Search

The article provides information on the undergraduate research papers on agricultural and applied economics that secured second and third place. Zeke Bryant of University of Georgia, secured second place for "An Analysis of U.S. Tariffs on Chinese Solar Cells." Heather Hatzenbuhler of University of Georgia, secured third place for his research on "Biofuels: Rational, Policy Failures and a Way Forward for the State of Georgia."

Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas ( GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are reduced and on what timescale, we construct the GHG balance of wood-pellet electricity. This GHG balance consists of supply chain and combustion GHG emissions, carbon sequestration during biomass growth and avoided GHG emissions through replacing fossil electricity. We investigate wood pellets from four softwood feedstock types: small roundwood, commercial thinnings, harvest residues and mill residues. Per feedstock, the GHG balance of wood-pellet electricity is compared against those of alternative scenarios. Alternative scenarios are combinations of alternative fates of the feedstock materials, such as in-forest decomposition, or the production of paper or wood panels like oriented strand board ( OSB). Alternative scenario composition depends on feedstock type and local demand for this feedstock. Results indicate that the GHG balance of wood-pellet electricity equals that of alternative scenarios within 0-21 years (the GHG parity time), after which wood-pellet electricity has sustained climate benefits. Parity times increase by a maximum of 12 years when varying key variables (emissions associated with paper and panels, soil carbon increase via feedstock decomposition, wood-pellet electricity supply chain emissions) within maximum plausible ranges. Using commercial thinnings, harvest residues or mill residues as feedstock leads to the shortest GHG parity times (0-6 years) and fastest GHG benefits from wood-pellet electricity. We find shorter GHG parity times than previous studies, for we use a novel approach that differentiates feedstocks and considers alternative scenarios based on (combinations of) alternative feedstock fates, rather than on alternative land uses. This novel approach is relevant for bioenergy derived from low-value feedstocks. [ABSTRACT FROM AUTHOR]

A variety of forces aligned at the turn of the last century to make ethyl alcohol - what is today known as ethanol - inefficient and uneconomical as a fuel alternative. Rather than a case of inevitable technological unfolding, the transition from King Coal to Big Oil was a sociologically contingent event. As a controversy study, this paper seeks to avoid the reductionist tendencies of past historical analyses of fuel. The author also seeks to redress a fundamental gap within the STS literature on the subject of automobile/fuel socio-technical systems, where the story of ethyl alcohol remains conspicuously absent. Among studies that examine how/why the automobile became locked in, little is said about ethyl alcohol, even though, as this paper details, it remained part of the fuel landscape well into the 20th century. The paper begins with an overview of the landscape developments of fuel during the later decades of the 19th century. Attention then turns to examining the various factors that went into shaping the automobile/fuel socio-technical system within the US during the first half of the 20th century. [ABSTRACT FROM AUTHOR]

This article reflects on the article "A Robust Strategy for Sustainable Energy," by Klaus S. Lackner and Jeffrey D. Sachs. The author agrees with the conclusion of the article which states that there is no shortage of energy on the horizon. It points out that the debate over the exhaustion of liquid fuels is mostly based on false premises. But the author feels a more complete discussion of the making of liquid fuel from biomass was missing from the article. Biomass, which would compete for land with food producers, and biomass such as corn stalks which can be used to create fuel. Lackner's and Sach's article constructs a baseline scenario for greenhouse gas emissions over the next century on the basis of an assumed convergence of income per capita around the world on income per capita in the United States.

The article presents a commentary on bioenergy in a global environment. The author mentions some papers focusing on biofuels and the effects of the industry on economic stability, global food prices, and climate change. The author comments on the papers and renders perspectives on the U.S. bioenergy sector and its policies.

A growing biofuels industry requires the devel- opment of effective methods to educate farmers, govern- ment, and agribusiness about biofuel feedstock produc- tion if the market is going to significantly expand beyond first generation biofuels. Extension and outreach educa- tion provides a conduit for important research, knowledge and information to be disseminated to producers and agri- business that can utilize the information to help establish biofuel feedstock enterprises and markets. This paper presents the results of a survey administered to extension and outreach agents in 10 western states in the United States to assess the current state of knowledge of exten- sion and outreach agents, their needs regarding feedstock production, and mechanisms used for outreach to their clientele. Results indicate that extension and outreach agents require additional training on biofuel feedstock production, especially economic and logistical aspects. In addition, extension and outreach agents showed a pref- erence for learning using alternative methods, including field days, seminars, face-to-face, community education events, and the internet. Results differ by region and type of extension and outreach agent. [ABSTRACT FROM AUTHOR]

Energy from biomass is potentially an important contributor to U.S. climate change mitigation efforts. However, large-scale implementation of bioenergy competes with other uses of land, including agriculture and forest production and terrestrial carbon storage in non-commercial lands. And with trade, bioenergy could mean greater reliance on imported energy. Based on EMF-24 policy specifications, this paper explores these dimensions of bioenergy's role in U.S. climate policy and the relationship to alternative measures for ameliorating the trade and land use consequences. It shows how widespread use of biomass in the U.S. could lead to imports; and it highlights that the relative stringency of domestic and international carbon mitigation policy will heavily influence the amount of imports. It demonstrates that limiting biomass imports could alter the balance of trade in other agricultural products. Finally, it shows that increasing efforts to protect both U.S. and international forests could also affect the balance of trade in other agricultural products. [ABSTRACT FROM AUTHOR]

Forests of the Midwestern United States are an important source of fiber for the wood and paper products industries. Scientists, land managers, and policy makers are interested in using woody biomass and/or harvest residue for biofuel feedstocks. However, the effects of increased biomass removal for biofuel production on forest production and forest system carbon balance remain uncertain. We modeled the carbon (C) cycle of the forest system by dividing it into two distinct components: (1) biological (net ecosystem production, net primary production, autotrophic and heterotrophic respiration, vegetation, and soil C content) and (2) industrial (harvest operations and transportation, production, use, and disposal of major wood products including biofuel and associated C emissions). We modeled available woody biomass feedstock and whole-system carbon balance of 220 000 km2 of temperate forests in the Upper Midwest, USA by coupling an ecosystem process model to a collection of greenhouse gas life-cycle inventory models and simulating seven forest harvest scenarios in the biological ecosystem and three biofuel production scenarios in the industrial system for 50 years. The forest system was a carbon sink (118 g C m−2 yr−1) under current management practices and forest product production rates. However, the system became a C source when harvest area was doubled and biofuel production replaced traditional forest products. Total carbon stores in the vegetation and soil increased by 5-10% under low-intensity management scenarios and current management, but decreased up to 3% under high-intensity harvest regimes. Increasing harvest residue removal during harvest had more modest effects on forest system C balance and total biomass removal than increasing the rate of clear-cut harvests or area harvested. Net forest system C balance was significantly, and negatively correlated ( R2 = 0.67) with biomass harvested, illustrating the trade-offs between increased C uptake by forests and utilization of woody biomass for biofuel feedstock. [ABSTRACT FROM AUTHOR]

The rise in world oil prices, coupled with heightened interest in the abatement of greenhouse gas emissions, led to a sharp increase in biofuels production around the world. Previous authors have devoted considerable attention to the impacts of these policies on a country-by-country basis. However, there are also strong interactions among these programs, as they compete in world markets for feedstocks and ultimately for a limited supply of global land. In this paper, we offer the first global assessment of biofuel programs -focusing particularly on the EU and US. We begin with an historical analysis of the period 2001-2006, which also permits us to validate the model. We then conduct an ex ante analysis of mandates in the year 2015. We find that if these mandates are indeed fulfilled the impact on global land use could be substantial, with potentially significant implications for greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Rapid growth of biofuel production in the United States and Brazil over the past decade has increased interest in replicating this success in other nations of the Pan American region. However, the continued use of food-based feedstock such as maize is widely seen as unsustainable and is in some cases linked to deforestation and increased greenhouse gas emissions, raising further doubts about long-term sustainability. As a result, many nations are exploring the production and use of cellulosic feedstock, though progress has been extremely slow. In this paper, we will review the North-South axis of biofuel production in the Pan American region and its linkage with the agricultural sectors in five countries. Focus will be given to biofuel policy goals, their results to date, and consideration of sustainability criteria and certification of producers. Policy goals, results, and sustainability will be highlighted for the main biofuel policies that have been enacted at the national level. Geographic focus will be given to the two largest producers-the United States and Brazil; two smaller emerging producers-Argentina and Canada; and one stalled program-Mexico. However, several additional countries in the region are either producing or planning to produce biofuels. We will also review alternative international governance schemes for biofuel sustainability that have been recently developed, and whether the biofuel programs are being managed to achieve improved environmental quality and sustainable development. [ABSTRACT FROM AUTHOR]

The article investigates the relationship between the food and fuel market and the impact of biofuels on commodity food prices in the U.S. It provides information on factors that determination of the price of biofuel and suggests that ethanol prices throughout the world are affected by both food and fuel prices.

• Substitution of 2nd generation for 1st generation biofuel is investigated. • An optimization model for the 2nd generation biofuel supply chain is proposed. • Both economic and environmental performance measures are examined. • 2nd generation biofuel is more cost effective than 1st generation biofuel. • Considering stover handling or not leads to different environmental performances. Multiple generations of biofuel manufacturing technologies have been proposed and developed, among which first generation technology is the most mature. It typically utilizes corn grain as feedstock in bio-refineries in many countries such as the United States. However, the use of edible matter of crops like corn may lead to a food-versus-fuel competition. To address such an issue, second generation biofuel manufacturing technology using the non-edible matter of crops has been developed. In this paper, the economic viability and environmental sustainability are analyzed and quantified, when restructuring the biofuel supply chain from employing first generation manufacturing technology to the one utilizing second generation technology considering the existing supply chain infrastructure. Two supply chain restructuring strategies, i.e., distributed and centralized preprocessing deployment, are modeled for implementing biomass preprocessing for second generation biofuel manufacturing. Bi-objective optimization formulations for the corn stover-sourced biofuel (a typical second generation biofuel) supply chain considering both economic and environmental aspects are proposed under both strategies. Different decision variables such as the locations selected for constructing preprocessing centers and the corresponding corn stover handling capacities of such centers, as well as the material flows between farms, preprocessing centers, and bio-refinery plants are identified. A case study based on the state of Missouri in the United States is implemented to illustrate the effectiveness of the proposed model and analyze the performance of different strategies. The results of the case study show that when corn stover is used as feedstock in bio-refineries, the unit cost of bioethanol production can be reduced, while the unit emission is increased compared to the corn-sourced supply chain under both supply chain restructuring strategies. Specifically, in Missouri where the daily stover handling amount per bio-refinery plant is relatively low and the stover collection radius is relatively small, the centralized strategy outperforms the distributed one with a higher cost reduction and a smaller increase in emissions. It reduces the unit cost by 27.39%, while increasing the unit emission by 24.42%, compared to the corn-sourced supply chain. [ABSTRACT FROM AUTHOR]

Abstract: During the last decade, countries around the world - especially the U.S., Brazil, and many in Europe - have worked to accelerate the commercialization of a biofuel industry. As pilot plant studies for the second-generation biofuel (e.g., cellulosic biofuel) currently seek to determine the most viable feedstocks and processing technologies, it is an opportune time to formulate operations research (OR) models of the biofuel supply chain (SC) so they might be used to implement the technologies that prove to be most promising. This paper provides a literature review of research on the biofuel SC. It classifies prior research according to decision time frame (i.e., strategic, tactical, operational, and integrated) as well as level in the supply chain (i.e., upstream, midstream, and downstream). In addition, it reviews related research on agri-products, which have some commonalities relative to harvesting and perishability; petroleum-based fuels, which have some commonalities related to distribution (some biofuels can be mixed with gasoline but others cannot); and generic supply chains, which provide some applicable modeling structures. Finally, this paper emphasizes unique needs to support decisions that integrate the farm with commercial levels (e.g., storage, pre-processing, refining, and distribution) and identifies fertile avenues for future research on the biofuel supply chain. OR models are needed to help assure the economic viability of the biofuel industry. They can be used by growers, processors, and distributors to design and manage an integrated system and by government to inform policies needed to stimulate the growth of the industry and, perhaps, subsidize it. [Copyright &y& Elsevier]

Switchgrass is a promising bioenergy feedstock, but industrial-scale production may lead to negative environmental effects. This study considers one such potential consequence: the life cycle monetized damages to human health from air pollution. We estimate increases in mortality from long-term exposure to fine particulate matter (PM 2.5 ), which is emitted directly (“primary PM 2.5 ”) and forms in the atmosphere (“secondary PM 2.5 ”) from precursors of nitrogen oxides (NO x ), sulfur oxides (SO x ), ammonia (NH 3 ), and volatile organic compounds (VOCs). Changes in atmospheric concentrations of PM 2.5 (primary + secondary) from on-site production and supporting supply chain activities are considered at 2694 locations (counties in the Central and Eastern US), for two biomass yields (9 and 20 Mg ha −1 ), three nitrogen fertilizer rates (50, 100, and 150 kg ha −1 ), and two nitrogen fertilizer types (urea and urea ammonium nitrate). Results indicate that on-site processes dominate life-cycle emissions of NH 3 , NO x , primary PM 2.5 , and VOCs, whereas SO x is primarily emitted in upstream supply chain processes. Total air quality impacts of switchgrass production, which are dominated by NH 3 emissions from fertilizer application, range widely depending on location, from 2 to 553 $ Mg −1 (mean: 45) of dry switchgrass at a biomass yield of 20 Mg ha −1 and fertilizer application of 100 kg ha −1 N applied as urea. Switching to urea ammonium nitrate solution lowers damages to 2 to 329 $ Mg −1 (mean: 28). This work points to human health damage from air pollution as a potentially large social cost from switchgrass production and suggests means of mitigating that impact via strategic geographical deployment and management. Furthermore, by distinguishing the origin of atmospheric emissions, this paper advances the current emerging literature on ecosystem services and disservices from agricultural and bioenergy systems. [ABSTRACT FROM AUTHOR]

Biofuels made from biomass and waste residues will largely contribute to United States' 2050 decarbonization goal in the aviation sector. While cellulosic biofuels have the potential fuel performance equivalent to petroleum-based jet fuel, the biofuel industry needs to overcome the supply chain barrier caused by temporal and spatial variability of biomass yield and quality. This study highlights the importance of incorporating spatial and temporal variability during biomass supply chain planning via optimization modeling that incorporates 10 years of drought index data, a primary factor contributing to yield and quality variability. The results imply that the cost of delivering biomass to biorefinery may be significantly underestimated if the multi-year temporal and spatial variation in biomass yield and quality is not captured. For long term sustainable biorefinery operations, the industry should optimize supply chain strategy by studying the variability of yield and quality of biomass in their supply sheds. [ABSTRACT FROM AUTHOR]

This paper aims to analyse: (a) how the attitude towards renewable energy-based heating systems, pro-environmental behaviour and the perceived attributes of technology influence intention to convert residential heating systems from fossil fuels to biofuels, and (b) the moderating role of culture based on Hofstede's individualism dimension. A total of 425 responses were collected from a panel of internet users from representative countries in three continents (the United States, the United Kingdom and South Africa); the data analysis was carried out using structural equation models in a multigroup analysis. The results showed that attitude towards renewable energy-based heating systems is influenced by environmental variables in the United States and the United Kingdom, and by the perceived attributes of clean residential heating systems in the United States and South Africa. Attitude, in turn, impacts on the intention to convert from fossil fuels to biofuels. In addition, individualism has a moderating effect between these variables and there are intercultural differences in the degree of importance attributed to them. The study concludes the use of these energy systems as drivers of environmentally-sustainable development. [ABSTRACT FROM AUTHOR]

The author comments on the article "The renewable fuel standard in competitive equilibrium: Market and welfare effects," which analyzes the potential impacts of U.S. biofuel policies. Topics discussed include the Renewable Identification Numbers (RIN) which is the tradeable record of biofuel production and the Renewable Fuel Standard (RFS) that imposes a hierarchical series of mandates based on the type of biofuel and the greenhouse gas emissions reduction.

Escalating demand, along with EPAct 2005, has led the United States government to assume a twofold leadership approach of energy security and environmental practices. This has initiated several important issues pertaining to cellulosic biofuel production. However, little is known about what is needed for the U.S. to lead long-term renewable energy security, how the US will develop and implement leading environmental energy practices, what supply capabilities and refining technologies are available to produce renewable fuels, and how funding can be used to adopt available technologies. This article examines geographical aspects, operational status, and barriers tending to prevent the successful commercialization of non-food cellulosic ethanol projects in the U.S. from secondary sources. Outcomes of this research can be used to further understand inhibitors that impact the production and commercialization of ethanol from non-food cellulosic sources. [ABSTRACT FROM AUTHOR]

In the early 2000s high expectations existed regarding the potential contribution of biofuels to the reduction of greenhouse gas emissions and substitution of fossil fuels in transport. In recent years sobering judgments prevailed. The major barriers for a further expansion of biofuels are their high costs (compared to fossil fuels), moderate ecological performances, limited feedstocks for biofuel production and their competition with food production. The objective of this paper is to investigate the market prospects of biofuels up to the year 2030. It focuses on the three currently most important regions for biofuels production and use: the US, EU and Brazil which in 2010 accounted together for almost three-quarters of global biofuel supply. Our method of approach is based on a dynamic economic framework considering the major cost components of biofuels and corresponding technological learning with respect to capital costs. Moreover, for the analysis of the competitiveness of biofuels with fossil fuels also taxes are considered. The most important result is that under existing tax policies biofuels are cost-effective today and also for the next decades in the regions investigated. However, their potentials are restricted especially due to limited crops areas, and their environmental performance is currently rather modest. The major final conclusions are: (i) To reveal the real future market value of biofuels, a CO 2 based tax system should be implemented for all types of fuels providing a neutral environmental incentive for competition between all types of fossil and renewable fuels; (ii) Moreover, the research and development for all types of biofuels, but especially for second generation biofuels, has to be intensified. [ABSTRACT FROM AUTHOR]

Regional‐scale estimations of sorghum biomass production allow identification of optimum genotype×environment×management (G×E×M) combinations for bioenergy generation. The objective of this study was to determine the degree of contributions of G, E, and M toward variability in sorghum biomass in the United States. Using the Agricultural Production Systems sIMulator in a grid computing platform, biomass was simulated for irrigated and rainfed conditions for 30 years across the United States for four sorghum varietal types (grain—GS, sudangrass—SS, photosensitive—PS, and photo‐insensitive—PI). Simulated biomass was assessed by environments clustered using the sum of intercepted solar radiation (ir), mean of temperature stress factor (tp) and water stress factor (sw). Simulated biomass ranged from 5.8 t ha−1 (GS‐rainfed) to 27.5 t ha−1 (PI‐irrigated). Under high‐temperature environments (mean annual temperature = 25°C), rainfed biomass between 40 and 80 days after planting (DAP) was strongly correlated with sw (r = 0.64–0.86) and irrigated biomass with ir (r = 0.68–0.81). Under low‐temperature environments (mean annual temperature = 18°C) after 40 DAP, tp and ir had greater effects than sw (r = 0.55–0.82). Biomass variance was mainly explained by varietal type (50%–76%) in all environments×irrigation combinations, except in the high‐ and mid‐temperature environments under rainfed conditions where rainfall had the major effect (25%–45%). However, when mean temperature during the growing season decreased from 25°C (high environments) to 18°C (low environments), the contribution of mean temperature to biomass variance increased from 7% to 34% (rainfed) and from 4% to 36% (irrigated). Varietal type had the larger interactions with other factors independently of the environment and irrigation. We demonstrated a need to quantify (i) the main G×E×M drivers of biomass variability based on environmental stress factors and (ii) the variance contribution of these drivers on sorghum biomass. Our regional‐scale estimations are key inputs for future robust biomass projections of energy sorghum genotypes integrating G×E×M under climate change scenarios. [ABSTRACT FROM AUTHOR]

Abstract: The Renewable Fuel Standard (2007) set aggressive cellulosic biofuel goals that have not been realized. Corn ethanol dominates the market and penetration of cellulosic ethanol is unlikely in the near term due to economic and technical barriers. This paper uses game theory to model biomass and ethanol production decisions and calculate the incentives that would be necessary to drive the industry to obtain the cellulosic ethanol goals. After identifying the desired performance of a cellulosic ethanol supply chain, a nonlinear optimization model is developed to analyze two major scenarios that estimate conservative and optimistic technological improvements in cellulosic biomass and ethanol production. A potential carbon market is explored to determine its efficacy as an incentive mechanism. Results indicate that a carbon market would only be sufficient to incentivize a cellulosic ethanol industry under the optimistic improvement scenario with the highest switchgrass price. For all other scenarios, the carbon price needed to incentivize the industry would exceed the reasonable range and additional incentives would be needed to achieve the production goals of the Renewable Fuel Standard. [Copyright &y& Elsevier]

The present paper studies the land use change impacts of fuels and biofuels. We test the theoretical hypothesis, which says that changes in fuel prices cause changes in land use both directly and indirectly and that, because of price inter-dependencies, biofuels reinforce the land use change impacts. We apply time-series analytical mechanisms to five major traded agricultural commodities, the cultivated area of agricultural land and crude oil price. Our data consists of yearly observations extending from 1950 to 2007 for the US. The empirical findings confirm that markets for crude oil and cultivated agricultural land are interdependent: an increase in oil price by 1dollar/barrel increases land use between 54,000 and 68,000ha. We also find that the increase of bioenergy sector accelerates land use change in the US, i.e. food commodities are being substituted for bioenergy crops. [Copyright &y& Elsevier]

Abstract: A review of the four main wood energy sectors in the U.S. was conducted to explore historic trends and the impact of alternative energy prices and public policies on wood energy consumption. High oil prices have triggered the adoption of government regulation and financial incentives to promote greater use of wood energy over the last four decades. However, the amount of wood energy consumed in the U.S. industrial sector was driven mainly by the output of the pulp and paper products industry and not by energy prices or any particular public policy incentive. Residential consumption of wood energy was positively correlated with competing energy prices. Public policies seem to have had a greater impact on wood energy consumption in the electric power sector and over the last four decades have concentrated on promoting biopower with a recent shift to liquid cellulosic biofuels. High oil prices and a series of public policies such as tax credits, loans, grants, and renewable energy standards have resulted in higher consumption of wood energy from 2004 to 2009 in the residential, electric power and commercial sectors by an estimated 5, 2, and less than 1 percent annually, respectively. The impact of new federal programs such as the Biomass Crop Assistance Program remains to be observed. Continuation of public incentives and preferential regulations for renewable energy appears to be necessary for a steady increase in U.S. wood energy consumption. [Copyright &y& Elsevier]

The article examines the treatment of the U.S. Environmental Protection Agency (EPA) on the uncertainty of governing biofuels policy on corn ethanol. It explores how EPA resolve problems associated with indirect land use change (ILUC) in the context of corn ethanol. Policy issues regarding ILUC are considered. The author concludes that the EPA has acted in good faith with regards ILUC, nevertheless, it suggests the need of development of better methods in addressing its uncertainty.

Abstract: Forest industry experts were consulted on the potential for hardwood tree species to serve as feedstock for bioenergy in the southeastern United States. Hardwoods are of interest for bioenergy because of desirable physical qualities, genetic research advances, and growth potential. Yet little data is available regarding potential productivity and costs. This paper describes required operations and provides a realistic estimate of the costs of producing bioenergy feedstock based on commercial experiences. Forestry practitioners reported that high productivity rates in southeastern hardwood plantations are confined to narrow site conditions or require costly inputs. Eastern cottonwood and American sycamore grow quickly on rich bottomlands, but are also prone to pests and disease. Sweetgum is frost hardy, has few pest or disease problems, and grows across a broad range of sites, yet growth rates are relatively low. Eucalypts require fewer inputs than do other species and offer high potential productivity but are limited by frost to the lower Coastal Plain and Florida. Further research is required to study naturally regenerated hardwood biomass resources. Loblolly pine has robust site requirements, growth rates rivaling hardwoods, and lower costs of production. More time and investment in silviculture, selection, and breeding will be needed to develop hardwoods as competitive biofuel feedstock species. Because of existing stands and fully developed operations, the forestry community considers loblolly pine to be a prime candidate for plantation bioenergy in the Southeast. [Copyright &y& Elsevier]

Abstract: In this paper, we provide an assessment of plantation forests and private land resources potentially available for pine plantation development in 11 southern states of the United States. After a sustained growth for 50 years, plantation forests (softwood and hardwood on both private and public lands) amounted to 18millionha or 24 percent of all timberlands in these states in 2007. The vast majority of the plantation forests were established on private lands with fast-growing loblolly pines and slash pines. While purposeful hardwood plantations were rare, there were hardwood stands growing on failed pine plantation sites. Using a two-stage Markov land use transition model, we forecast that private forest land in these states will decline about 7 percent or from 66millionha in 1997 to 61millionha in 2027, primarily due to urbanization, and that private pine plantations will rise nearly 40 percent from 11millionha to 16millionha. Further, growth in pine plantations will decline in coming decades, and states with low population and population growth have the greatest increase in plantations. These plantations, along with other woody biomass, are expected to play an important role in the emerging bio-energy sector. [Copyright &y& Elsevier]

Abstract: Next generation hydrocarbon biofuels have the potential to fulfill not only the biofuels production mandate of the Energy Independence and Security Act (EISA) of 2007, but also would not have to be exempted from the EISA-mandated increase in the corporate average fuel economy. Producing “green gasoline”, “green diesel” and “green jet fuel” from non-food lignocellulosic feedstocks such as forest waste and agricultural residue, and energy crops such as short rotation trees and perennial grasses grown on marginal or abandoned cropland will substantially lower greenhouse gas emissions and will not affect food prices. In this paper the development of the new paradigm of green gasoline from lignocellulose will be reviewed, the potential pathways to these infrastructure-compatible fuels will be discussed, and critical process design needs will be outlined. [Copyright &y& Elsevier]

Abstract: Saccharide compositions were measured in ambient particulate matter (PM) samples collected at four sites in Eastern Texas and Central Arizona in an effort to assess the contribution from biomass burning, atmospheric entrainment of soil, and primary biological aerosol particles (PBAPs) in regions with different climate patterns and ecosystems. In spite of the concentration difference, samples from the four study sites showed similar saccharide composition and seasonal variation, with the only exception being trehalose, likely resulting from the influence of local climatic conditions. Comparison of samples at the Arizona site showed different saccharide enrichment patterns between PM2.5 and PM10, which is consistent with their proposed sources as determined by a correlation analysis between observations. A positive matrix factorization (PMF) model was used to resolve three saccharide-related source factors and their relative source contributions to ambient PM using saccharides as tracers. Both the correlation and PMF model results indicate a stronger influence from local biogenic sources on aerosol saccharides at the rural sites than the urban site in Texas, and a greater impact from the PBAP and other biologically derived sources for PM collected in the Arizona location. This paper will provide the first analysis of saccharides in both fine and coarse PM in two US regions with dramatically different climates and ecosystem and provide a characterization of the ambient aerosol sources. [Copyright &y& Elsevier]

We estimate the contributions from biomass burning (summer wildfires, other fires, residential biofuel, and industrial biofuel) to seasonal and annual aerosol concentrations in the United States. Our approach is to use total carbonaceous (TC) and non-soil potassium (ns-K) aerosol mass concentrations for 2001–2004 from the nationwide IMPROVE network of surface sites, together with satellite fire data. We find that summer wildfires largely drive the observed interannual variability of TC aerosol concentrations in the United States. TC/ns-K mass enhancement ratios from fires range from 10 for grassland and shrub fires in the south to 130 for forest fires in the north. The resulting summer wildfire contributions to annual TC aerosol concentrations for 2001–2004 are 0.26μgCm−3 in the west and 0.14μgCm−3 in the east; Canadian fires are a major contributor in the east. Non-summer wildfires and prescribed burns contribute on an annual mean basis 0.27 and 0.31μgCm−3 in the west and the east, highest in the southeast because of prescribed burning. Residential biofuel is a large contributor in the northeast with annual mean concentration of up to 2.2μgCm−3 in Maine. Industrial biofuel (mainly paper and pulp mills) contributes up to 0.3μgCm−3 in the southeast. Total annual mean fine aerosol concentrations from biomass burning average 1.2 and 1.6μgm−3 in the west and east, respectively, contributing about 50% of observed annual mean TC concentrations in both regions and accounting for 30% (west) and 20% (east) of total observed fine aerosol concentrations. Our analysis supports bottom-up source estimates for the contiguous United States of 0.7–0.9TgCyr−1 from open fires (climatological) and 0.4TgCyr−1 from biofuel use. Biomass burning is thus an important contributor to US air quality degradation, which is likely to grow in the future. [Copyright &y& Elsevier]

Bio-based products are non-food, non-feed agricultural products that are used in a variety of commercial/ industrial applications, thereby harnessing the energy of the sun to provide raw materials for industry and transportation fuels. The importance of bio-based products in the U.S. and the global economy is expected to increase tremendously. The objectives of this paper are to: (1) identify various bio-based products and energy sources and their applications, (2) examine emerging importance of bio-based products in the U.S. and discuss technical marketing barriers and need for market development and maintenance of information resources, and (3) discuss a plan to prepare students to work in the bio-based product economy. [ABSTRACT FROM AUTHOR]

One way countries like the United States can comply with suggested rollbacks in greenhouse gas emissions is by employing power plants fueled with biomass. We examine the competitiveness of biomass-based fuel for electrical power as opposed to coal using a mathematical programming structure. We consider fueling power plants from milling residues, whole trees, logging residues, switch grass, or short-rotation woody crops. We do this using a combined model of the agricultural and forestry sectors. We find that the competitiveness of biomass depends in a key way upon the success of research in developing improved production methods for short-rotation woody crops without great increases in costs. [ABSTRACT FROM AUTHOR]

The article focuses on using biological sources for energy production. Most experts place the energy content of all annual biomass production at between 15 and 20 times the amount humans currently get from commercial energy sources, although other estimates range from 10 to 40 times. Agricultural residues, the inedible, unharvested portions of food crops are the largest potential source of energy from waste. The waste streams easiest to tap for fuels are probably those flowing from food production. Bagasse, the residue from sugarcane, has long been used as an energy source in most cane-growing regions. According to a study, collectible crop residues and feedlot wastes in the U.S. contain about 5 quadrillion kilojoules of energy, more energy than is used by the nation's farmers.

The recent historical increase in energy-related CO 2 emissions globally have put the United States of America's (USA) transportation sector in the spotlight, courtesy of the significantly high pollutant emissions from this particular sector. Taking a cue from this, this paper follows sustainable development goals of the United Nations, and investigates the impact of biomass energy consumption, fossil fuel energy consumption, and economic growth (GDP) on carbon dioxide (CO 2) emissions in the transportation sector of the USA. In doing so, this study also employs the Gregory-Hansen cointegration, Hatemi-J cointegration, cointegration regression (FMOLS, DOLS, and CCR), and Spectral Breitung-Candelon causality test for the period between 1981Q1 and 2019Q4. The findings reveal that (i) a significant nonlinear cointegration among the environmental quality determinants is observed, using the threshold cointegration test. This test determines the structural breaks endogenously and combines two cointegration tests, namely the Gregory-Hansen Cointegration and Hatemi-J Cointegration tests; (ii) while the use of biomass energy consumption and real GDP have a negative effect on CO 2 emissions in the transportation sector, the rising fossil fuel energy consumption is associated with increasing the CO 2 emissions that are stemming from the transportation sector; (iii) in the long-run, biomass energy consumption, fossil fuel energy consumption, and real GDP cause CO 2 emissions to stem from the transportation sector in the USA at different frequency levels. In general, the current study offers policy insights for the transportation sector of the USA and other similar economies that replicate the same conditions. Image 1 • We explore the driving forces of CO 2 emissions in the transport sector for the USA. • We employ advanced time series econometric techniques for empirical analysis. • Biomass energy and real GDP help to mitigate CO 2 emissions in the transport sector. • Fossil fuel energy has a positive impact on CO 2 emissions in the transport sector. • All variables have a causative relationship with CO 2 emissions in the long-run. [ABSTRACT FROM AUTHOR]

The article presents a study which analyzes the government economics and policy to increase biofuel dependency in the U.S. It states that President George W. Bush has signed the law "The Energy Independence and Security Act of 2007," which establishes the biggest increase in biofuels mandate, known as the Renewable Fuels Standard (RFS), in the country's history. The Congress has debated that RFS will diversify energy supplies and reduce dependence on oil from other countries, while limiting the impact of biofuels on food security and agricultural prices.

In this article the authors discuss the views on biomass as a biofuel feedstock in a special issue of the "Biofuels, Biproducts & Biorefining" journal. They assert that the special issue of the journal features a series of papers derived from the Role of Biomass in America's Energy Future (RBAEF) study. They cite that most of the biofuels scenarios offer comparable, if not lower, costs and significantly lessened greenhouse gas emissions, while various can realise similar efficiencies.

This study examines fresh renewable water resources available for bioenergy feedstock production in the United States. The impacts of feedstock irrigation on surface and groundwater resources available to nonbioenergy sectors were quantified using a pair of water availability indexes: streamflow availability index and percolation flow availability index. The two metrics were applied to both historical (2008) and three possible future biomass production scenarios from the 2016 U.S. Billion‐Ton Report at the county level. For both historical and future scenarios, we found that the consumptive irrigation requirements for bioenergy feedstock account for <0.01% of annual streamflow in all but three counties in Nebraska. Results suggest that the irrigation demand of future biomass production could be supplied by annual renewable groundwater flow in about 94% of feedstock‐growing counties that use groundwater for irrigation, representing about 92% of production tonnage. Counties that require irrigation from nonrenewable groundwater resources are mostly located in the Northern Plains and Pacific regions. We also evaluated the sensitivity of crop water footprint estimation to soil moisture carryover by comparing blue water estimates from six different empirical and process‐based methods. Our findings suggest that accounting for preseason soil moisture is critical for representative blue water estimation, so that the irrigation water consumption is not overestimated. This is especially true in the Corn Belt region, where blue water estimates with and without preseason soil moisture would be about 1.9 versus 45.5 billion m3/year under the historical scenario. This difference is smaller in semiarid regions like the High Plains, but the blue water estimate can still triple if soil moisture is not considered. From the perspective of renewable surface water and groundwater resources, scaling feedstock production up in the High Plains and California will require careful planning integrated with water management strategies to improve water resource conservation. Consumptive irrigation demand of biomass production is <0.1% of annual streamflow in most counties, which means 99.9% of streamflow is available to nonbioenergy sectors. Due to limited renewable groundwater resources, scaling feedstock production up in the High Plains and California will require careful planning. [ABSTRACT FROM AUTHOR]

Logging and mill residues are currently the largest sources of woody biomass for bioenergy in the United States, but short‐rotation woody crops (SRWCs) are expected to become a larger contributor to biomass production, primarily on lands marginal for food production. However, there are very few studies on the environmental effects of SRWCs, and most have been conducted at stand rather than at watershed scales. In this manuscript, we review the potential environmental effects of SRWCs relative to current forestry or agricultural practices and best management practices (BMPs) in the southeast United States and identify priorities and constraints for monitoring and modeling these effects. Plot‐scale field studies and a watershed‐scale modeling study found improved water quality with SRWCs compared to agricultural crops. Further, a recent watershed‐scale experiment suggests that conventional forestry BMPs are sufficient to protect water quality from SRWC silvicultural activities, but the duration of these studies is short with respect to travel times of groundwater transporting nitrate to streams. While the effects of SRWC production on carbon (C) and water budgets depend on both soil properties and previous land management, woody crops will typically sequester more C when compared with agricultural crops. The overall C offset by SRWCs will depend on a variety of management practices, the number of rotations, and climate. Effects of SRWCs on biodiversity, especially aquatic organisms, are not well studied, but a meta‐analysis found that bird and mammal biodiversity is lower in SRWC stands than unmanaged forests. Long‐term (i.e., over multiple rotations) water quality, water use, C dynamics, and soil quality studies are needed, as are larger‐scale (i.e., landscape scale) biodiversity studies, to evaluate the potential effects of SRWC production. Such research should couple field measurement and modeling approaches due to the temporal (i.e., multiple rotations) and spatial (i.e., heterogeneous landscape) scaling issues involved with SRWC production. Evaluating the environmental effects of short‐rotation woody crop (SRWC) production for bioenergy requires watershed‐scale experiments and long‐term observations coupled with watershed‐ to landscape‐scale models. These integrative approaches can evaluate environmental effects over multiple SRWC rotations. [ABSTRACT FROM AUTHOR]

We show that the cost of increasing biofuel mandates given a binding ethanol blend wall falls disproportionately on diesel fuel consumers. The extent of the burden on diesel fuel consumers is explained neither by their relatively more inelastic demand nor by blenders seeking to capitalize on the biodiesel tax credit. Relaxing the blend wall constraint by increasing the potential demand for high-ethanol blends is the only effective lever to insulate diesel fuel drivers from the one-sided welfare impacts of rising mandate levels. The independent effects of the nested mandate structure and the joint compliance base under the Renewable Fuel Standard (RFS) generate the link between motor gasoline and diesel fuel markets. Our results highlight the importance of evaluating the incidence of the RFS in a holistic framework taking both ethanol and biodiesel into account. [ABSTRACT FROM AUTHOR]

Expansion of ethanol production in the United States has raised concerns regarding its land-use change effects. However, little is known about the extent to which observed land use change in the United States can be attributed to ethanol plant proximity or is caused by changes in crop prices that may be partly induced by expansion in ethanol production. This study aims to examine the determinants of changes in corn acreage and aggregate crop acreage by simultaneously identifying the effects of establishment of ethanol plants serving as terminal markets for corn and the effects of changes in crop prices in the United States between 2003 and 2014. Our results show that corn acreage and total acreage are fairly inelastic with respect to both changes in ethanol capacity in the vicinity, as well as changes in crop prices. Our estimates of acreage elasticity with respect to corn ethanol production are smaller than those obtained by previous studies that disregard the price effect on crop acreage. We find that, ceteris paribus, the increase in ethanol capacity alone led to a modest 3% increase in corn acreage and less than a 1% increase in total crop acreage by 2012 when compared to 2008. The effect of corn price and aggregate crop price on acreage change from 2008 to 2012 was more than twice larger than that of effective ethanol production capacity over this period; but this price effect was largely reversed by the downturn in crop prices after 2012. This study shows that land-use change is not a static phenomenon and that it is important to examine how it evolves in response to various factors that may change over time. [ABSTRACT FROM AUTHOR]

Throughout the past decade, municipal governments have steadily increased climate change adaptation measures, natural resource conservation programs, and clean energy initiatives. Through energy efficiency measures and renewable energy mandates, cities are poised to make significant impacts in the reduction of greenhouse gas emissions and the mitigation of climate risks in the clean energy transition. This Article addresses municipal directives of advanced biofuels as an integral part of the clean energy transition. Existing laws and policies have critical design flaws. Specifically, the Renewable Fuel Standard ("RFS") has proven to be burdensome and complex, producing more unintended consequences than desired outcomes. Problems with the implementation of the RFS indicate that Congress overestimated the capacity of the biofuel industry to produce energy and the ability of the retail gasoline market to accommodate ethanol. Consumer resistance to ethanol use and market pressures create problems for biofuel use. This Article is the third in a series related to the law and policy of advanced biofuels. Previously, I examined international dimensions in Blood Biofuels (Duke Environmental Law & Policy Forum) and federal efforts in Resiliency and Responsive Regulation for Advanced Biofuels (Virginia Environmental Law Journal). [ABSTRACT FROM AUTHOR]

Due to its wide distribution across the world, the snail Radix auricularia plays a central role in the transferal of energy and biomass by consuming plant biomass in freshwater systems. The gut microbiota are involved in the nutrition, digestion, immunity, and development of snails, particularly for cellulolytic bacteria, which greatly contribute to the digestion of plant fiber. For the first time, this study characterized the gut bacterial communities of R. auricularia, as well as predicted functions, using the Illumina Miseq platform to sequence 16S rRNA amplicons. Both juvenile snails (JS) and adult snails (AS) were sampled. The obtained 251,072 sequences were rarefied to 214,584 sequences and clustered into 1,196 operational taxonomic units (OTUs) with 97% sequence identity. The predominant phyla were Proteobacteria (JS: 36.0%, AS: 31.6%) and Cyanobacteria (JS: 16.3%, AS: 19.5%), followed by Chloroflexi (JS: 9.7%, AS: 13.1%), Firmicutes (JS: 14.4%, AS: 6.7%), Actinobacteria (JS: 8.2%, AS: 12.6%), and Tenericutes (JS: 7.3%, AS: 6.2%). The phylum Cyanobacteria may have originated from the plant diet instead of the gut microbiome. A total of 52 bacterial families and 55 genera were found with >1% abundance in at least one sample. A large number of species could not be successfully identified, which could indicate the detection of novel ribotypes or result from insufficient availability of snail microbiome data. The core microbiome consisted of 469 OTUs, representing 88.4% of all sequences. Furthermore, the predicted function of bacterial community of R. auricularia performed by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States suggests that functions related to metabolism and environmental information processing were enriched. The abundance of carbohydrate suggests a strong capability of the gut microbiome to digest lignin. Our results indicate an abundance of bacteria in both JS and AS, and thus the bacteria in R. auricularia gut form a promising source for novel enzymes, such as cellulolytic enzymes, that may be useful for biofuel production. Furthermore, searching for xenobiotic biodegradation bacteria may be a further important application of these snails. [ABSTRACT FROM AUTHOR]

The Renewable Fuel Standard mandates large increases in U.S. biofuel consumption and is implemented using tradable compliance credits known as RINs. In early 2013, RIN prices soared, causing the regulator to propose reducing future mandates. We estimate empirically the effect of three "policy shocks" that reduced the expected mandates in 2013. We find that the largest of these shocks decreased the value of the fuel industry's 2013 compliance obligation by $7 billion. We then study the effects of the shocks on commodity markets and the market value of publicly-traded biofuel firms. Results show that the burden of the mandate reductions fell primarily on advanced biofuel firms and commodity markets of the marginal compliance biofuel. We argue that the policy shocks reduced the incentive to invest in the technologies required to meet the future objectives of the RFS, and discuss alternative policy designs to address the problems that arose in 2013. [ABSTRACT FROM AUTHOR]

Bioenergy with carbon capture and storage (BECCS) is a negative-emissions technology that may play a crucial role in climate change mitigation. BECCS relies on the capture and sequestration of carbon dioxide (CO2) following bioenergy production to remove and reliably sequester atmospheric CO2. Previous BECCS deployment assessments have largely overlooked the potential lack of spatial colocation of suitable storage basins and biomass availability, in the absence of long-distance biomass and CO2 transport. These conditions could constrain the near-term technical deployment potential of BECCS due to social and economic barriers that exist for biomass and CO2 transport. This study leverages biomass production data and site-specific injection and storage capacity estimates at high spatial resolution to assess the near-term deployment opportunities for BECCS in the United States. If the total biomass resource available in the United States was mobilized for BECCS, an estimated 370 Mt CO2⋅y-1 of negative emissions could be supplied in 2020. However, the absence of long-distance biomass and CO2 transport, as well as limitations imposed by unsuitable regional storage and injection capacities, collectively decrease the technical potential of negative emissions to 100 Mt CO2⋅y-1. Meeting this technical potential may require large-scale deployment of BECCS technology in more than 1,000 counties, as well as widespread deployment of dedicated energy crops. Specifically, the Illinois basin, Gulf region, and western North Dakota have the greatest potential for near-term BECCS deployment. Highresolution spatial assessment as conducted in this study can inform near-term opportunities that minimize social and economic barriers to BECCS deployment. [ABSTRACT FROM AUTHOR]

Plant location can be a major factor in the financial success of a company when feedstock transport costs are high, such as for wood-based biorefineries. Biorefineries sited near large amounts of forest residue can better mitigate against the risk of reduced feedstock availability due to exogenous market constraints. Two methodologies for estimating the volume and cost of delivered forest residues to a biorefinery are presented. Both methodologies are based on data provided by the U.S. Forest Service Forest Inventory and Analysis (FIA) program. The first methodology is past-predictive in that it uses individual state Timber Product Output (TPO) datasets, while the second methodology is future-predictive in that it uses a spatially explicit economic optimization model of the U.S. forestry sector coupled with stand data at FIA plot locations to project near- and medium-term residue volumes. A Total Delivered Feedstock Cost Model is used with both biomass estimation methods to enable comparison of facility supply curves. A case study assesses four pulp mills, considered as candidate repurposed biorefinery locations, for their ability to procure sufficient biomass under average- and low-yield scenarios utilizing both methods. The facility that procures sufficient feedstock to meet annual biorefinery demand at the least cost under both yield scenarios theoretically provides the least risk to investors in terms of insufficient feedstock availability. The past-predictive methodology was found to be best-suited for refining a list of candidate facilities for further analysis. The future-predictive methodology is best-suited for a robust analysis of facilities using multiple economic and policy scenarios. [ABSTRACT FROM AUTHOR]

We construct a tractable multi-market equilibrium model designed to evaluate alternative biofuel policies. The model integrates the U.S. agricultural sector with the energy sector and it explicitly considers both U.S. ethanol and biodiesel production. The model provides a structural representation of the renewable fuel standard (RFS) policies, and it uses the arbitrage conditions defining the core value of renewable identification number prices to identify the relevant competitive equilibrium conditions. The model is parameterized, based on elasticities and technical coefficients from the literature, to represent observed 2015 data. The model is simulated to analyze alternative scenarios, including repeal of the RFS, projected 2022 RFS mandates, and optimal (second-best) mandates. The results confirm that the current RFS program considerably benefits the agriculture sector, but also leads to overall welfare gains for the United States (mostly via beneficial terms of trade effects). Implementation of projected 2022 mandates, which would require further expansion of biodiesel production, would lead to a considerable welfare loss (relative to 2015 mandate levels). Constrained (second-best) optimal mandates would entail more corn-based ethanol and less biodiesel than currently mandated. [ABSTRACT FROM AUTHOR]