Most prior studies have found that substituting biofuels for gasoline will reduce greenhouse gases because biofuels sequester carbon through the growth of the feedstock. These analyses have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels. By using a worldwide agricultural model to estimate emissions from land-use change, we found that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50%. This result raises concerns about large biofuel mandates and highlights the value of using waste products.

We analyze the sensitivity of greenhouse gas (GHG) emissions from land-use change to modifications in assumptions concerning crop area, yield, and deforestation. For this purpose, we run a modified version of the Center for Agricultural and Rural Development (CARD) Agricultural Outlook Model, which was used previously to assess the impacts of energy price increases and biofuel policy changes on land conversion. To calculate the GHG implications of agricultural activity, we use GreenAgSiM, a model developed to evaluate emissions from land conversion and agricultural production. Both models are applied to scenarios that lead to higher US ethanol production. The results are contrasted with the findings of Searchinger et al., and we explain the role of model assumptions to elucidate the differences. We find that the payback period of corn ethanol's carbon debt is sensitive to assumptions concerning land conversion and yield growth and can range from 31 to 180 years.

We analyze the impact of trade liberalization and removal of the federal tax credit in the United States on ethanol markets using a multimarket international ethanol model. We find that U.S. trade barriers have been effective in protecting the ethanol industry. Under current policy, there is separability of the U.S. ethanol market from world markets. With trade liberalization, the ethanol market deepens, making it less susceptible to price volatility. The effect of trade liberalization extends beyond ethanol markets, affecting agricultural markets. The results show that the impact of removal of the tax credit overrides the impact of the tariff removal. Copyright 2008, Oxford University Press.

We quantify the emergence of biofuel markets and its impact on U.S. and world agriculture for the coming decade using the multi-market, multi-commodity international FAPRI (Food and Agricultural Policy Research Institute) model. The model incorporates the trade-offs between biofuel, feed, and food production and consumption and international feedback effects of the emergence through world commodity prices and trade. We examine land allocation by type of crop, and pasture use for countries growing feedstock for ethanol (corn, sorghum, wheat, sugarcane, and other grains) and major crops competing with feedstock for land resources such as oilseeds. We shock the model with exogenous changes in ethanol demand, first in the United States, then in Brazil, China, the European Union-25, and India, and compute shock multipliers for land allocation decisions for crops and countries of interest. The multipliers show at the margin how sensitive land allocation is to the growing demand for ethanol. Land moves away from major crops and pasture competing for resources with feedstock crops. Because of the high U.S. tariff on ethanol, higher U.S. demand for ethanol translates into a U.S. ethanol production expansion. The latter has global effects on land allocation as higher coarse grain prices transmit worldwide. Changes in U.S. coarse grain prices also affect U.S. wheat and oilseed prices, which are all transmitted to world markets. In contrast, expansion in Brazil ethanol use and production chiefly affects land used for sugarcane production in Brazil and to a lesser extent in other sugar-producing countries, but with small impacts on other land uses in most countries. AbstractWe quantify the emergence of biofuel markets and its impact on U.S. and world agriculture for the coming decade using the multi-market, multi-commodity international FAPRI (Food and Agricultural Policy Research Institute) model. The model incorporates the trade-offs between biofuel, feed, and food production and consumption and international feedback effects of the emergence through world commodity prices and trade. We examine land allocation by type of crop, and pasture use for countries growing feedstock for ethanol (corn, sorghum, wheat, sugarcane, and other grains) and major crops competing with feedstock for land resources such as oilseeds. We shock the model with exogenous changes in ethanol demand, first in the UnitedStates, then in Brazil, China, the European Union-25, and India, and compute shock multipliers for land allocation decisions for crops and countries of interest. The multipliers show at the margin how sensitive land allocation is to the growing demand for ethanol. Land moves away from major crops and pasture competing for resources with feedstock crops. Because of the high U.S. tariff on ethanol, higher U.S. demand for ethanol translates into a U.S. ethanol production expansion. The latter has global effects on land allocation as higher coarse grain prices transmit worldwide. Changes in U.S. coarse grain prices also affect U.S...

The Midwestern U.S. landscape is one of the most highly altered and intensively managed ecosystems in the country. The predominant crops grown are maize (Zea mays L.) and soybean [Glycine max (L.) Merr]. They are typically grown as monocrops in a simple yearly rotation or with multiple years of maize (2 to 3) followed by a single year of soybean. This system is highly productive because the crops and management systems have been well adapted to the regional growing conditions through substantial public and private investment. Furthermore, markets and supporting infrastructure are highly developed for both crops. As maize and soybean production have intensified, a number of concerns have arisen due to the unintended environmental impacts on the ecosystem. Many areas across the Midwest are experiencing negative impacts on water quality, soil degradation, and increased flood risk due to changes in regional hydrology. The water quality impacts extend even further downstream. We propose the development of an innovative system for growing maize and soybean with perennial groundcover to recover ecosystem services historically provided naturally by predominantly perennial native plant communities. Reincorporating perennial plants into annual cropping systems has the potential of restoring ecosystem services without negatively impacting grain crop production and offers the prospect of increasing grain crop productivity through improving the biological functioning of the system.

We analyse the impact of trade liberalisation, removal of production subsidies and elimination of consumption distortions in world sugar markets using a partial-equilibrium international sugar model calibrated on 2002 market data and current policies. The removal of trade distortions alone induces a 27% price increase while the removal of all trade and production distortions induces a 48% increase in 2011/2012 relative to the baseline. Aggregate trade expands moderately, but location of production and trade patterns change substantially. Protectionist Organisation for Economic Co-operation and Development (OECD) countries (the EU, Japan, the US) experience an import expansion or export reduction and a significant contraction of production in unfettered markets. Competitive producers in both OECD countries (Australia) and non-OECD countries (Brazil, Cuba), and even some protected producers (Indonesia, Turkey), expand production when all distortions are removed. Consumption distortions have marginal impacts on world markets and the location of production. We discuss the significance of these results in the context of mounting pressures to increase market access in highly protected OECD countries and the impact on non-OECD countries. Copyright 2006 Blackwell Publishing Ltd.

We estimate emissions from indirect land-use change associated with U.S. corn ethanol production by using the updated CARD/FAPRI global agricultural outlook model which incorporates sub-national landuse modeling in Brazil and endogenous crop yield-price relationships. Emissions estimates are 9.7-23.9 g CO 2 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 of 23.2-32.2 g CO 2 MJ −1. The addition of detailed modelling in Brazil, e.g., doublecropping, reduced estimates considerably and highlights the importance of continuous improvements in global agricultural models. 1 43% of all countries that experience land-use change expansion.

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