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In this paper, a semi-open air, open water humidification dehumidification (HDH) desalination system is proposed and studied. It is shown that for both water- and air-heated systems, when the top temperature of the system is fixed, this presented method for air circulation can enhance the performance of the system. Analyzing other parameters reveals that the impact of ambient temperature is more important than that of the ambient relative humidity on system performance; therefore, HDH is efficient for both dry and humid climates. Also, when the ambient temperature is high, closed air loop has a higher performance. Moreover, the proposed system is studied with a dual heating method, in which both water and air were heated using a wide range of heat rate ratio. The results show that the system will have the maximum performance when the heat rate ratio approximately equals one. In case only one of the streams is heated, if the energy intake is low, water heating is a better solution for an efficient system, but when the heat input is high, air heating is more effective. Finally, an entropy generation analysis of the proposed configuration and heating method is conducted. It is suggested that the exergy efficiency can be used for optimization. [ABSTRACT FROM AUTHOR]

Global circulation models (GCMs) are the best tool to understand climate change, as they attempt to represent all the important Earth system processes, including anthropogenic perturbation through fossil fuel burning. However, GCMs are computationally very expensive, which limits the number of simulations that can be made. Pattern scaling is an emulation technique that takes advantage of the fact that local and seasonal changes in surface climate are often approximately linear in the rate of warming over land and across the globe. This allows interpolation away from a limited number of available GCM simulations, to assess alternative future emissions scenarios. In this paper, we present a climate pattern-scaling set consisting of spatial climate change patterns along with parameters for an energybalance model that calculates the amount of global warming. The set, available for download, is derived from 22 GCMs of the WCRP CMIP3 database, setting the basis for similar eventual pattern development for the CMIP5 and forthcoming CMIP6 ensemble. Critically, it extends the use of the IMOGEN (Integrated Model Of Global Effects of climatic aNomalies) framework to enable scanning across full uncertainty in GCMs for impact studies. Across models, the presented climate patterns represent consistent global mean trends, with a maximum of 4 (out of 22) GCMs exhibiting the opposite sign to the global trend per variable (relative humidity). The described new climate regimes are generally warmer, wetter (but with less snowfall), cloudier and windier, and have decreased relative humidity. Overall, when averaging individual performance across all variables, and without considering co-variance, the patterns explain one-third of regional change in decadal averages (mean percentage variance explained, PVE, 34:25±5:21), but the signal in some models exhibits much more linearity (e.g. MIROC3.2(hires): 41.53) than in others (GISS_ER: 22.67). The two most often considered variables, near-surface temperature and precipitation, have a PVE of 85:44±4:37 and 14:98±4:61, respectively. We also provide an example assessment of a terrestrial impact (changes in mean runoff) and compare projections by the IMOGEN system, which has one land surface model, against direct GCM outputs, which all have alternative representations of land functioning. The latter is noted as an additional source of uncertainty. Finally, current and potential future applications of the IMOGEN version 2.0 modelling system in the areas of ecosystem modelling and climate change impact assessment are presented and discussed. [ABSTRACT FROM AUTHOR]

Accurate measurements of temperature and water vapor in the upper-air are of great interest in relation to weather prediction and climate change. Those measurements are mostly conducted using radiosondes equipped with a variety of sensors that are flown by a balloon up to lower stratosphere. Reference Upper Air Network (GRUAN) has identified water vapor pressure as one of the most important measurands and has set an accuracy requirement of 2 % in terms of the mixing ratio. In order to achieve the requirement, many errors in the humidity measurement such as a temperature dependency in sensing characteristics including measurement values and response time need to be corrected because humidity sensors of radiosondes pass through low-pressure (1 kPa) and low-temperature (- 80 ∘ C) environments in the upper-air. In this paper, the humidity sensing characteristics of Jinyang radiosonde sensors in relation to temperature dependencies were evaluated at low temperature using a newly developed ultralow-temperature humidity chamber. The sensitivity characteristic curve of the radiosonde sensors was evaluated down to - 80 ∘ C, and the calibration curves of the humidity sensor and the temperature sensor were obtained. The response time of humidity sensor slowly increased from 52 to 116 s at the temperature from 20 to - 40 ∘ C, respectively, and then rapidly increased to almost one hour at - 80 ∘ C. Those results will help to improve the reliability of the upper-air observation data. [ABSTRACT FROM AUTHOR]

This paper quantifies the vulnerability of and risk to water resources (VRWR) under a scenario of climate change in the arid and semi-arid region of West China. A new approach integrating hazard, sensitivity, resilience, exposure and risk is developed to assess the VRWR from climate change. Drought is regarded as the key hazard, with its frequency and severity defined using a surface humidity index. Exposure is quantitatively linked with indicators of population and social and economic characteristics using statistical and Geographical Information System (GIS) methodologies. Risk is defined as the product of hazard, exposure and vulnerability, while vulnerability is treated as a function of sensitivity and adaptation. Vulnerability and risk in the water resources system in the coming 20 years are assessed for the RCP 4.5 scenario. The results reveal that both hazard and exposure of water resources display strong spatial variation in the study area. High hazard and exposure are found in the northern Tianshan Mountain as well as the eastern part of Hexi Corridor. Water resources are particularly sensitive to variation in precipitation and potential evapotranspiration in the upstream areas of Hexi Corridor, rivers in Central Asia, headwater streams of Tarim River and most of Chang Tang Plateau. Our assessment shows that there is high vulnerability of and risk to water resources in the study area, especially in the areas of Hexi Corridor, northern Tianshan Mountain and Tarim River. Under the RCP 4.5 climate change scenario, the vulnerability and risk decline over the entire area but remain at a serious level in inland rivers in Hexi Corridor, northern Tianshan Mountain and headwater streams of Tarim River. Thus, these areas are the highest priority for strengthening policy measures to adapt to climate change and reduce exposure and vulnerability and their risk to water resources. [ABSTRACT FROM AUTHOR]

As Organic Photovoltaic (OPV) development matures, the demand grows for rapid characterisation of degradation and application of Quantitative Accelerated Life Tests (QALT) models to predict and improve reliability. To date, most accelerated testing on OPVs has been conducted using ISOS consensus standards. This paper identifies some of the problems in using and interpreting the results for predicting ageing based upon ISOS consensus standard test data. Design of Experiments (DOE) in conjunction with data from ISOS consensus standards are used as the basis for developing life test models for OPV modules. This is used to study their temperature-humidity and light-induced degradation, which enables failure rates during accelerated testing to be assessed against the typical outdoor operational conditions. The life test models are used to assess the relative severity of the ISOS standards and the impact of geographic and seasonal climatic changes on OPV degradation. [ABSTRACT FROM AUTHOR]

The hyper-arid climate of Ouargla area (Northern Sahara of Algeria) is important in the field of the paleoenvironmental reconstitution. This paper investigates the importance of palaeolake sediments as significant terrestrial archives for studying Quaternary climate changes. Through morphological and mainly micromorphological investigations of the studied sites (Sabkha of Ouargla and palaeolake of Mellala), we noted the fluctuation of climate between arid and more humid conditions during Quaternary. Some pedofeatures have recorded these environmental changes. The studied calcareous crusting has a lacustrine origin when precipitations were more important. The clay coatings around the quartz grains indicate an old origin and different geochemical conditions that led to their dissolution. Lenticular gypsum crystals were formed from groundwater saturated with Ca2+andions. Calcite pseudomorphs after lenticular gypsum crystals indicate changes in local climatic parameters. Gypsum crusts can be explained by formation under wet climatic conditions in a lagoonal environment. Black and gray layers indicate evolution of organic matter at a wetter period. This paper highlights an unknown palaeolake which can be useful for the comprehension of the ecological past of the Sahara. The comparison between this palaeolake and other Saharan palaeolakes has allowed us to assign it to a probable active period between 10000 and 4000 years B.P. [ABSTRACT FROM PUBLISHER]

Climate change shifts the distributions of a set of climatic variables, including temperature, precipitation, humidity, wind speed, sunshine duration, and evaporation. This paper explores the importance of those additional climatic variables other than temperature and precipitation. Using the county-level agricultural data from 1980 to 2010 in China, we find that those additional climatic variables, especially humidity and wind speed, are critical for crop growth. Therefore, omitting those variables is likely to bias the predicted impacts of climate change on crop yields. In particular, omitting humidity tends to overpredict the cost of climate change on crop yields, while ignoring wind speed is likely to underpredict the effect. Our preferred specification indicates that climate change is likely to decrease the yields of rice, wheat, and corn in China by 36.25%, 18.26%, and 45.10%, respectively, by the end of this century. [ABSTRACT FROM AUTHOR]

In light of current climate change projections in recent years, there has been an increasing interest in the assessment of indoor overheating in domestic environments in previously heating-dominated climates. This paper presents a monitoring study of overheating in 122 London dwellings during the summers of 2009 and 2010. Dry Bulb Temperature and Relative Humidity in the main living and sleeping area were monitored at 10 min intervals. The ASHRAE Standard 55 adaptive thermal comfort method was applied, which uses outdoor temperature to derive the optimum indoor comfort temperature. It was found that 29% of all living rooms and 31% of all bedrooms monitored during 2009 had more than 1% of summertime occupied hours outside the comfort zone recommended by the standard to achieve 90% acceptability. In 2010, 37% of monitored living rooms and 49% of monitored bedrooms had more than 1% of summertime occupied hours outside this comfort zone. The findings of this study indicate that London dwellings face a significant risk of overheating under the current climate. Occupant exposure to excess indoor temperatures is likely to be exacerbated in the future if climate change adaptation strategies are not incorporated in Building Regulations, building design and retrofit. [ABSTRACT FROM AUTHOR]

The Thornthwaite Moisture Index (TMI) is a climate classification used in biophysical and biological studies. A TMI mapping of Victoria/Australia over the century indicated its applicability to assess climate change induced patterns of moisture variability. This paper progresses upon this, developing analytical procedures to assess the quality of the climate data used as input, and to select suitable spatial resolution for the output map. It is argued here that these are interrelated issues, and that the selection of a certain data quality level or a spatial resolution for TMI mapping needs to consider a trade-off between precision and scale. Results indicated that different trade-off options affect the climate classification and, therefore, a proposed framework can be used for non-arbitrary decisions on TMI mapping. [ABSTRACT FROM PUBLISHER]

Global warming and climate change have increased the frequency of heavy precipitation. Heavy rainfall results in a large amount of water entering roadways within a short time period. Water remains in the pavement system for a certain time period, reduces strengths and moduli of granular bases and subgrades, and induces pavement distresses. Geotextiles are commonly used in roadways for drainage purposes, which require soil saturation. However, soil saturation does not always exist in roadways to enable gravity drainage of water by conventional geotextiles. Wicking geotextile, a new type of woven geotextile, was recently introduced to the market to remove moisture from unsaturated soils. The wicking geotextile includes special hydrophilic and hygroscopic 4 deep groove fibers with multichannel cross sections, which can induce high capillary force to wick water out of moist soil without saturation of soil. The ability and rate of this geotextile to remove water from moist soil depends on several factors, including temperature and relative humidity. In this study, a series of laboratory tests under controlled temperature and relative humidity were conducted to quantify the water removal rate of the wicking geotextile. A half length of the wicking geotextile was submerged in water tanks, and the other half was hung outside of the tanks. The water wicked from the tank into the geotextile evaporated into the air. Such tests were conducted under 12 different test conditions (i.e., different temperatures and relative humidities). Test results demonstrated that the wicking geotextile could remove water from the water tank at a certain rate. Three commonly used methods available in the literature were adopted to quantify the water removal rate of the wicking geotextile based on vapor pressure, temperature, and relative humidity. A new concept of equivalent water evaporation length of a wicking geotextile is proposed in this study. It should be pointed out that the tests presented in this paper aimed to determine the maximum water removal capacity of the geotextile given sufficient water supply. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach to incorporate the non-stationarities characterised in the GCM outputs, into the Predictor-Predictand Relationships (PPRs) in statistical downscaling models. In this approach, a series of 42 PPRs based on multi-linear regression (MLR) technique were determined for each calendar month using a 20-year moving window moved at a 1-year time step on the predictor data obtained from the NCEP/NCAR reanalysis data archive and observations of precipitation at 3 stations located in Victoria, Australia, for the period 1950–2010. Then the relationships between the constants and coefficients in the PPRs and the statistics of reanalysis data of predictors were determined for the period 1950–2010, for each calendar month. Thereafter, using these relationships with the statistics of the past data of HadCM3 GCM pertaining to the predictors, new PPRs were derived for the periods 1950–69, 1970–89 and 1990–99 for each station. This process yielded a non-stationary downscaling model consisting of a PPR per calendar month for each of the above three periods for each station. The non-stationarities in the climate are characterised by the long-term changes in the statistics of the climate variables and above process enabled relating the non-stationarities in the climate to the PPRs. These new PPRs were then used with the past data of HadCM3, to reproduce the observed precipitation. It was found that the non-stationary MLR based downscaling model was able to produce more accurate simulations of observed precipitation more often than conventional stationary downscaling models developed with MLR and Genetic Programming (GP). [ABSTRACT FROM AUTHOR]

The African continent is characterised by a wide range of hydroclimate regimes, ranging from humid equatorial West Africa to the arid deserts in the northern and southern subtropics. The livelihoods of much of its population are also vulnerable to future climate change, mainly through variability in rainfall affecting water resource availability. A growing number of data sources indicate that such hydroclimatic variability is an intrinsic component of Africa's natural environment. This paper, co-authored by members of the PAGES Africa 2k Working Group, presents an extensive assessment and discussion of proxy, historical and instrumental evidence for hydroclimatic variability across the African continent, spanning the last two millennia. While the African palaeoenvironmental record is characterised by spatially disjunctive datasets, with often less-than-optimal temporal resolution and chronological control, the available evidence allows the assessment of prominent spatial patterns of palaeomoisture variability through time. In this study, we focus sequentially on data for six major time windows: the first millennium CE, the Medieval Climate Anomaly (900–1250 CE), the Little Ice Age (1250–1750 CE), the end of the LIA (1750–1850 CE), the Early Modern Period (1850–1950), and the period of recent warming (1950 onwards). This results in a continent-wide synthesis of regional moisture-balance trends through history, allowing consideration of possible driving mechanisms, and suggestions for future research. [ABSTRACT FROM AUTHOR]

The aim of this paper is to assess the influence of meteorological conditions on the variability of haze in Shanghai during 1981-2013. Based on the observational data of haze and air quality in Shanghai during this period and on the National Centers for Environmental Prediction final analysis data, the long-term variability and the spatial distribution of the haze was analyzed as well as with relationship between haze and atmospheric variables, including visibility, relative humidity, and air quality. Temporal evolution showed that the annual number of haze days in Shanghai represented a rapid decline in the last decade, which was caused by the direct effects of relative humidity and visibility. Global warming-induced changes, such as a warmer temperature, lower relative humidity, and wind speed in winter, were other important factors in the decline. Spatial distribution showed that the annual number of haze days in mid-western Shanghai was higher than those in the southeastern suburbs. [ABSTRACT FROM AUTHOR]

• CatBoost regression model for prediction of surface chloride level. • The regression model has MAE and RMSE scores of 0.11 and 0.16 respectively. • Increase in chloride ingress with the increase in temperature and humidity. • Exposure zone has a significant effect on chloride ingress. • Temperature and humidity of RCP 2.6 and RCP 8.5 considered for analysis. This paper presents the effect of climate change on the long-term reliability of concrete structures due to chloride ingress. The impact has been demonstrated for three regions across the globe for the best and worst-case climate change scenarios. The methodology adopted here can be divided into three main steps. The first one is the development of a machine learning regression model using CatBoost for estimation of surface chloride levels, which is a function of temperature, concrete material properties, exposure conditions, and chloride levels in the seawater. The CatBoost model fitted over the experimental data has a mean absolute error (MAE) and root mean square error (RMSE) value of 0.11 and 0.16, respectively, and a high R2 value of 0.82. The second step is solving the coupled non-linear partial differential equation for temperature, humidity, and chloride ingress in concrete with time. A parametric study considering the effect of external parameters (temperature, humidity, exposure condition, and chloride levels in water) reveals the complexity and the dependencies of the chloride ingress process on external parameters. The final step involves the reliability analysis to estimate the time for chlorides to reach threshold levels at the rebar level using the numerical model. The input for the numerical model is temperature and humidity condition for different representative concentration pathways (RCP) scenarios, the material properties of concrete, and the exposure conditions. The reliability analysis shows that, for the concrete structure located in Dubai, UAE, and Cascais, Portugal, the mean time to corrosion initiation decreases due to climate change and it increases for the structure located in Tasmania, Australia. Further, the structures that are built in the future may have lower service life compared to the structures that were built in the past. Based on the study it concluded that it is necessary to consider the impact of climate change on service life to design resilient structures. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents the results of extensive measurements which took place in two sites with different characteristics in terms of street geometry, urban density and materials. The first experiment site was a traditional settlement in the island of Tinos, Greece, while the second was a relatively newly built part of the capital city of Tinos. The experimental measurements, which include air and surface temperature, air humidity and air velocity, were carried out in two sets, during the summer and winter period. The experimental measurements were compared to simulation results obtained by a special computer tool. The comparison led to the conclusion that experimental measurements and program results were in good agreement for the summer period, and the tool was subsequently used in order to perform parametric analysis of microclimate in urban canyons. Main parameters that affect urban canyon microclimate were examined, that is street geometry, street orientation, effect of trees, horizontal surface albedo, wind speed and wind direction. The paper aims in presenting the results obtained by the comparison of the two sites and in analyzing the effect of parameters such as urban layout, street geometry and orientation on urban canyon microclimate, with special reference on the characteristics of traditional architecture of the Cycladic islands. Also, the parametric analysis aims in investigating the parameters involved and their degree of influence on urban canyon microclimate. [Copyright &y& Elsevier]

Abstract: Natural weather changes due to diurnal and seasonal temperature and relative humidity cycles affect micro-environment of concrete; temperature and moisture content in the concrete fluctuate correspondingly with variations in the weather. At the same time, for concrete structures, the temperature and relative humidity in both the atmosphere and the concrete show obvious differences due to thermal conduction and pore structure densification of the concrete. Therefore, the temperature and moisture content in the concrete, which are defined as the micro-environmental indexes in the concrete in this paper, are main factors directly influencing concrete carbonation, chloride diffusion and the corrosion rate of steel bars. This paper mainly discusses the climate load based on natural weather and the effects of the climate load. The climate load includes the temperature, relative humidity, wind speed, sun shine and rain in a natural climate environment. The effects of the climate load are the responses of the micro-environment in the concrete under action of the climate load. Firstly, the experiments on responses of temperature and relative humidity in concrete were carried out in an artificial constant climate environment; at the same time, the behaviors about thermal conduction and moisture diffusion of the concrete were measured and modeled. Thereafter, a method for predicting the responses in concrete under a natural climate environment condition was built. In present studies, the temperature and the relative humidity responses in concrete under a natural climate environment condition show obvious hysteresis characteristics. The research findings illustrate that the predictions of the rate of the concrete carbonation, the chloride diffusion and the corrosion of bar in concrete should be depended on the micro-environment and the predictions based on the natural climate environment are not appropriate. [Copyright &y& Elsevier]

Summary: In a globally warming climate, observed rates of atmospheric evaporative demand have declined over recent decades. Several recent studies have shown that declining rates of evaporative demand are primarily governed by trends in the aerodynamic component (primarily being the combination of the effects of wind speed (u) and atmospheric humidity) and secondarily by changes in the radiative component. A number of these studies also show that declining rates of observed near-surface u (termed ‘stilling’) is the primary factor contributing to declining rates of evaporative demand. One objective of this paper was to review and synthesise the literature to assess whether stilling is a globally widespread phenomenon. We analysed 148 studies reporting terrestrial u trends from across the globe (with uneven and incomplete spatial distribution and differing periods of measurement) and found that the average trend was −0.014ms−1 a−1 for studies with more than 30 sites observing data for more than 30years, which confirmed that stilling was widespread. Assuming a linear trend this constitutes a −0.7ms−1 change in u over 50years. A second objective was to confirm the declining rates of evaporative demand by reviewing papers reporting trends in measured pan evaporation (E pan) and estimated crop reference evapotranspiration (ET o); average trends were −3.19mma−2 (n =55) and −1.31mma−2 (n =26), respectively. A third objective was to assess the contribution to evaporative demand trends that the four primary meteorological variables (being u; atmospheric humidity; radiation; and air temperature) made. The results from 36 studies highlighted the importance of u trends. We also quantified the sensitivity of rates of evaporative demand to changes in u and how the relative contributions of the aerodynamic and radiative components change seasonally over the globe. Our review: (i) shows that terrestrial stilling is widespread across the globe; (ii) confirms declining rates of evaporative demand; and (iii) highlights the contribution u has made to these declining evaporative rates. Hence we advocate that assessing evaporative demand trends requires consideration of all four primary meteorological variables (being u, atmospheric humidity, radiation and air temperature). This is particularly relevant for long-term water resource assessment because changes in u exert greater influence on energy-limited water-yielding catchments than water-limited ones. [ABSTRACT FROM AUTHOR]

This paper explores what the San Diego region may look like in the year 2050 as projected changes in regional climate conditions take place. Focusing on interrelated issues of climate change, sea level rise, population growth, land use, and changes in water, energy, public health, wildfires, biodiversity, and habitat, the paper reviews the potential impacts of a changing climate by 2050 and makes recommendations for changes in planning processes at the local and regional levels to prepare for these impacts. The original research for this study was completed in 2008 by a team of 40 experts from the region including universities, nonprofit organizations, local governments, public sector agencies and private sector entities. This paper has now been updated with more recent research regarding climate change adaptation while preserving the integrity of the original research team's work. The simulated impacts discussed in this study are based on regional projections of climate change generated by scientists at Scripps Institution of Oceanography, employing three climate models and two emissions scenarios used by the Intergovernmental Panel on Climate Change. The impacts are discussed in the context of significant regional growth expected during the period as well as an aging population base. Key issues explored in the report include potential inundation of six selected low-lying coastal areas in San Diego due to sea level rise, potential shortfalls in water deliveries, peak energy demand increases due to higher temperatures, growing risk of devastating wildfires, migrations of species in response to higher temperatures in an increasingly fragmented natural habitat, and public health issues associated with extreme temperature events. [ABSTRACT FROM AUTHOR]

This paper studies the impact of climate change on the electricity consumption by means of a fuzzy regression approach. The climate factors which have been considered in this paper are humidity and temperature, whereas the simultaneous effect of these two climate factors is considered. The impacts of other climate variables, like the wind, with a minor effect on energy consumption are ignored. The innovation which applies in this paper is the division of the year into two parts by using the temperature-day graph in the year. To index the humidity, data of the minimum humidity per day are used. For temperature, the maximum temperature of the first part of the year (warm days) and the minimum of the second part (cold days) are used. The indicator for the consumption is the daily peak load. The model results show high sensitivity to the temperature but low sensitivity to the humidity. Moreover, it is concluded that the model structure cannot be the same and for the cold par additional variables such as gas consumption should be considered. [ABSTRACT FROM AUTHOR]

This paper examines the interrelationship between the natural and human history of Sicily over the last 2000 years. It presents a close comparison of the data from the key multi-proxy site of Lago di Pergusa – located inland in the eastern part of Sicily – with the existing archaeological and textual evidence on the socio-economic processes. The article also includes a review of the available natural proxy archives from the Central Mediterranean. On the basis of the isotope and pollen data from the Lago di Pergusa core PRG2, we identified two humid periods (ca. 450–750 AD and ca. 1400–1800 AD) as well as a dry one (ca. 1100–1350 AD); our evidence corresponds closely with other environmental palaeoclimate proxies from the Mediterranean region. In our synthesis of the environmental, historical and archaeological evidence from southern Italy, we argue that during both periods of increased humidity – that is during the late antique-Byzantine times and during the late medieval and early modern periods – intense agricultural use of the Sicilian landscape developed on an unprecedented scale. This in turn contributed to the impressive demographic and economic expansion visible during these periods. A sudden period of aridity followed the first of these eras of humidity-related agricultural growth. This climatic shift, dated to around 750 AD, corresponds to a decrease in synanthropic taxa and a recovery of arboreal vegetation. We argue that in this case a climatic change contributed to socio-economic decline. Moreover, as this change occurred prior to the Arab invasion of Sicily in AD 827, the environmental processes may help to explain the collapse of Byzantine society on Sicily which, in turn made the Muslim conquest possible. After this event, there occurred a longer period of agricultural decline, lasting until around 1000 AD, after which we see the first signs of a slow recovery. Ongoing research in nearby archaeological sites will help defining if it was a local change or a regional, potentially climate-induced phenomenon. Although textual evidence records considerable population losses during the later Middle Ages as a result of the Black Death, the effects of the plague are not obviously apparent in the pollen data, except for some short term fluctuations. [ABSTRACT FROM AUTHOR]

This paper explores the possible links between rapid climate change (RCC) and social change in the Near East and surrounding regions (Anatolia, central Syria, southern Israel, Mesopotamia, Cyprus and eastern and central Sahara) during the ‘long’ 4th millennium (∼4500–3000) BC. Twenty terrestrial and 20 marine climate proxies are used to identify long-term trends in humidity involving transitions from humid to arid conditions and vice versa. The frequency distribution of episodes of relative aridity across these records is calculated for the period 6300–2000 BC, so that the results may be interpreted in the context of the established arid episodes associated with RCC around 6200 and 2200 BC (the 8.2 and 4.2 kyr events). We identify two distinct episodes of heightened aridity in the early-mid 4th, and late 4th millennium BC. These episodes cluster strongly at 3600–3700 and 3100–3300 BC. There is also evidence of localised aridity spikes in the 5th and 6th millennia BC. These results are used as context for the interpretation of regional and local archaeological records with a particular focus on case studies from western Syria, the middle Euphrates, southern Israel and Cyprus. Interpretation of the records involves the construction of plausible narratives of human–climate interaction informed by concepts of adaptation and resilience from the literature on contemporary (i.e. 21st century) climate change and adaptation. The results are presented alongside well-documented examples of climatically-influenced societal change in the central and eastern Sahara, where detailed geomorphological studies of ancient environments have been undertaken in tandem with archaeological research. While the narratives for the Near East and Eastern Mediterranean remain somewhat speculative, the use of resilience and adaptation frameworks allows for a more nuanced treatment of human–climate interactions and recognises the diversity and context-specificity of human responses to climatic and environmental change. Our results demonstrate that there is a need for more local environmental data to be collected ‘at source’ during archaeological excavations. [ABSTRACT FROM AUTHOR]

This paper assesses intermodel spread in the slope of global-mean precipitation change Δ P with respect to surface temperature change. The ambiguous estimates in the literature for this slope are reconciled by analyzing four experiments from phase 5 of CMIP (CMIP5) and considering different definitions of the slope. The smallest intermodel spread (a factor of 1.5 between the highest and lowest estimate) is found when using a definition that disentangles temperature-independent precipitation changes (the adjustments) from the slope of the temperature-dependent precipitation response; here this slope is referred to as the hydrological sensitivity parameter η. The estimates herein show that η is more robust than stated in most previous work. The authors demonstrate that adjustments and η estimated from a steplike quadrupling CO2 experiment serve well to predict Δ P in a transient CO2 experiment. The magnitude of η is smaller in the coupled ocean-atmosphere quadrupling CO2 experiment than in the noncoupled atmosphere-only experiment. The offset in magnitude due to coupling suggests that intermodel spread may undersample uncertainty. Also assessed are the relative contribution of η, the surface warming, and the adjustment on the spread in Δ P on different time scales. Intermodel variation of both η and the adjustment govern the spread in Δ P in the years immediately after the abrupt forcing change. In equilibrium, the uncertainty in Δ P is dominated by uncertainty in the equilibrium surface temperature response. A kernel analysis reveals that intermodel spread in η is dominated by intermodel spread in tropical lower tropospheric temperature and humidity changes and cloud changes. [ABSTRACT FROM AUTHOR]

The Sun's contribution to climate variations was highly questioned recently. In this paper we show that bi-decadal variability of solar magnetic field, modulating the intensity of galactic cosmic ray (GCR) at the outer boundary of heliosphere, could be easily tracked down to the Earth's surface. The mediator of this influence is the lower stratospheric ozone, while the mechanism of signal translation consists of: (i) GCR impact on the lower stratospheric ozone balance; (ii) modulation of temperature and humidity near the tropopause by the ozone variations; (iii) increase or decrease of the greenhouse effect, depending on the sign of the humidity changes. The efficiency of such a mechanism depends critically on the level of maximum secondary ionisation created by GCR (i.e. the Pfotzer maximum) – determined in turn by heterogeneous Earth's magnetic field. Thus, the positioning of the Pfotzer max in the driest lowermost stratosphere favours autocatalytic ozone production in the extra-tropical Northern Hemisphere (NH), while in the SH– no suitable conditions for activation of this mechanism exist. Consequently, the geomagnetic modulation of precipitating energetic particles – heterogeneously distributed over the globe – is imprinted on the relation between ozone and humidity in the lower stratosphere (LS). The applied test for causality reveals that during the examined period 1957–2012 there are two main centres of action in the winter NH, with tight and almost stationary winter ozone control on the near tropopause humidity. Being indirectly influenced by the solar protons, the variability of the SH lower stratospheric ozone, however, is much weaker. As a consequence, the causality test detects that the ozone dominates in the interplay with ULTS humidity only in the summer extra-tropics. [ABSTRACT FROM AUTHOR]

The paper has examined the impact of variations of Atlantic multidecadal oscillation on the change in air temperature during the summer season on the territory of Montenegro. Starting from the fact that in recent years more and more extreme weather events occur, as well as from the intention to comprehensively consider the temperature conditions in the territory of Montenegro, first analysis is of changes in air temperature in 8 parameters, of which 5 climate indices; connections with Atlantic multidecadal oscillation have also been analyzed. To study changes in temperature extreme indexes proposed by the WMO CCL/CLIVAR are used. Research within the listed topics was realized using data from 23 meteorological stations for the period 1951-2010 and the calculations are done for the summer season. The results show that there is increased number of maximum and minimum daily temperatures of warmer value. The impact assessment Atlantic multidecadal oscillation, teleconnection pattern that is quite distant, showed that its variability affects changes in summer temperatures in Montenegro, both in terms of mean values, and the frequency of extreme actions presented by climate indices. [ABSTRACT FROM AUTHOR]

The study of climate changes is most often based on the analysis of time series of temperature and precipitation in urban areas and the increase in the emission of gases having a greenhouse effect. On the other hand, the selection of representative and relevant stations and comprehensive analysis of climate indicators lead to better and more exact assessments on climate changes at the regional level. In order to connect climate changes with agricultural, biological, socio-economic, and tourism databases, the paper deals with the dynamic analysis of changes in thermal component expressed through the values of regional climate indices in four climatological stations with different geographical positions in Serbia. There are significant differences between the two time series data (1961-1990 and 1991-2013) on temperature and humidity, precipitation, insolation, and wind speed. However, after using the climatic indices as a tool for assessing climate changes, the results of the study suggest the relative influence of the thermal component on the change of climate indices, with a slight increase in the index of significance for human activities. Relying on the results of this alternative approach to the study of climate changes, the fact remains that the climate is not fixed but highly variable factor that should be taken into consideration in terms of monitoring, evaluation, and management of the area. [ABSTRACT FROM AUTHOR]

The concentration of sugar in the nectars of unprotected flowers of several species was measured and did not reach the high values that would be in equilibrium with the daytime humidities recorded outside the corolla, although the sugar concentration was highly correlated with ambient relative humidity. This paper examines features that maintain low nectar sugar concentrations at low ambient humidities. Post-secretory changes in concentration are influenced to a small extent by nectar composition but depend largely on physico-chemical and microclimatic effects. Factors contributing to the maintenance of steep gradients in water activity between the nectar and the ambient air include corolla morphology, sugar concentration gradients and waterproofing lipid monolayers on the nectar surface. This paper considers the relative importance of such features in relation to the pollination syndrome. A simple technique is described for the measurement of intrafloral relative humidity. [ABSTRACT FROM AUTHOR]

To design and assess indoor climate, thermal comfort, and the hygrothermal performance of a historic building it is essential to obtain data on the indoor temperature and humidity conditions. This paper analyses indoor climate conditions in historic wooden apartment buildings in Estonia and presents an applicable hygrothermal load model for designers. The average indoor temperature of 41 apartments in historic wooden apartment buildings was 21.0 °C in winter and 24.5 °C in summer. Using the indoor climate category III of the standard EN 15251, it was found that the temperature was outside the target values in 83% of the apartments in winter and in 25% in summer. Throughout the year, the indoor temperature was below the target values during 20% of the time while in winter it was above the target values during 4% of the time. Variations in indoor temperature reflect occupants' main complaints about unstable temperature and cold floors during the winter period. The daily average moisture excess was 3.3 g/m³ during the cold period and 0.6 g/m³ during the warm period at the average air change rate of 0.56 h-1 and 0.79 h-1, respectively. Moisture generation indoors was 60 g/h at the average living density of 26 m² /person in the historic wooden apartment buildings. For stochastic analyses in historic wooden buildings, we developed an indoor hygrothermal load model that is in good agreement with measured results. [ABSTRACT FROM AUTHOR]

The question of why, in the annual-mean, the northern hemisphere (NH) is warmer than the southern hemisphere (SH) is addressed, revisiting an 1870 paper by James Croll. We first show that ocean is warmer than land in general which, acting alone, would make the SH, with greater ocean fraction, warmer. Croll was aware of this and thought it was caused by greater specific humidity and greenhouse trapping over ocean than over land. However, for any given temperature, it is shown that greenhouse trapping is actually greater over land. Instead, oceans are warmer than land because of the smaller surface albedo. However, hemispheric differences in planetary albedo are negligible because the impact of differences in land-sea fraction are offset by the SH ocean and land reflecting more than their NH counterparts. In the absence of a role for albedo differences it is shown that, in agreement with Croll, northward cross-equatorial ocean heat transport (X-OHT) is critical for the warmer NH. This is examined in a simple box model based on the energy budget of each hemisphere. The hemispheric difference forced by X-OHT is enhanced by the positive water vapor-greenhouse feedback, and is partly compensated by the southward atmospheric energy transport. Due to uncertainties in the ocean data, a range of X-OHT is considered. A X-OHT of larger than 0.5 PW is needed to explain the warmer NH solely by X-OHT. For smaller X-OHT, a larger basic state greenhouse trapping in the NH, conceived as imposed by continental geometry, needs to be imposed. Numerical experiments with a GCM coupled to a slab ocean provide evidence that X-OHT is fundamentally important in determining the hemispheric differences in temperature. Therefore, despite some modifications to his theory, analysis of modern data confirms Croll's 140-year-old theory that the warmer NH is partly because of northward X-OHT. [ABSTRACT FROM AUTHOR]

Thermal comfort is one of the many aspects that affect human well-being and productivity. There is an increasing interest in understanding occupants’ requirements for maintaining the indoor comfort range while minimizing energy wastage. In this paper, a thermal perception map was developed for residential buildings in the humid tropics of Malaysia using logistic regression. Sharma and Ali's [1] concept was used for the elaboration of the thermal comfort map. This map helps in exploring the effect of climate changes on subjects’ thermal perceptions at various indoor air temperatures. The thermal comfort map should be useful for researchers in order to accurately estimate the required energy for maintenance of comfortable temperature. [ABSTRACT FROM AUTHOR]

There is growing scientific interest in the potential role that precision irrigation (PI) can make towards improving crop productivity, and increasing water and energy efficiency in irrigated agriculture. Most progress has been made in arid and semi-arid climates for use in high value crop production where irrigation costs coupled with concerns regarding water scarcity have stimulated PI innovation and development. In temperate and humid climates where irrigation is supplemental to rainfall, PI is less developed but nevertheless offers scope to make more effective use of rainfall, help reduce the non-beneficial losses associated with irrigation (deep drainage, nitrate leaching) and provide farmers with evidence to demonstrate environmentally sustainable practices to processors and retailers. This paper reports on recent experiences in developing precision irrigation in UK field-scale agriculture, drawing on evidence from field research and modelling studies. By combining data from these sources, a critical evaluation focusing on selected technical, agronomic and engineering challenges that need to be overcome are described, including issues regarding PI scheduling, and the delineation of irrigation management zones to ensure compatibility with existing methods of overhead irrigation. The findings have relevance to other countries where irrigation is supplemental and where precision agriculture is gaining popularity. [ABSTRACT FROM AUTHOR]

Background Over the last decade, the incidence of confirmed malaria has declined significantly in Nepal. The aim of this paper is to assess the spatio-temporal distribution of malaria and its association with climatic factors and vector control interventions in two high-risk districts of Nepal. Methods Hotspot analysis was used to visualize the spatio-temporal variation of malaria incidence over the years at village level and generalized additive mixed models were fitted to assess the association of malaria incidence with climatic variables and vector control interventions. Results Opposing trends of malaria incidence were observed in two high-risk malaria districts of eastern and far-western Nepal after the introduction of long-lasting insecticidal nets (LLINs). The confirmed malaria incidence was reduced from 2.24 per 10,000 in 2007 to 0.31 per 10,000 population in 2011 in Morang district but increased from 3.38 to 8.29 per 10,000 population in Kailali district. Malaria hotspots persisted mostly in the same villages of Kailali district, whereas in Morang district malaria hotspots shifted to new villages after the introduction of LLINs. A 1° C increase in minimum and mean temperatures increased malaria incidence by 27% (RR =1.27, 95% CI =1.12-1.45) and 25% (RR =1.25, 95% CI =1.11-1.43), respectively. The reduction in malaria incidence was 25% per one unit increase of LLINs (RR =0.75, 95% CI =0.62-0.92). The incidence of malaria was 82% lower in Morang than in Kailali district (RR =0.18, 95% CI =0.11-0.33). Conclusions The study findings suggest that LLIN coverage should be scaled up to entire districts rather than high-incidence foci only. Climatic factors should be considered for malaria microstratification, mosquito repellents should be prescribed for those living in forests, forest fringe and foothills and have regular visits to forests, and imported cases should be controlled by establishing fever check posts at border crossings. [ABSTRACT FROM AUTHOR]

This paper presents the moisture performance of a novel radiant cooling system connected in series to an Airbox convector adapted to hot and humid climate. Radiant cooling systems have a major benefit in terms of energy savings; however, there is a risk of condensation on the surface of the chilled panel when a room has outside humid air infiltration or high internal moisture gains. Therefore, in order to activate the radiant cooling system, the air in the space needs to be dehumidified to a steady state humidity ratio below 13 g/kg, which causes a significant time delay before startup. Implementing an Airbox convector system connected to the radiant ceiling panel reduces the risk of moisture condensation because it simultaneously dehumidifies indoor air and increases the surface temperature of the chilled panel. This study shows the findings on its humidity performance and ability to reduce the risk of condensation by means of numerical modeling and experimentation. This novel system is sufficiently effective to be used in environments with high infiltration of humid outdoor air because the Airbox convector reduces the time delay when activating the radiant panel system, dehumidifies indoor air and increases the dew point temperature of the ceiling panels. [ABSTRACT FROM AUTHOR]

The change in climate has led to an interest in how this will affect the energy consumption in buildings. Most of the work in the literature relates to offices and homes. However, this paper investigates a supermarket in northern England by means of a multiple regression analysis based on gas and electricity data for 2012. The equations obtained in this analysis use the humidity ratio derived from the dry-bulb temperature and the relative humidity in conjunction with the actual dry-bulb temperature. These equations are used to estimate the consumption for the base year period (1961-1990) and for the predicted climate period 2030-2059. The findings indicate that electricity use will increase by 2.1% whereas gas consumption will drop by about 13% for the central future estimate. The research further suggests that the year 2012 is comparable in temperature to the future climate, but the relative humidity is lower. Further research should include adaptation/mitigation measures and an evaluation of their usefulness. [ABSTRACT FROM AUTHOR]

Highlights: [•] The paper assesses the impact of spring meteorology on Mediterranean forest GPP. [•] The investigation is based on the analysis of ground and remote sensing data. [•] The start of the dry season (SDS) affects inter-annual forest GPP variations. [•] The impact of SDS is attenuated moving toward more humid environments. [•] The eco-physiological bases of these phenomena are identified and discussed. [Copyright &y& Elsevier]

The Murray dairy region produces approximately 1.85 billion litres of milk each year, representing about 20 % of Australia's total annual milk production. An ongoing production challenge in this region is the management of the impacts of heat stress during spring and summer. An increase in the frequency and severity of extreme temperature events due to climate change may result in additional heat stress and production losses. This paper assesses the changing nature of heat stress now, and into the future, using historical data and climate change projections for the region using the temperature humidity index (THI). Projected temperature and relative humidity changes from two global climate models (GCMs), CSIRO MK3.5 and CCR-MIROC-H, have been used to calculate THI values for 2025 and 2050, and summarized as mean occurrence of, and mean length of consecutive high heat stress periods. The future climate scenarios explored show that by 2025 an additional 12-15 days (compared to 1971 to 2000 baseline data) of moderate to severe heat stress are likely across much of the study region. By 2050, larger increases in severity and occurrence of heat stress are likely (i.e. an additional 31-42 moderate to severe heat stress days compared with baseline data). This increasing trend will have a negative impact on milk production among dairy cattle in the region. The results from this study provide useful insights on the trends in THI in the region. Dairy farmers and the dairy industry could use these results to devise and prioritise adaptation options to deal with projected increases in heat stress frequency and severity. [ABSTRACT FROM AUTHOR]

Based on the daily data of relative humidity from 23 meteorological stations in the Tarim River Basin of northwest China during the period from 1961 to 2010, this paper analyzed the multifractal and long memory property of humidity process. Main findings are as follows: (1) The processes present scaling and multifractal property. (2) The left-skewed multifractal spectrum f( α) indicates that the time series of relative humidity is predominated by small fluctuations. (3) There exists long memory with the δ ∈ (0, 0.5) in the processes, except for Kalpin and Aksu's exhibiting non-stationary long memory with the parameter δ being 0.67 and 0.69 respectively. (4) We found that on the whole, the degree of multifractality exhibits a strengthening trend with the longitude and latitude increasing, but decreasing trend with elevation rising; For length of long memory, we investigated that on the whole, the δ values increased with the longitude and latitude increasing, which indicates that the bigger the longitude and latitude is, the longer the memory of humidity process is, but the higher the elevation is, the shorter the memory of humidity process is. [ABSTRACT FROM AUTHOR]

• The paper estimated the direction and strength of driving factors on PM2.5 concentrations in Chinese cities. • A geographically and temporally weighted regression model (GTWR) was adopted in this study. • Higher temperature and wind speed were found to alleviate air pollution in the southeast China. • Per capita GDP and population density were shown to intensify PM2.5 pollution in northwest China. • Urban built-up area was more positively associated with PM2.5 pollution in southeast than in other cities in China. Particulate pollution is currently regarded as a severe environmental problem, which is intimately linked to reductions in air quality and human health, as well as global climate change. Objective : Accurately identifying the key factors that drive air pollution is of great significance. The temporal and spatial heterogeneity of such factors is seldom taken into account in the existing literature. In this study, we adopted a geographically and temporally weighted regression model (GTWR) to explore the direction and strength of the influences of natural conditions and socioeconomic issues on the occurrence of PM 2.5 pollutions in 287 Chinese cities covering the period 1998 to 2015. Cities with serious PM 2.5 pollution were discovered to mainly be situated in northern China, whilst cities with less pollution were shown to be located in southern China. Higher temperature and wind speed were found to be able to alleviate air pollution in the country's southeast, where enhanced precipitation was also shown to reduce PM 2.5 concentrations; whilst in southern and central and western regions, precipitation and PM 2.5 concentrations were positively correlated. Increased relative humidity was found to reinforce PM 2.5 concentration in southwest and northeast China. Furthermore, per capita GDP and population density were shown to intensify PM 2.5 concentrations in northwest China, inversely, they imposed a substantial adverse effect on PM 2.5 concentration levels in other areas. The amount of urban built-up area was more positively associated with PM 2.5 concentration levels in southeastern cities than in other cities in China. PM 2.5 concentrations conformed to a series of stages and demonstrated distinct spatial differences in China. The associations between PM 2.5 concentration levels and their determinants exhibit obvious spatial heterogeneity. The findings of this paper provide detailed support for regions to formulate targeted emission mitigation policies. [ABSTRACT FROM AUTHOR]

This paper studies the impact of climate change on the nutritional status of very young children between the ages of 0–3 years by using weather data from the last half century merged with rich information on child, mother, and household characteristics in rural coastal Bangladesh. We evaluate the health consequences of rising temperature and relative humidity and varying rainfall jointly employing alternate functional forms. Leveraging models that control for annual trends and location-specific seasonality, and that allow the impacts of temperature to vary non-parametrically while rainfall and humidity have flexible non-linear forms, we find that temperatures that exceed 25 °C (the "comfortable" benchmark) in the month of birth exert negative effects on children's nutritional status as measured by mid upper arm circumference. Humidity has a positive impact which persists when child, mother and household controls are included. We find that exposure to changing climate in utero also matters. Explanations for these results include consequences of weather fluctuations on the extent of pasture, cropland, and rainfed lands planted with rice and other crops, and on mother's age at first marriage. Our results underline that climate change has real consequences for the health of very young populations in vulnerable areas. • We study the impact of climate change over 50 years on the nutritional status of very young children. • We evaluate the consequences of temperature, relative humidity, and rainfall jointly. • Excess heat at birth has negative effects while humidity has positive effects on children's MUAC. • The impact of humidity persists when child, mother and household controls are included. • Mechanisms include changes in cropland, rainfed rice lands, and in mother's age at first marriage. [ABSTRACT FROM AUTHOR]

This paper presents a discussion on assessing the potential impacts of climate change on the atmospheric corrosion rates of exposed steel structures. The effects on atmospheric corrosion due to changes in the environmental temperature, carbon dioxide, relative humidity, wind, rainfall and pollution are considered. The limitations and complexities of these assessments are discussed. To demonstrate the use and limitations of this science to evaluate effects related to climate change, a model developed in Australia to predict corrosion is combined with climate change models to project the change in the corrosion rates of steel components and protective zinc coatings in constructions. The method is applied to constructions located along the coastal areas of two Australian cities: Melbourne and Brisbane. These assessments are made using the A1FI scenario, the highest emission scenario defined by the Intergovernmental Panel on Climate Change, applied to nine general circulation models. The projected changes in corrosion rates were found to be an increase of ∼14% for both zinc and steel in Brisbane and a decrease of ∼14% for steel and 9% for zinc in Melbourne. It was also found that the uncertainties associated with the climate change models were small compared to those involved in modelling corrosion for engineering purposes. [ABSTRACT FROM AUTHOR]

This paper summarizes the results from microclimatic monitoring of the impacts related to the construction and exploration phase of a hydroelectric powerplant in the upper Douro River (Portugal). Reference climatic elements for both periods were obtained and the impacts of the reservoir water mass on the region's microclimate were evaluated. For this purpose, Sen's slope estimate non-parametric test was used to detect the meteorological variables' trends over 10 years, considering the division into the construction (2011–2015) and exploration (2016–2020) phases. A network of meteorological stations located close to the dam, in addition to a control station relatively distant from the dam, was used to collect the meteorological data. The control station is still integrated into the same regional climatic context but not exposed to the direct influence of the resulting reservoirs. As a result, temporal differences were determined for temperature and relative humidity. The results show a statistically significant increase in the minimum relative humidity, accompanied by a statistically significant decrease in the daily and seasonal temperature amplitudes between the construction and the exploration phase periods. These outcomes thereby suggest that large reservoirs affect the local climate and may create new microclimates, in the surrounding area, with both positive and negative potential effects. [ABSTRACT FROM AUTHOR]

This paper compares three existing Palmer Drought Severity Index (PDSI) formulations for simulating summer moisture variability in western Canada and a preliminary analysis of climate change impacts on summer moisture anomalies. The three models considered are Palmer's original algorithm (orPDSI), the self-calibrating PDSI (scPDSI), and a version modified for Canadian Prairie conditions (cpPDSI). In all formulations, potential evapotranspiration was parameterized by the Penman-Monteith method instead of the traditional Thornthwaite method. The scPDSI was used as a benchmark for evaluation as it is more appropriate for comparing drought severity of diverse climates. The results confirm that orPDSI produces inflated drought statistics as compared to scPDSI, whereas cpPDSI produced more conservative drought statistics than scPDSI. On the basis of results from scPDSI, historical moisture availability in the Canadian Prairies has shown a significant downward trend since 1950 at the 5% level, whereas southern British Columbia has shown a significant increasing trend. No discernible trend was found in the northern parts of the study area. These results were corroborated by trends in annual precipitation and summer temperature over the respective regions. When scPDSI parameters were calibrated using historical climate data, simulations for the 2050s using climate change scenarios from the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4) showed increases in summer moisture deficit relative to the 1961-90 baseline. However, projecting the extent to which the frequency of extreme drought and/or wet spell categories will change is not trivial since the computation of scPDSI is tied to the definition of the frequency of extreme events. [ABSTRACT FROM AUTHOR]

Fire danger indices are descriptors of fire potential in a large area, and combine a few variables that affect the initiation, spread and control of forest fires. The Canadian Fire Weather Index (FWI) is one of the most widely used fire danger indices in the world, and it is built upon instantaneous values of temperature, relative humidity and wind velocity at noon, together with 24 hourly accumulated precipitation. However, the scarcity of appropriate data has motivated the use of daily mean values as surrogates of the instantaneous ones in several studies that aimed to assess the impact of global warming on fire. In this paper we test the sensitivity of FWI values to both instantaneous and daily mean values, analyzing their effect on mean seasonal fire danger (seasonal severity rating, SSR) and extreme fire danger conditions (90th percentile, FWI90, and FWI>30, FOT30), with a special focus on its influence in climate change impact studies. To this aim, we analyzed reanalysis and regional climate model (RCM) simulations, and compared the resulting instantaneous and daily mean versions both in the present climate and in a future scenario. In particular, we were interested in determining the effect of these datasets on the projected changes obtained for the mean and extreme seasonal fire danger conditions in future climate scenarios, as given by a RCM. Overall, our results warn against the use of daily mean data for the computation of present and future fire danger conditions. Daily mean data lead to systematic negative biases of fire danger calculations. Although the mean seasonal fire danger indices might be corrected to compensate for this bias, fire danger extremes (FWI90 and specially FOT30) cannot be reliably transformed to accommodate the spatial pattern and magnitude of their respective instantaneous versions, leading to inconsistent results when projected into the future. As a result, we advocate caution when using daily mean data and strongly recommend the application of the standard definition for its calculation as closely as possible. Threshold-dependent indices derived from FWI are not reliably represented by the daily mean version and thus can neither be applied for the estimation of future fire danger season length and severity, nor for the estimation of future extreme events. [ABSTRACT FROM AUTHOR]

Since several destructive floods have occurred in Germany in the last decades, it is of considerable interest and relevance ( e.g., when undertaking flood defense design) to take a closer look at the climatic factors driving the changes in flood hazard in Germany. Even if there also exist non-climatic factors controlling the flood hazard, the present paper demonstrates that climate change is one main driver responsible for the increasing number of floods. Increasing trends in temperature have been found to be ubiquitous in Germany, with impact on air humidity and changes in (intense) precipitation. Growing trends in flood prone circulation pattern and heavy precipitation are significant in many regions of Germany over a multi-decade interval and this can be translated into the rise of flood hazard and flood risk. [ABSTRACT FROM AUTHOR]

The water vapour feedback probably makes the largest contribution to climate sensitivity, and the second-largest contribution to its uncertainty, in the sense of disagreement between General Circulation Models (GCMs, the most physically detailed models of climate we have). Yet there has been no quantification of it which allows these differences to be attributed physically with the aim of constraining the true value. This paper develops a new breakdown of the non-cloud LW (longwave) response to climate change, which avoids the problems of the conventional breakdown, and applies it to a set of 4 GCMs. The basic physical differences are that temperature is used as the vertical coordinate, and relative humidity as the humidity variable. In this framework the different GCMs' feedbacks look more alike, consistent with our understanding that their water vapour responses are physically very similar. Also, in the global mean all the feedback components have the same sign, allowing us to conveniently attribute the overall response fractionally (e.g. about 60% from the 'partly-Simpsonian' component). The systematic cancellation between different feedback components in the conventional breakdown is lost, so now a difference in a feedback component actually contributes to a difference in climate sensitivity, and the differences between these GCMs in the non-cloud LW part of this can be traced to differences in formulation, mean climate and climate change response. Physical effects such as those due to variations in the formulation of LW radiative transfer become visible. Differences in the distribution of warming no longer dominate comparison of GCMs. The largest component depends locally only on the GCM's mean climate, so it can in principle be calculated for the real world and validated. However, components dependent on the climate change response probably account for most of the variation between GCMs. The effect of simply changing the humidity variable in the conventional breakdown is also examined. It gives some of this improvement-the loss of the cancellations that leave the conventional breakdown of no use to understand differences between GCMs' climate sensitivities-but not the link to mean climate. [ABSTRACT FROM AUTHOR]

The global community is in panic with fear of changing climate. Though it is very difficult to experience phenomenon of climate change but we can say that the climate is showing huge variability. To understand the impact of human on climate and vice-versa the knowledge of climate variability is necessary and moreover it helps in prediction of future trends of climate. In this paper spatio-temporal analysis of climate variation has been done by using interpolation technique. About 61 % of total area of India has dry climate and its typical example is western part of Rajasthan. In the Western Rajasthan during last 31 years the temperature has shown a great variability with an average rise of about 0.5 °C for the month of June and 0.8 °C for the month of January. During the same period the average annual rainfall has shown a decrease of 50 mm. With an overall rise in temperature over the region and changing precipitation trends the humidity provinces as defined by Thornthwaite, have shifted eastward. The climate variability studies can help to identify vulnerability of a region towards climate change which further helps in formulation of mitigation and adaptation strategies. [ABSTRACT FROM AUTHOR]

The aim of this paper was to investigate the relationship between land use and topography on the variations of temperature and relative humidity in urban and rural municipalities in the Contagem and Betim, south-central state of Minas Gerais- Brazil. The measurement of climatic data occurred during the winter (20/06 - 21/09/2011) continuously and simultaneously, at intervals of sixty minutes, using the automatic sensors (dataloggers - Icel HT model 4000). The weather station INMET, headquartered on the campus of UFMG were used for calibration of instruments and control of the local variations of climatic elements. The data obtained were analyzed in a comparative way in a time sequence taking into account the environmental characteristics (topography and land use) and atmospheric. The temperature of the air taken in urban showed count on "delay" in its development in hourly and lower amplitude when compared to data measured in Betim (rural area). Was attributed these facts to the topographical situation of each of the positions and characteristics of conservation and heat production in the urban environment associated with low specific heat of the materials used in construction, higher density of buildings, relative lack of green areas and participation additional sources of anthropogenic heat. [ABSTRACT FROM AUTHOR]

Abstract: The recent increase in food prices has revealed that climate, combined with an expanding population and a widespread change in diet, may result in an end to an era of predictable abundance of global cereal crops. The objective of this paper is to estimate changes of agriculturally-relevant growing season parameters, including the start of the season, length of the growing period and the position of the height or peak of the season, in the primary regions with rainfed agriculture during the past 26years. Our analysis found that globally, 27% of cereal crop areas have experienced changes in the length of the growing season since 1981, the majority of which had seasons that were at least 2.3days per year longer on average. We also found both negative and positive trends in the start of season globally, with different effects of changing temperature and humidity being isolated depending on the country and region. We investigated the correlation between the peak timing of the growing season and agricultural production statistics for rain fed agriculture. We found that two thirds of the countries investigated had at least 25% of pixels with crop production that behaved differently than expected from the null hypothesis of no correlation. The results show that variations in the peak of the growing season have a strong effect on global food production in these countries. We show that northern hemisphere countries and states appear to have improved model fit when using phenological models based on humidity while southern hemisphere countries and states have improved model fit by phenological models based on accumulated growing degree days, showing the impact of climate variability during the past two and a half decades. [Copyright &y& Elsevier]

Abstract: A broad category of cultural heritage objects are multilayer structures composed of organic, humidity-sensitive materials – wood, animal glue, paper, leather, bone or paints. They respond to variations in relative humidity (RH) in their environment by cyclically gaining and losing moisture, and consequently swelling and shrinking. Differences in the moisture response of the materials induce internal stresses in the individual layers of the structures, which cause objects to deform and crack. Polychrome wood is examined in detail. The cumulative physical damage of the design layer on wood due to repeated RH variations is quantified in terms of their magnitude and number of times they occur. The climatological risk index for accumulated, ‘fatigue’ damage is established, using a procedure to reduce irregular real-world climate histories into simple RH cycles of known damage impact. Using output from the Hadley Model (HadCM3) and simple transfer functions predicting indoor temperature and RH from outdoor climate, changes in the indoor climate through to 2100 were forecast for unheated buildings. European maps highlighting the areas in which painted wood may be significantly affected by climate change are presented. [Copyright &y& Elsevier]

Impact models investigating climate change effects on food safety often need detailed climate data. The aim of this study was to select climate change projection data for selected crop phenology and mycotoxin impact models. Using the ENSEMBLES database of climate model output, this study illustrates how the projected climate change signal of important variables as temperature, precipitation and relative humidity depends on the choice of the climate model. Using climate change projections from at least two different climate models is recommended to account for model uncertainty. To make the climate projections suitable for impact analysis at the local scale a weather generator approach was adopted. As the weather generator did not treat all the necessary variables, an ad-hoc statistical method was developed to synthesise realistic values of missing variables. The method is presented in this paper, applied to relative humidity, but it could be adopted to other variables if needed. [ABSTRACT FROM PUBLISHER]

Abstract: Stack ventilation and wind-induced ventilation are the two main methods for inducing natural ventilation. Stack ventilation by itself cannot create enough air flow to achieve good indoor air quality for building occupants under hot and humid climatic conditions. The low performance of stack ventilation in hot and humid climate is due to the low temperature differences between indoor and outdoor temperature of a building. On the other hand, the wind-induced ventilation method performance is independent of low temperature difference. Therefore, it has potential use to improve the indoor air quality for buildings in the hot and humid climate. This paper examines the wind-induced natural ventilation tower performs under hot and humid climate. The study reveals that the wind-induced ventilation tower has higher extraction airflow rate comparing to other wind ventilators in the market. Analysis shows the wind-induced natural ventilation tower can produce high air changes per hour (ACH) for indoor building environment in the hot and humid climate. Study results also show the wind-induced ventilation tower''s extraction flow rate is 10,000m3/h at external wind velocity of 0.1m/s. With the same external wind velocity, it produces average of 57 ACH. The results of this study will be useful for designing wind-induced natural ventilation tower in hot and humid climate. [Copyright &y& Elsevier]