scholarly journals Possible causes of contemporary Nisava River discharge variability

2009 ◽  
Vol 89 (4) ◽  
pp. 255-276 ◽  
Author(s):  
Vladan Ducic ◽  
Jelena Lukovic
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Air Temperature ◽  
River Discharge ◽  
Anthropogenic Impact ◽  
Climatic Factors ◽  
Regional Models ◽  
The South ◽  
The Future ◽  
Morava River

Nisava River is the largest tributary of the South Morava River of length 248 km, of which 151 km is in Serbia. Annually to all three hydrological profiles (Pirot, Bela Palanka and Nis) in the reporting period (1961-2000) has been observed decrease in discharge. That would be in accordance with the IPCC's claims about the domination of the influence of anthropogenic greenhouse gases on the reduction of rainfall and discharge in Serbia. However, the area of the Nisava basin in the second half of the XX century has shown decrease in air temperature. The station Dimitrovgrad, in the upper part of the basin, from 1949 to 2007 showed trend of annual temperature of -0.0049?C per year, which does not fit to the concept of dominance of anthropogenic greenhouse gases. And the trend of rainfall in this period, changes sign from negative to positive (0.1175mm per year), so that it does not fit the concept of domination of the global anthropogenic impact on regional models of IPCC. Regarding to this and projections of possible climate change in the future all potential climatic factors should be taking into account.

scholarly journals Assessing the Sensitivity of Main Crop Yields to Climate Change Impacts in China

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 172
Author(s):  
Yuan Xu ◽  
Jieming Chou ◽  
Fan Yang ◽  
Mingyang Sun ◽  
Weixing Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Crop Yield ◽  
Food Production ◽  
Crop Yields ◽  
Climatic Factors ◽  
Climatic Data ◽  
The South ◽  
The North ◽  
Output Elasticity ◽  
The Impact

Quantitatively assessing the spatial divergence of the sensitivity of crop yield to climate change is of great significance for reducing the climate change risk to food production. We use socio-economic and climatic data from 1981 to 2015 to examine how climate variability led to variation in yield, as simulated by an economy–climate model (C-D-C). The sensitivity of crop yield to the impact of climate change refers to the change in yield caused by changing climatic factors under the condition of constant non-climatic factors. An ‘output elasticity of comprehensive climate factor (CCF)’ approach determines the sensitivity, using the yields per hectare for grain, rice, wheat and maize in China’s main grain-producing areas as a case study. The results show that the CCF has a negative trend at a rate of −0.84/(10a) in the North region, while a positive trend of 0.79/(10a) is observed for the South region. Climate change promotes the ensemble increase in yields, and the contribution of agricultural labor force and total mechanical power to yields are greater, indicating that the yield in major grain-producing areas mainly depends on labor resources and the level of mechanization. However, the sensitivities to climate change of different crop yields to climate change present obvious regional differences: the sensitivity to climate change of the yield per hectare for maize in the North region was stronger than that in the South region. Therefore, the increase in the yield per hectare for maize in the North region due to the positive impacts of climate change was greater than that in the South region. In contrast, the sensitivity to climate change of the yield per hectare for rice in the South region was stronger than that in the North region. Furthermore, the sensitivity to climate change of maize per hectare yield was stronger than that of rice and wheat in the North region, and that of rice was the highest of the three crop yields in the South region. Finally, the economy–climate sensitivity zones of different crops were determined by the output elasticity of the CCF to help adapt to climate change and prevent food production risks.

scholarly journals Rates of consumption of atmospheric CO<sub>2</sub> through the weathering of loess during the next 100 yr of climate change

2013 ◽  
Vol 10 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Y. Goddéris ◽  
S. L. Brantley ◽  
L. M. François ◽  
J. Schott ◽  
D. Pollard ◽  
...  
Keyword(s):  
Climate Change ◽  
Reaction Front ◽  
Numerical Models ◽  
Atmospheric Co2 ◽  
Co2 Production ◽  
Depth Interval ◽  
Mississippi Valley ◽  
The South ◽  
The North ◽  
The Future

Abstract. Quantifying how C fluxes will change in the future is a complex task for models because of the coupling between climate, hydrology, and biogeochemical reactions. Here we investigate how pedogenesis of the Peoria loess, which has been weathering for the last 13 kyr, will respond over the next 100 yr of climate change. Using a cascade of numerical models for climate (ARPEGE), vegetation (CARAIB) and weathering (WITCH), we explore the effect of an increase in CO2 of 315 ppmv (1950) to 700 ppmv (2100 projection). The increasing CO2 results in an increase in temperature along the entire transect. In contrast, drainage increases slightly for a focus pedon in the south but decreases strongly in the north. These two variables largely determine the behavior of weathering. In addition, although CO2 production rate increases in the soils in response to global warming, the rate of diffusion back to the atmosphere also increases, maintaining a roughly constant or even decreasing CO2 concentration in the soil gas phase. Our simulations predict that temperature increasing in the next 100 yr causes the weathering rates of the silicates to increase into the future. In contrast, the weathering rate of dolomite – which consumes most of the CO2 – decreases in both end members (south and north) of the transect due to its retrograde solubility. We thus infer slower rates of advance of the dolomite reaction front into the subsurface, and faster rates of advance of the silicate reaction front. However, additional simulations for 9 pedons located along the north–south transect show that the dolomite weathering advance rate will increase in the central part of the Mississippi Valley, owing to a maximum in the response of vertical drainage to the ongoing climate change. The carbonate reaction front can be likened to a terrestrial lysocline because it represents a depth interval over which carbonate dissolution rates increase drastically. However, in contrast to the lower pH and shallower lysocline expected in the oceans with increasing atmospheric CO2, we predict a deeper lysocline in future soils. Furthermore, in the central Mississippi Valley, soil lysocline deepening accelerates but in the south and north the deepening rate slows. This result illustrates the complex behavior of carbonate weathering facing short term global climate change. Predicting the global response of terrestrial weathering to increased atmospheric CO2 and temperature in the future will mostly depend upon our ability to make precise assessments of which areas of the globe increase or decrease in precipitation and soil drainage.

scholarly journals Historical and future temporal trends in the summer Urban Heat Island of Athens (Greece) 

2021 ◽  
Author(s):  
Tim van der Schriek ◽  
Konstantinos V. Varotsos ◽  
Dimitra Founda ◽  
Christos Giannakopoulos
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Temperature ◽  
Temporal Trends ◽  
Temperature Data ◽  
Climate Change Scenarios ◽  
Heat Island ◽  
Hot Days ◽  
The Future ◽  
Urban Heat

&lt;p&gt;Historical changes, spanning 1971&amp;#8211;2016, in the Athens Urban Heat Island (UHI) over summer were assessed by contrasting two air temperature records from established meteorological stations in urban and rural settings. When contrasting two 20-year historical periods (1976&amp;#8211;1995 and 1996&amp;#8211;2015), there is a significant difference in summer UHI regimes. The stronger UHI-intensity of the second period (1996&amp;#8211;2015) is likely linked to increased pollution and heat input. Observations suggest that the Athens summer UHI characteristics even fluctuate on multi-annual basis. Specifically, the reduction in air pollution during the Greek Economic Recession (2008-2016) probable subtly changed the UHI regime, through lowering the frequencies of extremely hot days (T&lt;sub&gt;max&lt;/sub&gt; &gt; 37 &amp;#176;C) and nights (T&lt;sub&gt;min&lt;/sub&gt; &gt; 26 &amp;#176;C).&lt;/p&gt;&lt;p&gt;Subsequently, we examined the future temporal trends of two different UHIs in Athens (Greece) under three climate change scenarios. A five-member regional climate model (RCM) sub-ensemble from EURO-CORDEX with a horizontal resolution of 0.11&amp;#176; (~12 &amp;#215; 12 km) simulated air temperature data, spanning the period 1976&amp;#8211;2100, for the two station sites. Three future emissions scenarios (RCP2.6, RCP4.5 and RCP8.5) were implanted in the simulations after 2005. The observed daily maximum and minimum air temperature data (T&lt;sub&gt;max&lt;/sub&gt; and T&lt;sub&gt;min&lt;/sub&gt;) from two historical UHI regimes (1976&amp;#8211;1995 and 1996&amp;#8211;2015, respectively) were used, separately, to bias-adjust the model simulations thus creating two sets of results.&lt;/p&gt;&lt;p&gt;This novel approach allowed us to assess future temperature developments in Athens under two different UHI intensity regimes. We found that the future frequency of days with T&lt;sub&gt;max&lt;/sub&gt; &gt; 37 &amp;#176;C in Athens was only different from rural background values under the intense UHI regime. There is a large increase in the future frequency of nights with T&lt;sub&gt;min&lt;/sub&gt; &gt; 26 &amp;#176;C in Athens under all UHI regimes and climate scenarios; these events remain comparatively rare at the rural site.&lt;/p&gt;&lt;p&gt;This study shows a large urban amplification of the frequency of extremely hot days and nights which is likely forced by increasing air pollution and heat input. Consequently, local mitigation policies aimed at decreasing urban atmospheric pollution are expected to be also effective in reducing urban temperatures during extreme heat events in Athens under all future climate change scenarios. Such policies therefore have multiple benefits, including: reducing electricity (energy) needs, improving living quality and decreasing heat- and pollution related illnesses/deaths.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Does Climate Change Affect the Yield of the Top Three Cereals and Food Security in the World?

Earth ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 45-71
Author(s):  
Dhurba Neupane ◽  
Pramila Adhikari ◽  
Dwarika Bhattarai ◽  
Birendra Rana ◽  
Zeeshan Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Food Security ◽  
Greenhouse Gases ◽  
Prediction Models ◽  
Molecular Techniques ◽  
Lower Amount ◽  
Cereal Crops ◽  
The World ◽  
The Future ◽  
World Food Security

Climate prediction models suggest that agricultural productivity will be significantly affected in the future. The expected rise in average global temperature due to the higher release of greenhouse gases (GHGs) into the atmosphere and increased depletion of water resources with enhanced climate variability will be a serious threat to world food security. Moreover, there is an increase in the frequency and severity of long-lasting drought events over 1/3rd of the global landmass and five times increase in water demand deficits during the 21st century. The top three cereals, wheat (Triticum aestivum), maize (Zea mays), and rice (Oryza sativa), are the major and staple food crops of most people across the world. To meet the food demand of the ever-increasing population, which is expected to increase by over 9 billion by 2050, there is a dire need to increase cereal production by approximately 70%. However, we have observed a dramatic decrease in area of fertile and arable land to grow these crops. This trend is likely to increase in the future. Therefore, this review article provides an extensive review on recent and future projected area and production, the growth requirements and greenhouse gas emissions and global warming potential of the top three cereal crops, the effects of climate change on their yields, and the morphological, physiological, biochemical, and hormonal responses of plants to drought. We also discuss the potential strategies to tackle the effects of climate change and increase yields. These strategies include integrated conventional and modern molecular techniques and genomic approach, the implementation of agronomic best management (ABM) practices, and growing climate resilient cereal crops, such as millets. Millets are less resource-intensive crops and release a lower amount of greenhouse gases compared to other cereals. Therefore, millets can be the potential next-generation crops for research to explore the climate-resilient traits and use the information for the improvement of major cereals.

scholarly journals Sources of uncertainty in climate change impacts on river discharge and groundwater in a headwater catchment of the Upper Nile Basin, Uganda

2010 ◽  
Vol 14 (7) ◽  
pp. 1297-1308 ◽  
Author(s):  
D. G. Kingston ◽  
R. G. Taylor
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Climate Sensitivity ◽  
River Discharge ◽  
Hydrological Model ◽  
Nile Basin ◽  
Freshwater Resources ◽  
Depth Analysis ◽  
Global Mean ◽  
Impacts Of Climate Change

Abstract. The changing availability of freshwater resources is likely to be one of the most important consequences of projected 21st century climate change for both human and natural systems. However, substantial uncertainty remains regarding the precise impacts of climate change on water resources, due in part due to uncertainty in GCM projections of climate change. Here we explore the potential impacts of climate change on freshwater resources in a humid, tropical catchment (the River Mitano) in the Upper Nile Basin of Uganda. Uncertainty associated with GCM structure and climate sensitivity is explored, as well as parameter specification within hydrological models. These aims are achieved by running pattern-scaled output from seven GCMs through a semi-distributed hydrological model of the catchment (developed using SWAT). Importantly, use of pattern-scaled GCM output allows investigation of specific thresholds of global climate change including the purported 2 °C threshold of "dangerous" climate change. In-depth analysis of results based on the HadCM3 GCM climate scenarios shows that annual river discharge first increases, then declines with rising global mean air temperature. A coincidental shift from a bimodal to unimodal discharge regime also results from a projected reduction in baseflow (groundwater discharge). Both of these changes occur after a 4 °C rise in global mean air temperature. These results are, however, highly GCM dependent, in both the magnitude and direction of change. This dependence stems primarily from projected differences in GCM scenario precipitation rather than temperature. GCM-related uncertainty is far greater than that associated with climate sensitivity or hydrological model parameterisation.

scholarly journals Mapping Climate Changes in Iraq By Using Geographical Information System (GIS)

2018 ◽  
Vol 7 (4.20) ◽  
pp. 578 ◽  
Author(s):  
Zainab Sahib Jawad ◽  
Fatima Asaad Tayeb ◽  
Asaad Tayeb Kareem Jebur
Keyword(s):  
Climate Change ◽  
Information System ◽  
Greenhouse Gases ◽  
Geographical Information System ◽  
Air Temperature ◽  
Greenhouse Effect ◽  
Interpolation Method ◽  
Geographical Information ◽  
Spatial Interpolation Method ◽  
Carbon Dioxide Co2

The Trapped sun’s thermal radiation in the earth’s atmosphere is known as the greenhouse effect.  This process is considered very important since it keeps the earth warm and hence possible to live in. Greenhouse gases such as carbon dioxide (CO2) and methane (CH4) are considered very important contributors to the greenhouse effect. During the last two decades, the level of greenhouse gases has increased, which plays a major role in global warming and climate change. The Middle East is considered among the most affected areas by climate change. In the current study, Geographical Information System (GIS) has been used to create some temperature maps that could show the air temperature distribution and difference between two different periods of time (past and recent) in different stations that cover the Iraqi governorates. A spatial interpolation method has been used. This method considers known values of temperature at a given location (stations in the current study) to estimate a continuous surface map during a specific period of time. The results of this study showed no significant increase in the average air temperature values, however the area of high air temperature values is growing during the cold and hot months of the year.  

scholarly journals Locomotion of Slope Geohazards Responding to Climate Change in the Qinghai-Tibetan Plateau and Its Adjacent Regions

2021 ◽  
Vol 13 (19) ◽  
pp. 10488
Author(s):  
Yiru Jia ◽  
Jifu Liu ◽  
Lanlan Guo ◽  
Zhifei Deng ◽  
Jiaoyang Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Climatic Factors ◽  
High Sensitivity ◽  
Spatial Location ◽  
Future Climate ◽  
Tibet Plateau ◽  
The South ◽  
Climate Conditions ◽  
Temperature And Precipitation ◽  
Qinghai Tibet Plateau

Slope geohazards, which cause significant social, economic and environmental losses, have been increasing worldwide over the last few decades. Climate change-induced higher temperatures and shifted precipitation patterns enhance the slope geohazard risks. This study traced the spatial transference of slope geohazards in the Qinghai-Tibet Plateau (QTP) and investigated the potential climatic factors. The results show that 93% of slope geohazards occurred in seasonally frozen regions, 2.6% of which were located in permafrost regions, with an average altitude of 3818 m. The slope geohazards are mainly concentrated at 1493–1988 m. Over time, the altitude of the slope geohazards was gradually increased, and the mean altitude tended to spread from 1984 m to 2562 m by 2009, while the slope gradient varied only slightly. The number of slope geohazards increased with time and was most obvious in spring, especially in the areas above an altitude of 3000 m. The increase in temperature and precipitation in spring may be an important reason for this phenomenon, because the results suggest that the rate of air warming and precipitation at geohazard sites increased gradually. Based on the observation of the spatial location, altitude and temperature growth rate of slope geohazards, it is noted that new geohazard clusters (NGCs) appear in the study area, and there is still a possibility of migration under the future climate conditions. Based on future climate forecast data, we estimate that the low-, moderate- and high-sensitivity areas of the QTP will be mainly south of 30° N in 2030, will extend to the south of 33° N in 2060 and will continue to expand to the south of 35° N in 2099; we also estimate that the proportion of high-sensitivity areas will increase from 10.93% in 2030 to 14.17% in 2060 and 17.48% in 2099.

scholarly journals Limits on Use of Diesel in Brazil: Measurement of Increase of Biodiesel in Mitigation of GHG

2020 ◽  
Vol 31 (1) ◽  
pp. 171
Author(s):  
Vallência Maíra Gomes ◽  
Alexandre Magno De Melo Faria
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Co2 Emissions ◽  
National Policy ◽  
National Program ◽  
Top Down ◽  
The Future ◽  
Future Demand

Once set the mitigation of greenhouse gases in the National Policy on Climate Change (NPCC) with the National Program for Production and Use of Biodiesel (NPPB) in Brazil, this paper aims to estimate the need for biodiesel blended with petroleum diesel to 2020, taking into account the expansion limits of diesel. To estimate the future demand for diesel and CO2 emissions, the Box-Jenkins methodology and top-down were used respectively. The results show that the mixture in Brazil is expected to reach between B31 (31% of blend) and B67 (67% of blend) in 2020, to meet the objectives of the NPCC.

scholarly journals Projected Future Temporal Trends of Two Different Urban Heat Islands in Athens (Greece) under Three Climate Change Scenarios: A Statistical Approach

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 637 ◽  
Author(s):  
Tim van der Schriek ◽  
Konstantinos V. Varotsos ◽  
Christos Giannakopoulos ◽  
Dimitra Founda
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Temperature ◽  
Temporal Trends ◽  
Temperature Data ◽  
Rural Site ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Future ◽  
The Impact

This is the first study to look at future temporal urban heath island (UHI) trends of Athens (Greece) under different UHI intensity regimes. Historical changes in the Athens UHI, spanning 1971–2016, were assessed by contrasting two air temperature records from stable meteorological stations in contrasting urban and rural settings. Subsequently, we used a five-member regional climate model (RCM) sub-ensemble from EURO-CORDEX with a horizontal resolution of 0.11° (~12 × 12 km) to simulate air temperature data, spanning the period 1976–2100, for the two station sites. Three future emissions scenarios (RCP2.6, RCP4.5, and RCP8.5) were implanted in the simulations after 2005 covering the period 2006–2100. Two 20-year historical reference periods (1976–1995 and 1996–2015) were selected with contrasting UHI regimes; the second period had a stronger intensity. The daily maximum and minimum air temperature data (Tmax and Tmin) for the two reference periods were perturbed to two future periods, 2046–2065 and 2076–2095, under the three RCPs, by applying the empirical quantile mapping (eqm) bias-adjusting method. This novel approach allows us to assess future temperature developments in Athens under two UHI intensity regimes that are mainly forced by differences in air pollution and heat input. We found that the future frequency of days with Tmax > 37 °C in Athens was only different from rural background values under the intense UHI regime. Thus, the impact of heatwaves on the urban environment of Athens is dependent on UHI intensity. There is a large increase in the future frequency of nights with Tmin > 26 °C in Athens under all UHI regimes and climate scenarios; these events remain comparatively rare at the rural site. This large urban amplification of the frequency of extremely hot nights is likely caused by air pollution. Consequently, local mitigation policies aimed at decreasing urban atmospheric pollution are expected to be highly effective in reducing urban temperatures and extreme heat events in Athens under future climate change scenarios. Such policies directly have multiple benefits, including reduced electricity (energy) needs, improved living quality and strong health advantages (heat- and pollution-related illness/deaths).

scholarly journals Uncertainty in climate change impacts on water resources in the Rio Grande Basin, Brazil

2011 ◽  
Vol 15 (2) ◽  
pp. 585-595 ◽  
Author(s):  
M. T. Nóbrega ◽  
W. Collischonn ◽  
C. E. M. Tucci ◽  
A. R. Paz
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
River Discharge ◽  
Greenhouse Gas Emission ◽  
Circulation Model ◽  
Rio Grande ◽  
Climate Projections ◽  
Temperature Pattern ◽  
Rio Grande Basin ◽  
Global Mean

Abstract. We quantify uncertainty in the impacts of climate change on the discharge of Rio Grande, a major tributary of the Paraná River in South America and one of the most important basins in Brazil for water supply and hydro-electric power generation. We consider uncertainty in climate projections associated with the greenhouse-gas emission scenarios (A1b, A2, B1, B2) and increases in global mean air temperature of 1 to 6° C for the HadCM3 GCM (Global Circulation Model) as well as uncertainties related to GCM structure. For the latter, multimodel runs using 6 GCMs (CCCMA CGCM31, CSIRO Mk30, IPSL CM4, MPI ECHAM5, NCAR CCSM30, UKMO HadGEM1) and HadCM3 as baseline, for a +2° C increase in global mean temperature. Pattern-scaled GCM-outputs are applied to a large-scale hydrological model (MGB-IPH) of Rio Grande Basin. Based on simulations using HadCM3, mean annual river discharge increases, relative to the baseline or control run period (1961–1990), by +5% to +10% under the SRES emissions scenarios and from +8% to +51% with prescribed increases in global mean air temperature of between 1 and 6° C. Substantial uncertainty in projected changes to mean river discharge (−28% to +13%) under the 2° C warming scenario is, however, associated with the choice of GCM. We conclude that, in the case of Rio Grande Basin, the most important source of uncertainty derives from the GCM rather than the emission scenario or the magnitude of rise in mean global temperature.

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