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We estimate emissions from indirect land‐use change associated with U.S. corn ethanol production by using the updated Center for Agricultural and Rural Development/Food and Agricultural Policy Research Institute global agricultural outlook model, which incorporates sub‐national land‐use modeling in Brazil and endogenous crop yield‐price relationships. Emissions estimates range between 9.7–23.9 g CO2 per mega Joule (MJ−1), which is consistent with other estimates. We compare the results of the current model to the 2008 model version. Using the data from the 2016 model in the 2008 model results in emissions that range from 23.2–32.2 g CO2 MJ−1. The addition of detailed modelling in Brazil, for example, double‐cropping, reduced estimates considerably and highlights the importance of continuous improvements in global agricultural models. [ABSTRACT FROM AUTHOR]

Abstract: A partial solution to problems associated with anthropogenic greenhouse gas (GHG) emissions could be the development and deployment of carbon-negative technologies, i.e., producing energy while reducing atmospheric carbon dioxide levels. Biofuels have been considered a possibility but have faced limitations due to competition with food production and GHG emissions through indirect land-use change (ILUC). In this article, we show how emissions from ILUC can potentially be reduced by producing food and bioenergy from biochar amended soils. The possibility of yield improvements from biochar would reduce the land requirement for crop production and thus, lead to a reduction in emissions from ILUC. In our application, biochar and bio-oil are produced via fast pyrolysis of corn stover. Bio-oil is subsequently upgraded into a fuel suitable for use in internal combustion engines. Applying the U.S. regulatory method used to determine biofuel life cycle emissions, our results show that a biochar-induced yield improvement in the U.S. Midwest ranging from 1% to 8% above trend can lead to an ILUC credit between 1.65 and 14.79 t CO2-equivalent ha−1 year−1 when future emissions are assessed over the next 30 years. The model is generalizable to other feedstocks and locations and illustrates the relationship between biochar and crop production. [Copyright &y& Elsevier]

• Carbon tax on energy inputs reduces land allocated to crops in the United States. • U.S. carbon tax on energy inputs shifts some cropland to other countries. • Small carbon leakage from shifting agricultural production. • Increase in carbon emissions offset by overall emission reduction. There is increased interest in a carbon tax in the United States (U.S.) and policy makers, farmers, and other stakeholders need to understand the various economic and environmental aspects of such a policy on agriculture. A global agricultural simulation model assesses changes in production, commodity prices, and trade resulting from a U.S. carbon tax. In addition, greenhouse gas (GHG) emissions from land-use change are quantified to evaluate the possible unintended consequence of increasing emissions in the rest of the world. Three U.S. carbon tax scenarios are evaluated ranging from $15–$144 per metric ton of carbon dioxide equivalent (t−1 CO 2 -e) and covering a 10-year projection period. The results show that the production cost for corn and soybeans increase by a maximum of 32.6% and 22.4%, respectively at a carbon tax of $144 t−1 CO 2 -e. The production cost increase is compensated in part by an increase in commodity prices. Hence, the decrease in net returns for corn, soybeans, and wheat is 11.4%, 8.7%, and 11.0%, respectively, in the scenario with the highest carbon price. U.S. exports decrease for major commodities such as corn (24.9%), sorghum (20.5%), and wheat (8.7%). Barley, soybeans, and sunflower see an increase in exports of 1.2–8.8%. These changes in trade patterns also result in a re-allocation of land-use in the rest of the world leading to a slight increase in global GHG emissions from land-use change representing 1.8% of total U.S. emissions in 2017. The increase in emissions is small compared to the overall projected reduction from the carbon tax. Policy makers need to be cognizant of leakage in terms of land-use change and that measures must be taken to avoid expansion into carbon rich native vegetation. [ABSTRACT FROM AUTHOR]