Bioenergy: Biofuel production on the margins

Productive agricultural land that could otherwise be used to produce much-needed food crops is being diverted towards grain-based ethanol production in both Europe and the United States, partly in response to government legislation. An alternative is to grow cellulosic crops on so-called marginal lands. An evaluation of the potential of marginal lands in the Midwestern United States to produce biofuel while mitigating direct greenhouse gas emissions now finds that they have the capacity to produce a significant amount of biofuel energy without the initial carbon debt and indirect land-use costs associated with food-based biofuels

Air and water pollution over time and industries with stochastic dominance

We employ a stochastic dominance (SD) approach to analyze the components that contribute to environmental degradation over time. The variables include countries\u2019 greenhouse gas (GHG) emissions and water pollution. Our approach is based on pair-wise SD tests. First, we study the dynamic progress of each separate variable over time, from 1990 to 2005, within 5-year horizons. Then, pair-wise SD tests are used to study the major industry contributors to the overall GHG emissions and water pollution at any given time, to uncover the industry which contributes the most to total emissions and water pollution. While CO2 emissions increased in the first order SD sense over 15 years, water pollution increased in a second-order SD sense. Electricity and heat production were the major contributors to the CO2 emissions, while the food industry gradually became the major water polluting industry over time. SD sense over 15 years, water pollution increased in a second-order SD sense. Electricity and heat production were the major contributors to the CO2 emissions, while the food industry gradually

Energy Efficiency Analysis: Biomass-to-Wheel Efficiency Related with Biofuels Production, Fuel Distribution, and Powertrain Systems

BACKGROUND: Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). METHODOLOGY/PRINCIPAL FINDINGS: We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements--biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case--corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. SIGNIFICANCE: In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens

The Compact Linear Collider (CLIC) - 2018 Summary Report

The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear $e^+e^-$ collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years

Science and the stock market: Investors' recognition of unburnable carbon

This paper documents the stock market's reaction to a 2009 paper in the Nature journal of science, which concluded that only a fraction of the world's existing oil, gas, and coal reserves could be emitted if global warming by 2050 were not to exceed 2 °C above pre-industrial levels. This Nature article is now one of the most cited environmental science studies in recent years. Our analysis indicates that this publication prompted an average stock price drop of 1.5% to 2% for our sample of the 63 largest U.S. oil and gas firms. Later, in 2012-2013, the press "discovered" this article, writing hundreds of stories on the grim consequences of unburnable carbon for fossil fuel companies. We show only a small negative reaction to these later stories, mostly in the two weeks following their publication. This limited market response contrasts with the predictions of some analysts and commentators of a substantial decline in the shareholder value of fossil fuel companies from a carbon bubble. Our paper discusses possible reasons for this discrepancy

Science and the stock market: Investors' recognition of unburnable carbon

This paper documents the stock market's reaction to a 2009 paper in the Nature journal of science, which concluded that only a fraction of the world's existing oil, gas, and coal reserves could be emitted if global warming by 2050 were not to exceed 2 °C above pre-industrial levels. This Nature article is now one of the most cited environmental science studies in recent years. Our analysis indicates that this publication prompted an average stock price drop of 1.5% to 2% for our sample of the 63 largest U.S. oil and gas firms. Later, in 2012-2013, the press "discovered" this article, writing hundreds of stories on the grim consequences of unburnable carbon for fossil fuel companies. We show only a small negative reaction to these later stories, mostly in the two weeks following their publication. This limited market response contrasts with the predictions of some analysts and commentators of a substantial decline in the shareholder value of fossil fuel companies from a carbon bubble. Our paper discusses possible reasons for this discrepancy

Climate change would increase the water intensity of irrigated corn ethanol

Changes in atmospheric CO2 concentrations, temperature, and precipitation affect plant growth and evapotranspiration. However, the interactive effects of these factors are relatively unexplored, and it is important to consider their combined effects at geographic and temporal scales that are relevant to policymaking. Accordingly, we estimate how climate change would affect water requirements for irrigated corn ethanol production in key regions of the U.S. over a 40 year horizon. We used the geographic-information-system-based environmental policy integrated climate (GEPIC) model, coupled with temperature and precipitation predictions from five different general circulation models and atmospheric CO2 concentrations from the Special Report on Emissions Scenarios A2 emission scenario of the Intergovernmental Panel on Climate Change, to estimate changes in water requirements and yields for corn ethanol. Simulations infer that climate change would increase the evaporative water consumption of the 15 billion gallons per year of corn ethanol needed to comply with the Energy Independency and Security Act by 10%, from 94 to 102 trillion liters/year (tly), and the irrigation water consumption by 19%, from 10.22 to 12.18 tly. Furthermore, on average, irrigation rates would increase by 9%, while corn yields would decrease by 7%, even when the projected increased irrigation requirements were met. In the irrigation-intensive High Plains, this implies increased pressure for the stressed Ogallala Aquifer, which provides water to seven states and irrigates one-fourth of the grain produced in the U.S. In the Corn Belt and Great Lakes region, where more rainfall is projected, higher water requirements could be related to less frequent rainfall, suggesting a need for additional water catchment capacity. The projected increases in water intensity (i.e., the liters of water required during feedstock cultivation to produce 1 L of corn ethanol) because of climate change highlight the need to re-evaluate the corn ethanol elements of the Renewable Fuel Standard