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1.
The shape of the non-linear relationship between temperature and mortality varies among cities with different climatic conditions. There has been little examination of how these curves change over space and time. We evaluated the short-term effects of hot and cold temperatures on daily mortality over six 7-year periods in 211 US cities, comprising over 42 million deaths. Cluster analysis was used to group the cities according to similar temperatures and relative humidity. Temperature–mortality functions were calculated using B-splines to model the heat effect (lag 0) and the cold effect on mortality (moving average lags 1–5). The functions were then combined through meta-smoothing and subsequently analyzed by meta-regression. We identified eight clusters. At lag 0, Cluster 5 (West Coast) had a RR of 1.14 (95% CI: 1.11,1.17) for temperatures of 27 °C vs 15.6 °C, and Cluster 6 (Gulf Coast) has a RR of 1.04 (95% CI: 1.03,1.05), suggesting that people are acclimated to their respective climates. Controlling for cluster effect in the multivariate-meta regression we found that across the US, the excess mortality from a 24-h temperature of 27 °C decreased over time from 10.6% to 0.9%. We found that the overall risk due to the heat effect is significantly affected by summer temperature mean and air condition usage, which could be a potential predictor in building climate-change scenarios.  相似文献   

2.
The Senegal sole, Solea senegalensis, is a species of flatfish that has several distinct cohorts of 0-group juveniles which use estuarine nurseries in summer and winter. The early cohort is more abundant and grows faster than the late cohort that stays in the nurseries during winter; however, climate warming may have an impact on the dynamics of this species’ juveniles. This study aimed to compare mortality, metabolic response and growth of S. senegalensis juveniles at different temperatures, reflecting present-day temperature (winter—12 °C; summer—24 °C) and future temperature (plus 3 °C) conditions, in estuarine nurseries in the southern European population. Mortality was low at 12 °C, being only 10 %, increasing to 30 % at 15 °C, 40 % at 24 °C and at 27 °C it hit 70 %. Metabolic rate increased steadily with increasing temperatures, yet it increased steeply from 24 to 27 °C. Thermal sensitivity was high for the temperature interval between 24 and 27 °C. Growth was very slow at 12 °C, at a rate of 0.03 mm day?1, increasing to 0.22 mm day?1 at 15 °C, and to 0.60 mm day?1, at 24 °C. However, at 27 °C growth rapidly declined to 0.12 mm day?1. Warming will be beneficial for the late cohort, resulting in a major increase in growth. However, the early cohort will not benefit from warming, due to high mortality and arrested growth, which clearly indicates that this species is under severe thermal stress at 27 °C. Thus, here we show, for the first time, that climate change may induce contrasting seasonal impacts on fish bio-ecology and physiology, namely in species with several cohorts over the course of the year. Phenotypic and/or genotypic plasticity may limit the impacts of climate change.  相似文献   

3.
We present climate change projections and apply indices of weather extremes for the Mediterranean island Cyprus using data from regional climate model (RCM) simulations driven by the IPCC A1B scenario within the ENSEMBLES project. Daily time-series of temperature and precipitation were used from six RCMs for a reference period 1976–2000 and for 2026–2050 (‘future‘) for representative locations, applying a performance selection among neighboring model grid-boxes. The annual average temperatures of the model ensemble have a ±1.5°C bias from the observations (negative for maximum and positive for minimum temperature), and the models underestimate annual precipitation totals by 4–17%. The climatological annual cycles for the observations fall within the 1σ range of the 6-model average, highlighting the strength of using multi-model output. We obtain reasonable agreement between models and observations for the temperature-related indices of extremes for the recent past, while the comparison is less good for the precipitation-related extremes. For the future, the RCM ensemble shows significant warming of 1°C in winter to 2°C in the summer for both maximum and minimum temperatures. Rainfall is projected to decrease by 2–8%, although this is not statistically significant. Our results indicate the shift of the mean climate to a warmer state, with a relatively strong increase in the warm extremes. The precipitation frequency is projected to decrease at the inland Nicosia and at the coastal Limassol, while the mountainous Saittas could experience more frequent 5–15 mm/day rainfall. In future, very hot days are expected to increase by more than 2 weeks/year and tropical nights by 1 month/year. The annual number of consecutive dry days shows a statistically significant increase (of 9 days) in Limassol. These projected changes of the Cyprus climate may adversely affect ecosystems and the economy of the island and emphasize the need for adaptation strategies.  相似文献   

4.
Russian Journal of Ecology - It has been shown that the main drivers of the dynamics of cladoceran and copepod abundances can be predators (fish), the quantity and/or quality of food in terms of...  相似文献   

5.
To better understand how Batrachupems tibetanus responds to different temperature regimes in the blood parameters and to estimate the change in plasma cortisol level in this species exposed to different temperatures, the animals were stochastically divided into three groups and exposed respectively to 4.6°C, 14.6°C and 19.6°C for 12 days. The concentrations of glucose, total protein, albumin, triacylglycerol, Ca2+, K+, Na+, Cl, and plasma cortisol level were measured respectively. There was no significant difference between the plasma cortisol level of the control group and the experiment groups. Glucose level at 4.6°C and 19.6°C was significantly lower than glucose level at 14.6°C. The plasma triacylglycerol level was significantly influenced by acclimation temperature. The concentration of total protein, albumin, globulin and the ratio between albumin and globulin were not significantly influenced by temperature when compared with control group. There was no significant change in concentration of Ca2+ at different temperatures. The concentration of K+ was significantly influenced by temperature. Plasma K+ level significantly increased at 19.6°C. The plasma Na+ level and Cl were significantly influenced by temperature. Na+: Cl ratio was significantly influenced by temperature. Therefore, glucose, triacylglycerol, Na+ and Cl levels could be considered as indicators of thermal stress in B. tibetanus; plasma cortisol, albumin, globulin levels, and albumin/globulin ratio are not influenced by temperature.  相似文献   

6.
Regional Siberian studies have already registered climate warming over the last several decades. We evaluated ongoing climate change in central Siberia between 1991 and 2010 and a baseline period, 1961–1990, and between 1991 and 2010 and Hadley 2020 climate change projections, represented by the moderate B1 and severe A2 scenarios. Our analysis showed that winters are already 2–3°C warmer in the north and 1–2°C warmer in the south by 2010. Summer temperatures increased by 1°C in the north and by 1–2°C in the south. Change in precipitation is more complicated, increasing on average 10% in middle latitudes and decreasing 10–20% in the south, promoting local drying in already dry landscapes. Hot spots of possible forest shifts are modeled using our Siberian bioclimatic vegetation model and mountain vegetation model with respect to climate anomalies observed pre-2010 and predicted 2020 Hadley scenarios. Forests are predicted to shift northwards along the central Siberian Plateau and upslope in both the northern and southern mountains. South of the central Siberian Plateau, steppe advancement is predicted that was previously non-existent north of 56°N latitude. South of 56°N, steppe expansion is predicted in the dry environments of Khakasiya and Tyva. In the southern mountains, it is predicted that the lower tree line will migrate upslope due to increased dryness in the intermontane Tyvan basins. The hot spots of vegetation change that are predicted by our models are confirmed by regional literature data.  相似文献   

7.
Although amaranth is consumed in large quantities as a food dye, its mutagenicity and/or carcinogenicity is still controversial. Therefore, the investigation of the genetic activity induced by this dye might assist in the evaluation of its possible dangers to human health. Both bacteria and yeast strains were used for testing the mutagenic activity of amaranth. When the fluctuation test was used, amaranth was found to enhance both forward and reverse mutations in bacterial strains that contain R-plasmids. Amaranth was not found to induce any genetic activity in yeast cells at 28 °C but a significant increase in mitotic gene conversions was recorded at 37 °C in both acidic and neutral media. It has been postulated that amaranth has optimal action on microbial cells at 37 °C and should be considered a weak mutagen.  相似文献   

8.
One of the targets of the United Nations ‘Millennium Development Goals’ adopted in 2000 is to cut in half the number of people who are suffering from hunger between 1990 and 2015. However, crop yield growth has slowed down in much of the world because of declining investments in agricultural research, irrigation, and rural infrastructure and increasing water scarcity. New challenges to food security are posed by accelerated climatic change. Considerable uncertainties remain as to when, where and how climate change will affect agricultural production. Even less is known about how climate change might influence other aspects that determine food security, such as accessibility of food for various societal groups and the stability of food supply. This paper presents the likely impacts of thermal and hydrological stresses as a consequence of projected climate change in the future potential agriculture productivity in South Asia based on the crop simulation studies with a view to identify critical climate thresholds for sustained food productivity in the region. The study suggests that, on an aggregate level, there might not be a significant impact of global warming on food production of South Asia in the short term (<2°C; until 2020s), provided water for irrigation is available and agricultural pests could be kept under control. The increasing frequency of droughts and floods would, however, continue to seriously disrupt food supplies on year to year basis. In long term (2050s and beyond), productivity of Kharif crops would decline due to increased climate variability and pest incidence and virulence. Production of Rabi crops is likely to be more seriously threatened in response to 2°C warming. The net cereal production in South Asia is projected to decline at least between 4 and 10% under the most conservative climate change projections (a regional warming of 3°C) by the end of this century. In terms of the reference to UNFCCC Article 2 on dangerous anthropogenic (human-induced) interference with the climate system, the critical threshold for sustained food productivity in South Asia appears to be a rise in surface air temperature of ~2°C and a marginal decline in water availability for irrigation or decrease in rainfall during the cropping season.  相似文献   

9.
The effect of reduced air infiltration rate caused by energy-saving measures has been studied by comparing the indoor climate in 25 sealed apartments with the conditions in 25 unsealed apartments in four seasonal periods. The indoor temperature in bedrooms during February and March was 19.3 °C in sealed apartments and 17.8 °C in unsealed apartments, and the occupants in the sealed apartments correspondingly complained less frequently of draught problems during the winter. When the frequency of window opening was at its minimum (February–March), there was a higher indoor humidity in sealed compared with unsealed apartments, and this probably accounts for an increased occurrence of house-dust mites in dust from the sealed apartments during the winter. Also in February–March there was a slight increase in the concentration of suspended particulate matter in sealed apartments. Considering health effects of a reduced air infiltration rate, it can be predicted that the increased indoor air humidity will indirectly increase the frequency and severity of house-dust mite allergy in the population.  相似文献   

10.
The distribution of three chromosome races (Moscow, Western Dvina, and Seliger) of the common shrew Sorex araneus L. in the zone of contact between their ranges in the Valdai Heights (32°00′ E, 57°00′ N) is discussed. The area co-inhabited by all the three races is extremely small. Representatives of all the three races have been captured on only one trap line, although there are no obstacles to the expansion of shrews. The extremely small area co-inhabited by the three races, as well as the strictly parapatric distribution of the Moscow and Western Dvina races, may be related with competition forms such as avoidance of contacts and separation of ecological niches.  相似文献   

11.
In the present study, a natural circulation thermosyphon flat plate solar water heater has been tested at the CDFD, Hyderabad (17.37°N, 78.43°E) Andhra Pradesh, India. Experimental data were noted on a sunny day. Dynamic response of the system to variations in solar insulation was studied and analyzed. T inlet °C and T outlet °C temperatures were recorded. The performance of the system can be improved by using aluminum tape inserts into the collector fins. The objective of the present study is to evaluate the performance of flat plate collector with and without inserts (aluminum strip of 1 mm thick, 3 mm width and 203 mm length). It is expected that with the same collector with the same flow rate, higher efficiency can be obtained by inserting the tapes inside the collector copper fins (9 mm). Thus, the cost of the system can be further bringing down by enhancing the collector efficiency.  相似文献   

12.
Competition between several cladoceran species has been studied with the use of simulation. The results have demonstrated that, in most cases, one or two species survive. Under conditions of the minimum food supply, the most competitive species have the selective advantage. With an increase in food supply, the survival of low-competitive species was observed more often. The mean body size of surviving species increases with an increase in food reproduction.  相似文献   

13.
There is an urgent need to mitigate climate change-induced heat stress in livestock and poultry in the Caribbean, given the deleterious effects it has on food and nutrition security. The temperature humidity index (THI) was used to assess the potential for heat stress on four types of livestock and poultry (broiler and layer chickens, pigs and ruminants) for three different agro-ecological locations in Jamaica. The THI was formulated specifically to each livestock type and was examined for 2001–2012 for seasonal and annual patterns of variability. Differences in THI were observed between summer (July to September) and winter (December to February) with some moderation due to agro-ecological location. Our results suggest that animals in ambient field conditions in Jamaica may already be experiencing considerable periods of heat stress even during the relatively cooler northern hemisphere winter months. Future patterns of heat stress relative to a 1961–1990 baseline were derived from a regional climate model when mean global surface air temperature is 1.5, 2.0 and 2.5 °C above pre-industrial levels. At 1.5 °C, marked increases were noted in THI and almost persistent year-round heat stress is projected for Caribbean livestock. Conditions will be exacerbated at the higher global warming states. Possible response strategies such as cooling technologies are discussed.  相似文献   

14.
This paper examines historical and future changes in normalised damages resulting from climate-related natural disasters for the Caribbean. Annualised damages of USD824 million are shown to be non-stationary over the historical period 1964 to 2013. Perturbations of (i) sea surface temperatures (SST) in the tropical North Atlantic (TNA) and (ii) the Atlantic multi-decadal oscillation (AMO) appear to be associated with historical damages. Both the TNA and AMO are known modulators of hurricane activity and rainfall amounts in the Caribbean. Indicative future damages are determined using (i) cumulative distribution functions (CDFs) of perturbed climate states and (ii) an artificial neural network (ANN) model of damages using projected TNA values and the state of the AMO derived from an ensemble of five coupled model intercomparison project phase 5 (CMIP5) global climate models (GCMs) run under the RCP 4.5 scenario. Estimates of future damages are determined when global mean surface temperatures (GMST) reach and exceed 1.5 °C above preindustrial levels. Annual normalised damages may potentially increase to at least USD1395 million or close to double for 1.5 °C. At 2 °C, higher damages may occur; however, large uncertainty across all GCMs prohibits the identification of significant difference between 1.5 and 2 °C. Significant differences in damages do, however, exist for at least two of the GCMs for the two climate states. The robustness of the results is discussed in light of a number of issues, including limitations associated with the data.  相似文献   

15.
This contribution presents an assessment of the potential vulnerabilities to climate variability and change (CV & C) of the critical transportation infrastructure of Caribbean Small Island Developing States (SIDS). It focuses on potential operational disruptions and coastal inundation forced by CV & C on four coastal international airports and four seaports in Jamaica and Saint Lucia which are critical facilitators of international connectivity and socioeconomic development. Impact assessments have been carried out under climatic conditions forced by a 1.5 °C specific warming level (SWL) above pre-industrial levels, as well as for different emission scenarios and time periods in the twenty-first century. Disruptions and increasing costs due to, e.g., more frequent exceedance of high temperature thresholds that could impede transport operations are predicted, even under the 1.5 °C SWL, advocated by the Alliance of Small Island States (AOSIS) and reflected as an aspirational goal in the Paris Climate Agreement. Dynamic modeling of the coastal inundation under different return periods of projected extreme sea levels (ESLs) indicates that the examined airports and seaports will face increasing coastal inundation during the century. Inundation is projected for the airport runways of some of the examined international airports and most of the seaports, even from the 100-year extreme sea level under 1.5 °C SWL. In the absence of effective technical adaptation measures, both operational disruptions and coastal inundation are projected to increasingly affect all examined assets over the course of the century.  相似文献   

16.
Projected climate change over Turkey has been analyzed by using the reference (1961–1990) and future (2071–2100) climate simulations produced by ICTP-RegCM3. Since examining Turkey as a single region could be misleading due to the existence of complex topography and different climatic regions, Turkey has been separated into seven climatic regions to evaluate the surface temperature and precipitation changes. Comparison of the reference simulation with observations was made spatially by using a monthly gridded data set and area-averaged surface data compiled from 114 meteorological stations for each climatic region of Turkey. In the future simulation, warming over Turkey’s climatic regions is in the range of 2–5 °C. Summer warming over western regions of Turkey is 3 °C higher than the winter warming. During winter, in the future simulation, precipitation decreases very significantly over southeastern Turkey (24 %), which covers most of the upstream of Euphrates and Tigris river basin. This projected decrease could be a major source of concern for Turkey and the neighboring countries. Our results indicate that a significant increase (48 %) in the autumn season precipitation is simulated over southeastern Turkey, which may help to offset the winter deficit and therefore reduce the net change during the annual cycle.  相似文献   

17.
High population density, inadequate infrastructure and low adaptive capacity have made the urban population of Bangladesh highly vulnerable to climate change. Trends in climate and climate-related extreme events in five major cities have been analyzed in this paper to decipher the variability and ongoing changes in urban Bangladesh. An analysis of 55 years (1958–2012) of daily rainfall and temperature data using nonparametric statistical methods shows a significant increase in annual and seasonal mean daily maximum and minimum temperatures in all five cities. A significant increase in climate-related extreme events, such as heavy rainfall events (>20 mm), hot days (>32 °C) and hot nights (>25 °C), is also observed. Climate model results suggest that these trends will continue through the twenty-first century. Vulnerability of urban livelihoods and physical structures to climate change is estimated by considering certainty and timing of impacts. It has been predicted that public health and urban infrastructures, viz. water and power supply, would be the imminent affected sectors in the urban areas of Bangladesh. Adaptation measures that can be adopted to mitigate the negative impacts of climate change are also discussed.  相似文献   

18.
Climate change projections have drawn attention to the risks of extreme heat and the importance of public health interventions to minimise the impact. The city of Perth, Western Australia, frequently experiences hot summer conditions, with recent summers showing above average temperatures. Daily maximum and minimum temperatures, mortality, emergency department (ED) presentations and hospital admissions data were acquired for Perth for the period 1994 to 2008. Using an observed/expected analysis, the temperature thresholds for mortality were estimated at 34–36 °C (maximum) and 20 °C (minimum). Generalised estimating equations (GEEs) were used to estimate the percentage increase in mortality and morbidity outcomes with a 10 °C increment in temperature, with adjustment for air pollutants. Effect estimates are reported as incidence rate ratios (IRRs). The health impact of heatwave days (three or more days of ≥ 35 °C) was also investigated. A 9.8% increase in daily mortality (IRR 1.098; 95%CI: 1.007–1.196) was associated with a 10 °C increase in maximum temperature above threshold. Total ED presentations increased by 4.4% (IRR 1.044; 95%CI: 1.033–1.054) and renal-related ED presentations by 10.2% (IRR 1.102; 95%CI: 1.071–1.135) per 10 °C increase in maximum temperature. Heatwave days were associated with increases in daily mortality and ED presentations, while total hospital admissions were decreased on heatwave days. Public health interventions will be increasingly important to minimise the adverse health impacts of hot weather in Perth, particularly if the recent trend of rising average temperatures and more hot days continues as projected.  相似文献   

19.
Despite recent calls to limit future increases in the global average temperature to well below 2 °C, little is known about how different climatic thresholds will impact human society. Future warming trends have significant global food security implications, particularly for small island developing states (SIDS) that are recognized as being among the most vulnerable to global climate change. In the case of the Caribbean, any significant change in the region’s climate is likely to have significant adverse effects on the agriculture sector. This paper explores the potential biophysical impacts of a +?1.5 °C warming scenario on several economically important crops grown in the Caribbean island of Jamaica. Also, it explores differences to a >?2.0 °C warming scenario, which is more likely, if the current policy agreements cannot be complied with by the international community. We use the ECOCROP niche model to estimate how predicted changes in future climate could affect the growing conditions of several commonly cultivated crops from both future scenarios. We then discuss some key policy considerations for Jamaica’s agriculture sector, specifically related to the challenges posed to future adaptation pathways amidst growing climate uncertainty and complexity. Our model results show that even an increase less than +?1.5 °C is expected to have an overall negative impact on crop suitability and a general reduction in the range of crops available to Jamaican farmers. This observation is instructive as increases above the +?1.5 °C threshold would likely lead to even more irreversible and potentially catastrophic changes to the sustainability of Jamaica’s agriculture sector. The paper concludes by outlining some key considerations for future action, paying keen attention to the policy relevance of a +?1.5 °C temperature limit. Given little room for optimism with respect to the imminent changes that SIDS will need to confront in the near future, broad-based policy engagement by stakeholders in these geographies is paramount, irrespective of the climate warming scenario.  相似文献   

20.
Monitoring and detecting trends of climatic variables like rainfall and temperature are essential for agricultural developments in the context of climate change. The present study has detected trends in annual and cropping seasonal rainfall and temperature data for the period of 1961–2011 using Mann–Kendall (MK) test, Spearman’s rho (SR) test and modified Mann–Kendall test that has been applied to the significant lag-1 serial correlated time series data, and slope has been estimated using Sen’s Slope estimator for twelve meteorological stations located in the western part of Bangladesh covering about 41 % of the country. Almost 71 % trends explored by MK test in annual rainfall are statistically insignificant, and SR test also complies it. The spatial distribution of rainfall trend shows insignificant positive trends in major part of the area. Significant positive trends both by MK test and by SR test at 95 % confidence levels are observed at rates of 8.56, 11.15 and 13.66 mm/year at Dinajpur, Rangpur and Khepupara stations, respectively, and the Kharif season rainfall of these stations also shows significant increasing trends except Dinajpur. On the other hand, significant decreasing trends in annual rainfall are found at Bhola (?11.67 mm/year) and Rajshahi (?5.951 mm/year) stations and decreasing trends in rainfall dominated the Pre-Kharif season over the area. But, 83.33 % of the stations show rising trends in annual mean temperature with significant positive trends (as observed by both MK test and SR test) at Rangpur, Bogra, Faridpur, Jessore and Bhola stations where the rate of changes vary from 0.013 °C/year at Faridpur to 0.08 °C/year at Bhola. Most of the trends in Rabi and Pre-Kharif seasons of mean temperatures are not statistically significant. However, all stations except Barisal show significant rising trends in temperature in Kharif season. To cope with this changing pattern of rainfall and temperature, effective adaptation strategies should be taken to keep up the agricultural production that is related to livelihood of the most people and to ensure the country’s food security.  相似文献   

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