Biofuels and climate change mitigation : a CGE analysis incorporating land-use change

The question of whether biofuels help mitigate climate change has attracted much debate in the literature. Using a global computable general equilibrium model that explicitly represents land-use change impacts due to the expansion of biofuels, this study attempts to shed some light on this question. The study shows that if biofuel mandates and targets currently announced by more than 40 countries around the world are implemented by 2020 using crop feedstocks, and if both forests and pasture lands are used to meet the new land demands for biofuel expansion, this would cause a net increase of greenhouse gas emissions released to the atmosphere until 2043, since the cumulative greenhouse gas emissions released through land-use change would exceed the reduction of emissions due to replacement of gasoline and diesel until then. However, if the use of forest lands is avoided by channeling only pasture lands to meet the demand for new lands, a net increase of cumulative greenhouse gas emissions would occur but would cease by 2021, only a year after the assumed full implementation of the mandates and targets. The study also shows, contrary to common perceptions, that the rate of deforestation does not increase with the rate of biofuel expansion; instead, the marginal rate of deforestation and corresponding land-use emissions decrease even if the production of biofuels increases.Climate Change Mitigation and Green House Gases,Climate Change Economics,Energy and Environment,Environment and Energy Efficiency,Climate Change and Environment

World oil price and biofuels : a general equilibrium analysis

The price of oil could play a significant role in influencing the expansion of biofuels. However, this issue has not been fully investigated yet in the literature. Using a global computable general equilibrium model, this study analyzes the impact of oil price on biofuel expansion, and subsequently, on food supply. The study shows that a 65 percent increase in oil price in 2020 from the 2009 level would increase the global biofuel penetration to 5.4 percent in 2020 from 2.4 percent in 2009. A doubling of oil price in 2020 from its baseline level, or a 230 percent increase from the 2009 level, would increase the global biofuel penetration in 2020 to 12.6 percent. The penetration of biofuels is highly sensitive to the substitution possibility between biofuels and their fossil fuel counterparts. The study also shows that aggregate agricultural output drops due to an oil price increase, but the drop is small in major biofuel producing countries as the expansion of biofuels would partially offset the negative impacts of the oil price increase on agricultural outputs. An increase in oil price would reduce global food supply through direct impacts as well as through diversion of food commodities and cropland toward the production of biofuels.Energy Production and Transportation,Climate Change Economics,Markets and Market Access,Renewable Energy,Food&Beverage Industry

Under what conditions does a carbon tax on fossil fuels stimulate biofuels ?

A carbon tax is an efficient economic instrument to reduce emissions of carbon dioxide released from fossil fuel burning. Its impacts on production of renewable energy depend on how it is designed -- particularly in the context of the penetration of biofuels into the energy supply mix for road transportation. Using a multi-sector, multi-country computable general equilibrium model, this study shows first that a carbon tax with the entire tax revenue recycled to households through a lump-sum transfer does not stimulate biofuel production significantly, even at relatively high tax rates. This reflects the high cost of carbon dioxide abatement through biofuels substitution, relative to other energy substitution alternatives; in addition, the carbon tax will have negative economy-wide consequences that reduce total demand for all fuels. A combined carbon tax and biofuel subsidy policy, where part of the carbon tax revenue is used to finance a biofuel subsidy, would significantly stimulate market penetration of biofuels. Although the carbon tax and biofuel subsidy policy would cause higher loss in global economic output compared with the carbon tax with lump sum revenue redistribution, the incremental output loss is relatively small.Climate Change Mitigation and Green House Gases,Transport Economics Policy&Planning,Taxation&Subsidies,Environment and Energy Efficiency,Energy and Environment

IMPACTS OF LARGE SCALE EXPANSION OF BIOFUELS ON GLOBAL POVERTY AND INCOME DISTRIBUTION

This paper analyzes the impact of expansion in biofuels on the global economy, income distribution and poverty. It utilizes simulation results of two World Bank models: a global computable general equilibrium (CGE) model integrated with biofuels, land-use, and climate change modules, and a global income distribution model that utilizes household survey data of 116 countries. The first model simulates the effects over time of large scale expansion of biofuels on resource allocation, output prices, commodity prices, factor prices, and household income of the different countries and regions in the world. The second model uses these results recursively to calculate the impact on global income distribution and poverty. The results from the CGE model indicate that large scale expansion of biofuels lead to higher world prices of sugar, corn, oilseeds, wheat, and other grains, which lead to higher food prices. The increase in food inflation is higher in developing countries than in developed countries. The expansion of biofuels results in higher wages of unskilled rural labor relative to wages of the other labor types which are skilled urban, skilled rural, and unskilled urban, especially in developing countries. These positive wage effects on unskilled rural labor trigger movement of unskilled urban labor towards rural and agriculture. This is because production of feedstock in developing countries is relatively intensive in the use of unskilled rural labor. The effects of large scale expansion of biofuels on poverty vary across regions. But overall there is a slight increase in global poverty. The increase largely comes from South Asia (particularly India) and Sub-Saharan Africa. Significant number of countries in Sub-Saharan Africa show higher poverty with large scale expansion of biofuels. However, poverty declines in East Asia and Latin America regions. Overall, there is a slight increase in the GINI coefficient. There is a slight increase in the GINI coefficient in Sub-Saharan Africa and East Asia. There is a small reduction in the GINI coefficient in the rest of the regions.Agricultural and Food Policy, Environmental Economics and Policy, Food Security and Poverty, International Relations/Trade, Land Economics/Use, Resource /Energy Economics and Policy,

The impacts of biofuel targets on land-use change and food supply : a global CGE assessment

This study analyzes the long-term impacts of large-scale expansion of biofuels on land-use change, food supply and prices, and the overall economy in various countries or regions using a global computable general equilibrium model, augmented by a land-use module and detailed representation of biofuel sectors. The study finds that an expansion of global biofuel production to meet currently articulated or even higher national targets in various countries for biofuel use would reduce gross domestic product at the global level; however, the gross domestic product impacts are mixed across countries or regions. The expansion of biofuels would cause significant land re-allocation with notable decreases in forest and pasture lands in a few countries. The results also suggest that the expansion of biofuels would cause a reduction in food supply. Although the magnitude of the impact on food supply at the global level is not as large as perceived earlier, it would be significant in developing countries like India and those in Sub-Saharan Africa. Agricultural commodities such as sugar, corn, and oil seeds, which serve as the main biofuel feedstocks, would experience significant increases in their prices in 2020 compared with the prices at baseline due to the expansion of biofuels to meet the existing targets.Agribusiness,Food&Beverage Industry,Wetlands,Crops&Crop Management Systems,Renewable Energy

Two-color Time-resolved Spectroscopy of Helium Using High-order Harmonics

The radiative lifetime of the 1s2p(1)P state of helium is measured in a two-colour ionization experiment with a 5% accuracy. The state is excited by the 13th harmonic of a tunable 80 ps laser and ionized by a synchronous ultraviolet laser, with a variable time delay. This experiment demonstrates that the high harmonics generated in a jet of rare gas exposed to an intense laser field provide a tunable short-pulse xuv source ideally suited for pump/probe type of studies and, in particular, short lifetime measurements

PROBAVNI SUSTAV KOŠTUNJAČA PERSORBIRA MIKROČESTICE

The ability of the teleost gut to absorb microparticulate material was examined following rectal intubation (3.5 g kg -1 ) of commercial grade cornstarch (≈21 mm diameter), or potato starch (≈43 mm diameter). Tissue samples were taken from the mid - and hind-gut of control and treated fish 18 h postintubation. Collected samples were processed using standard plastic and staining protocols and resultant photomicrographs examined by computer-assisted image analysis. Cornstarch particles (8-14 mm), were observed to pass from gut lumen to the lamina propria via a paracellular or persorptive route only. No evidence for the like passage of potato starch was found.Mogućnost probavnog sustava koštunjavičastih vrsta riba da apsorbiraju sitne čestice pojedinih tvari bila je istraživana s pomoću rektalne intubacije (3, 5 g kg -1 ) komercijalnoga škroba kukuruza (promjera ≈21 mm) i škroba krumpira (promjera ≈ 43 mm). Uzorci tkiva uzeti su iz srednjeg i stražnjeg dijela crijeva kontrolne i tretirane skupine riba, i to 18 sati nakon intubacije. Sakupljeni su uzorci spremljeni u standardne plastike i obojeni prema protokolu, te fotomikrografski snimljeni na računalu. Čestice škroba kukuruza (8-14 mm) zapažene su da iz lumena crijeva prolaze u laminu propriju samo paracelularnim ili persorptivnim putem. No, nije zapažen prolazak čestica škroba krumpira

Frequency-domain subspace identification of nonlinear mechanical systems - Application to a solar array structure

The present paper addresses the experimental identification of a simplified realisation of a solar array structure in folded configuration. To this end, a nonlinear subspace identification technique formulated in the frequency domain, referred to as the FNSI method, is exploited. The frequency response functions of the underlying linear structure and the nonlinear coefficients are estimated by this approach. Nonlinearity is caused by impacts between adjacent panels and friction and gaps appearing in their clamping interfaces. This application is challenging for several reasons, which include high modal density and the complicated nature of the involved nonlinear mechanisms

Behavioral and Endocrine Consequences of Simultaneous Exposure to Two Different Stressors in Rats: Interaction or Independence?

Although behavioral and endocrine consequences of acute exposure to stressors have been extensively studied, little is known about how simultaneous exposure to two different stressors interacts to induce short- and long-term effects. In the present experiment we studied this interaction in adult male rats exposed to cat fur odor (impregnated cloth) or immobilization on boards either separately or simultaneously. We reasoned that exposure to the odor of a potential predator while immobilized, may potentiate its negative consequences as compared to exposure to only one of the stressors. Exposure to cat odor elicited the expected reduction of activity and avoidance of the area where the impregnated cloth was located. The endocrine response (plasma levels of ACTH and corticosterone, as a measure of the hypothalamic-pituitary-adrenal axis, HPA) was markedly greater after immobilization than after cat fur odor and no additive effects were found by simultaneous exposure to both stressors. Cat odor, but not immobilization, increased anxiety-like behavior as evaluated in the elevated plus-maze 7 days after the stressors, with no evidence of enhanced HPA activation. In addition, cat odor exposure resulted in long-lasting (8 days later) fear conditioning to the box containing a clean cloth, which was reflected by hypoactivity, avoidance of the cloth area and enhanced HPA activation. All these effects were similarly observed in rats exposed simultaneously to cat odor and immobilization. In rats only exposed to immobilization, only some weak behavioral signs of fear conditioning were found, but HPA activation in response to the context paired to immobilization was enhanced to the same extent as in cat odor-exposed animals, supporting a certain degree of endocrine conditioning. The present results did not reveal important behavioral interactions between the two stressors when animals experienced both simultaneously, whereas some interactions were found regarding HPA activation. Theoretical implications are discussed