Harmonization of land-use scenarios for the period 1500�C2100: 600?years of global gridded annual land-use transitions, wood harvest, and resulting secondary lands     

G. C. Hurtt  L. P. Chini  S. Frolking  R. A. Betts  J. Feddema  G. Fischer  J. P. Fisk  K. Hibbard  R. A. Houghton  A. Janetos  C. D. Jones  G. Kindermann  T. Kinoshita  Kees Klein Goldewijk  K. Riahi  E. Shevliakova  S. Smith  E. Stehfest  A. Thomson  P. Thornton  D. P. van Vuuren  Y. P. Wang 《Climatic change》2011,109(1-2):117-161

In preparation for the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), the international community is developing new advanced Earth System Models (ESMs) to assess the combined effects of human activities (e.g. land use and fossil fuel emissions) on the carbon-climate system. In addition, four Representative Concentration Pathway (RCP) scenarios of the future (2005?C2100) are being provided by four Integrated Assessment Model (IAM) teams to be used as input to the ESMs for future carbon-climate projections (Moss et al. 2010). The diversity of approaches and requirements among IAMs and ESMs for tracking land-use change, along with the dependence of model projections on land-use history, presents a challenge for effectively passing data between these communities and for smoothly transitioning from the historical estimates to future projections. Here, a harmonized set of land-use scenarios are presented that smoothly connects historical reconstructions of land use with future projections, in the format required by ESMs. The land-use harmonization strategy estimates fractional land-use patterns and underlying land-use transitions annually for the time period 1500?C2100 at 0.5°?×?0.5° resolution. Inputs include new gridded historical maps of crop and pasture data from HYDE 3.1 for 1500?C2005, updated estimates of historical national wood harvest and of shifting cultivation, and future information on crop, pasture, and wood harvest from the IAM implementations of the RCPs for the period 2005?C2100. The computational method integrates these multiple data sources, while minimizing differences at the transition between the historical reconstruction ending conditions and IAM initial conditions, and working to preserve the future changes depicted by the IAMs at the grid cell level. This study for the first time harmonizes land-use history data together with future scenario information from multiple IAMs into a single consistent, spatially gridded, set of land-use change scenarios for studies of human impacts on the past, present, and future Earth system.  相似文献   

A climate-isotope regression model with seasonally-varying and time-integrated relationships     

Matt J. Fischer  Lisa M. Baldini 《Climate Dynamics》2011,37(11-12):2235-2251

This study investigates multivariable and multiscalar climate-??¹⁸O relationships, through the use of statistical modeling and simulation. Three simulations, of increasing complexity, are used to generate time series of daily precipitation ??¹⁸O. The first simulation uses a simple local predictor (daily rainfall amount). The second simulation uses the same local predictor plus a larger-scale climate variable (a daily NAO index), and the third simulation uses the same local and non-local predictors, but with varying seasonal effect. Since these simulations all operate at the daily timescale, they can be used to investigate the climate-??¹⁸O patterns that arise at daily-interannual timescales. These simulations show that (1) complex links exist between climate-??¹⁸O relationships at different timescales, (2) the short-timescale relationships that underlie monthly predictor-??¹⁸O relationships can be recovered using only monthly ??¹⁸O and daily predictor variables, (3) a comparison between the simulations and observational data can elucidate the physical processes at work. The regression models developed are then applied to a 2-year dataset of monthly precipitation ??¹⁸O from Dublin and compared with event-scale data from the same site, which illustrates that the methodology works, and that the third regression model explains about 55% of the variance in ??¹⁸O at this site. The methodology introduced here can potentially be applied to historic monthly ??¹⁸O data, to better understand how multiple-integrated influences at short timescales give rise to climate-??¹⁸O patterns at monthly-interannual timescales.  相似文献   

Energy use, climate change and folk psychology: Does sustainability have a chance? Results from a qualitative study in five European countries     

Anke Fischer  Vera PetersJan Vávra  Mirjam NeebeBoldizsár Megyesi 《Global Environmental Change》2011,21(3):1025-1034

Citizens’ support for policies that aim to curb carbon emissions and energy use is often seen as informed by their values, attitudes and perceptions of the environmental problem in question. We argue that we also need to understand how people conceptualise policies and the governance approaches underpinning them to be able to judge the likely acceptance of policy change.In this study, we draw on qualitative interviews (n = 202) from five European countries to explore citizens’ views on governance approaches to stimulate behavioural change in the field of resource use, including regulations, price changes, collective action, technological change and education.We found that many of our interviewees referred to generalised characteristics of humankind and contemporary society to back up their arguments for or against specific governance approaches. In particular, many interviewees concurred that people in general were so self-centred, driven by habit and money- and consumption-oriented that only strict regulations, drastic price changes and technological innovation could possibly achieve widespread behavioural change. As a consequence, such ‘folk psychologies’ can have substantial impact not only on public acceptance, but also on the success of policy measures that aim to reduce citizens’ resource use.  相似文献   

The first definite record of a Valanginian ichthyosaur and its implications on the evolution of post-Liassic Ichthyosauria     

V. Fischer  A. ClémentM. Guiomar  P. Godefroit 《Cretaceous Research》2011,32(2):155-163

A complete ichthyosaur rostrum, with 124 associated teeth, was recently discovered in Laux-Montaux locality, department of Drôme, southeastern France. The associated belemnites and ammonites indicate a late Valanginian age (Neocomites peregrinus Zone, Olcostephanus nicklesi Subzone) for this fossil, which consequently represents the first diagnostic ichthyosaur ever reported from Valanginian strata. This specimen also represents the first occurrence of Aegirosaurus outside the Tithonian (Upper Jurassic) lithographic limestones of Bavaria (southern Germany). Tooth morphology and wear pattern suggest that Aegirosaurus belonged to the “Pierce II/ Generalist” feeding guild, which was hitherto not represented in post-Liassic ichthyosaurs. Most Late Jurassic ichthyosaurs actually crossed the Jurassic-Cretaceous boundary.  相似文献   

Environmental control of the oxygen isotope composition of Porites coral microatolls     

H.V. McGregor  M.J. Fischer  D. Fink 《Geochimica et cosmochimica acta》2011,75(14):3930-3944

Understanding the influence of climatic and non-climatic factors on geochemical signals in corals is critical for assessing coral-derived records of tropical climate variability. Porites microatolls form large, disk-shaped colonies constrained in their upward growth by exposure at or close to mean spring low water level, and occur on Indo-Pacific reefs. Microatolls appear suitable for paleoclimate reconstruction, however the systematics of the microatoll chemistry-climate relationship are yet to be characterized. In this study, the δ¹⁸O signal in Porites microatolls from well-flushed reef flats on Kiritimati (Christmas) Island, central Pacific was investigated for intra-coral (growth aspect and extension rate effects) and between-coral effects, and to explore the climate signal contained within their skeletons. Samples for δ¹⁸O analysis were taken from six individual transects from different positions within Porites microatoll XM22. The results show that: (1) the average standard deviation for the mean δ¹⁸O values of transects that represent the same time periods is 0.03‰, and is within measurement error for a single analysis (0.04‰); (2) the average standard deviation for time-equivalent, near-monthly samples along the transects within the same microatoll is 0.07‰ and; (3) comparison of the average δ¹⁸O values of records for different microatolls from across Kiritimati Island show only a small between-coral differences of 0.04‰ and 0.11‰ for different time periods. These differences in mean δ¹⁸O are within the range for intra- and inter-colony differences in seasonal and interannual δ¹⁸O reported for dome-shaped Porites. Based on these results, a stacked microatoll δ¹⁸O record was constructed for the period 1978-2007 for comparison with published coral δ¹⁸O records for nearby dome-shaped Porites. There is a systematic offset between the two types of records, which is probably due to variations in δ¹⁸O seawater across Kiritimati Island. Despite the offset, all records show similar amplitudes for the seasonal-cycle of δ¹⁸O, and there is a strong correlation (r = −0.71) between microatoll δ¹⁸O and local sea surface temperature (SST). The δ¹⁸O-SST slope relationship for microatolls is −0.15‰/°C, very similar to that reported for fast-growing domed corals (−0.18‰ to −0.22‰/°C). Statistical analysis of the stacked microatoll δ¹⁸O record shows that it is correlated with both local and large-scale climate variables (primarily SST) at semiannual, annual and interannual timescales. Our results show that the signal reproducibility and fidelity of skeletal δ¹⁸O in coral microatolls is comparable to that observed for more conventional coral growth forms. Longer-lived, and fossil, Porites microatolls, where they have grown in suitably flushed environments, are likely to contain δ¹⁸O signals that can significantly extend instrumental records of tropical climate variability.  相似文献   

It starts at home? Climate policies targeting household consumption and behavioral decisions are key to low-carbon futures     

Ghislain Dubois  Benjamin Sovacool  Carlo Aall  Maria Nilsson  Carine Barbier  Alina Herrmann  Sébastien Bruyère  Camilla Andersson  Bore Skold  Franck Nadaud  Florian Dorner  Karen Richardsen Moberg  Jean Paul Ceron  Helen Fischer  Dorothee Amelung  Marta Baltruszewicz  Jeremy Fischer  Françoise Benevise  Rainer Sauerborn 《Chemie der Erde / Geochemistry》2013

Through their consumption behavior, households are responsible for 72% of global greenhouse gas emissions. Thus, they are key actors in reaching the 1.5 °C goal under the Paris Agreement. However, the possible contribution and position of households in climate policies is neither well understood, nor do households receive sufficiently high priority in current climate policy strategies. This paper investigates how behavioral change can achieve a substantial reduction in greenhouse gas emissions in European high-income countries. It uses theoretical thinking and some core results from the HOPE research project, which investigated household preferences for reducing emissions in four European cities in France, Germany, Norway and Sweden. The paper makes five major points: First, car and plane mobility, meat and dairy consumption, as well as heating are the most dominant components of household footprints. Second, household living situations (demographics, size of home) greatly influence the household potential to reduce their footprint, even more than country or city location. Third, household decisions can be sequential and temporally dynamic, shifting through different phases such as childhood, adulthood, and illness. Fourth, short term voluntary efforts will not be sufficient by themselves to reach the drastic reductions needed to achieve the 1.5 °C goal; instead, households need a regulatory framework supporting their behavioral changes. Fifth, there is a mismatch between the roles and responsibilities conveyed by current climate policies and household perceptions of responsibility. We then conclude with further recommendations for research and policy.  相似文献   

Gaps in cubic closest packing: from MgO via spinel to the pharmacosiderite crystal structure type     

Werner H. Baur  Reinhard X. Fischer 《Mineralogy and Petrology》2013,107(2):153-162

Numerous ordered defect structures are known that are related to the sodium chloride (or MgO) structure type, thus they are basically cubic closest packed (ccp) arrangements with vacancies. For example the NbO type is an MgO type in which one quarter each of the anions and the cations are missing compared to the ccp in such a way that both anions and cations are in square-planar coordination. In spinel, Al₂MgO₄, one half of the octahedrally coordinated cations are missing compared with the MgO type and only one eighth of the tetrahedrally coordinated sites within the ccp are occupied. What these cases have in common is that all these derivatives are rather dense. This is different in pharmacosiderite, K[Fe₄(OH)₄As₃O₁₂]. 6 to 7H₂O, where one half of the anion positions, three quarters of the octahedral sites and five eighth of the tetrahedral sites remain vacant, compared to the spinel type. Pharmacosiderite is a wide open porous structure with zeolitic properties. We are illustrating these relationships using a Bärnighausen symmetry tree and by tables relating the various structure types to each other.  相似文献   

A data exploration framework for validation and setup of hydrological models   总被引：5，自引：5，他引：0  

Karsten Rink  Thomas Fischer  Benny Selle  Olaf Kolditz 《Environmental Earth Sciences》2013,69(2):469-477

Over the course of hydrological research projects often a large number of heterogeneous data sets are acquired from sources as diverse as boreholes, gauging stations or satellite imagery. This data then need to be integrated into models for the simulation of hydrological processes. We propose a framework for exploration of geoscientific data and visually guided preparation of such models. Data sets from a large number of sources can be imported, combined and validated to avoid potential problems due to artefacts or inconsistencies between data sets in a subsequent simulation. Boundary conditions and domain discretisations for surface and subsurface models can be created and tested regarding criteria indicating possible numerical instabilities. All data sets including simulation results can be integrated into a user-controlled 3D scene and aspects of the data can be enhanced using a number of established visualisation techniques including thresholding and user-defined transfer functions. We present the application of this framework for the preparation of a model for simulation of groundwater flow in a river catchment in southwest Germany investigated in the scope of the WESS project.  相似文献   

Mechanical intrusion models and their implications for the possibility of magma-driven swarms in NW Bohemia Region     

T. Dahm  T. Fischer  S. Hainzl 《Studia Geophysica et Geodaetica》2008,52(4):529-548

Earthquake swarms are often assumed to be caused by magmatic or fluid intrusions, where the stress changes in the vicinity of the intrusion control the position, strength and rate of seismicity. Fracture mechanical models of natural intrusions or man-made hydrofractures pose constraints on orientation, magnitude, shape and growing rate of fractures and can be used to estimate stress changes in the vicinity of the intrusions. Although the idea of intrusion-induced seismicity is widely accepted, specific comparisons of seismicity patterns with fracture models of stress changes are rarely done. The goal of the study is to review patterns of intrusion-induced earthquake swarms in comparison to the observations of the swarm in NW Bohemia in 2000. We analyse and discuss the theoretical 3D shape of intrusions under mixed mode loading and apparent buoyancy. The aspect ratio and form of the intrusion is used to constrain parameters of the fluid, the surrounding rock and stress. We conclude that the 2000 NW Bohemia swarm could have been driven by a magmatic intrusion. The intrusion was, however, inclined to the maximal principal stress and caused shear displacement additional to opening. We estimate that the density diference between magma and rock was small. The feeding reservoir was possibly much larger than the area affected from earthquakes and may be a vertical dike beneath the swarm region.  相似文献   

Chemical evolution of thermal waters and changes in the hydrothermal system of Papandayan volcano (West Java,Indonesia) after the November 2002 eruption     

Agnès Mazot  Alain Bernard  Tobias Fischer  Salvatore Inguaggiato  Igan S. Sutawidjaja 《Journal of Volcanology and Geothermal Research》2008

Papandayan is a stratovolcano situated in West Java, Indonesia. Since the last magmatic eruption in 1772, only few hydrothermal explosions have occurred. An explosive eruption occurred in November 2002 and ejected ash and altered rocks. The altered rocks show that an advanced argillic alteration took place in the hydrothermal system by interaction between acid fluids and rocks. Four zones of alteration have been defined and are limited in extension and shape along faults or across permeable structures at different levels beneath the active crater of the volcano.  相似文献