Possible Effects Of Global Warming Research Articles

River flow in the near future: a global perspective in the context of a high-emission climate change scenario

Abstract. There is high confidence that global warming intensifies all components of the global water cycle. This work investigates the possible effects of global warming on river flows worldwide in the coming decades. We conducted 18 global hydrological simulations to assess how river flows are projected to change in the near future (2015–2050) compared to the recent past (1950–2014). The simulations are forced by runoff from the High Resolution Model Intercomparison Project (HighResMIP) CMIP6 global climate models (GCMs), which assume a high-emission scenario for the projections. The assessment includes estimating the signal-to-noise (S/N) ratio and the time of emergence (ToE) of all the rivers in the world. Consistently with the water cycle intensification, the hydrological simulations project a clear positive global river discharge trend from ∼2000 that emerges beyond the levels of natural variability and becomes “unfamiliar” by 2017 and “unusual” by 2033. Simulations agree that the climate change signal is dominated by strong increases in the flows of rivers originating in central Africa and South Asia and those discharging into the Arctic Ocean, partially compensated for by the reduced flow projected for Patagonian rivers. The potential implications of such changes may include more frequent floods in central African and South Asian rivers, driven by the projected magnification of the annual cycles with unprecedented peaks, a freshening of the Arctic Ocean from extra freshwater release, and limited water availability in Patagonia given the projected drier conditions of its rivers. This underscores the critical need for a paradigm shift in prioritizing water-related concerns amidst the challenges of global warming.

Thermal tolerance in an extremophile fish from Mexico is not affected by environmental hypoxia.

The thermal ecology of ectotherm animals has gained considerable attention in the face of human-induced climate change. Particularly in aquatic species, the experimental assessment of critical thermal limits (CTmin and CTmax) may help to predict possible effects of global warming on habitat suitability and ultimately species survival. Here we present data on the thermal limits of two endemic and endangered extremophile fish species, inhabiting a geothermally heated and sulfur-rich spring system in southern Mexico: The sulfur molly (Poecilia sulphuraria) and the widemouth gambusia (Gambusia eurystoma). Besides physiological challenges induced by toxic hydrogen sulfide and related severe hypoxia during the day, water temperatures have been previously reported to exceed those of nearby clearwater streams. We now present temperature data for various locations and years in the sulfur spring complex and conducted laboratory thermal tolerance tests (CTmin and CTmax) both under normoxic and severe hypoxic conditions in both species. Average CTmax limits did not differ between species when dissolved oxygen was present. However, critical temperature (CTmax=43.2°C) in P. sulphuraria did not change when tested under hypoxic conditions, while G. eurystoma on average had a lower CTmax when oxygen was absent. Based on this data we calculated both species' thermal safety margins and used a TDT (thermal death time) model framework to relate our experimental data to observed temperatures in the natural habitat. Our findings suggest that both species live near their thermal limits during the annual dry season and are locally already exposed to temperatures above their critical thermal limits. We discuss these findings in the light of possible physiological adaptions of the sulfur-adapted fish species and the anthropogenic threats for this unique system.

Seasonality and risk factor analysis of respiratory syncytial virus infection in children in Taiwan-A retrospective study from 1995 to 2005.

Respiratory syncytial virus (RSV) is one of the important pathogens leading to acute respiratory tract infection in infants and young children. We aimed to investigate the seasonality of RSV infection in different parts of Taiwan and to delineate the risk factors for severe RSV infections. We collected RSV-infected patients' data by retrospective chart review. A total of 1740 RSV-infected children aged under 18 years were enrolled. The infection was acquired during hospitalization in 103 (7.1%) children, while none of them required ventilator support or needed intensive care before RSV infection. The need for intensive care or ventilator support was significantly associated with congenital heart disease (CHD), chronic lung disease, and neuromuscular diseases. Age <1 year and nosocomially acquired infection are also significant predictors for the need of intensive care. Only the presence of CHD, especially acyanotic CHD, was significantly associated with a fatal outcome. RSV infection occurs all year round. Monthly distribution of RSV infections in Northern Taiwan showed a bimodal pattern, with one peak from March to May, and another from August to October. The distribution in Southern Taiwan showed a single peak from April to July. The occurrence of RSV correlates positively with temperature and rain. The bimodal seasonal distribution pattern in Northern Taiwan may be a transitional pattern shifting from a single high winter peak in temperate areas to a wider summer peak in tropical areas. Continuous surveillance is needed to explore the possible effect of global warming on the seasonality of RSV infection.

Photoluminous Response of Biocomposites Produced with Charcoal.

Due to the possible effects of global warming, new materials that do not have a negative impact on the environment are being studied. To serve a variety of industries and outdoor applications, it is necessary to consider the impact of photoluminosity on the performance of biocomposites in order to accurately assess their durability characteristics and prevent substantial damage. Exposure to photoluminosity can result in adverse effects such as discoloration, uneven surface, loss of mass, and manipulation of the intrinsic mechanical properties of biocomposites. This study aims to evaluate general charcoal from three pyrolysis temperatures to understand which charcoal is most suitable for photoluminosity and whether higher pyrolysis temperatures have any significant effect on photoluminosity. Porosity, morphology, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy of charcoal were analyzed. Charcoal obtained at a temperature of 800 °C demonstrates remarkable potential as a bioreinforcement in polymeric matrices, attributable to its significantly higher porosity (81.08%) and hydrophobic properties. The biocomposites were characterized for flexural strength, tensile strength, scanning electron microscopy (SEM), FTIR, and x-ray diffraction (XRD). The results showed an improvement in tensile strength after exposure to photoluminosity, with an increase of 69.24%, 68.98%, and 54.38% at temperatures of 400, 600, and 800 °C, respectively, in relation to the treatment control. It is notorious that the tensile strength and modulus of elasticity after photoluminosity initially had a negative impact on mechanical strength, the incorporation of charcoal from higher pyrolysis temperatures showed a substantial increase in mechanical strength after exposure to photoluminosity, especially at 800 °C with breaking strength of 53.40 MPa, and modulus of elasticity of 4364.30 MPA. Scanning electron microscopy revealed an improvement in morphology, with a decrease in roughness at 800 °C, which led to greater adhesion to the polyester matrix. These findings indicate promising prospects for a new type of biocomposite, particularly in comparison with other polymeric compounds, especially in engineering applications that are subject to direct interactions with the weather.

Hurricane season complexity: The case of North-Atlantic tropical cyclones

The forecast of tropical cyclone (TC) seasons remains an elusive subject of study. In order to characterize their complexity, the energy of North Atlantic (NA) TC seasons is studied in this research work. The time evolution of the accumulated cyclone energy probability distribution is analyzed using mobile windows to calculate the statistical parameters: mean, standard deviation, kurtosis and skewness. A nonstationary distribution with clear excess of extreme energetic seasons when compared to a Gaussian distribution was found for the most recent years. The data also show a clear correlation between variability and mean, i.e. more energetic periods are more variable. Finally, the dynamics is analyzed using several techniques such as the lag plot, Hurst exponent and fractal dimension. A stochastic but persistent behavior was found. It is finally concluded that the NA TC season energy seems to be increasing both in magnitude and variability. This helps to elucidate the possible effect of global warming into increasing hurricane hazards.

Global warming, renal function and heart failure: a 20-year follow-up study

Abstract Background There is a growing concern about the possible effects of global warming on human health. In HF outpatients, renal function significantly worsens during summer. More specific analyses on the impact of increasing temperatures on body homeostasis are lacking. Purpose We investigated the relationship between the trend of temperatures from 2002 to 2021 and renal function in heart failure (HF) outpatients. Methods All creatinine and estimated glomerular filtration rate (eGFR) values of HF outpatients followed at one tertiary hospital in a Mediterranean area of Spain were retrieved from electronic health records. eGFR was calculated through the CKD-EPI formula. Temperature data from the local municipality were derived from the Meteocat service; as temperatures from the years 2004–2005 were not available, these years were not analysed. Summer was defined as the timespan from June to September included. We calculated average values of creatinine and eGFR during summer and the rest of the same year, considering each patient and each year. Similarly, we averaged temperature values during summer and the rest of the same year. Results We derived 6,307 couples of average creatinine/eGFR values in summer and in the rest of the year from 2,194 patients. Across all the years (2002–2003 and 2006–2021), creatinine was slightly higher in summer than in the rest of the year (1.26 vs. 1.21 mg/dL, p&amp;lt;0.001), and eGFR was lower (65 vs. 67 mL/min/1.73 m2, p&amp;lt;0.001). Temperatures in summer and the rest of the year increased gradually, albeit not linearly, from 2002 to 2021 (Figure 1). The absolute (Δ) and percent changes (Δ%) in median temperatures between summer and the rest of the year increased across years (r=0.149, p=0.001 and r=0.144, p=0.002, respectively), as well as Δ and Δ% of the monthly median of maximal temperatures (r=0.119, p&amp;lt;0.001 and r=0.052, p&amp;lt;0.001, respectively) (Figure 1). The Δ and Δ% temperatures between summer and the rest of the year displayed several significant correlations with Δ and Δ% creatinine and eGFR after adjusting for several variables including age, sex, HF therapies, and creatinine outside of summer (Figure 2). Conclusions Over a 20-year timespan there has been an increase in 1) temperatures in summer and in the rest of the year, and 2) the temperature excursion between summer and the rest of the year. Changes in temperatures between summer and the rest of the year correlated with the magnitude of the decrease in renal function during summer, likely because of worse dehydration with higher temperatures. Therefore, the progressive rise in temperature may have detrimental effects on renal function during summer in HF outpatients. Funding Acknowledgement Type of funding sources: None.

Projections of precipitation and temperature in Southern Iraq using a LARS-WG Stochastic weather generator

Iraq is located in the Middle East, a climatic region distinguished by arid and semi-arid environments and which is expected being more susceptible to possible effects of global warming and climate change. In current research, a stochastic weather generator, LARS-WG 6.0, was utilized to simulate historical and projected future daily climatic data and the appropriateness of the model to project daily temperature and daily precipitation. Considering the enormous uncertainties associated with future climate projections, five general circulation models (GCMs), MIROC5, CanESM2, HadGEM2-ES, NorESM1-M, and CSIRO-Mk3.6.0, which represent the most suitable models for the region according to previous studies, were utilized to project the future climate depending on two important scenarios of emissions, RCP4.5 and RCP8.5, across the current century by three periods. The climate data from six meteorological stations located in Southern Iraq were used to validate the model, which was based on historical data spanning thirty years (1980–2010). According to the findings, the yearly maximum temperature will rise based on the generated predictions at the end of the twenty-first century by 1.32–3.94 °C under RCP4.5 and 1.50–5.92 °C under RCP8.5 for all stations studied. For precipitation, the model projections show that there are various trends over all the GCMs used. This denotes the high level of uncertainty of the precipitation prediction if applied to one model only, as some models, e.g., CanESM2, predict an increase in precipitation while other models, e.g., MIROC5, refer to a decreasing trend or no change in precipitation in the future. Changes in rainfall and temperature will have a big effect on how much water is available in the south of Iraq, especially in the marsh and agricultural areas, which will face desertification, water shortages, and other environmental problems.

Larval Development in Tropical Gar (Atractosteus tropicus) Is Dependent on the Embryonic Thermal Regime: Ecological Implications under a Climate Change Context

In ectotherm species, environmental temperature plays a key role in development, growth, and survival. Thus, determining how temperature affects fish populations is of utmost importance to accurately predict the risk of climate change over fisheries and aquaculture, critical to warrant nutrition and food security in the coming years. Here, the potential effects of abnormal thermal regimes (24, 28 and 32 °C; TR24, TR28, and TR32, respectively) exclusively applied during embryogenesis in tropical gar (Atractosteus tropicus) has been explored to decipher the potential consequences on hatching and growth from fertilization to 16 days post-fertilization (dpf), while effects on skeletal development and body morphology were explored at fertilization and 16 dpf. Egg incubation at higher temperatures induced an early hatching and mouth opening. A higher hatching rate was obtained in eggs incubated at 28 °C when compared to those at 24 °C. No differences were found in fish survival at 16 dpf, with values ranging from 84.89 to 88.86%, but increased wet body weight and standard length were found in larvae from TR24 and TR32 groups. Thermal regime during embryogenesis also altered the rate at which the skeletal development occurs. Larvae from the TR32 group showed an advanced skeletal development, with a higher development of cartilaginous structures at hatching but reduced at 16 dpf when compared with the TR24 and TR28 groups. Furthermore, this advanced skeletal development seemed to determine the fish body morphology. Based on biometric measures, a principal component analysis showed how along development, larvae from each thermal regime were clustered together, but with each population remaining clearly separated from each other. The current study shows how changes in temperature may induce craniofacial and morphological alterations in fish during early stages and contribute to understanding the possible effects of global warming in early development of fish and its ecological implications.

A higher incidence of moult–breeding overlap in great tits across time is linked to an increased frequency of second clutches: a possible effect of global warming?

The rise of temperatures due to global warming is related to a lengthening of the breeding season in many bird species. This allows more pairs to attempt two clutches within the breeding season, thus finishing their breeding activity later in the season and therefore potentially overlapping these with post–breeding moult. We tested whether this occurred in two Spanish great tit Parus major populations. The proportion of pairs laying second clutches increased from 1 % to 32 % over the study period in one of the populations (Sagunto, 1995–2019), while it did not change in the other (Quintos, 2006–2019; mean 5 %). We did not find any temporal trend for moult start date of late–breeding birds in any population. The proportion of individuals of both sexes that overlapped moult and breeding increased in Sagunto. For this latter population, sex and age, but not clutch type, contributed to the variability in the probability of overlapping in late–breeding individuals, this being higher for first–year males and lower for older females.

Fishing under climate change: Dynamics of composition and structure of catches in the Russian Black Sea in the XXI century

Currently, the Black Sea ecosystem is undergoing significant changes, and that affects the dynamics of the species composition of catches. The main reasons for the change in the Black Sea ichthyofauna are considered to be: fishing, anthropogenic water pollution, invasion of new species, and the effect of large-scale climatic and related oceanological and hydrological processes on the productivity characteristics of commercial Black Sea fish. With no understanding the patterns of the effect of these factors on ichthyofauna, it is impossible to rationally use bioresources and protect nature. The aim of the work was to study the effect of climate warming on the species composition and structure of catches in the Russian Black Sea in the XXI century. The authors had used: the results of own ichthyological observations; data published on the composition of the Black Sea catches; and the information available on the official websites of the Ministry of Agriculture of the Russian Federation, the Federal Agency for Fishery, and its Sea of Azov – Black Sea Territorial Administration. The analysis of the possible effect of global warming on the results of fishing in the Russian Black Sea was carried out. It is shown that in the XXI century, the ratio of thermophilic fish, which spawn in the summer, increased; those species are European anchovy Engraulis encrasicolus (Linnaeus, 1758), red mullet Mullus barbatus Linnaeus, 1758, and horse mackerel Trachurus mediterraneus (Steindachner, 1868). As established, the dynamics of the ichthyofauna in the area is determined by at least four processes related to water warming: improvement of reproduction conditions and increased survival of eggs and juveniles of thermophilic species; change in the intraspecific structure; invasion and naturalization of Mediterranean species with the subsequent change in the food relationships within the ecosystem; and concentration of psychrophilic species at greater depths. The need for a thorough study of this issue is concluded, aimed at long-term forecasting of the raw material base state of the fishing industry in the Russian Black Sea.

Predicting past, current and future habitat suitability and geographic distribution of the Iranian endemic species Microgecko latifi (Sauria: Gekkonidae)

The genus Microgecko Nikolsky 1907 belongs to the family Gekkonidae and contains eight species distributed in Iran, Pakistan, Afghanistan, northwestern India and, probably, in Iraq. Among them, the Latifi's dwarf gecko, Microgecko latifi, is endemic to central and southwestern Iran. We used MaxEnt modeling approach to investigate the effects of climate change and potential distribution of M. latifi. A total of 29 presence records and five factors related to precipitation and temperature were collected and used in the modeling approach for past, present and future. Our findings showed that Central Persia, the largest terrestrial ecoregion of Iran, hosts the most suitable environment for M. latifi under the current climate as well as under future scenarios. Differently, Zagros Mountains hosted the most suitable environment for this species under past climate. This is in line with previous studies that identified Zagros, Alborz, Kopet-Dagh Mountains and northwestern Iran as important Pleistocene refugia. Among environmental variables, precipitation of the warmest quarter was the most important driving factor for all models. According to other studies, species richness and diversity of lizards in Iran are higher in hot and arid environments; also considering the possible effects of global warming, further investigations are required in those environments.

Abrupt changes in mean temperature over India during 1901–2010

Since eternity, the Earth’s temperature has varied or fluctuated; it has its cooling and hot timing dependency on its orbital position as well as the isolation received from the Sun. The global climate continues to change rapidly compared to the speed of the natural variations in climate. Therefore, the spatially complete representations of surface climate are required for many purposes in applied sciences. But in recent centuries, the main matter of concern is that Earth’s normal temperature fluctuation is being influenced by some external factors such as enhanced greenhouse gases because of extreme uses of fossil fuels, severe industrialization, advance urbanization, etc. This study presents a comprehensive surface temperature dataset of Climatic Research Unit (CRU) available since 1901 for India, which is used to document significant changes in Indian temperature over ten decades, during winter season (January and February), pre-monsoon (March–May), monsoon (June–September) and post-monsoon (October–December) to examine the patterns and possible effects of global warming. A strong increasing pattern is observed with the fast growing of the development after 1950 which has shown nearly doubled in the last 50 yrs. The mean temperature during winter for the 2000s shows a consistent pattern of warming over the Himalayan region, northwestern and southern India, and a pattern of the warming observed over northeastern India and extending southwestward across central India during post-monsoon.

The influence of climate change in Superpave binder selection for Chile

One of the relevant effects of anthropogenic climate change has been an anomalous increase in temperature near the earth’s surface. In the context of pavement engineering, materials that are thermally susceptible could be affected by these changes. For this reason, the possible effects of global warming in binder selection for asphalt pavements in Chile were studied. Two global warming scenario results obtained with MICRO5 model plus local downscaling with WRF model were used. The estimated temperature changes were calculated for the period 2030–2059 for the 94 weather stations previously used for the Chilean Superpave zonings. Three pavement temperatures models were used together with these new air temperature databases: SHRP, LTPP 2.1 and LTPP 3.1. The results were compared with the original Superpave zonings obtained with the same models. A significant number of stations underwent a change in PG grade for the period considered. Most of the predicted changes were increased in the high-temperature PG grade. The areas of use for the softer binder PG52-34 gradually decreased, while the areas for the stiffer PG64-22 increased. A new even stiffer binder PG70-16 had to be introduced into the new Superpave zonings.

Decadal surface temperature trends in India based on a new high-resolution data set

A new comprehensive surface temperature data set for India is used to document changes in Indian temperature over seven decades, in order to examine the patterns and possible effects of global warming. The data set is subdivided into pre-monsoon, monsoon, and post-monsoon categories in order to study the temperature patterns in each of these periods. When the decade means in maximum, minimum and daily mean temperature for the 2000s are compared to those of the 1950s, a consistent pattern of warming is found over northwestern and southern India, and a pattern of cooling is seen in a broad zone anchored over northeastern India and extending southwestward across central India. These patterns are explained by the presence of a large region of anthropogenic brown haze over India and adjacent ocean regions. These aerosols absorb solar radiation, leading to warming of the haze layer over northeastern and central India and to cooling of the surface air beneath. The heated air rises and then sinks to the north and south of the haze region over northwestern and southern India, warming the air by compression as it sinks in those regions. The possible impact of these temperature patterns on Indian agriculture is considered.

GLOBAL CLIMATE CHANGING AND ITS AFTER-EFFECTS

The article studies the acute issues of global climate change, which today is one of the most burning problems of the world. Analysis of different sources dealing with climate changes in the second half of the 20-th and early 21st centuries conducted by the authors gave them an opportunity to identify problems of ecological nature influencing climate changes. They grounded topicality of problems of global and regional environment and climate changes due to increasing impact of anthropogenic factors, including the continuous growth in concentration of CO2 and other green house gases in the atmosphere. The authors underline topicality of researching different effects of climate change, which could be harmful and at the same time become catalysts of various changes in many industries of economy. The article analyzes different points of view on the process of climate change, its forecast and consequences. Risks of disasters in technological and social spheres caused by global warming were demonstrated. Possible effects of global warming on the territory of Russia were shown, including those in the Arctic zone. Climatic policy and the Climatic Doctrine of the Russian Federation for the period up to 2020 were discussed. Participation of Russia in the system of global management of climate changes was underlined.

Assessing Effects of Temperature Change on Four Limonium Species from Threatened Mediterranean Salt-Affected Habitats

Evaluation of tolerance to temperatures in the germination stage is an important tool to foresee the possible effect of global warming. Moreover, establishing germination protocols for endemic and threatened species is most interesting for restoration and management plans that focus on habitat conservation. Seed germination was analysed in four species of the genus Limonium (L. virgatum, L. narbonense, L. girardianum and L. santapolense) growing in two saline habitats on the eastern coast of the Iberian Peninsula. The study aim was to compare responses of seed germination to different temperature regimes. Seeds were collected in two protected areas, ‘L´ Albufera de Valencia’ (province of Valencia) and ‘Clot de Galvany’ (province of Alicante). Responses to temperature were checked within a constant range, 10-30 °C at 5 °C intervals, by considering the environmental conditions at both sampling sites. The final germination percentage and mean germination time (MGT) were calculated after 30 days. In order to compare thermal responses, base temperature (Tb) and thermal time (S) were determined for each species. The possible correlations of soil parameters with the species´ germination pattern were also analysed. To identify distinct behavioural groups, a non-linear principal component analysis was performed. Significant differences between species were found in the velocity of germination. A fast response as opportunistic germination was observed in all the species. The base temperature and thermal time showed significant differences in competitiveness between species.

A Multi-parametric Climatological Approach to Study the 2016 Amatrice–Norcia (Central Italy) Earthquake Preparatory Phase

Based on observations prior to earthquakes, recent theoretical considerations suggest that some geophysical quantities reveal abnormal changes that anticipate moderate and strong earthquakes, within a defined spatial area (the so-called Dobrovolsky area) according to a lithosphere–atmosphere–ionosphere coupling model. One of the possible pre-earthquake effects could be the appearance of some climatological anomalies in the epicentral region, weeks/months before the major earthquakes. In this paper, the period of 2 months preceding the Amatrice–Norcia (Central Italy) earthquake sequence, that started on 24 August 2016 with an M6 earthquake and a few months later produced other two major shocks (i.e. an M5.9 on 26 October and then an M6.5 on 30 October), was analyzed in terms of skin temperature, total column water vapour and total column of ozone, compared with the past 37-year trend. The novelty of the method stands in the way the complete time series is reduced, where also the possible effect of global warming is properly removed. The simultaneous analysis showed the presence of persistent contemporary anomalies in all of the analysed parameters. To validate the technique, a confutation/confirmation analysis was undertaken where these parameters were successfully analyzed in the same months but considering a seismically “calm” year, when significant seismicity was not present. We also extended the analysis to all available years to construct a confusion matrix comparing the occurrence of climatological data anomalies with real seismicity. This work confirms the potentiality of multi parameters in anticipating the occurrence of large earthquakes in Central Italy, thus reinforcing the idea of considering such behaviour an effective tool for an integrated system of future earthquake prediction.

Short-term predicted extinction of Andean populations of the lizard Stenocercus guentheri (Iguanidae: Tropidurinae)

We studied the thermal physiology of the Andean lizard Stenocercus guentheri in order to evaluate the possible effects of global warming on this species. We determined the preferred body temperature (Tpref), critical thermals (CTmin, CTmax), and hours of restriction and activity. Tpref was 32.14±1.83°C; CTmin was 8.31°C in adults and 9.14°C in juveniles, whereas CTmax was 43.28°C in adults and 41.68°C in juveniles. To assess extinction risk, we used the model created by Sinervo et al. (2010) and predicted that 16.7% of populations will have a high risk of extinction by 2020, with an increase to 26.7% by 2050. These results suggest that this species, despite being able to maintain its Tpref through behavioral thermoregulation and habitat selection, could be physiologically sensitive to climate warming; thus, the potential for local adaptation may be limited under a warmer climate. Further studies focusing on the ability of S. guentheri to evolve higher Tpref and thermal tolerances are needed to understand the ability of this species to respond to climate change.

Spatial Redistribution of U.S. Tornado Activity between 1954 and 2013

AbstractClimate change over the past several decades prompted this preliminary investigation into the possible effects of global warming on the climatological behavior of U.S. tornadoes for the domain bounded by 30°–50°N and 80°–105°W. On the basis of a warming trend over the past 30 years, the modern tornado record can be divided into a cold “Period I” from 1954 to 1983 and a subsequent 30-year warm “Period II” from 1984 to 2013. Tornado counts and days for (E)F1–(E)F5, significant, and the most violent tornadoes across a 2.5° × 2.5° gridded domain indicate a general decrease in tornado activity from Period I to Period II concentrated in Texas/Oklahoma and increases concentrated in Tennessee/Alabama. These changes show a new geographical distribution of tornado activity for Period II when compared with Period I. Statistical analysis that is based on field significance testing and the bootstrapping method provides proof for the observed decrease in annual tornado activity in the traditional “Tornado Alley” and the emergence of a new maximum center of tornado activity. Seasonal analyses of both counts and days for tornadoes and significant tornadoes show similar results in the spring, summer, and winter seasons, with a substantial decrease in the central plains during summer. The autumn season displays substantial increases in both tornado counts and significant-tornado counts in the region stretching from Mississippi into Indiana. Similar results are found from the seasonal analysis of both tornado days and significant-tornado days. This temporal change of spatial patterns in tornado activity for successive cold and warm periods may be suggestive of climate change effects yet warrants the climatological study of meteorological parameters responsible for tornado formation.

Variation of growth rate and survival in embryos and larvae of Rana temporaria populations from the Pyrenees

Variations on embryonic and larval life history traits of ectotherm organisms are strongly affected by temperature conditions. However, these effects can vary between species and populations depending on the mechanisms that act in a determinate local habitat. In the present study, we analysed the effects of temperature on several embryonic and larval traits (survival, development and growth rate until the metamorphosis) of Rana temporaria in two populations living at different altitude (1540 and 2100 m) in the Pyrenees. Five spawns from each population were distributed in a common garden experiment at different temperature treatments according to the normal temperature range that tadpoles might experience in the field and also considering a high treatment (24 °C) to test a possible effect of global warming. Like in other studies of the same species in a latitudinal gradient, the temperature effects depended on the analysed trait. Our results support the general rule that the rate of development is faster at higher temperatures, although survival was significantly affected by the highest temperature in the highland population. Size varied at embryonic and larval stages and was largest at metamorphosis in the highland population. In concordance, the growth rate was higher in the highland population suggesting a countergradient variation in response to the short growing season. However, this possible adaptation can be altered in a global warming scenario with an increase of mortality and limited growth.