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State of the arte assimilation techniques, such as 3D-Var, are relatively seldom used within climate analysis frameworks, partly because of the enormous numerical costs. In order to face this issue ESA''s high performance computing Grid on-Demand (G-POD) is used. We assimilate Global Navigation Satellite System (GNSS) based radio occultations (RO). RO data in general exhibit some favorable properties, like global coverage, all-weather capability expected long-term stability and accuracy. These properties and the continuity of data offered by the Meteorological Operational Satellite (MetOp) program and other RO missions are an ideal opportunity to study the long term atmospheric and climate variability. This paper investigates the assimilation of RO refractivity profiles into first guess fields derived from 21 years of ECMWF''s ERA40 dataset on a monthly mean basis divided into four synoptic time layers in order to take the diurnal cycle into account. In contrast to NWP systems, the assimilation procedure is applied without cycling, thus enabling us to run our 3D-Var implementation within G-POD parallel for different time layers. Results indicate a significant analysis increment which is partly systematic, emphasizing the ability of RO data to add independent information to ECMWF analysis fields, with a potential to correct biases. This work lays the ground for further studies using data from existing instruments within a framework based on a mature methodology. [Copyright &y& Elsevier]

Abstract: Climate change has already affected the phenology of several species. To be able to assess the impacts of climate change under various climate scenarios, we need superior models of the phenology of different species. Linear regression methods alone are of limited value for the analyses of natural indicators or phenological data because most time series of naturally occurring events in ecosystems do change in a nonlinear way. In this paper, we applied a Bayesian probability approach to investigate time series of the phenological phase of bud burst in Norway spruce (Picea abies (L.) Karst.) and mean monthly/weekly temperatures of corresponding climate stations in Germany. In these temperature and Norway spruce bud burst time series we detected years with the highest probability for discontinuities. We analysed rates of change and the relationship between temperature changes and bud burst of Norway spruce in the 51-year period 1953–2003. We used a Bayesian method for a coherence analysis between phenological onset dates and an effective temperature generated as a weighted average of monthly and weekly means from January to May. Weight coefficients were obtained from an optimization of the coherence factor by simulated annealing. In all investigated cases we found coherence factors that suggested a relationship between temperature and phenological time series. Norway spruce bud burst and mean temperature times series of April and May exhibited abrupt changes, particularly at the beginning of the 1980s. April and May temperature time series revealed an increased warming until 2003, and bud burst events advanced. Norway spruce bud burst, in particular, exhibited responses to temperatures of the previous (April) and current month (May). We suggest that besides commonly used sums of daily mean temperatures, forcing temperatures in phenology models should also include solutions where weighted effective temperatures in a sensitive time span are considered. [Copyright &y& Elsevier]

Abstract: The paper analyses Italian hydrogen scenarios to meet climate change, environmental and energy security issues. An Italy-Markal model was used to analyse the national energy–environment up to 2050. About 40 specific hydrogen technologies were considered, reproducing the main chains of production, transport and consumption, with a focus on transport applications. The analysis is based on the Baseline and Alternative scenario results, where hydrogen reaches a significant share. The two scenarios constitute the starting points to analyse the hydrogen potential among the possible energy policy options. The energy demand in the Baseline scenario reaches values around 240Mtoe at 2030, with an average annual growth of 0.9%. The Alternative scenario reduces consumption down to 220Mtoe and stabilizes the emissions. The Alternative scenario expects a rapid increase of hydrogen vehicles in 2030, up to 2.5 million, corresponding to 1Mtoe of hydrogen consumption. A sensitivity analysis shows that the results are rather robust. [Copyright &y& Elsevier]

Abstract: The transportation sector, led by the automobile, has been cited constantly as a major contributor through human intervention to climate change. Short of banning car use, the challenge remains one of understanding better what mix of actions might contribute in non-marginal ways to reducing the growth of greenhouse gas emissions and the absolute amount of CO2 produced by automobiles. This paper evaluates instruments aimed at a number of policy objectives linked to efficiency, sustainability and equity, focusing on social surplus gains in addition to cost effectiveness; but in particular the ability to reduce CO2. TRESIS, an integrated transport, land use and environmental strategy impact simulation program, is used to assess the influence on CO2 of a number of ‘at source’ and ‘mitigation’ instruments such as improvements in fuel efficiency, a carbon tax, variable user charges, and improvements in public transit. TRESIS is applied to the Sydney metropolitan area with instruments enacted in 2010 up to 2015. [Copyright &y& Elsevier]

Abstract: Regarding fluvial response to recent climate change, it is important to identify and understand previous changes of fluvial dynamics related to past climatic shifts. In this paper, periods of increased flood activity in Central Tunisian river systems are presented. Changes in Holocene flood dynamics are reconstructed through a comprehensive analysis of 195 radiocarbon dates from alluvial archives. Holocene floodplain deposits in Central Tunisia normally consists of cohesive overbank fines, which exhibit excellent preservation conditions against lateral erosion and, therefore, permit chronostratigraphic records of the entire Holocene at most. Based on published radiocarbon dates, two 14C cumulative probability density plots are created for Central Tunisia: the former represents ‘activity dates’ indicating phases of increased fluvial dynamics, the latter documents ‘stability dates’ showing periods of soil formation and enhanced landscape stability within the floodplain and the catchment. Due to geomorphological considerations, ‘activity dates’ and ‘stability dates’ should be mutually exclusive. There is a good match for the Mid-Holocene with increased periods of flooding from 6.2 to 6.0, 4.8 to 4.5, 4.1 to 3.7, and 3.3 to 3.0ka. These flood periods coincide with low soil formation signals. On the other hand, periods of increased alluvial soil formation from 6.8 to 6.6, 5.9 to 4.8, 4.5 to 4.1, 3.7 to 3.3, 3.0 to 2.8, and 1.8 to 1.6ka coincide with periods of low flood plain aggradation. The data reveal a coupling with North Atlantic cooling. Short-term periods of enhanced fluvial dynamics in Central Tunisia match well with North Atlantic cooling. The findings indicate a strong climatic link from 4.7ka until today. Compared to the Holocene floodplain dynamics in Tunisian drylands, the temperate mid-latitudes show Mid-Holocene switches in fluvial dynamics with opposite signs. Especially after 5ka North Atlantic driven flooding in the temperate Central European river systems contrast sharply to flood dynamics in arid to semiarid Mediterranean Tunisia. While under temperate climate conditions floodplain sedimentation decreases, it increases under more arid conditions. This may indicate that fluvial archives of dissimilar climatic zones reveal different threshold values and sedimentation patterns, and, therefore, different responses to climatic shifts. [Copyright &y& Elsevier]

Abstract: The zonal displacement of the western Pacific subtropical high remarkably influences the climate anomalies in China. In this paper, a new zonal index of the subtropical high is defined by modifying previous indices, and is used to investigate the relationship between the zonal displacement of the subtropical high and the dominant modes of 850-hPa circulations. It is found that the zonal displacement of the subtropical high is significantly correlated with the first two leading modes of circulations. In particular, the correlation coefficient between the index and the time series associated with the second mode is as high as 0.78 in 1958–2003 (46years). Since the second mode is not associated with significant anomalies of sea surface temperatures, the above results imply the difficulty in seasonal forecasting of the zonal displacement of the subtropical high. In addition, the interannual variability in the zonal displacement of the subtropical high has been considerably enhanced since 1978, due to the effects of both dominant modes, especially the second mode. This is likely to account for the frequent occurrence of anomalous climate in China during the recent two decades. [Copyright &y& Elsevier]

Abstract: INTegration of Ice-core, MArine and TErrestrial records (INTIMATE) is a core project of the INQUA Palaeoclimate Commission, the primary goal of which is to synchronise records of the Last Glacial–Interglacial Transition (LGIT). Through a series of international workshops, INTIMATE has encouraged direct collaboration between scientists with interests and expertise in a wide range of palaeoenvironmental approaches. The workshops have focused on the dissemination of good practice in the dating, correlation and synthesis of diverse palaeoenvironmental records that span the LGIT. This special issue of Quaternary Science Reviews presents some of the outcomes of the 8th INTIMATE International Workshop held in Iceland in September 2005, and focuses on four themes considered vital to INTIMATE''s long-term strategy. (1) An event stratigraphy approach, which uses the Greenland oxygen isotope record as a stratotype sequence, lies at the core of INTIMATE''s operations. A revised event stratigraphy scheme for application to North Atlantic LGIT records is presented, which is based on the new GICC05 Greenland ice-core chronology. (2) New tree-ring data from Switzerland and the application of Bayesian-based procedures in the analysis of comprehensive radiocarbon data sets provide much potential for reducing the uncertainties in radiocarbon-based age models. (3) Three of the contributions present new evidence that helps to refine the tephrostratigraphy of the LGIT in the NE Atlantic and New Zealand regions. (4) Establishing the precise order and synchroneity of events during the LGIT is vital to understand the causes and effects of abrupt climate change. Data are presented from the Baltic region and Alaska, which vary in degree of compatibility with North Atlantic records. Two final papers consider the roles of Dansgaard–Oeschger events on thermokarst during the Middle Weichselian and of solar activity variations during the mid-Holocene; both illustrate how the INTIMATE event stratigraphy approach can apply to the study of other time intervals. [Copyright &y& Elsevier]

Abstract: In this paper, we describe a method for constructing regional electricity demand data sets at 30min intervals, which are consistent with climate change scenarios. Specifically, we modify a commonly used linear regression model between regional electricity demand and climate to also describe intraday variability in demand so that regional load duration curves (LDCs) can be predicted. The model is evaluated for four different Australian states that are participants in the Australian National Electricity Market (NEM) and the resultant data sets are found to reproduce each state''s LDCs with reasonable accuracy. We also apply the demand model to CSIRO''s Mk 3 global climate model data sets that have been downscaled to 60km resolution using CSIRO''s conformal-cubic atmospheric model to estimate how LDCs change as a consequence of a 1°C increase in the average temperature of Australian state capital cities. These regional electricity demand data sets are then useful for economic modelling of electricity markets such as the NEM. [Copyright &y& Elsevier]

Abstract: This paper seeks to discern the influence of environmental variability on pastoral conflict in the Horn of Africa. While the literature on environmental factors in civil wars is rich in empirical research and explanatory power, the dearth of data is an obstacle to the study of other important forms of violence such as pastoral conflict. If environmental factors are associated with pastoral conflict then what are they, and can they be used as early warning indicators to prevent its escalation or mitigate its effects? These questions are increasingly important given the expected impact of climate change on pastoral societies worldwide. To help answer these questions we draw on data collected by field monitors with the Inter-Governmental Authority on Development''s (IGAD) Conflict Early Warning and Response Network (CEWARN) and environmental data for the same region. Field monitors collect incident and situation reports from more than two dozen areas of reporting along the borders of Ethiopia, Kenya and Uganda collectively known at the Karamoja Cluster. We compare these conflict data with three environmental indicators: precipitation, vegetation and forage. Preliminary statistical analyses of the data suggest that aggravating behavior, along with a reduction in peace initiatives and reciprocal exchanges, is associated with an escalation in pastoral conflict, particularly when coupled with an increase in vegetation that may provide cover for organized raids. We therefore recommend that conflict early warning systems integrate both response options and salient environmental indicators into their analyses to better deal with the complexity of the relationships between pastoral conflict and the environment in an era of climate change. [Copyright &y& Elsevier]

An integrated index which can be used to indicate the advance of subtropical summer monsoon in East Asia has been proposed in this paper. The index was combined by three variables including precipitation, wind and pseudo-equivalent potential temperature. The northernmost summer monsoon location (NSML) was identified by using this index annually. It was found that the NSML experienced an interdecadal shift in the period 1977-1979 based on the annual index analysis from 1961 to 2001. A comparison of the NSML with other four summer monsoon indices has also been made. The result showed that the NSML could well represent the interan- nual and interdecadal variability of summer monsoon precipitation in North Chins (beyond 35°N), while other four indices could well indicate the precipitation anomalies of East Asian summer monsoon along the Yangtze River valley (around 30°N). [ABSTRACT FROM AUTHOR]

This paper discusses results concerning multivariate normal distributions that are subject to truncation by a hyperplane and how such results can be applied to uncertainty analysis in the environmental sciences. We present a suite of results concerning truncated multivariate normal distributions, some of which already appear in the mathematical literature. The focus here is to make these types of results more accessible to the environmental science community and to this end we include a conceptually simple alternative derivation of an important result. We illustrate how the theory of truncated multivariate normal distributions can be employed in the environmental sciences by means of an example from the economics of climate change control. [Copyright &y& Elsevier]

Summary: Understanding the process of groundwater recharge is fundamental to the management of groundwater resources. Quantifying the future evolution of recharge over time requires not only the reliable forecasting of changes in key climatic variables, but also modelling their impact on the spatially varying recharge process. This paper presents a physically based methodology that can be used to characterize both the temporal and spatial effect of climate change on groundwater recharge. The method, based on the hydrologic model HELP3, can be used to estimate potential groundwater recharge at the regional scale with high spatial and temporal resolution. In this study, the method is used to simulate the past conditions, with 40years of actual weather data, and future changes in the hydrologic cycle of the Grand River watershed. The impact of climate change is modelled by perturbing the model input parameters using predicted changes in the regions climate. The results of the study indicate that the overall rate of groundwater recharge is predicted to increase as a result of climate change. The higher intensity and frequency of precipitation will also contribute significantly to surface runoff, while global warming may result in increased evapotranspiration rates. Warmer winter temperatures will reduce the extent of ground frost and shift the spring melt from spring toward winter, allowing more water to infiltrate into the ground. While many previous climate change impact studies have focused on the temporal changes in groundwater recharge, our results suggest that the impacts can also have high spatial variability. [Copyright &y& Elsevier]

Quantitative reconstruction of the climatic history of the Chinese Loess Plateau is important for understanding present and past environment and climate changes in the Northern Hemisphere. Here, we reconstructed mean annual temperature (MAT) and mean annual precipitation (MAP) trends during the last 136ka based on the analysis of phytoliths from the Weinan loess section (34°24′N, 109°30′E) near the southern part of the Loess Plateau in northern China. The reconstructions have been carried out using a Chinese phytolith–climate calibration model based on weighted averaging partial least-squares regression. A series of cold and dry events, as indicated by the reconstructed MAT and MAP, are documented in the loess during the last glacial periods, which can be temporally correlated with the North Atlantic Heinrich events. Our MAT and MAP estimations show that the coldest and/or driest period occurred at the upper part of L2 unit (Late MIS 6), where MAT dropped to ca 4.4°C and MAP to ca 100mm. Two other prominent cold-dry periods occurred at lower Ll-5 (ca 77–62ka) and L1-1 (ca 23–10.5ka) where the MAT and MAP decreased to about 6.1–6.5°C and 150–370mm, respectively, ca 6.6–6.2°C and 400–200mm lower than today. However, the highest MAT (average 14.6°C, max. 18.1°C) and MAP (average 757mm, max. 1000mm) occurred at Sl interval (MIS 5). During the interstadial of L1-4–L1-2 (MIS 3) and during the Holocene warm-wet period, the MAT was about 1–2°C and MAP 100–150mm higher than today in the Weinan region. The well-dated MAT and MAP reconstructions from the Chinese Loess Plateau presented in this paper are the first quantitatively reconstructed proxy record of climatic changes at the glacial–interglacial timescale that is based on phytolith data. This study also reveals a causal link between climatic instability in the Atlantic Ocean and climate variability in the Chinese Loess Plateau. [Copyright &y& Elsevier]

Abstract: This paper discusses the diverse climate forcings that impact agricultural systems, and contrasts the current paradigm of using global models downscaled to agricultural areas (a top-down approach) with a new paradigm that first assesses the vulnerability of agricultural activities to the spectrum of environmental risk including climate (a bottom-up approach). To illustrate the wide spectrum of climate forcings, regional climate forcings are presented including land-use/land-cover change and the influence of aerosols on radiative and biogeochemical fluxes and cloud/precipitation processes, as well as how these effects can be teleconnected globally. Examples are presented of the vulnerability perspective, along with a small survey of the perceived drought impacts in a local area, in which a wide range of impacts for the same precipitation deficits are found. This example illustrates why agricultural assessments of risk to climate change and variability and of other environmental risks should start with a bottom-up perspective. [Copyright &y& Elsevier]

Abstract: A method for surface modeling of land cover change (SMLC) is developed on the basis of establishing transition probability matrixes between land cover types and HLZ types. SMLC is used to simulate land cover scenarios of China for the years 2039, 2069 and 2099, for which HLZ scenarios are first simulated in terms of HadCM3 climatic scenarios that are downscaled in zonal model of spatial climate change in China. This paper also analyzes spatial distribution of land cover types, area change and mean center shift of each land cover type, ecotope diversity, and patch connectivity under the land cover scenarios. The results show that cultivated land would decrease and woodland would expand greatly with climatic change, which coincides with consequences expected by implementation of Grain-for-Green policy. Nival area would shrink, and desertification area would expand at a comparatively slow rate in future 100 years. Climate change would generally cause less ecotope diversity and more patch connectivity. Ecosystems in China would have a pattern of beneficial cycle after efficient ecological conservation and restoration. However, if human activities would exceed regulation capacity of ecosystems themselves, the ecosystems in China might deteriorate more seriously. [Copyright &y& Elsevier]

Abstract: Based upon climate change research conducted with Inuit from Chesterfield Inlet, Nunavut and a philosopher from Iqaluit, Nunavut, this paper proposes that market economic rationality limits the general Western approach towards climate change and indigenous knowledges. Building upon ecological economic research which indicates that there is little difference between the economic assumptions which are related to the onset of human-induced climate change and those underlying the proposed solution, these Inuit voices critique the separation of their knowledge—Inuit Qaujimaningit—into the research categories of ecological knowledge and traditional understandings as a means for economically adapting to climate change. It is suggested that Inuit knowledge of climate change offers a challenge to economic rationalization if researchers move beyond a mere documentation of ecological knowledge and engage the interconnected cultural understandings. The conclusion proposes that the relation between culture and ecology should be of significant interest to ecological economic thinking that aims to consider economic rationality, the global economy, and its climatic impacts in the context of bioregional adaptations. [Copyright &y& Elsevier]

Abstract: Hydrological model sensitivity to climate change can be defined as the response of a particular hydrological model to a known quantum of climate change. This paper estimates the hydrological sensitivity, measured as the percentage change in mean annual runoff, of two lumped parameter rainfall-runoff models, SIMHYD and AWBM and an empirical model, Zhang01, to changes in rainfall and potential evaporation. These changes are estimated for 22 Australian catchments covering a range of climates, from cool temperate to tropical and moist to arid. The results show that the models display different sensitivities to both rainfall and potential evaporation changes. The SIMHYD, AWBM and Zhang01 models show mean sensitivities of 2.4%, 2.5% and 2.1% change in mean annual flow for every 1% change in mean annual rainfall, respectively. All rainfall sensitivities have a lower limit of 1.8% and show upper limits of 4.1%, 3.4% and 2.5%, respectively. The results for potential evaporation change are −0.5%, −0.8% and −1.0% for every 1% increase in mean annual potential evaporation, respectively, with changes rainfall being approximately 3–5 times more sensitive than changes in potential evaporation for each 1% change in climate. Despite these differences, the results show similar correlations for several catchment characteristics. The most significant relationship is between percent change in annual rainfall and potential evaporation to the catchment runoff coefficient. The sensitivity of both A and B factors decreases with an increasing runoff coefficient, as does the uncertainty in this relationship. The results suggest that a first-order relationship can be used to give a rough estimate of changes in runoff using estimates of change in rainfall and potential evaporation representing small to modest changes in climate. Further work will develop these methods further, by investigating other regions and changes on the subannual scale. [Copyright &y& Elsevier]

Summary: This paper explores the potential impacts of climate change upon flood frequency for the gauged, Lossie catchment in the northeast of Scotland, UK. This catchment has significant flooding problems, but only limited data availability (particularly with respect to rainfall). A continuous simulation methodology, which uses a stochastic rainfall model to drive the rainfall-runoff model TOPMODEL, is utilised. Behavioural parameter sets for TOPMODEL are identified prior to the climate change runs using the Generalised Likelihood Uncertainty Estimation (GLUE) methodology. The “Low Emissions”, “Medium-Low Emissions”, “Medium-High Emissions” and “High Emissions” UKCIP02 climate change scenarios, obtained from the HadCM3 global climate model (GCM) and HadRM3 regional climate model (RCM) simulations, are used at the catchment scale. Two further scenarios (“H-Dry” and “H-Wet”), based upon the model uncertainty margins available for the UKCIP02 “High Emissions” scenario, are also developed in order to explore the possible range of changes to daily rainfall and temperature estimated from GCMs other than HadCM3. It is demonstrated that, while flood magnitude changes under all six of the climate change scenarios considered, the magnitude and direction of that change is dependent upon the choice of scenario. An overlap between the likelihood weighted uncertainty bounds estimated under the conditions of the current climate and those estimated under the four UKCIP02 scenarios and the “H-Dry” scenario is also observed. These findings highlight the need to consider multiple climate change scenarios and account for model uncertainties when estimating the possible effects of climate change upon flood frequency. [Copyright &y& Elsevier]

Abstract: We show the massive reduction achievable, in both emissions and climate change impact, from enhanced nuclear energy use on the forecasts of future world energy use and its associated environmental impacts. A range encompassing the major scenarios for the World''s energy demand have been analyzed using the latest version of the climate-modeling MAGICC/SCENGEN software (Version 4.1). We have updated and predicted the impacts of 80% substitution with CO2-free sources (likely predominantly nuclear) for coal-fired electricity (by 2030) and for transportation fuel (by 2040). For transportation, hydrogen produced by CO2-free sources would replace gasoline and diesel fuels. In this paper, to bracket the range of futures, we simply focus on two scenarios from the Intergovernmental Panel on Climate Change''s (IPCC), one (A1FI) that is energy-profligate and one (B2) that is energy-conserving. The results show that, interestingly, projected average global temperatures for all scenarios are fairly similar until about 2035 (a further rise beyond the 1990 average temperature of +0.75±0.1K) regardless of energy usage and its sources. However, by 2050, the different IPCC scenarios diverge markedly. Understandably, A1FI is projected to have noticeably stronger effects than B2 on average global temperatures (about 0.3K more in 2050) but the effect is much stronger over land at mid and high latitudes (up to almost 1K more). What is most striking is that the substitution of CO2-free sources gives projected average temperature rises in 2050 over key land areas (North America and China) that are very similar for the two energy-use scenarios—typically 1–1.5K because A1FI''s additional energy is predominantly supplied by nuclear. In contrast, projected rises with the unaltered cases are markedly different being about 2.5K for A1FI and 1.5–2K for B2. The projected changes in rainfall distribution show similar patterns, especially for the expected increases in higher latitudes. With the assumption of no additional policies for substitution of energy sources beyond 2040, temperature divergence between the two scenarios of relative energy profligacy or conservation grows in the latter half of the 21st century, even with substitution. However, the early substitution of nuclear energy and hydrogen appears to buy time and is not crucially dependent on severe, near-term curtailment of energy use. Near-term curtailment is too difficult to implement at a time of rapid industrialization of major emerging economies. Of course, proportionately larger deployments of CO2-free energy sources are needed for more energy-intensive scenarios. Nuclear power must dominate as the source of CO2-free energy since it is proven, dependable, available on a large scale, and economic. Social objections to nuclear energy in some countries and quarters are seen as well-meaning but misguided distractions from solving the energy and environmental crises that are now facing world sustainability. The time for real technical, social and political action is now. [Copyright &y& Elsevier]

Abstract: During the boreal summer the Western Hemisphere warm pool (WHWP) stretches from the eastern North Pacific to the tropical North Atlantic and is a key feature of the climate of the Americas and Africa. In the summers following nine El Niño events during 1950–2000, there have been five instances of extraordinarily large warm pools averaging about twice the climatological annual size. These large warm pools have induced a strengthened divergent circulation aloft and have been associated with rainfall anomalies throughout the western hemisphere tropics and subtropics and with more frequent hurricanes. However, following four other El Niño events large warm pools did not develop, such that the mere existence of El Niño during the boreal winter does not provide the basis for predicting an anomalously large warm pool the following summer. In this paper, we find consistency with the hypothesis that large warm pools result from an anomalous divergent circulation forced by sea surface temperature (SST) anomalies in the Pacific, the so-called atmospheric bridge. We also find significant explanations for why large warm pools do not always develop. If the El Niño event ends early in the eastern Pacific, the Pacific warm anomaly lacks the persistence needed to force the atmospheric bridge and the Atlantic portion of the warm pool remains normal. If SST anomalies in the eastern Pacific do not last much beyond February of the following year, then the eastern North Pacific portion of the warm pool remains normal. The overall strength of the Pacific El Niño does not appear to be a critical factor. We also find that when conditions favor a developing atmospheric bridge and the winter atmosphere over the North Atlantic conforms to a negative North Atlantic Oscillation (NAO) pattern (as in 1957–58 and 1968–69), the forcing is reinforced and the warm pool is stronger. On the other hand, if a positive NAO pattern develops the warm pool may remain normal even if other circumstances favor the atmospheric bridge, as in 1991–92. Finally, we could find little evidence that interactions internal to the tropical Atlantic are likely to mitigate for or against the formation of the largest warm pools, although they may affect smaller warm pool fluctuations or the warm pool persistence. [Copyright &y& Elsevier]

This paper presents fossil beetle data from a Last Glacial Maximum site at the Lyndon Stream, in the Canterbury foothills, South Island, New Zealand. Paleotemperatures are derived using the maximum likelihood envelope (MLE) model developed for regions where modern distribution data are incomplete [Marra et al., 2004. Late quaternary climate change in the Awatere Valley, South Island, New Zealand using a sine model with a maximum likelihood envelope on fossil beetle data. Quaternary Science Reviews 23, 1637–1650]. The MLE model results indicate that summer temperatures in the Canterbury foothills, in close proximity to the major Rakaia glacier, at ca 22,000 14C yr BP were between 0.5°C warmer and 1.9°C cooler than present day in February (summer). Mean minimum winter temperatures ranged between 1°C warmer and 2.2°C cooler than the present day. These apparently surprising results confirm and quantify existing climate reconstructions from plant macrofossils from this site [Soons, J.M., Burrows, C.J., 1978. Dates for Otiran deposits, including plant microfossils and macrofossils, from Rakaia Valley. New Zealand Journal of Geology and Geophysics 21, 607–615]. They are consistent with new evidence of relatively mild conditions at least during some periods within the Last Glacial Maximum chron in New Zealand. [Copyright &y& Elsevier]

Abstract: Climate change, air quality and energy security will change the way energy is used and supplied over the next century. Supplying increasing amounts of clean and secure energy will be a challenge that will require a great deal of innovation and investment. However, this paper shows that there are visible paths to clean and secure energy. There are plenty of resource and technology options that could lead to emissions reductions in the heat, transport and electricity sector, while improving energy security. The costs of supplying energy from different options vary widely. However, several clean energy options are viable today and several others are likely to be so in the future, as technologies improve, costs are reduced, and the competitive landscape for energy technologies evolves. Tackling climate change and energy security requires the simultaneous deployment of available commercial clean technologies, demonstration and commercialisation of technologies at the advanced research, development and demonstration stage, and research into new technologies. [Copyright &y& Elsevier]

Abstract: The perception of a changing climate, which impacts also hydrological processes, is now generally admitted. However, the way of handling the changing nature of climate in hydrologic practice and especially in hydrological statistics has not become clear so far. The most common modelling approach is to assume that long-term trends, which have been found to be omnipresent in long hydrological time series, are ‘deterministic’ components of the time series and the processes represented by the time series are nonstationary. In this paper, it is maintained that this approach is contradictory in its rationale and even in the terminology it uses. As a result, it may imply misleading perception of phenomena and estimate of uncertainty. Besides, it is maintained that a stochastic approach hypothesizing stationarity and simultaneously admitting a scaling behaviour reproduces climatic trends (considering them as large-scale fluctuations) in a manner that is logically consistent, easy to apply and free of paradoxical results about uncertainty. [Copyright &y& Elsevier]

Abstract: Climatic change has often been cited as a determining factor in cultural changes in the context of the Harappan Civilisation of northwestern South Asia, 2500–1900BC. While these claims have been critiqued by archaeologists they continue to be accepted by non-archaeologists, including Quaternary scientists. The purpose of this paper is to assess the available evidence and published arguments and to provide a constructive working synthesis of evidence for the palaeoenvironmental setting of northwestern South Asia for the mid- to late Holocene, especially ca 4000–1000calBC, and its possible connection to important cultural changes. We conclude that Harappan urbanism emerged on the face of a prolonged trend towards declining rainfall. No climatic event can be blamed for a precipitous end of this civilisation, although strategic local shifts in agriculture that may have begun in response to prolonged droughts at ca 2200BC may have contributed to the de-urbanisation process and the restructuring of human communities over the following 200–300yr. [Copyright &y& Elsevier]

Abstract: This paper offers an alternative to the use of geomorphological and sedimentological evidence for the reconstruction of flood and low flow frequencies. It is based on a technique developed to estimate the hydrological impact of future climate change and it uses either observed or calculated meteorological parameters. It is possible to use this method directly without modification to ‘hindcast’ events within the period of regional meteorological records, which in areas like the UK extend back over the last 150 years. It should also be possible to extend the approach to earlier periods using reconstructed meteorological parameters based on surrogate data, such as ships'' logs. The resulting extreme flow sequences may be used to study past hydrological regimes or to improve estimates of present-day risks by extending the flow records. The technique uses an airflow index-based stochastic weather generator to create hydrometeorological parameters to input into a physically based hydrological simulation model. The method is illustrated here in a reconstruction of daily flow series for the River Wye catchment above Rhayader, mid-Wales, for the period 1889–1998. The method makes use of observed climatic variables for the entire period, with the aim of capturing actual climate variability occurring over the 110-year period. Changes in high flow characteristics are assessed using the mean annual flood (MAF), Q 5 flow and peaks-over-threshold (POT) calculated from the 110-year simulated daily flow series. This particular application shows evidence of a possible trend towards increasing magnitude and frequency of high flow events, which, if continued, would have implications for flood and water resource management. Looking at evidence from the last 110 years helps to place possible future trends within the context of past variations in high flow extremes due to both natural and anthropogenically influenced fluctuations in climate. [Copyright &y& Elsevier]

Abstract: The recognition and interpretation of glacigenic sediments in the ancient rock record has important implications for understanding processes and patterns of climate change. Diamictite facies from the Neoproterozoic Port Askaig Formation, Scotland, have been variously interpreted as evidence for grounded glacier ice, mass-movements on a glacially influenced submarine slope, and subaqueous mass movements in a non-glacial environment. These contrasting interpretations imply widely differing degrees of ice cover, and have contrasting implications for Neoproterozoic (“Snowball”) glaciations. In this paper, we focus on the Great Breccia and the Disrupted Beds, two controversial units in the Port Askaig Formation. We present evidence that they were formed by the proglacial and subglacial deformation, respectively, of pre-existing shallow marine facies during an advance of grounded ice. Quaternary examples provide remarkably exact analogues for the Great Breccia and Disrupted Beds, illustrating the potential value of applying litho- and tectono-facies models to ancient sedimentary successions. [Copyright &y& Elsevier]

Abstract: This paper describes the influence of high environmental stress on evolutionary trends in some selected Mesozoic ammonite lineages and some protists. During extinction periods, many ammonoids are affected by drastic simplifications of their shell geometry, ornamentation and suture line. We observe that relatively tightly coiled ammonites can give rise to highly evolute forms or uncoiled heteromorphs with simple ornamentation and almost ceratitic suture line—a phenomenon called “proteromorphosis”. Such simplifications often correspond to a reappearance of ancestral geometries (primitive ornamentation, evolute coiling or uncoiling) which suggest that the evolutionary clock of these organisms can be reinitialized by extreme, sublethal, environmental stress such as giant volcanism (including its consequences on diverse pollutions and on climatic changes) and major regressive events. [Copyright &y& Elsevier]

Abstract: This paper investigates whether it is possible to find a solar signature in the current Earth’s climatic warming. The attempt seems audacious as, on one hand, solar output variability on the atmosphere is far to be understood, and on the other hand, there is evidence that most of the warming observed over the last 50 years can be attributed to human activities. However, series of the annual global average temperature, from 1861 up to now are available, showing periods of warming and cooling that are statistically significant. From recent findings, it is also known that solar irradiance shows a variability and can be modeled today with a good accuracy over the last century. The idea was to compare the likelihood linear trends shown in the climatic data with those of the irradiance, during same well defined time ranges. Changes from 1861 to 1975 show an unexpected remarkable correlation, whereas the period 1976–2000 completely deviates from the previous analysis. The 1861–1975 set of data supports the suggestion of an influence of solar irradiance on global climate, which was checked as a natural forcing: the response is found to be λ =0.46°C/Wm−2, a quite reasonable value, bearing in mind the imprecision in the irradiance modeling. This analysis is also discussed in the scope of other forcings and uncertainties in the data. [Copyright &y& Elsevier]

Abstract: Climatic change is one of the most important issues of present times. Unlike the greenhouse gases, which have a predominantly warming effect, atmospheric aerosols could either warm or cool the atmosphere depending upon the size, distribution and optical properties. Of all the climatic elements, temperature plays a major role in detecting climatic change brought about by urbanization and industrialization. This paper, therefore, attempts to study temporal variation in temperature over Pune city, India, during the period 1901–2000. The long-term change in temperature has been evaluated by Mann–Kendall rank statistics and linear trend. The analysis reveals significant decrease in mean annual and mean maximum temperature. This decrease in temperature is more pronounced during the winter season, which can be ascribed to a significant increase in the amount of suspended particulate matter (SPM) in the ambient air during the last decade. On the contrary, monsoon season shows warming. This warming can be attributed to a significant increase in the low cloud amount. [Copyright &y& Elsevier]

Abstract: There is a broad consensus that the costs of abatement of global climate change can be reduced efficiently through the assignment of quota rights and through international trade in these rights. There is, however, no consensus on whether the initial assignment of emissions permits can affect the Pareto-optimal global level of abatement. This paper provides some insight into the equity–efficiency puzzle. Qualitative results are obtained from a small-scale model; then quantitative evidence of separability is obtained from MERGE, a multiregion integrated assessment model. It is shown that if all the costs of climate change can be expressed in terms of GDP losses, Pareto-efficient abatement strategies are independent of the initial allocation of emissions rights. This is the case sometimes described as ‘market damages’. If, however, different regions assign different values to nonmarket damages such as species losses, different sharing rules may affect the Pareto-optimal level of greenhouse gas abatement. Separability may then be demonstrated only in specific cases (e.g. identical welfare functions or quasi-linearity of preferences or small shares of wealth devoted to abatement). [Copyright &y& Elsevier]

Abstract: The objective of this paper is to synthesize the large literature recording changing patterns of precipitation in the observed data, thus indicating that climate change is already a reality. Such a synthesis is required not only for environmental researchers but also for policy makers. The key question is the broad picture at major regional and continental levels. Some interesting conclusions for this survey are emerging. For example, the review shows increased variance of precipitation everywhere. Consistent with this finding, we observe that wet areas become wetter, and dry and arid areas become more so. In addition, the following general changing pattern is emerging: (a) increased precipitation in high latitudes (Northern Hemisphere); (b) reductions in precipitation in China, Australia and the Small Island States in the Pacific; and (c) increased variance in equatorial regions. The changes in the major ocean currents also appear to be affecting precipitation patterns. For example, increased intensity and frequency of El Niño and ENSO seem associated with evidence of an observed “dipole” pattern affecting Africa and Asia, although this time series is too short so far. But the changing pattern calls for renewed efforts at adaptation to climate change, as the changing precipitation pattern will also affect the regional availability of food supply. [Copyright &y& Elsevier]

Abstract: Climate variability at decadal scales influences not only the growth of widely distributed species such as Pinus ponderosa, but also can have an effect on the timing and severity of fire and insect outbreaks that may alter species distributions. In this paper, we present a spatial modelling technique to assess the influence of climatic variability on the annual productivity of P. ponderosa in the Pacific Northwest (PNW) of North America over the past 100 years and infer how a sustained change in climate might alter the geographic distribution of this species across defined ecotones. Field observations were used to establish criteria for P. ponderosa dominance including: (1) maximum summer leaf area index (LAI), ranges between 1.5 and 2.5; (2) 80% of available soil water is depleted during summer months; and (3) soil water will return to full capacity at least once during the year. Where these three criteria were not met, eventual replacement of P. ponderosa would be predicted. We utilized a simple physiological model, Physiological Principles for Predicting Growth (3-PG) to predict annual variation in LAI from climatic data provided by the Oregon Climate Service over the period from 1900 to 2000 and from broad scale 0.5°-spatial resolution future climate projections produced by the Hadley Climate Center, UK. From these simulations we produced a series of maps that display predicted shifts of zones where ponderosa pine might be expected to contract or expand its range if modeled climatic conditions at annual and decadal intervals were sustained. From the historical simulations, the most favorable year for pine dominance was 1958 and the least favorable, 1924. The most favorable decade was in the 1900s and the least favorable in the 1930s. The future predictions indicate a reduction in the current range of the P. ponderosa type along the western Cascade Range however, an increase along the east side and inland PNW. The model predicts that pine dominance should increase between 5 and 10% over the next century, mainly in inland Oregon, Idaho, and Washington. [Copyright &y& Elsevier]

Abstract: Climate varies from seasonal to centennial time scales. In the last two decades progress has been made to better understand several aspects of short-term variability of the Earth’s climate system. Tropical Pacific is dominated by a single mode of interannual climate variability, which reflects the coupling of the Ocean and the atmosphere and is expressed by the El Niño/Southern Oscillation (ENSO) phenomenon. The Pacific climate contains another mode of variability similar to the ENSO, but varying on a decadal scale, the Pacific Decadal Oscillation (PDO) mode. Variations of the sea surface temperature (SST) in the Tropical Atlantic also play an important role in modulating the climate variability. The SST variability in this basin might be explained by at least five modes: separate modes in the Tropical North Atlantic and Tropical South Atlantic, equatorial mode, dipole mode and cross-equatorial SST anomaly gradient mode. Among these modes, the equatorial mode contains strong interannual variability, while the dipole and the cross-equatorial SST anomaly gradient modes contain strong decadal variability. Some aspects of the climate variability, with emphasis on the ENSO, PDO modes in the Pacific and the Atlantic SST modes on the interannual and decadal time scales, are discussed in the present paper. [Copyright &y& Elsevier]

Abstract: The debate on the enhanced greenhouse effect continues, confusing the climate change impact analysis and the decision makers. Hence, this paper is addressed to the extreme regional-scale evaluation of global climate model (GCM). Given that assessment of models is crucial to consider future scenarios in climate change impact analyses, the exploratory work is essential, as it identifies the strengths and weaknesses of GCM to regional-scale differences in model performance, providing insights on regional-scale climate interactions and processes. That is why this manuscript attempts to compare the spatial pattern of a longer temporal aggregation period (1960/61–1989/90) for extreme temperatures simulated by a particular GCM (HadCM3) to that of NCEP Reanalyses, which are considered as “truth”. Climatic risk analyses and forecasting, concern among other topics, assess an interpretation in intensity and frequency of recurrence of long duration extreme values (heat/cold waves). One study assesses the impact of extreme events analysing the temporal dependence of extreme events. The present study leads to the conclusion that the HadCM3 Simulations do not reproduce reasonably the NCEP Reanalyses over the Modelling the Impact of Climate Extremes (MICE—EU Project) domain, even despite the fact that the climatology of extremes has demonstrated very similar spatial patterns. Consequently, all diagnostics of extremes led support to the fitted Generalised Extreme Value (GEV) model for extrapolation, suggesting that the HadCM3 is not adequate for forecasting, simulating future scenarios of extremes based on the analysis of risk or probability maps for spatial uncertainties. The greatest difference between the two models is in terms of the precision of estimation. [Copyright &y& Elsevier]

Abstract: This short introductory paper illustrates some key issues concerning extremes by focusing on daily temperature extremes defined using quantiles and threshold exceedances. The examples include both a low- and a high-elevation site in the Swiss Alps where long records of homogenous daily data are readily available. The analysis of extremes highlights several features, some of them taken from the 2003 heat wave that affected Europe, in particular significant changes in the trends of quantiles in the course of the 20th century, differences in the altitudinal behavior of maximum or minimum temperatures, and close links between means and the extreme quantiles of daily temperatures. [Copyright &y& Elsevier]

When the pollution level is influenced by climatic changes, its behaviour is very dynamic. In the Gulf of Mexico, climatic conditions with strong wind (more than 40 km/h maintained) are known as “Norths”. A “North” generates an abrupt change in the pollution level on the external insulation in distribution networks. This paper describes climatic changes during a “North”, and its influence over the pollution level. The pollution level is evaluated during a “North” by means of the leakage current (LC) and surface resistance (SR) variations in several profiles of insulators. The ESDD measurements after a “North” are included too. [Copyright &y& Elsevier]

This paper investigates the response of the Antarctic ice sheet shape and volume to changes in outlet flow boundary conditions. We model the transmission of outlet flow boundary perturbations toward the inland ice sheet by taking into account the dynamical properties of the profile. We investigate the effect of outlet perturbations according to their time scales. We derive the analytical relation between the temporal wavelength of the perturbations and the induced wavelength of surface undulations. We show that the inland undulation wavelength and transmission increase with the temporal wavelength of the perturbation, so that the short time scale perturbations are strongly filtered. For a given outlet perturbation, the induced frequency depends on the distance to the coast and on the dynamical characteristics of the profile, so that two adjacent flow lines may have different signals. Because outlet perturbations are poorly quantified, it is difficult to predict their impact on sea level change. However, the impact seems to be smaller than that induced by other random processes, such as accumulation rate fluctuations. Finally, an analysis of the ice sheet topography anomalies suggests that in some places, the actual response to a past outlet perturbation can be suspected. [Copyright &y& Elsevier]

The sulphate glacio-chemical profiles constitute a reliable proxy marker for reconstruction of past volcanic history, assuming a reliable method to distinguish sulphate spikes and to evaluate the flux of individual events is set up. The resulting volcanic event profile is used to reconstruct past event frequencies, and to investigate possible links between volcanism and climatic changes. Volcanic event signatures are useful also in comparing time scales from ice cores drilled at different locations. In this paper, a new method to pick out volcanic signals is proposed. It improves on methods based on the calculation of a threshold using a general mean value plus a multiple of the standard deviation by adding: (1) quantification of nonvolcanic sulphate contributions; (2) sulphate fluxes, instead of concentrations, accounting for accumulation rate changes; (3) data treatment using a log-normal statistic, instead of a Gaussian-type distribution, to take into account the real sulphate distribution; (4) a smoothed curve (weighted fitting) to better understand the residual variability of the sulphate background.This method is used to detect volcanic events throughout the 45 ky time span of the EDC96 ice core, drilled at Dome C on the East Antarctic plateau. A total of 283 volcanic signatures are recovered, with a mean of 6.3 events per millennium. The temporal event frequencies indicate that the last 2000 years were probably characterized by the highest volcanic activity in the period covered by the core and that there is no clear link between number of events recorded and climatic changes. [Copyright &y& Elsevier]

It has been identified that, long-term climatic changes (Pleistocene ice ages) have been caused by periodic changes in the distribution of incoming solar radiation due to the variations in the earth’s orbital geometry, that is the tilt, precision of equinoxes and eccentricity which take place with periodicity ranging from 41 to 9508 thousand years. However, it has been considered that the major potential mechanism of climate change over the next few hundred years will be anthropogenic green house gas warming up. A number of gases that occur naturally in the atmosphere in small quantities are known as ”greenhouse gases. Water vapour, carbon dioxide, ozone, methane, and nitrous oxide trap solar energy in much the same way as do the glass panes of a greenhouse or a closed automobile. This natural greenhouse gases effect has kept the earth’s atmosphere some 30°C hotter, than it would otherwise be, making it possible for humans to exist on earth. Human activities, however, are now raising the concentrations of these gases in the atmosphere and thus increasing their ability to trap energy. The enhanced greenhouse gas effect is expected to cause high temperature increase globally (1–3.5°C) and this will lead to an increase in precipitation in some regions while other regions will experience reduced precipitation (±20%). The impact of expected climate change will affect almost all the sectors of the human endeavor. However, the major purpose of this project is to evaluate the impact of climate change on hydrology and water resources and establish the appropriate adaptation strategies for Swaziland. The impact of climate change on hydrology and water resources will be evaluated using General Circulation Model results (rainfall, potential evapotranspiration, air temperature, etc.) as inputs to a rainfall runoff model. Water use in all the sectors of the human endeavor will be determined in order to establish the water availability given different climate change scenarios. Three catchments have been selected for this exercise. This paper therefore, presents the background information, objectives and significance of the study, literature review, methodology, data collection and processing. [Copyright &y& Elsevier]

It is well known that there is a vast expanse of grassland on the Tibetan Plateau, China. It is suggested that a major climatic factor limiting production of the grassland ecosystem is the low thermo-conditions on the Tibetan Plateau. An increase in temperature may therefore increase the productivity of grasslands on the Plateau. Monthly mean temperature and monthly precipitation data for recent years on the Tibetan Plateau were analyzed. It is clear that the increase in air temperature on the Plateau is greater than that in the whole China and East Asia. On the other hand, statistics show that the production of livestock or meat in the Tibetan Plateau has increased by one to three times since 1978, which means that there should be an equivalent increase in the consumption of plant biomass from the grassland. How is the “increased biomass” related to human activities and climate changes? This paper tries to clarify the relationship between human activities and climate change and to propose a possible answer by laying emphasis on the importance of grassland protection and CO2 flux monitoring. It is suggested that there is a positive feedback in which degradation of grassland by overgrazing will increase potential evapotranspiration level thereby promoting the climate warming and the degradation process. This feedback should be considered seriously in the future. [Copyright &y& Elsevier]

Climate in northeast Qinghai–Tibetan Plateau is characterised by the alternation of summer and winter monsoon circulation, which is generated by thermodynamic and kinetic effects of the immense plateau. The Plateau Monsoon system during the recent geological past has been investigated through a 44-m loess–paleosol section and a 17-m well to obtain the Plateau Monsoon climate changes during the last glacial–interglacial cycle.Thermoluminescence (TL) and optically stimulated luminescence (OSL) methods, as well as field observations and stratigraphic correlation, are used to date the deposit. Magnetic susceptibility (MS), frequency-dependent magnetic susceptibility (FMS), and calcium carbonate content, which are regarded as proxy indicators of strength of the Plateau Summer Monsoon (PSM), are measured. Measurement of grain size distribution, which is regarded as a proxy index of strength of the Plateau Winter Monsoon (PWM), is also carried out. The results show that changes of the unique Plateau Monsoon system during the past 130 kyr are associated with the glacial and interglacial alternations in the Northern Hemisphere. The PSM was unusually strengthened during a period matching the marine oxygen isotope stage 5e (OIS 5e), but it was weak during the OIS 5a and OIS 5c, and was close to that of the OIS 3. The PWM was significantly depressed during OIS 3, and was as weak as that in the Holocene. The PWM and PSM circulations were not always coupled during the last glacial cycle. Changes of the Plateau Monsoon system did not always parallel the SE Asian monsoon, although linkage between them existed to some extent.There are millennial-scale variations in the Plateau Monsoon system, but this is not further discussed in this paper. [Copyright &y& Elsevier]

The confirmation of an eolian origin of the Tertiary ‘Red Clay’ from North China would make it a valuable terrestrial paleoclimatic record. However, it is still controversial as to which wind primarily transported the dust forming the ‘Red Clay’ onto the Loess Plateau. Careful consideration of this question is a prerequisite for better understanding the history of atmospheric circulation in central and East Asia during the Miocene and Pliocene epochs.In this paper, the grain-size distributions of bulk samples and chemically isolated quartz grains of the Late Tertiary ‘Red Clay’ were investigated to explore the potential transportation mechanisms of the dust as well as the atmospheric circulation at the time of deposition. The samples were taken from six localities spanning across 550 km on the Loess Plateau.The results show that the mean grain size of both bulk and quartz samples decreases southward, as does the coarse fraction content (>42 μm). These data not only give new evidence for the eolian origin of the ‘Red Clay’, but also indicate that the ‘Red Clay’ was probably transported mainly by northerly low-level winds, or the winds at least had a strong northerly component. Therefore, the spatial distribution of grain size of the ‘Red Clay’ is comparable to that of the overlying Quaternary eolian loess, which demonstrates a remarkable northwest–southeast decrease in grain size, sedimentation rate, and thickness during the Last Glacial, coinciding with the dominant wind direction of the northwesterly East Asian winter monsoon. However, the grain size of the ‘Red Clay’ is generally finer than the corresponding loess. This indicates that the ‘Red Clay’ may have been transported by a weaker winter monsoon associated with stronger pedogenic modification, and/or the dust source area was not extensive compared to that during the Quaternary. Moreover, the high content of grains coarser than 19 μm, transported mainly by energetic low-level winds over short distances, suggests that the dusts were not transported by upper-level westerly. [Copyright &y& Elsevier]

Peatland surface wetness records provide long Holocene palaeoclimate reconstructions at 101–102 year resolution. They reflect changes in water balance but the relative strength of precipitation and temperature signals are not known. In common with other non-annually resolved records, there has been no testing of the reconstructions against instrumental climate data. In this paper high-resolution records of palaeohydrological change reconstructed from testate amoebae analysis are used to examine critically the relationships between reconstructed water table change, instrumental water table and climate data. A 200-year record of reconstructed water table from northern England shows that the strongest control on reconstructed mean annual water table change is summer precipitation, with summer temperature becoming more important over longer time periods. A 50-year record from Estonia shows that both measured and reconstructed water table records are strongly correlated with summer precipitation. Summer temperature is also correlated with reconstructed water table. We conclude that peatland surface wetness records should be interpreted as primarily reflecting summer precipitation variability, with summer temperature increasingly important in more continental settings. [Copyright &y& Elsevier]

The persistence of the weather is a well-known phenomenon. If, for example, one day is sunny and warm, there is a high tendency that the next day remains similar. In this paper, we review recent results showing that the long-term persistence, characterized by the correlation C(s) of temperature variations separated by s days, decays for large s as a power law. For continental stations, the exponent is always close to 0.7, while for stations on islands as well as for sea surface temperatures, the exponent is close to 0.4. In contrast to the temperature fluctuations, the fluctuations of the rainfall usually are not characterized by long-term power-law correlations but rather by short-term correlations. The universal persistence law for the temperature fluctuations on continental stations represents an ideal (and uncomfortable) test bed for the state-of-the-art global climate models and allows to evaluate their performance. [Copyright &y& Elsevier]

Analysis of the response to climate change and sea-level rise requires a link from climate change science to the resulting impacts and their policy implications. This paper explores the impacts of sea-level rise, particularly increased coastal flooding due to storm surges. In particular, it asks the simple question “how much will projected global sea-level rise exacerbate coastal flood problems, if ignored?” This is an important question to the intergovernmental process considering climate change. Further many countries presently ignore sea-level rise in long-term coastal planning, even though global sea levels are presently slowly rising.Using the model of Nicholls et al. [Global Environmental Change 9 (1999) S69], the analysis considers the flood impacts of sea-level rise on an “IS92a world” based on a consistent set of scenarios of global-mean sea-level rise, subsidence (where appropriate), coastal population change (usually increase), and flood defence standards (derived from GDP/capita). Two of the protection scenarios consider the possible upgrade of flood defences, but no allowance for global-mean sea-level rise is allowed to ensure consistency with the question being investigated. This model has been validated against national- and regional-scale assessments indicating that the relative results are reasonable, and the absolute results are of the right order of magnitude.The model estimates that 10 million people experienced flooding annually in 1990. It also predicts that the incidence of flooding will change without sea-level rise due to changes to the other three factors. Taking the full range of scenarios considered by 2100 the number of people flooded could be from 0.4 to 39 million/year. All the sea-level rise scenarios would cause an increase in flooding during the 21st century if measures to adapt to sea-level rise are not taken. However, there are significant uncertainties and the number of people who are estimated to experience flooding in 2100 is 16–388 million for the mid (55-cm) global-mean sea-level rise scenarios, and up to 510 million people/year for the high (96-cm) scenario. These results suggest that sea-level rise could be a significant problem if it is ignored, and hence it needs to be considered within the policy process considering climate change in terms of mitigation (reducing greenhouse gas emissions) and adaptation (improved coastal management and planning) needs. [Copyright &y& Elsevier]

The Late Mississippian and Pennsylvanian have been referred to as the Coal Age due to enormous paleotropical peat accumulations (coal beds). Numerous fossil floras have been collected from these coals, and their associated seat-earth paleosols and roof-shales, over more than two centuries, leading to the inference of vast swampy wetlands covering the Pangean tropics during the Pennsylvanian. In contrast, the Permian tropics are characterized as more arid, with sparser and more heterogeneous vegetation than inferred for the Pennsylvanian. In the tropics, the Pennsylvanian to Permian transition has been described as a changeover from a pteridophyte-dominated "Paleophytic flora", to a seed-plant dominated "Mesophytic flora. This view notwithstanding, floras dominated by xeromorphic seed plants also are well known from the Pennsylvanian tropics. Some authors have characterized these plants as being occupants of uplands, subsequently transported into basinal-lowland, preservational environments. In this model, uplands are well drained, causing areas of drought under otherwise everwet climates. In this paper, we present an alternative interpretation: that the apparent transition in Pennsylvanian-Permian tropical vegetation reflects two types of taphonomic megabias. First is a preservational megabias, strongly favoring the vegetation of humid climates over that of seasonally dry climates. Accordingly, tropical-plant preservational potential fluctuated in concert with Late Paleozoic Ice Age glacial-interglacial oscillations, and contemporaneous sea-level and climatic changes. Second is an analytical megabias, strongly favoring the discovery and collection of the wetland biome from Pennsylvanian strata, overlooking the less frequently and more poorly preserved drought-tolerant biome. By Permian times, vast wetlands, and their fossil record, had largely disappeared from central Pangea (although continuing in Cathaysia), making drought-tolerant vegetation more "visible" to searchers, without changing its preservational circumstances. We demonstrate that the upland model is untenable, being inconsistent with the principles of plant biogeography and with geological aspects of the fossil record. • Pennsylvanian-Permian boundary floristic change reflects a taphonomic megabias • Tropical wetland and drought-tolerant biomes existed contemporaneously throughout the Pennsylvanian • Megabias 1: The wetland biome was much more likely to be preserved than the drought-tolerant biome • Megabias 2: Coal mining means much more collection of wetland biome than drought-tolerant biome • The "Upland" model does not conform to modern or fossil plant biogeographic principles [ABSTRACT FROM AUTHOR]

• CIRFs are useful for exploring risks of system failure under climate change. • Synthetic streamflow series are generated using SA and linked to climate conditions. • Logistic regression relates system responses to climate drivers. • System failure defined according to performance (reliability) and threshold. • LR model detects climate conditions which would require adaptation. Climate Impact Response Functions (CIRFs) can be useful for exploring potential risks of system failure under climate change. The performance of a water resource system can be synthesized through a CIRF that relates climate conditions to system behavior in terms of a specified threshold of deliveries to demands or environmental flow requirements. However, in highly regulated water resource systems this relationship may be quite complex, depending on storage capacity and system operation. In this paper we define a CIRF for these types of systems through a multivariable logistic regression (LR) model where a binary variable (system response) is explained by two continuous variables or predictors (precipitation and temperature). The approach involves generating multivariate synthetic inflow time series and relating them to specific climate conditions. Next, these inflows are used as inputs in a water management model, and the outcome is coded as a binary variable (failure or its absence) depending on selected vulnerability criteria. To identify the time span before the failure event in which climate variables are relevant, we characterized drought development stages through relative standardized indices. Mean values of precipitation and temperature for the selected time span are computed and used as explanatory variables through a LR model, which is validated using data from several climate models and scenarios. Results show that the predictive capacity of LR models is acceptable, so that they could be used as screening tools to detect challenging climate conditions for the system which would require adaption actions. [ABSTRACT FROM AUTHOR]

The frequency and intensity of extreme climate events are increasing all around the world, due to climate change. Climate adaptation strategies are therefore needed, since mitigation strategies alone are not sufficient to avoid serious impacts of climate change. However, adaptation to climate change is not straightforward, as it is highly influenced by diverse and conflicting interests as well as epistemological (or scientific) uncertainties. Therefore, a minimum requirement for its success is the active participation of stakeholders and citizens in the adaptation policy cycle. This paper presents a case study on a participatory process involving civil servants from different municipalities in Malaysia, in Southeast Asia, with a view to considering the optimal level of engagement that is required for climate adaptation planning. The exercise consisted of a Focus Group session, where participants were asked to discuss the level of stakeholder and citizen participation that should be adopted within the Global Covenant of Mayors for Climate and Energy initiative. Contrary to authors' expectations, the participants tended to suggest medium to high levels of participation in the planning process. During the dialogues, a walking activity through the city, aimed at identifying hotspots of climate risks and defined as "safety walks", was one of the ideas proposed as a high-potential participatory method, spreading in the adaptation framework. Safety walks could complement climate modelling and enhance the robustness of climate risk assessments. • A focus group session on stakeholders participation in adaptation planning • Medium-high levels of participation in the planning process were suggested. • Technical expertise from local community is needed • "Safety walks" suggested as a high-potential stakeholder-involving participatory technique • Site-specific challenging issues were addressed through active discussion and best practices [ABSTRACT FROM AUTHOR]

Fossil pollen records are well-established indicators of past vegetation changes. The prevalence of pollen across environmental settings including lakes, wetlands, and marine sediments, has made palynology one of the most ubiquitous and valuable tools for studying past environmental and climatic change globally for decades. A complementary research focus has been the development of statistical techniques to derive quantitative estimates of climatic conditions from pollen assemblages. This paper reviews the most commonly used statistical techniques and their rationale and seeks to provide a resource to facilitate their inclusion in more palaeoclimatic research. To this end, we first address the fundamental aspects of fossil pollen data that should be considered when undertaking pollen-based climate reconstructions. We then introduce the range of techniques currently available, the history of their development, and the situations in which they can be best employed. We review the literature on how to define robust calibration datasets, produce high-quality reconstructions, and evaluate climate reconstructions, and suggest methods and products that could be developed to facilitate accessibility and global usability. To continue to foster the development and inclusion of pollen climate reconstruction methods, we promote the development of reporting standards. When established, such standards should 1) enable broader application of climate reconstruction techniques, especially in regions where such methods are currently underused, and 2) enable the evaluation and reproduction of individual reconstructions, structuring them for the evolving open-science era, and optimising the use of fossil pollen data as a vital means for the study of past environmental and climatic variability. We also strongly encourage developers and users of palaeoclimate reconstruction methodologies to make associated programming code publicly available, which will further help disseminate these techniques to interested communities. [ABSTRACT FROM AUTHOR]

Climate change will affect psychological wellbeing. Substantial research has documented harmful impacts on physical health, mental health, and social relations from exposure to extreme weather events that are associated with climate change. Recently, attention has turned to the possible effects of climate change on mental health through emotional responses such as increased anxiety. This paper discusses the nature of climate anxiety and some evidence for its existence, and speculates about ways to address it. Although climate anxiety appears to be a real phenomenon that deserves clinical attention, it is important to distinguish between adaptive and maladaptive levels of anxiety. A focus on individual mental health should not distract attention from the societal response that is necessary to address climate change. [ABSTRACT FROM AUTHOR]