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The northern edge of the East Asian monsoon region is also a transition zone of temperate continental and monsoon climate, which is a sensitive zone of global climate and ecological environment change. It is an urgent problem to find out the long-term climate change rules of this region. Using 101 tree core samples obtained from 54 trees, a 343-year tree-ring width chronology of the Platycladus orientalis (L.) Franco (1673–2016) in the Wula Mountains, Inner Mongolia, China was established. The analysis shows that the radial growth of P. orientalis is closely related to hydrothermal conditions, the average minimum temperature and relative humidity are the main factors that determine the growth of P. orientalis. Based on the strong correlation between the tree-ring indices and the annual average minimum temperature (r = −0.870, p < 0.001), we reconstructed an average annual minimum temperature series from 1673 to 2016 using a linear regression equation, and the reconstructed equation can explain 75.724% of the variance, respectively. According to the data from the past 343 years, the changes in the annual average minimum temperature series had the cycles of 58.6-, 7.7-, 3.4-, 3.1-, 2.2-, and 2.1-years; the series showed three warm periods (1824–1830, 1909–1922, and 1986–2011) and 4 cold periods (1703–1712, 1731–1738, 1754–1763, and 1937–1951). The low temperature periods recorded in the reconstructed series for the 17th and 18th centuries are consistent with the Little Ice Age that occurred in the northern hemisphere, and the heating rate significantly increased at the end of the 20th century. In addition, the cold and warm periods recorded by the reconstruction result is basically consistent with the extreme climate events recorded in the historical documents of the region and the reconstruction results in other regions. In this paper, the world's first chronology of P. orientalis tree ring width was established. A historical sequence of annual average minimum temperature of 343 years was reconstructed in a typical region of the East Asian monsoon climate. It fills in the blank of reconstruction sequence and variation characteristics of mean minimum temperature in the northern edge of East Asian monsoon and transition zone of temperate continental and monsoon climate in recent four centuries. [ABSTRACT FROM AUTHOR]

Abstract Over the past few decades, climate change has become a significant problem, the ramifications of which are of concern around the world. Global warming is a long-term process caused by phenomena such as increased levels of carbon dioxide (CO 2) concentration in the atmosphere, increases in rainfall, changes in relative humidity and changes in temperature. Thus, this will aggravate the degradation process of reinforced concrete (RC) structures, leading to the decrease of durability, safety and serviceability. Regarding the durability of concrete structures, carbonation-induced corrosion is definitely a significant and costly source of degradation, directly related to climatic parameters such as CO 2 , temperature and relative humidity. In Paraguay, the lack of control during the construction of buildings often leads to weak structures highly vulnerable to the attack of harmful external agents. Therefore, this paper seeks to provide an analysis of the correlation between real degradation data and a numerical carbonation model for concrete structures in the country. According to the Intergovernmental Panel on Climate Change (IPCC) reports, climatic parameters will increase in the future. For this reason, an analysis of the decreasing performance of these structures caused by climate change will be addressed in this paper. This research aims to choose the most accurate mathematical model that can be applied in Paraguay for the prediction of the service life of concrete structures subjected to carbonation-induced corrosion. For that purpose, parameters and variables of the selected model have been defined and subsequently validated through carbonation tests results carried out in a set of RC structures built in the country. The results of this paper should be considered as a first stage for the further formulation of maintenance strategies, which is highly necessary for Paraguay. [ABSTRACT FROM AUTHOR]

The paper deals with the use of thermography to assess landslide risk. Landslide is a natural process which affects soil. In specific conditions, it can even become cause of death and damages to buildings and structures. Due to climate changes, landslide events have increased in the last years. Sensor networks are today widely used to monitor landslide triggering events. Main problems concern the development costs of such networks, so today attention is principally focused on the use of measurement systems which allow to monitor wide zones at distance. Recently researchers are considering the use of infrared thermography as a promising tool for monitoring landslide process. The paper aims to describe the current potentialities of thermography and its limitations. Several issues and open problems are still to be faced before considering such technique as an effective monitoring tool. For this reason, the author reports the results of a measurement campaign to prove the strengths and weakness of the methodology. Relevant aspects concerning the limits of this measurement technique are described in the following to provide suggestions to users and researchers working in this field. [ABSTRACT FROM AUTHOR]

The urban heat island (UHI) is a phenomenon whereby temperature levels in urban areas are higher than in surrounding rural settings. Urban heat islands are a matter of increasing concern, since they can affect communities by exacerbating air pollution and greenhouse gas emissions (due to the greater use of air conditioning) and the occurrence of heat-related illness, and may lead to higher levels of mortality. This paper provides a description of the phenomena of (UHI) and an analysis of how cities are vulnerable to it. It highlights the need for resilience and the variety of means by which the UHI can be tackled. It describes a set of trends in two regions in Germany and Australia, which illustrate the scope of the problem in the northern and southern hemispheres, and the scale of vulnerability. Then, existing UHI vulnerability assessments are analysed to highlight common features and differences. Based on this, we propose a classification of adaptability parameters to support vulnerability assessments. The paper also discusses current mitigation approaches mentioned in the literature, and how these address some vulnerabilities. It concludes that both a better understanding of the UHI phenomena and consideration of the particular context of each city is needed to make urban areas more resilient to UHI. [ABSTRACT FROM AUTHOR]

• A coupled humid-mechanical-damage model was utilized. • The influence of humidity on the stability of Longyou Grottoes was investigated. • The cave roof is the most dangerous position under humidity variation. • Fissures act as shortcuts for humidity diffusion and stress generation. • Waterproof measurements contribute to the stability and durability of the grottoes. Silty sandstone grottoes are suffered climate changes. The Longyou Grottoes are typical argillaceous siltstone. This paper utilized the coupled humid-mechanical-damage model to investigate the influence of environmental humidity change on the deformation and stability of Cave 4 and Cave 5 in Longyou Grottoes. It is found that the change in environmental humidity significantly influences the stability of caves in Longyou Grottoes. The water saturation of surrounding rock changes with the increase or decrease of ambient humidity. The water swelling and dry shrinkage processes greatly affect the stress state and mechanical properties of the surrounding rock, resulting in micro-cracks which may form fractures that disturb the structural integrity and aggravate the geological hazard of weathering. The cave roof is the most dangerous position during the humidity variation. Pre-existing fissures act as shortcuts for humidity diffusion and stress generation. In turn, the fast diffusion rate and high stress cause further propagation of the fissures. Repairing pre-existing fissures and applying waterproof measurements on the inner wall of caves contributes to the stability and durability of the grottoes. This study improves the understanding of the relationship between the changes in environmental humidity and the weathering of grottoes and provides theoretical support for the subsequent disaster risk management and preservation of Longyou Grottoes. [ABSTRACT FROM AUTHOR]

Shading and insect-proof screens are widely used in agriculture for passive microclimate control and for insect exclusion. It is an efficient tool for crop production in adverse climatic and environmental condition. As screens are made of a porous material, the protected environment usually interacts with the outside and hence screens provide only moderate microclimatic modifications. Nevertheless, such modifications might be crucial for certain horticultural processes, thus may strongly influence production and quality. Depending on the type of screen, structure configuration, crop and climatic region, recent studies have shown that compared to open field conditions, screens reduce solar radiation and air velocity by about 15–39% and 50–87%, respectively; increase air relative humidity by 2–21%; decrease air temperature and evapotranspiration by 2.3–2.5 °C and 17.4–50% respectively. This paper seeks to review recent advances regarding effects of such screens on microclimate, crop water use and production. Therefore, the ultimate objective of this review is to assist both researchers and growers. For researchers the review provides up-to-date information of the recent studies as well as knowledge gaps that call for future research. For growers and extension service experts this review would assist in choosing the appropriate screen for a specific application, based on the current knowledge. [ABSTRACT FROM AUTHOR]

Abstract Relative humidity (RH) is one of the most important parameters in the study of fog-haze. This paper first estimates the contributions of the key quantities (temperature, water vapor, air pollutant) and their combinations to the relative change of RH , and then investigates the relationships of RH with the long-term variation of haze and fog days based on the meteorological data in the Yangtze River Delta over the period 1970–2010. The main conclusions are as follows. (1) Temperature is the foremost factor influencing RH , with the effect of specific humidity and direct contribution of air pollutant being second and third. (2) RH shows a prominent descending trend in the Yangtze River Delta, due to global warming and the 'analogous heat island effect' (AHIE). (3) Decreasing RH was responsible for the reduction of fog days. The AHIE can explain the phenomenon in which fog days in metropolises are less than in small cities. (4) Granger causality analysis of inter-annual variation further shows that increasing aerosol loading Ganger-causes the increasing haze days, rather than meteorological parameters such as RH. High RH would enhance hygroscopic growth of particle and then suppress the planet boundary layer height (PBLH) and lead to more haze days, lower PBLH further increases aerosols and RH , this positive feedback mechanism can be established under the condition of aerosol loading being relatively stable and beyond the threshold for haze formation. (5) If aerosol emissions maintain the status quo, climate cooling would result in serious fog-haze events occurring more frequently in Yangtze River Delta. The research provide a scientific basis for understanding the influence of meteorological factors on RH and the connection between the variation of long term fog-haze days and RH under the background of climate change. Highlights • Factors affecting relatively humidity (RH). • Relative changes of RH caused by three factors and their combinations. • Reasons for the long-term variations of haze and fog days. • Climate cooling may intensify the frequency of "fog-haze" weather. [ABSTRACT FROM AUTHOR]

To address the problems and limitations identified through a comprehensive evaluation in Part I paper, several modifications are made in model inputs, treatments, and configurations and sensitivity simulations with improved model inputs and treatments are performed in this Part II paper. The use of reinitialization of meteorological variables reduces the biases and increases the spatial correlations in simulated temperature at 2-m (T2), specific humidity at 2-m (Q2), wind speed at 10-m (WS10), and precipitation (Precip). The use of a revised surface drag parameterization further reduces the biases in simulated WS10. The adjustment of only the magnitudes of anthropogenic emissions in the surface layer does not help improve overall model performance, whereas the adjustment of both the magnitudes and vertical distributions of anthropogenic emissions shows moderate to large improvement in simulated surface concentrations and column mass abundances of species in terms of domain mean performance statistics, hourly and monthly mean concentrations, and vertical profiles of concentrations at individual sites. The revised and more advanced dust emission schemes can help improve PM predictions. Using revised upper boundary conditions for O 3 significantly improves the column O 3 abundances. Using a simple SOA formation module further improves the predictions of organic carbon and PM 2.5 . The sensitivity simulation that combines all above model improvements greatly improves the overall model performance. For example, the sensitivity simulation gives the normalized mean biases (NMBs) of −6.1% to 23.8% for T2, 2.7–13.8% for Q2, 22.5–47.6% for WS10, and −9.1% to 15.6% for Precip, comparing to −9.8% to 75.6% for T2, 0.4–23.4% for Q2, 66.5–101.0% for WS10, and 11.4%–92.7% for Precip from the original simulation without those improvements. It also gives the NMBs for surface predictions of −68.2% to −3.7% for SO 2 , −73.8% to −20.6% for NO 2 , −8.8%–128.7% for O 3 , −61.4% to −26.5% for PM 2.5 , and −64.0% to 7.2% for PM 10 , comparing to −84.2% to −44.5% for SO 2 , −88.1% to −44.0% for NO 2 , −11.0%–160.3% for O 3 , −63.9% to −25.2% for PM 2.5 , and −68.9%–33.3% for PM 10 from the original simulation. The improved WRF/Chem is applied to estimate the impact of anthropogenic aerosols on regional climate and air quality in East Asia. Anthropogenic aerosols can increase cloud condensation nuclei, aerosol optical depth, cloud droplet number concentrations, and cloud optical depth. They can decrease surface net radiation, temperature at 2-m, wind speed at 10-m, planetary boundary layer height, and precipitation through various direct and indirect effects. These changes in turn lead to changes in chemical predictions in a variety of ways. [ABSTRACT FROM AUTHOR]

The paper introduces a novel method for risk assessment and preventive conservation of organic hygroscopic cultural heritage objects. The method is based on the analysis of the historic climate that is established in the European Standard EN 15757:2010. This new approach enables interpreting visible damage and assessing cause–effect relationships and it finds practical application in improving conservation strategies for real life buildings and objects. The paper investigates how it may be advantageous to reconstruct the historic climate back in time to obtain sound information about the target relative humidity (RH) level and the domain of RH fluctuations that can be considered safe for conservation. The method was applied to an inlaid wooden choir in the basilica of S. Giustina, Padua, Italy. The past indoor climate has been reconstructed over the whole life of the object, built in 1477, with documentary proxy data, instrumental readings and building simulation. Winter has been found to be the most critical season for the mechanical stress and wood yield. For the future, the indoor climate has been simulated until 2100 to timely devise preventive conservation measures to reduce the risk induced by climate change. Finally an evaluation of uncertainties has been considered. [ABSTRACT FROM AUTHOR]

Previous work by the same authors has shown that in mixed-humid climates, tight, super-insulated residential structures can experience high humidity events in summer months. Standard, commercially available vapor compression-based air conditioners struggle to control humidity in such structures with low cooling loads. Therefore a desiccant-assisted heat pump system for tight, super-insulated residential structures is proposed. This paper first reviews solid desiccant cooling cycles. Then a hybrid desiccant cooling cycle is explained and a prototype machine based on the cycle is described. The machine, known as HAWC (hybrid air/water conditioner), accomplishes cooling, dehumidification, ventilation, and domestic hot water heating. This paper models the HAWC within the framework of dynamic building energy modeling software and concludes that a refined version of the HAWC prototype is capable of completely eliminating high humidity events in the summer time while still saving energy as compared to a traditional HVAC system. [ABSTRACT FROM AUTHOR]

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]

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]

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 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]

• 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 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]

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]

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]

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 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]

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]

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]

Abstract: In this paper, an exergy analysis is applied to indicate the exergy efficiency and irreversibility of common models of evaporative cooling. Exergy analysis of conditioned air are based on the results of experimental investigations on the direct, indirect, and two-stage indirect/direct evaporative cooling for six cities in Iran, each having various weather conditions. For this purpose, exergy balances of three cooling methods are derived. The results obtained reveal that for a comprehensive efficiency analysis, both the first and second law of thermodynamics should be considered. Furthermore, the direct evaporative coolers work best in temperate and dry climate with estimated exergy efficiency of 20%. The indirect evaporative coolers are more efficient in hot and dry climate with approximate exergy efficiency of 55%. The indirect/direct evaporative coolers are better choice for hot and semi-humid climate with exergy efficiency of about 62%. [Copyright &y& Elsevier]

Abstract: Temperature and moisture content are the main factors that influence concrete carbonization, chloride diffusion, and corrosion rate of reinforced bars placed in concrete. Climate variations can induce the variation of the micro-environment of concrete. Therefore, temperature and relative humidity in the natural climate environment serve as the climate load, and the variations in the micro-environment corresponding to the climate variations are the effect of the climate load. Based on these, the present paper attempts to build climate temperature and relative humidity action spectrums as a climate load model. The climate action spectrums of temperature and relative humidity are built based on meteorological data of the temperature and the relative humidity variations. The effects of sunshine and rain are included in the construction of the action spectrum. Series of tests are conducted under artificially controlled climate environment (ACCE) and natural climate environment (NCE) conditions to support the construction of the spectrum. [Copyright &y& Elsevier]

Abstract: The present and future spatiotemporal characteristics of reference evapotranspiration (ET0) are examined in this paper. ET0 during 1961–2009 are calculated by the Penman–Monteith method recommended by FAO (Food and Agriculture Organization) with historical weather data while ET0 during 2011–2099 are downscaled from HadCM3 (Hadley Centre Coupled Model, version 3) outputs under two emission scenarios (A2 and B2) by SDSM (Statistical DownScaling Model). The spatial distribution and temporal trend in ET0 are interpreted by Inverse Distance Weighted Interpolation and Mann–Kendall method, respectively. Results show that the annual mean ET0 is 1060.3mm, the lowest and highest values are found in the southwest and northwest region due to the spatial distribution of climatic factors, respectively. ET0 has increased significantly due to the downward trend in relative humidity and upward trend in temperature on the Loess Plateau during 1961–2009. HadCM3 projects a continuous increase in ET0 in the 21st century and the upward trend will be more pronounced after 2050. Averaged over the two emission scenarios for the whole area, the projected increase are 4%, 7% and 12% for the three periods 2011–2040, 2041–2070 and 2071–2099, respectively; the increase under A2 scenario are slightly greater than those under B2 scenario. An obvious gradient is detected for the projected increase in ET0 from northeast to southwest region in the 21st century. The increase in ET0 will possibly influence the water resource on the Loess in the 21st century and some countermeasures should be taken to reduce the adverse impacts. [Copyright &y& Elsevier]

Abstract: In variable humidity conditions, wood absorbs or desorbs moisture from the air. Unless the change in humidity is very slow, this will develop moisture gradients in the wood sections. These gradients will develop stresses due to constrained swelling or shrinkage strains. These stresses are named moisture-induced stresses. The present paper investigates the main parameters affecting such moisture-induced stresses, including the type of climate, the size of the timber cross-section, and the type of protective coating. A first attempt to identify moisture-induced stresses in different European climatic regions was made. For each climatic region, relative humidity and temperature histories were identified, and characteristic and mean values of yearly and daily variations were calculated. Using a finite element model implemented in Abaqus, the moisture content and stress distribution were computed on different timber cross-sections exposed to the climatic regions and protected with different types of coating. A Fickian moisture transfer model was used to compute the moisture distribution, and a mechanical model for time-dependent behaviour of wood was implemented to calculate the corresponding stress distribution. The variation of moisture was found to result in stresses of magnitudes that would probably cause cracking of wood in the perimeter of any uncoated cross-section size. The use of a protective coating, however, reduced considerably the moisture-induced stresses, and can be regarded as an effective protective measure to avoid cracking due to humidity variations. Considering European climates, Northern climates were found to result in higher surface tensile stresses than Southern climates. [Copyright &y& Elsevier]

Abstract: In earlier work , NIST developed a climate suitability analysis method to evaluate the potential of a given location for direct ventilative cooling and nighttime ventilative cooling. The direct ventilative cooling may be provided by either a natural ventilation system or a fan-powered economizer system. The climate suitability analysis is based on a general single-zone thermal model of a building configured to make optimal use of direct and/or nighttime ventilative cooling. This paper describes a new tool implementing this climate suitability methodology and its capability to consider an adaptive thermal comfort option and presents results from its application to analyze a variety of U.S. climates. The adaptive thermal comfort option has the potential to substantially increase the effectiveness of natural ventilation cooling for many U.S. cities. However, this impact is very dependent on the acceptable humidity range. If a dewpoint limit is used, the increase is significant for a dry climate such as Phoenix but much smaller for humid climates such as Miami. While ASHRAE Standard 55 does not impose a limit on humidity when using the adaptive thermal comfort option, the necessity of limiting humidity for other reasons needs to be considered. [Copyright &y& Elsevier]

Abstract: The coupled heat, air and moisture transfer between building envelopes and indoor air is complicated, and has a significant influence on the indoor environment and the energy performance of buildings. In the paper, a model for predicting coupled multi-zone hygrothermal-airflow transfer is presented. Both heat and moisture transfer in the building envelope and multi-zone indoor airflow are simultaneously considered; their interactions are modeled. The coupled system model is implemented into Matlab–Simulink, and is validated by using a series of testing tools and experiments. The new program is applied to investigate the moisture transfer effect on indoor air humidity and building energy consumption in different climates (hot-humid, temperate and hot-dry climates). The results show that not accounting for hygrothermal effects in modeling will result in overestimation of energy costs for hot and humid climate situations and possible over sizing of plant leading to inefficient operation. [ABSTRACT FROM AUTHOR]

Bioenergy is considered a promising alternative to achieve carbon neutrality and emission reduction. There is a debate over the role of bioenergy in climate change mitigation because of carbon emissions from the production and utilization of biofuels. Recently, studies on emissions of biogenic volatile organic compounds (BVOCs) have substantially increased as they have a significant impact on human health and climate change due to large emissions and high reactivity. A scientometric analysis of 2895 journal papers during 1991 and 2020 related to BVOC emissions from the Web of Science Core Collection was conducted by CiteSpace and Carrot2. Results showed that three main knowledge domains were BVOC emissions and drivers, BVOCs and their oxidation products in biosphere-atmosphere exchange, and soil BVOCs in plant-microbe interactions during the period under study. Generally, the relationships between plant BVOC emissions and environmental variables (e.g., temperature, drought, light solar radiation, humidity, availability of nutrients, carbon dioxide, ozone, etc.) can be investigated by measurement techniques (i.e., chamber) or models (i.e., Model of Emissions of Gases and Aerosols from Nature). Soils could work as both the sink and source of BVOCs through various processes that are affected by soil temperatures, pH, organic matter, and moisture. Anthropogenic activities might affect the emission of BVOCs and promote the formation of BVOC-derived pollutants (e.g., ozone, particles, etc.). Incorporating BVOC emissions and their relationships with pollutants, biomass, and energy into environmental management and decision-making is a promising direction. [Display omitted] • A scientometric analysis was conducted on the research evolution of BVOC emissions. • Ten clusters generated by CiteSpace were logically reclassified into three hotspots. • MEGAN is the most frequently empirical model for BVOC emission assessment. • BVOC-derived pollutants like SOA are likely affected by anthropogenic activities. • Soils in terrestrial ecosystems can act as both the source and sink of BVOCs. [ABSTRACT FROM AUTHOR]

Abstract: This paper analyses the relationship between the evolution of the Late Miocene and Early Pliocene rodent and insectivore assemblages from the Granada Basin (southern Spain) and climate changes. These climatic changes, in terms of humidity and temperature fluctuations, are inferred from variations of the relative abundances of taxons with definite ecological preferences. There is a general tendency towards a temperature increase from the latest Tortonian (Middle Turolian) to the Messinian (Late Turolian), and towards a decrease from the Mio-Pliocene boundary (latest Turolian–earliest Ruscinian) to the end of the Zanclean (Late Ruscinian). Dry conditions predominate in the latest Tortonian (Middle Turolian). At the beginning of the Messinian (Late Turolian) there was a significant increase in humidity, followed by an aridification throughout the end of the Messinian and Zanclean (Late Turolian and Ruscinian). These climatic variations are in accordance with the sedimentary evolution of the basin, and agree with the climatic interpretations inferred from the shallow-marine carbonate sediments (temperate/ tropical) deposited in the marine basins of southeastern Spain during the studied time interval. [Copyright &y& Elsevier]

Abstract: South Africa''s winter-rainfall zone is a climatically sensitive region, lying at the interface of the earth''s temperate and sub-tropical climatic systems. Its seasonally arid climate has generally prevented the preservation of long and organic-rich sedimentary deposits, producing a spatially limited and temporally biased Quaternary record. This paper seeks to address this issue further and develop a fuller understanding of the wider climatic changes in this region during the Late Quaternary. Modern climatic data does not support the definitions of the “winter-rainfall zone” presented in previous syntheses and this factor, amongst others, may explain difficulties in resolving the palaeoenvironmental record in this region. We present palaeoenvironmental evidence from the Agulhas Plain, an area marginal to the modern winter-rainfall zone. Cored sedimentological and palynological records from two pans are integrated with previously reported records of aeolian activity, providing evidence for phases of enhanced aridity and humidity during the Late Quaternary. The record is fragmentary, which may reflect the cycling of sediment between the pans and their accompanying lunette dunes. Lacustrine sedimentary sequences dating to c. 33 ka – >47 ka provide evidence for enhanced humidity consistent with evidence in the winter and year-round rainfall zones. Increased humidity is also recorded from c. 2ka, following drier conditions than the present c. 2.7–2.5ka. Palynological evidence supports the sedimentological interpretations of pan water status and offers rare insights into the nature of the region''s unique Fynbos vegetation during the Late Pleistocene. [Copyright &y& Elsevier]

This paper studies the effect of large- and small-scale changes of soil temperature and humidity on soil microbial biomass C and N, ergosterol, carbon utilization potential, organic and inorganic N and rate of C and N mineralization at 25°C. Large-scale variations are identified with seasonal changes in temperature and humidity. To simulate small-scale changes, soil temperature and humidity were manipulated in the field. The treatment resulted in damping of temperature fluctuations and a decrease of soil humidity.The majority of the studied variables exhibit pronounced seasonality, showing a clear-cut distinction between summer (July–August) and winter (December). In summer, C mineralization rate and carbon utilization potential was high but microbial and fungal biomass (ergosterol) was low.C and N mineralization rate and microbial and fungal biomass were only affected by sampling date, demonstrating that gross parameters of biomass and activity of microorganisms are not affected by small-scale changes in temperature and humidity. In contrast, variables relating to N availability (organic N, NH4+ and NO3-, microbial biomass N) and carbon utilization potential of the microbial community were highly affected by small-scale changes in soil abiotic conditions. The results suggest that changes in N dynamics induced by small-scale changes of temperature and humidity are caused by shifts in the structure of the microbial community rather than by variations in microbial biomass. [Copyright &y& Elsevier]