenhouse gas reductions in the EIS lack a
credible basis or substantial evidence. 

	Another concern with the draft EIS is that it fails to acknowledge
the prominent role that reduced food consumption due to higher food
prices plays in CARB's lifecycle analysis for biofuels, and
particularly ethanol. These effects were revealed in a paper
published by the original GTAP modelers for CARB (Hertel et al.
2010). This effect was also further elaborated in a paper by
Searchinger (Searchinger et al. 2015), and was the focus of
comments by Berry when hired as an expert consultant by CARB at the
time GTAP was first used. 

To summarize the implications for food consumption, one prediction
of the GTAP model is that roughly half of the crop calories
diverted to corn ethanol are not replaced. The reduced food
consumption by people or by the livestock they eat results in
reduced respiration of carbon dioxide. The way the lifecycle
calculation works, this reduction in respiration works as an offset
to the greenhouse gas emissions that occur when ethanol is
combusted. (Illustrations showing how this offset works in
lifecycle analyses are shown in Searchinger [2010]). Without this
effect, the GTAP model would have found that ethanol increases
greenhouse gas emissions. Although the lack of credibility of the
GTAP model makes this finding questionable, if CARB relies on the
GTAP model, the role of reduced food consumption should be
prominently disclosed to allow a proper consideration of the
proposed rule. There is also more reliable evidence that in the
short-term, biofuel increases do result in reduced food consumption
(Roberts and Schlenker 2013). 


References

Hertel, Thomas W., Alla A. Golub, Andrew D. Jones, Michael O'Hare,
Richard J. Plevin, and Daniel M. Kammen. 2010. "Effects of US Maize
Ethanol on Global Land Use and Greenhouse Gas Emissions: Estimating
Market-Mediated Responses." BioScience 60 (3): 223-31.
https://doi.org/10.1525/bio.2010.60.3.8.
Roberts, Michael J, and Wolfram Schlenker. 2013. "Identifying
Supply and Demand Elasticities of Agricultural Commodities:
Implications for the US Ethanol Mandate." American Economic Review
103 (6): 2265-95. https://doi.org/10.1257/aer.103.6.2265.
Searchinger, T.D. 2010. "Biofuels and the Need for Additional
Carbon." Environmental Research Letters 5 (2): 024007.
https://doi.org/10.1088/1748-9326/5/2/024007.
Searchinger, T.D., R. Edwards, D. Mulligan, R. Heimlich, and R.
Plevin. 2015. "Do Biofuel Policies Seek to Cut Emissions by Cutting
Food?" Science 347 (6229): 1420-22.
https://doi.org/10.1126/science.1261221.