Tehran, in the south of Alborz Mountains, is faced with three types of weather risk, weather risk caused by geography, climatic risks caused by air resistance and weather risk due to global warming. The aim of this study is to examine the three types of risk in Tehran. The method of this study was to evaluate the CHANGEs of synoptic factors that affect global warming and urban development. In order to detect the height CHANGEs of 500 hPa two 5-year periods including 1948 to 1952 and 2010 to 2014, were studied.The results showed that CHANGEs in heights of 500 geopotential, there was an increased risk in the city of Tehran. The effect of CLIMATE CHANGE in recent decades, increased the stability of air in Tehran. Human factors in the formation of heat islands, increase LCL height and density of the air balance is transferred to a higher altitude. Changing urban wind field, atmospheric turbulence intensified, exacerbated thermodynamic gradient, fat and refugee cyclones, heat island effect of the city.Thermal stability in the warm period will appear. The thermal stability of all levels of lower, middle and upper troposphere was intensified. Thermal stability couraged the development of subtropical high pressure in the area. With the arrival of the atmospheric pressure during calm and humid days the stability and pollution were increased. Negative vorticity from early June developed the intensive high pressure over the region. Compare the conditions of the two study periods showed that: the height of the high pressure was 100 meters higher than the second period. The number of days of intensified subtropical high increased during the second period. The high pressure has moved to the northern areas during the second period. This CHANGE in the subtropical high pressure increased the dry periods motivating the loss of vegetation. Heat island effect was increased as well. More than 90% of the temperature inversions occurred at an altitude of less than 500 meters in both warm and cold periods of year. Wind direction at both stations has shown that the establishment of any pollutant source in the West of Tehran will increase the pollution.

Links between CLIMATE policy and health policy must not be overlooked. In November 2010, representatives from countries around the world will meet in Cancún, Mexico, at the 2010 United Nations CLIMATE CHANGE Conference.1 Here they will attempt to draft a treaty aimed at stabilizing atmospheric greenhouse gas concentrations at a level that will prevent catastrophic CLIMATE CHANGE. What a pity the meeting had not been scheduled in Pakistan. Then the anger of those whose livelihoods have been destroyed by the biblical floods that have washed away the hopes of a nation would surely have focused the delegates’ minds. ...

Background and Objective: Process of CLIMATE CHANGE, particularly CHANGEs in temperature and precipitation; have raised the most discussion in the realm of environmental science. Human systems that are dependent on climatic elements such as agriculture and industry were designed based on stable CLIMATE. Method: In this study the output of general circulation models (GFCM21, HADCM3, INCM3, IPCM4 and NCCCSM) was used to simulate the CLIMATE parameters (minimum temperature, maximum temperature, precipitation and sunshine hours) in Hamadan station during 2046-2065. Three scenarios A1B, A2 and B1 were considered. Monthly CHANGEs of CLIMATE parameters were calculated by LARS-WG model. Findings: The results showed that the most increasing in minimum temperature were seen under A1B scenario of GFCM21 model (2. 5˚ C). The least increasing was related to INCM3 under B1 scenario (1˚ C). The highest and lowest increasing in maximum temperature were seen in GFCM21 model under A1B and B1 scenarios by 2. 4 and 1. 4˚ C, respectively. B1 scenario of IPCM4 model showed the highest increase in precipitation by 15. 8 percent and A1B scenario of GFCM21 model reported the highest decrease by 13 percent. Solar radiation project by HADCM3 model, A1B scenario showed the most increase about 24 percent and based on NCCCSMmodel, A2 scenario lowest increase (by 13 percent) was seen. Discussion and Conclusion: The results of this study indicated minimum and maximum temperatures will increase in period of 2046-2065. Both increases and decreases in precipitation were seen. Also variations sun hour is very little.

Over the last three decades, CLIMATE CHANGE has emerged as one of the most crucial issues for humankind, with serious implications for sustainable development. In recent decades, CHANGEs in CLIMATE have caused the impacts on natural and human systems on all continents and across the oceans. Human activities are estimated to have caused approximately 1. 0° C of global warming above pre-industrial levels, with a likely range of 0. 8° C to 1. 2° C. Global warming is likely to reach 1. 5° C between 2030 and 2052 if it continues to increase at the current rate. CLIMATE CHANGE increases variability in the water cycle, inducing extreme weather events such as droughts and more erratic storms, reducing the predictability of water availability, affecting water quality and threatening sustainable development and biodiversity worldwide. Agriculture is the sector most vulnerable to CLIMATE CHANGE due to its high dependence on CLIMATE and weather. It is important to determine the impacts of CLIMATE CHANGE on water resources in order to develop possible adaptation strategies to improve water productivity. This paper discusses the observed CLIMATE CHANGE over the past few decades; the CLIMATE CHANGE-induced impacts, such as rising sea levels, changing rainfall patterns, increased droughts, and more erratic storms; the future CLIMATE CHANGE; the CLIMATE CHANGE impacts on water productivity; and the strategies to improve the water productivity such as improved policies, emphasis on sustainability, improving water resource management and use of appropriate models.

Global CLIMATE has CHANGEd since pre-industrial time. Atmospheric CO2 a major greenhouse gas has increased by nearly 30% and temperature has risen by 0.3-0.6oC. It is predicted that with current emission scenario, global mean temperature would rise between 0.9 and 3.5oC by the year 2100. The impact of CLIMATE CHANGE would be felt in three areas: in losses from plant diseases, efficacy of disease management strategies and in the geographical distribution of plant diseases.CLIMATE CHANGE would have positive, negative or no impact on individual plant diseases. Doubling CO2 has been shown to increase crop yield by 30% but whether these benefits would still be realized in the presence of pests and disease is unknown. CLIMATE CHANGE has great effect on overwintering and over summering of the pathogen, pest and vectors. This will affect on survival, movement and reproduction. In many cases temperature increases are predicted to lead to the geographic expansion of pathogen and vector distribution bringing pathogen into contact with more potential hosts and providing new opportunities for pathogen hybridization. The effect of CLIMATE CHANGE on plant diseases has not been studied much and most of the information is from recent years. In this review attempts were made to collect recent information on pathogen-host -interaction due to CLIMATE CHANGE. New strategies will be required for disease management under CLIMATE CHANGE. If consumption of fossil fuel continues and results in CO2 accumulation and also land use by deforestation, we expect more detrimental effects on CLIMATE CHANGE in the future.

In this research, prediction of precipitation and temperature values using general circulation models of the atmosphere in the period 2021-2050 were carried out. CLIMATE data such as rainfall and average temperature were obtained from the Meteorological Organization. For future CLIMATE scenarios, the output from general circulation model HadCM3 under the A2 emissions scenario was used. Due to the low resolution of general circulation models, downscaling model of SDSM4. 2 was used and CLIMATE CHANGEs in precipitation and mean temperature were simulated for future periods. In this study, for SDSM model calibration, among the 26 large-scale climatic parameters (NCEP), an average of 3 parameters most correlated with mean temperature and 6 parameters are most correlated with average rainfall in Seymare drainage basin. The results showed that the predicted climatic parameters for the simulation of CLIMATE parameters with high accuracy for the average temperature, but with less accuracy for rainfall. This is due to lack of normal and unconditional situation of rainfall data. The results indicate that the average temperature of the area in the period 2050-2021 compared to the observation period (2008-1979) showed an increasing of 1. 7 ° C and average rainfall showed a decrease of 47%.