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The impurity composition of natural and isotopically enriched silane obtained from magnesium silicide and silicon tetrafluoride is studied by gas chromatography-mass-spectrometry. The impurities characteristic of silane with natural and isotopically enriched composition are atmospheric gases; carbon dioxide; hydrides; saturated, unsaturated, and aromatic hydrocarbons; halogenated hydrocarbons; alkyl derivatives and silane homologues, siloxanes. The impurity content of high-purity silane does not exceed 10.sup.-7-10.sup.-5 mol % After synthesis, the concentrations of impurities in the silane and fractions isolated by its distillation purification lie in the range n x 10.sup.-6 - n x 10 mol % The limits of detection for impurities are 1 x 10.sup.-8-9 x 10.sup.-4 mol %, Author(s): A. Yu. Sozin [sup.1], V. A. Krylov [sup.2], O. Yu. Chernova [sup.1], T. G. Sorochkina [sup.1], A. D. Bulanov [sup.1], O. Yu. Troshin [sup.1], A. P. Kotkov [sup.3], N. [...]

Increased storage of carbon in the oceans has been proposed as a mechanism to explain lower concentrations of atmospheric carbon dioxide during ice ages; however, unequivocal signatures of this storage have not been found.sup.1. In seawater, the dissolved gases oxygen and carbon dioxide are linked via the production and decay of organic material, with reconstructions of low oxygen concentrations in the past indicating an increase in biologically mediated carbon storage. Marine sediment proxy records have suggested that oxygen concentrations in the deep ocean were indeed lower during the last ice age, but that near-surface and intermediate waters of the Pacific Ocean--a large fraction of which are poorly oxygenated at present--were generally better oxygenated during the glacial.sup.1-3. This vertical opposition could suggest a minimal net basin-integrated change in carbon storage. Here we apply a dual-proxy approach, incorporating qualitative upper-water-column and quantitative bottom-water oxygen reconstructions.sup.4,5, to constrain changes in the vertical extent of low-oxygen waters in the eastern tropical Pacific since the last ice age. Our tandem proxy reconstructions provide evidence of a downward expansion of oxygen depletion in the eastern Pacific during the last glacial, with no indication of greater oxygenation in the upper reaches of the water column. We extrapolate our quantitative deep-water oxygen reconstructions to show that the respired carbon reservoir of the glacial Pacific was substantially increased, establishing it as an important component of the coupled mechanism that led to low levels of atmospheric carbon dioxide during the glacial. A downward expansion of oxygen depletion in the eastern Pacific Ocean during the last ice age suggests an increase in the respired carbon reservoir, contributing to the lower levels of atmospheric carbon dioxide during this period., Author(s): Babette A. A. Hoogakker [sup.1] [sup.2] , Zunli Lu [sup.3] [sup.4] , Natalie Umling [sup.5] , Luke Jones [sup.2] , Xiaoli Zhou [sup.6] , Rosalind E. M. Rickaby [sup.2] [...]

The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (C[O.sub.2]), methane (C[H.sub.4]) and nitrous oxide ([N.sub.2]O), and therefore has an important role in regulating atmospheric composition and [...]

No single mechanism can account for the full amplitude of past atmospheric carbon dioxide (C[O.sub.2]) concentration variability over glacial-interglacial cycles (1). A build-up of carbon in the deep ocean has [...]

The latest science news, in brief. The latest science news, in brief., Author Affiliations: Coronavirus nixes conference, twilight zone beckons and a faded star brightens Although thought to be the most abundant vertebrates on Earth, little is known about the species of [...]

The rising atmospheric concentration of carbon dioxide (C[O.sub.2]) should stimulate ecosystem productivity, but to what extent is highly uncertain, particularly when combined with changing temperature and precipitation (1). Ecosystem response to C[O.sub.2] is complicated by biogeochemical feedbacks (2) but must be understood if carbon storage and associated dampening of climate warming are to be predicted (3). Feedbacks through the hydrological cycle are particularly important (4) and the physiology is well known; elevated C[O.sub.2] reduces stomatal conductance and increases plant water use efficiency (the amount of water required to produce a unit of plant dry matter) (5). The C[O.sub.2] response should consequently be strongest when water is limiting (6); although this has been shown in some experiments (7), it is absent from many (8-11). Here we show that large annual variation in the stimulation of aboveground biomass by elevated C[O.sub.2] in a mixed [C.sub.3]/[C.sub.4] temperate grassland can be predicted accurately using seasonal rainfall totals; summer rainfall had a positive effect but autumn and spring rainfall had negative effects on the C[O.sub.2] response. Thus, the elevated C[O.sub.2] effect mainly depended upon the balance between summer and autumn/spring rainfall. This is partly because high rainfall during cool, moist seasons leads to nitrogen limitation, reducing or even preventing biomass stimulation by elevated C[O.sub.2]. Importantly, the prediction held whether plots were warmed by 2°C or left unwarmed, and was similar for [C.sub.3] plants and total biomass, allowing us to make a powerful generalization about ecosystem responses to elevated C[O.sub.2]. This new insight is particularly valuable because climate projections predict large changes in the timing of rainfall, even where annual totals remain static (12). Our findings will help resolve apparent differences in the outcomes of C[O.sub.2] experiments and improve the formulation and interpretation of models that are insensitive to differences in the seasonal effects of rainfall on the C[O.sub.2] response (7,13,14)., Anthropogenic emissions of C[O.sub.2] have been increasing, reaching 9.7billion tonnes of carbon (C) in 2012 (ref. 15). The biosphere absorbs approximately 50% of anthropogenically emitted carbon per annum (16), so [...]

The Savage Effects of Global Warming: How Heat Influences Aggression in the City. Sara M. Wallace and Jeffrey K. Lake, Adrian College Increasing atmospheric carbon dioxide concentrations have been leading [...]

Author(s): Kristie L. Ebi 1,*, Lewis H. Ziska 2 Summary points Higher atmospheric concentrations of carbon dioxide (CO[sub.2] ) increase the growth of cereal crops. At the same time, CO[sub.2] [...]

Author(s): Don A. Cowan; Thulani P. Makhalanyane It might be surprising to some people that the Antarctic continent is not entirely covered by ice. Ice-free areas represent less than 0.4% [...]

The promulgation of the Mandatory Reporting of Greenhouse Gases Rule stands as the first step to developing a comprehensive national approach to climate change. However, what role, if any, did interest groups play in the development of this rule? This paper applies Kingdon's multiple streams model as a descriptive framework to analyze interview data for this rule to better understand interest group involvement across all the stages of the rule-making process (rule development, notice and comment phase, and rule finalization). Our research suggests that interest groups were indeed influential throughout the process, but those involved during rule development were clearly at an advantage. KEY WORDS: climate change, energy, governance, regional governance, Introduction The U.S. Congress has yet to pass comprehensive legislation to address global climate change. One pathway around this congressional policy gridlock is administrative rule making (McGrory Klyza & Sousa, [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2010.06.016 Byline: Nguyen Phuc Thanh, Yasuhiro Matsui, Takeshi Fujiwara Abstract: This study was undertaken to evaluate the quantity and composition of household solid waste to identify opportunities for waste recycling in Can Tho city, the capital city of the Mekong Delta region in southern Vietnam. Two-stage survey of 100 households was conducted for dry season and rainy season in 2009. Household solid waste was collected from each household and classified into 10 physical categories and 83 subcategories. The average household solid waste generation rate was 285.28g per capita per day. The compostable and recyclable shares respectively accounted for 80.02% and 11.73%. The authors also analyzed the relations between some socioeconomic factors and household solid waste generation rates by physical categories and subcategories. The household solid waste generation rate per capita per day was positively correlated with the population density and urbanization level, although it was negatively correlated with the household size. The authors also developed mathematical models of correlations between the waste generation rates of main physical categories and relevant factors, such as household size and household income. The models were proposed by linear models with three variables to predict household solid waste generation of total waste, food waste, and plastic waste. It was shown that these correlations were weak and a relationship among variables existed. Comparisons of waste generation by physical compositions associated with different factors, such as seasonal and daily variation were conducted. Results presented that the significant average differences were found by the different seasons and by the different days in a week; although these correlations were weak. The greenhouse gas baseline emission was also calculated as 292.25g (CO.sub.2 eq.) per capita per day from biodegradable components. Author Affiliation: Graduate School of Environmental Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan Article History: Received 6 April 2010; Revised 12 June 2010; Accepted 16 June 2010

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1467-9701.2010.01270.x Byline: John Ballingall (1), Niven Winchester (2) Abstract: Abstract Food miles measure the distance food travels to reach consumers' plates. Although substituting local food for imported produce will not necessarily reduce greenhouse gas (GHG) emissions, the food miles movement is widely supported by consumers and import-competing producers, especially in some parts of Western Europe. We investigate the economic implications of food miles preference changes in the UK, France and Germany on other nations using an economy-wide model. Among the regions we consider, New Zealand is the most distant from Western Europe and Madagascar and Malawi export the most agro-food products relative to GDP, so food miles movements have the largest impacts on these regions. When there is a linear relationship between distance and preference changes, food miles campaigns decrease welfare in New Zealand, Madagascar and Malawi by 0.30, 0.12 and 0.28 per cent, respectively. When there is a preference shift away from imported food unrelated to distance, proportional welfare losses in the three countries are, respectively, 0.11, 0.08 and 0.24 per cent. With the exception of New Zealand, these findings indicate that some of the world's poorest nations will suffer the most from European food miles lobbying. We conclude that food miles campaigns will increase global inequality without necessarily improving environmental outcomes. Author Affiliation: (1)New Zealand Institute of Economic Research (2)Massachusetts Institute of Technology and University of Otago

Byline: Richard T. Wetherald (1) Abstract: This paper examines the subject of hydrologic variability and its changes in two separate integrations of a coupled ocean-atmosphere general circulation model developed at the Geophysical Fluid Dynamics Laboratory/NOAA assuming a 1% per year increase to a doubling and quadrupling of CO.sub.2, respectively. Changes in time mean state and variability of precipitation, runoff and soil moisture are evaluated using monthly and seasonal mean data derived from these integrations. Various statistical tests are then performed on the resulting time mean and variability changes. The patterns of hydrologic change for these three quantities are similar to those obtained from previous studies. In northern middle to higher latitudes for the time means, the changes include increases in monthly mean precipitation, increases in monthly mean runoff during the fall, winter and spring seasons and decreases of monthly mean soil moisture during summer. Many of these changes are found to be statistically significant at the 5% significance level for both the time mean and variability especially for the results where CO.sub.2 is quadrupled such as monthly mean precipitation. Significant changes also include increases of runoff variability during spring, winter and spring and increases of soil moisture variability during the summer season. These results support statements made in previous IPCC reports that increasing greenhouse gases can lead to more severe and frequent floods and droughts depending upon season and latitude. This study also indicates that the approaches to equilibrium of these two integrations, and the resulting hydrologic changes, take place over time scales of hundreds of years in agreement with several previous investigations. Author Affiliation: (1) Geophysical Fluid Dynamics Laboratory (GFDL), NOAA, Princeton, NJ, 08542, USA Article History: Registration Date: 03/09/2009 Received Date: 21/11/2008 Accepted Date: 27/08/2009 Online Date: 11/11/2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.solener.2010.07.004 Byline: J. Korecko (a), V. Jirka (a), B. Sourek (a)(b), J. Cerveny (a)(c) Keywords: Rasters made of glass; Greenhouse; Solar architecture; Fresnel lens; Mathematical simulation Abstract: Since the eighties of the 20th century, various types of linear glass rasters for architectural usage have been developed in the Czech Republic made by the continuous melting technology. The development was focused on two main groups of rasters - active rasters with linear Fresnel lenses in fixed installation and with movable photo-thermal and/or photo-thermal/photo-voltaic absorbers. The second group are passive rasters based on total reflection of rays on an optical prism. During the last years we have been working on their standardization, exact measuring of their optical and thermal-technical characteristics and on creation of a final product that could be applied in solar architecture. With the project supported by the Ministry of Environment of the Czech Republic we were able to build an experimental greenhouse using these active and passive optical glass rasters. The project followed the growing number of technical objectives. The concept of the greenhouse consisted of interdependence construction - structural design of the greenhouse with its technological equipment securing the required temperature and humidity conditions in the interior of the greenhouse. This article aims to show the merits of the proposed scheme and presents the results of the mathematical model in the TRNSYS environment through which we could predict the future energy balance carried out similar works, thus optimizing the investment and operating costs. In this article description of various technology applications for passive and active utilization of solar radiation is presented, as well as some results of short-term and long-term experiments, including evaluation of 1-year operation of the greenhouse from the energy and interior temperature viewpoints. A comparison of the calculated energy flows in the greenhouse to real measured values, for verification of the installed model is also involved. Author Affiliation: (a) ENKI, o.p.s., Dukelska 145, 379 01 Trebon, Czech Republic (b) Czech Technical University of Prague, Technicka 4, 166 07 Prague, Czech Republic (c) Institute of Physical Biology, Zamek 136, 373 33 Nove Hrady, Czech Republic Article History: Received 17 April 2009; Revised 1 June 2010; Accepted 3 July 2010 Article Note: (miscellaneous) Associate Editor - I. Farkas

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2010.04.001 Byline: Vamilson PrudA*ncio da Silva (a)(c), Hayo M.G. van der Werf (a)(b), Airton Spies (d), Sebastiao Roberto Soares (c) Abstract: Soybean production and its supply chain are highly dependent on inputs such as land, fertilizer, fuel, machines, pesticides and electricity. The expansion of this crop in Brazil in recent decades has generated concerns about its environmental impacts. To assess these impacts, two representative chains supplying soybeans to Europe were identified: Center West (CW) and Southern (SO) Brazil. Each supply chain was analyzed using Life Cycle Assessment methodology. We considered different levels of use of chemical and organic fertilizers, pesticides and machinery, different distances for transportation of inputs and different yield levels. Because transportation contributed strongly to environmental impacts, a detailed study was performed to identify the routes used to transport soybeans to seaports. Additionally, we considered different levels of land occupation and land transformation to represent the impact of deforestation in the CW region. Environmental impacts were calculated for 1000 kg of soybean up to and including the delivery to Europe at the seaport in Rotterdam, at 13% humidity. Overall results showed that the impacts are greater for CW than for SO for all impact categories studied, including acidification (7.7 and 5.3 kg SO.sub.2 eq., respectively), climate change (959 and 510 kg CO.sub.2 eq.), cumulative energy demand (12,634 and 6,999 MJ) and terrestrial ecotoxicity (4.9 and 3.1 kg 1,4-DCB eq.), except eutrophication and land occupation. The same trend was observed for the crop-production stage. Efforts to reduce chemical fertilizers and diesel consumption can reduce CO.sub.2 emissions. Although deforestation for crop production has decreased in recent years, the contribution of deforestation to climate change and cumulative energy demand remains significant. In the CW scenario deforestation contributed 29% to climate change and 20% to cumulative energy demand. Results also showed that although there are different transportation options in Brazil, the current predominance of road transport causes severe environmental impacts. In CW, road transport contributed 19% to climate change and 24% to cumulative energy demand, while in SO it contributed 12% and 15% to these impacts, respectively. Improvements in the logistics of transportation, giving priority to rail and river transports over road transport, can contribute significantly to reducing greenhouse gas emissions and decreasing energy use. Future studies involving Brazilian soybeans should take into account the region of origin as different levels of environmental impact are predicted. Author Affiliation: (a) INRA, UMR 1069 Sol Agro et hydrosysteme Spatialisation, F-35000 Rennes, France (b) Agrocampus Rennes, UMR 1069 Sol Agro et hydrosysteme Spatialisation, F-35000 Rennes, France (c) Univ. Federal de Santa Catarina, Dep. de Eng. Sanitaria e Ambiental, 88040-970, Florianopolis, Brazil (d) EPAGRI/CEPA, Rod. Admar Gonzaga, 1347, 88034901 Florianopolis, Brazil Article History: Received 11 September 2009; Revised 18 March 2010; Accepted 7 April 2010

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2010.05.008 Byline: N.K. Bigalke (a), L.I. Enstad (b), G. Rehder (c), G. Alendal (d) Abstract: Understanding the upward motion of CO.sub.2 droplets or CH.sub.4 bubbles in oceanic waters is prerequisite to predict the vertical distribution of the two most important greenhouse gases in the water column after these have been released from the seabed. One of the key parameters governing the fate of droplets or bubbles dissolving into the surrounding seawater as they rise, is the terminal velocity, u.sub.T. The latter is strongly influenced by the ability of both compounds to form skins of gas hydrate, if pressure and temperature satisfy thermodynamic framework conditions. Experimental efforts aiming to elucidate the rise properties of CO.sub.2 droplets and CH.sub.4 bubbles and specifically the influence of hydrate skins open the possibility to obtain a parameterization of u.sub.T applicable to both hydrate-coated and pure fluid particles of CH.sub.4 and CO.sub.2. With the present study, we report on experimentally determined terminal velocities of single CH.sub.4 bubbles released to pressurized and temperature-regulated seawater. Hydrate skins were identified by high bubble sphericities and changed motion characteristics. Based on these experiments as well as published data on the rise of hydrate-coated and pure liquid CO.sub.2 droplets and physical principles previously successfully used for clean bubbles near atmospheric pressures, a new parameterization of u.sub.T is proposed. Model predictions show a good agreement with the data base established from the laboratory-based measurements. Author Affiliation: (a) Leibniz Institute of Marine Sciences at the University of Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany (b) Uni Research, ThormA[cedilla]hlensgt. 55, N-5008 Bergen, Norway (c) Leibniz Institute for Baltic Sea Research at the University of Rostock, Seestr. 15, 18119 Rostock, Germany (d) Mathematical Department, University of Bergen, Johannes Bruns gt. 12, N-5007 Bergen, Norway Article History: Received 18 January 2010; Revised 18 May 2010; Accepted 27 May 2010

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2010.01.006 Byline: Alberto G. Fairen Keywords: Mars, Surface; Mars, Climate; Geological processes; Astrobiology Abstract: Water on Mars has been explained by invoking controversial and mutually exclusive solutions based on warming the atmosphere with greenhouse gases (the 'warm and wet' Mars) or on local thermal energy sources acting in a global freezing climate (the 'cold and dry' Mars). Both have critical limitations and none has been definitively accepted as a compelling explanation for the presence of liquid water on Mars. Here is considered the hypothesis that cold, saline and acidic liquid solutions have been stable on the sub-zero surface of Mars for relatively extended periods of time, completing a hydrogeological cycle in a water-enriched but cold planet. Computer simulations have been developed to analyze the evaporation processes of a hypothetical martian fluid with a composition resulting from the acid weathering of basalt. This model is based on orbiter- and lander-observed surface mineralogy of Mars, and is consistent with the sequence and time of deposition of the different mineralogical units. The hydrological cycle would have been active only in periods of dense atmosphere, as having a minimum atmospheric pressure is essential for water to flow, and relatively high temperatures (over [approximately equal to]245K) are required to trigger evaporation and snowfall; minor episodes of limited liquid water on the surface could have occurred at lower temperatures (over [approximately equal to]225K). During times with a thin atmosphere and even lesser temperatures (under [approximately equal to]225K), only transient liquid water can potentially exist on most of the martian surface. Assuming that surface temperatures have always been maintained below 273K, Mars can be considered a 'cold and wet' planet for a substantial part of its geological history. Author Affiliation: NASA Ames Research Center, Space Science and Astrobiology Division, Moffett Field, 94035 CA, USA Article History: Received 13 May 2009; Revised 29 November 2009; Accepted 8 January 2010

Byline: Robert McLeman (1) Keywords: Climate change; Vulnerability; Adaptation; Adaptive capacity; Climate; Migration; Demographic change; Social networks; Ontario; Addington Highlands; Environment Abstract: This article describes and analyzes the impacts of population and demographic change on the vulnerability of communities to climate change and variability. It begins with a review of existing literature on the effects of population change on anthropogenic greenhouse gas emissions, the exposure of settlements to climate risks, and on the capacity to adapt to climate change. The article explores the relationship between population change and adaptive capacity through detailed examination of empirical findings from a study of small communities in eastern Ontario, Canada currently experiencing a combination of changes in local climatic conditions and rapid demographic change caused by in-migration of urban retirees and out-migration of young, educated people. The combination of changing demographic and climatic patterns has placed increased stress on local social networks that have long been critical to climate adaptation in that region. The case study and literature review are used to create a general typology of the relationship between population change and vulnerability that may be used as a framework for future research in this field. Author Affiliation: (1) Department of Geography, University of Ottawa, Room 031 Simard Hall, Ottawa, ON, K1N 6N5, Canada Article History: Registration Date: 18/09/2009 Online Date: 17/12/2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.11.013 Byline: Diedrich T.F. Mohlmann Keywords: Ices; Mars; Mars, Surface Abstract: It is investigated whether conditions for melting can be temporarily created in the upper sub-surface parts of snow/ice-packs on Mars at subzero surface temperatures by means of the solid-state greenhouse effect, as occurs in snow- and ice-covered regions on Earth. The conditions for this possible temporary melting are quantitatively described for bolometric albedo values A =0.8 and A =0.2, and with model parameters typical for the thermo-physical conditions at snow/ice sites on the surface of present Mars. It is demonstrated by numerical modelling that there are several sets of parameters which will lead to development of layers of liquid water just below the top surface of snow- and ice-packs on Mars. This at least partial liquefaction occurs repetitively (e.g. diurnally, seasonally), and can in some cases lead to liquid water persisting through the night-time in the summer season. This liquid water can form in sufficient amounts to be relevant for macroscopic physical (rheology, erosion), for chemical, and eventually also for biological processes. The creation of temporary pockets of sub-surface water by this effect requires pre-existing snow or ice cover, and thus is more likely to take place at high latitudes, since the present deposits of snow/ice can mainly be found there. Possible rheologic and related erosion consequences of the appearance of liquid sub-surface water in martian snow/ice-packs are discussed in view of current observations of recent rheologic processes. Author Affiliation: DLR Institut fur Planetenforschung, Rutherfordstr. 2, D 12489 Berlin, Germany Article History: Received 22 February 2009; Revised 10 November 2009; Accepted 13 November 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jeem.2010.01.002 Byline: Mort Webster (a), Ian Sue Wing (b), Lisa Jakobovits (a) Keywords: Uncertainty; Climate change; Instrument choice; Safety valve; Intensity target Abstract: Current proposals for greenhouse gas emissions regulations in the United States mainly take the form of emissions caps with tradable permits. Since Weitzman's (1974) study of prices vs. quantities, economic theory predicts that a price instrument is superior under uncertainty in the case of stock pollutants. Given the general belief in the political infeasibility of a carbon tax in the US, there has been recent interest in two other policy instrument designs: hybrid policies and intensity targets. We extend the Weitzman model to derive an analytical expression for the expected net benefits of a hybrid instrument under uncertainty. We compare this expression to one developed by Newell and Pizer (2006) for an intensity target, and show the theoretical minimum correlation between GDP and emissions required for an intensity target to be preferred over a hybrid. In general, we show that unrealistically high correlations are required for the intensity target to be preferred to a hybrid, making a hybrid a more practical instrument in practice. We test the predictions by performing Monte Carlo simulation on a computable general equilibrium model of the US economy. The results are similar, and we show with the numerical model that when marginal abatement costs are non-linear, an even higher correlation is required for an intensity target to be preferred over a safety valve. Author Affiliation: (a) MIT Joint Program for the Science and Policy of Global Change, Massachusetts Institute of Technology, USA (b) Department of Geography & Environment, Boston University, USA Article History: Received 10 December 2007

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.reseneeco.2009.11.012 Byline: Dana Marie Bauer (a), Stephen K. Swallow (b), Peter W.C. Paton (c) Keywords: Conservation planning; Economic-ecological modeling; Land-use; Policy analysis; Wetlands Abstract: Exurban areas have increasingly become zones of conflict as conservation and development compete for the same finite land resources. Conversion of natural areas to land dominated by human use results in loss, degradation, and fragmentation of wildlife habitat which often lead to species endangerment or even extinction. Recently, reserve site selection models have begun to integrate spatial attributes in order to design more compact and connected reserve networks that are thought to improve long-term species persistence. While these models are a good step forward to designing conservation reserve networks, they might not be adequate for use in exurban areas that consist of heterogeneous mosaics of land uses where habitat fragmentation already exists and not all parcels are available for preservation. This paper presents a species conservation framework that expands upon traditional reserve site selection models in three ways. First, because of the focus on exurban areas, the framework used here allows for land conversion within core habitat patches. Second, the framework provides a more robust assessment of connectivity among patches by accounting for land-use heterogeneity in the dispersal matrix. And third, the framework explicitly incorporates species population dynamics. We apply our conservation framework to the case of pond-breeding salamanders in an exurban community in Rhode Island, USA. Comparisons are made between the outcomes for uniform conservation policies and more flexible policies that accommodate ecological and economic heterogeneity. As expected, policies that offer more flexibility in the decision-making process are less costly in terms of foregone development. Conservation planners should consider core habitat patches, dispersal matrix, and spatial scale in their decision making. By not assessing the potential impact of dispersal barriers, reserve site selection models will result in conservation plans that may not protect species over the long term, particularly for species residing in highly fragmented landscapes such as those found in many exurban communities. Author Affiliation: (a) Department of Geography and Environment, Boston University, 675 Commonwealth Avenue, Boston, MA 02215, USA (b) Department of Environmental and Natural Resource Economics, University of Rhode Island, 1 Greenhouse Road, Kingston, RI 02881, USA (c) Department of Natural Resources Science, University of Rhode Island, 1 Greenhouse Road, Kingston, RI 02881, USA Article History: Received 1 September 2008; Revised 1 March 2009; Accepted 1 November 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2009.10.010 Byline: Min Zhao (a), Zheng-hong Kong (b), Francisco J. Escobedo (c), Jun Gao (a) Abstract: This study quantified carbon storage and sequestration by urban forests and carbon emissions from energy consumption by several industrial sources in Hangzhou, China. Carbon (C) storage and sequestration were quantified using urban forest inventory data and by applying volume-derived biomass equations and other models relating net primary productivity (NPP) and mean annual biomass increments. Industrial energy use C emissions were estimated by accounting for fossil fuel use and assigning C emission factors. Total C storage by Hangzhou's urban forests was estimated at 11.74Tg C, and C storage per hectare was 30.25t C. Carbon sequestration by urban forests was 1,328, 166.55t C/year, and C sequestration per ha was 1.66t C/ha/year. Carbon emissions from industrial energy use in Hangzhou were 7Tg C/year. Urban forests, through sequestration, annually offset 18.57% of the amount of carbon emitted by industrial enterprises, and store an amount of C equivalent to 1.75 times the amount of annual C emitted by industrial energy uses within the city. Management practices for improving Hangzhou's urban forests function of offsetting C emissions from energy consumption are explored. These results can be used to evaluate the urban forests' role in reducing atmospheric carbon dioxide. Author Affiliation: (a) Urban Ecology and Environment Research Center, Shanghai Normal University, Shanghai 200234, China (b) Key Laboratory of Urbanization and Ecological Restoration, East China Normal University, Shanghai 200062, China (c) School of Forest Resources & Conservation, University of Florida-IFAS, Gainesville, FL 32611, USA Article History: Received 26 March 2009; Revised 27 September 2009; Accepted 23 October 2009

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1467-9701.2009.01229.x Byline: Christoph Bohringer (1), Thomas F. Rutherford (2) Abstract: Abstract Canada has committed itself under the Kyoto Protocol to reduce greenhouse gas emissions between 2008 and 2012 on average by six per cent from the base 1990 level. As of 2009, however, Canada's greenhouse gas emissions are far above its 1990 level which calls for stringent short-term policy measures if Canada is to meet its legally binding commitment. This paper uses a multi-region, multi-commodity static general equilibrium model to quantify the economic impacts of alternative compliance strategies for Canada in the context of climate policies undertaken by other Kyoto parties. The numerical results confirm fears by Canadian policymakers of substantial economic adjustment costs should Canada fulfill its Kyoto commitments solely through domestic action. However, a rigorous use of the project-based CDM on top of international emissions trading could allow Canada to live up to its international climate policy commitment at politically much more tolerable costs. Author Affiliation: (1)University of Oldenburg, Germany (2)Center for Energy Policy and Economy, ETH Zurich

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.earscirev.2009.11.004 Byline: John K. Warren Keywords: evaporite; deposition; marine; nonmarine; plate tectonics; economic geology; classification Abstract: Throughout geological time, evaporite sediments form by solar-driven concentration of a surface or nearsurface brine. Large, thick and extensive deposits dominated by rock-salt (mega-halite) or anhydrite (mega-sulfate) deposits tend to be marine evaporites and can be associated with extensive deposits of potash salts (mega-potash). Ancient marine evaporite deposition required particular climatic, eustatic or tectonic juxtapositions that have occurred a number of times in the past and will so again in the future. Ancient marine evaporites typically have poorly developed Quaternary counterparts in scale, thickness, tectonics and hydrology. When mega-evaporite settings were active within appropriate arid climatic and hydrological settings then huge volumes of seawater were drawn into the subsealevel evaporitic depressions. These systems were typical of regions where the evaporation rates of ocean waters were at their maximum, and so were centred on the past latitudinal equivalents of today's horse latitudes. But, like today's nonmarine evaporites, the location of marine Phanerozoic evaporites in zones of appropriate adiabatic aridity and continentality extended well into the equatorial belts. Exploited deposits of borate, sodium carbonate (soda-ash) and sodium sulfate (salt-cake) salts, along with evaporitic sediments hosting lithium-rich brines require continental-meteoric not marine-fed hydrologies. Plots of the world's Phanerozoic and Neoproterozoic evaporite deposits, using a GIS base, shows that Quaternary evaporite deposits are poor counterparts to the greater part of the world's Phanerozoic evaporite deposits. They are only directly relevant to same-scale continental hydrologies of the past and, as such, are used in this paper to better understand what is needed to create beds rich in salt-cake, soda-ash, borate and lithium salts. These deposits tend be Neogene and mostly occur in suprasealevel hydrographically-isolated (endorheic) continental intermontane and desert margin settings that are subject to the pluvial-interpluvial oscillations of Neogene ice-house climates. When compared to ancient marine evaporites, today's marine-fed subsealevel deposits tend to be small sea-edge deposits, their distribution and extent is limited by the current ice-house driven eustasy and a lack of appropriate hydrographically isolated subsealevel tectonic depressions. For the past forty years, Quaternary continental lacustrine deposit models have been applied to the interpretation of ancient marine evaporite basins without recognition of the time-limited nature of this type of comparison. Ancient mega-evaporite deposits (platform and/or basinwide deposits) require conditions of epeiric seaways (greenhouse climate) and/or continent-continent proximity. Basinwide evaporite deposition is facilitated by continent-continent proximity at the plate tectonic scale (Late stage E through stage B in the Wilson cycle). This creates an isostatic response where, in the appropriate arid climate belt, large portions of the collision suture belt or the incipient opening rift can be subsealevel, hydrographically isolated (a marine evaporite drawdown basin) and yet fed seawater by a combination of ongoing seepage and occasional marine overflow. Basinwide evaporite deposits can be classified by their tectonic setting into: convergent (collision basin), divergent (rift basin; prerift, synrift and postrift) and intracratonic settings. Ancient platform evaporites can be a subset of basinwide deposits, especially in intracratonic sag basins, or part of a widespread epeiric marine platform fill. In the latter case they tend to form mega-sulfate deposits and are associated with hydrographically isolated marine fed saltern and evaporitic mudflat systems in a greenhouse climatic setting. The lower amplitude 4 and 5th order marine eustatic cycles and the greater magnitude of marine freeboard during greenhouse climatic periods encourages deposition of marine platform mega-sulfates. Platform mega-evaporites in intracratonic settings are typically combinations of halite and sulfate beds. Author Affiliation: Petroleum Geoscience Program, Department of Geology, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand Article History: Received 25 February 2009; Accepted 10 November 2009

Quantifying atmospheric C[O.sub.2] concentrations ([[C[O.sub.2]].sub.atm]) during Earth's ancient greenhouse episodes is essential for accurately predicting the response of future climate to elevated C[O.sub.2] levels. Empirical estimates of [[C[O.sub.2]].sub.atm] during Paleozoic and Mesozoic greenhouse climates are based primarily on the carbon isotope composition of calcium carbonate in fossil soils. We report that greenhouse [[C[O.sub.2]].sub.atm] have been significantly overestimated because previously assumed soil C[O.sub.2] concentrations during carbonate formation are too high. More accurate [[C[O.sub.2]].sub.atm], resulting from better constraints on soil C[O.sub.2], indicate that large (1,000s of ppmV) fluctuations in [[C[O.sub.2].sub.atm] did not characterize ancient climates and that past greenhouse climates were accompanied by concentrations similar to those projected for A.D. 2100. paleosol barometer | carbon isotopes | pedogenic carbonate | Phanerozoic | climate sensitivity www.pnas.org/cgi/doi/10.1073/pnas.0902323106