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1.
This study investigates future impacts of global warming on climate and extreme climate events in Nigeria, the most populous African country that depends on rain-fed agriculture. Past and future climate simulations from 9 GCMs were downscaled (using a statistical model) and analyzed for the study. The study considers the impacts of two emission scenarios (B1 and A2) on the future climates (2046–2065 and 2081–2100) over ecological zones in Nigeria. The model evaluation shows that the downscaling adds values to the GCMs simulation, and the results capture all the important climatic features over the country. The model projections show that both B1 and A2 scenarios change the future climate over Nigeria. They significantly increase the temperature over all the ecological zones, with greatest warming (between 1 and 4 °C) over the Sudan (short grass) Savanna in March. The warming, which increases the occurrence of extreme temperature and heat wave events over the entire country, enhances the frequency of the extreme rainfall events in the south and southeast and reduces the annual rainfall over the northeast. Since heavy rains and floods are major problems in the south and southeast, and drought is major problem in the northeast, the global warming may further aggravate these environmental problems in future. These could have negative impacts on agriculture and further threaten livelihood and food security in the rapidly growing country. Hence, there is need for further studies on adaptation and mitigation strategies to address the impacts of global warming in Nigeria.  相似文献   

2.
了解和认识百年来中国气候发生的变化、引起其变化的驱动因素以及未来的可能变化,可以更好地适应和减缓气候变化。本文综合评估了观测到的中国气候变化事实、中国气候变化的驱动力、中国未来气候变化预估三大方面,分析了气候变暖的趋势、水循环以及降水和冰川变化、极端天气气候事件变化、生物化学循环、海洋和土地覆盖变化及其气候效应以及未来气候变化的特点和趋势等最新科学进展。在中国百年温度趋势、气候系统多气候指标变化特征、极端天气气候事件中的人类活动作用以及气候系统模拟能力等方面的研究有了新的进展。可以看到中国气候变暖趋势持续、大气二氧化碳等长寿命温室气体浓度继续增长、人为强迫影响了多种气候要素在强度和频率的变化,中国陆地生态系统的固碳量增加。本文最后提出未来中国气候变化研究需要进一步加强的问题,包括:中国气候变化中的城市化效应、气候系统内部变率在年代际变化中的作用、气溶胶-云-降雨相互作用的机理、大范围土地利用变化(如大规模生态恢复工程)的气候效应,以及云辐射反馈、海洋环流对气候变化的响应与反馈、气候-碳循环反馈等过程对气候模拟不确定的影响等。  相似文献   

3.
Climate change impact on countrywide water balance in Bolivia   总被引:1,自引:0,他引:1  
There is increasing concern about the ongoing reduction in water supplies in the tropical Andes due to climate change effects such as glacier/snow melting resulting from rising air temperatures. In addition, extreme events and population growth are already directly affecting life and water renewability in the country. A countrywide integrated national plan for improving basin-scale water management in Bolivia is needed to assure water availability for agriculture, industry, mining, and human consumption. This study aims to provide a modeling tool to assess Bolivia’s past, current, and future water availability and identify basins at risk of water deficits. The Soil Water Assessment Tool was used to simulate the monthly water balance from 1997 to 2008, as well as the water balance projected to 2050 for the entire country. It considers possible changes in air temperatures and precipitation proposed by 17 Global Circulation Models as well as carbon dioxide projections derived from the Special Report Emission Scenario. Overall, model results were close to satisfactory compared to observations, with some exceptions due to lack of information for expanding the timeline and improving calibration. Based on the calculation of three hydrologic indicators, the study identifies basins that would be the most susceptible to water deficits for a baseline from 1997 to 2008, and in the event of the projected climate change, to 2050.  相似文献   

4.
Numerous analyses of the possible impacts of future climatic changes on tree species composition have been published for both lowland and high-elevation forests. Most of these studies were based on the application of forest "gap" models, and the vast majority of them considered only changes in the average of climatic parameters over time. In this study, we use a unique data set on reconstructed past climatic variations to analyse forest dynamics simulated by the forest gap model ForClim. This analysis forms the basis for a systematic exploration of the ecological effects of changing means vs. changing variability of climate on central European forests. A reconstruction of historical climate covering the last 470 years in the Swiss lowlands (ClimIndex) is extrapolated to a transect across the alpine (cold) treeline and used to simulate the influence of climate variations on the time scale of decades on forest biomass and tree species composition at both sites. While the simulation at the low-elevation site shows little sensitivity to climate variations, the results from upper subalpine forests suggest that two major dieback events would have occurred at elevations above the current but below the climatic tree line, induced by clusters of exceptionally cold summers. The results are in agreement with available dendrochronological data and with documentary evidence on massive negative impacts on flora and fauna at high elevations during these periods. We conclude that ForClim is capable of capturing the effects on tree population dynamics of climate variability at these sites as reconstructed from the ClimIndex record. A factorial design is used to address the sensitivity of ForClim to changes of the long-term averages vs. changes of the variability of monthly temperature and precipitation data. To this end, the simulated tree species composition of near-natural forests is examined along a climate gradient in Europe. The results indicate that there are three types of forest response: (1) little sensitivity to both kinds of change, (2) strong sensitivity to changes in the means, but little sensitivity to changing variability, and (3) strong sensitivity to changing variability at least in parts of the examined climate space. Half of the cases investigated fall under the third category, suggesting that emphasis should be placed on also assessing the sensitivity of ecosystems to future changes in climate variability rather than on changes of average values alone. Electronic Publication  相似文献   

5.
Planning for adaptation to climate change is often regarded to be a local imperative and considered to be more effective if grounded on a solid evidence base and recognisant of relevant climate projections. Research has already documented some of the challenges of making climate information usable in decision-making but has not yet sufficiently reflected on the role of the wider institutional and regulatory context. This article examines the impact of the external institutional context on the use and usability of climate projections in local government through an analysis of 44 planning and climate change (adaptation) documents and 54 semi-structured interviews with planners in England and Germany conducted between July 2013 and May 2014. We show that there is little demand for climate projections in local adaptation planning in either country due to existing policy, legal and regulatory frameworks. Local government in England has not only experienced a decline in use of climate projections, but also the waning of the climate change adaptation agenda more widely, amidst changes in the planning and regulatory framework and severe budget cuts. In Germany, spatial planning makes substantial use of past and present climate data, but the strictly regulated nature of planning prevents the use of climate projections, due to their inherent uncertainties. Findings from the two countries highlight that if we are to better understand the usability of climate projections, we need to be more aware of the institutional context within which planning decisions are made. Otherwise we run the risk of continuing to provide tools and information that are of limited use within their intended context.  相似文献   

6.
Small island developing states (SIDS) face multiple threats from anthropogenic climate change, including potential changes in freshwater resource availability. Due to a mismatch in spatial scale between SIDS landforms and the horizontal resolution of global climate models (GCMs), SIDS are mostly unaccounted for in GCMs that are used to make future projections of global climate change and its regional impacts. Specific approaches are required to address this gap between broad-scale model projections and regional, policy-relevant outcomes. Here, we apply a recently developed methodology that circumvents the GCM limitation of coarse resolution in order to project future changes in aridity on small islands. These climate projections are combined with independent population projections associated with shared socioeconomic pathways (SSPs) to evaluate overall changes in freshwater stress in SIDS at warming levels of 1.5 and 2 °C above pre-industrial levels. While we find that future population growth will dominate changes in projected freshwater stress especially toward the end of the century, projected changes in aridity are found to compound freshwater stress for the vast majority of SIDS. For several SIDS, particularly across the Caribbean region, a substantial fraction (~?25%) of the large overall freshwater stress projected under 2 °C at 2030 can be avoided by limiting global warming to 1.5 °C. Our findings add to a growing body of literature on the difference in climate impacts between 1.5 and 2 °C and underscore the need for regionally specific analysis.  相似文献   

7.
The weight of scientific evidence suggests that human activities are noticeably influencing the world's climate. However, the effects of global climate change will be unevenly spread, due to local variations in vulnerability and adaptive capacity. Using downscaled projections of future UK climates over the next 50 years, this paper investigates the impacts of, and possible responses to, climate change in one small area in eastern England, selected as a test-bed for sustainable agriculture. It shows that local agricultural systems are vulnerable to changes in the climate. At present, however, these considerations have a limited effect on agricultural operations, which are mainly driven by short-term events and 'non-climate' policies, such as agricultural price support. The capacity of agricultural systems to adapt successfully to climate change will be determined by the ability of producers to integrate climate change into their planning strategies with a view to ultimately ensuring sustainable agricultural practices in the long term. Electronic Publication  相似文献   

8.
According to observed twentieth century temperature trends and twenty-first century climate model projections, the region that encompasses the eastern Mediterranean and the Middle East (EMME) is identified as a climate change hot spot. We extend previous studies by a comprehensive climatology of heat waves in the EMME based on regional climate model simulations for the recent past and the end of the twenty-first century. A percentile-based definition of heat waves is used to account for local climatic conditions. Spatial patterns of several heat wave properties are assessed and associated with atmospheric circulation regimes over specific locations. To cover a range of possible future climates, we use three SRES emission scenarios. According to our results, all indices that characterize heat wave severity will strongly increase compared with the control period of 1961–1990. The northern part of the EMME could be exposed to increased heat wave amplitudes by 6–10 °C, and the southern part may experience 2–3 months more combined hot days and tropical nights. Heat wave peak temperatures will be higher due to the overall mean warming as well as stronger summer anticyclonic conditions. The projected changes will affect human health and the environment in multiple ways and call for impact studies to support the development of adaptation strategies.  相似文献   

9.
Tourism is a vital sector of Cyprus economy, attracting millions of tourists every year and providing economic growth and employment for the country. The aim of this study was to investigate the impacts of projected climate change in the tourism industry in Cyprus (Republic of Cyprus) using both “Tourism Climate Index” (TCI) and “Beach Climate Index” (BCI). TCI refers to tourism activities mainly related to sightseeing, nature-based tourism, and religious tourism etc., while BCI represents beach tourism that constitutes 85 % of tourism activities in Cyprus. The projections of climate change impacts in tourism are performed for 2071–2100 period, using regional climate model output employing the A1B greenhouse gas emissions scenario. The 1961–1990 period is used as the control run to compare the respective results of the future projections. The significant warming anticipated in the distant future (increases in annual and summer temperatures close to 4 °C) will have adverse impacts on Cyprus tourism industry regarding sightseeing tourism. TCI results for the distant future period show only acceptable conditions for general tourism activities during summer in contrast with the good/very good conditions in the present climate. Conversely, this type of tourism seems to be benefited in shoulder seasons, i.e., during spring and autumn; TCI and hence tourist activities improve in the distant future in relation to the present climate. On the other hand, concerning beach tourism, future projections indicate that it will not be negatively affected by future climate change and any changes will be positive.  相似文献   

10.
This article intends to shed a light on air quality in Turkey and compare air pollutant emissions on a national scale with that of the European countries. In order to estimate the quantities of Turkish emissions in the past and their future predictions, a national emission inventory was prepared with respect to five major pollutants consisting of particulate matter(PM), SOx, NOx, non-methane volatile organic compounds, and CO with 5-year intervals between 1985 and 2005. The results suggest that Turkey is a rather large emission source at the European scale, although emission indicators on unit area and per capita were shown to be somewhat smaller in magnitude. Levels of air pollution in some of the big cities in Turkey were also evaluated from available national monitoring data. These evaluations for the urban air qualities covered SO2 and PM parameters between 1986 and 1996, and results were compared with the present Turkish air quality limits, their probable revisions, WHO (Europe) guidelines and related EC directives. Results showed that the air quality limits were not met, especially during the winter periods in Turkish cities. Urban air pollutants characterizing the air in Turkish cities other than SO2 and PM, however, could not have been evaluated as these pollutants were not systematically monitored in these cities.  相似文献   

11.
Climate change has in the past led to shifts in vegetation patterns; in a future, warmer climate due to enhanced greenhouse-gas concentrations, vegetation is also likely to be highly responsive to such warming. Mountain regions are considered to be particularly sensitive to such changes. In this paper we present an approach to assess the impact of climate change on long-term vegetation plots at the high-elevation site of the Schynige Platte, 2000 m above sea level, in the Bernese Alps (Switzerland). Records of vegetation spanning the period from 1928 to today at two different sites, each with several plots, were considered. The observed change in the species composition was then related to changes in land use and climate. We used daily values of temperature, snow and precipitation from several high-elevation weather stations to conduct these analyses. The correlation between climate and vegetation patterns revealed that species that prefer low thermal conditions move out of the plots, i.e., their frequency of occurrence is negatively correlated with the average number of degree-days over the last six decades. On the other hand, species with higher thermal demands are seen to be invading the plots, i.e., their frequency of occurrence is positively correlated to the average number of degree-days. Nutrient changes – though independent from climate – also play an important role in the observed shifts in species. Received: 20 June 1999 · Accepted: 14 January 2000  相似文献   

12.
Many studies have identified climate warming to be among the most important threats to biodiversity. Climate change is expected to have stronger effects on species with low genetic diversity, ectothermic physiology, small ranges, low effective populations sizes, specific habitat requirements and limited dispersal capabilities. Despite an ever-increasing number of studies reporting climate change-induced range shifts, few of these have incorporated species’ specific dispersal constraints into their models. Moreover, the impacts of climate change on genetic variation within populations and species have rarely been assessed, while this is a promising direction for future research. Here we explore the effects of climate change on the potential distribution and genetic variation of the endemic Pyrenean newt Calotriton asper over the period 2020–2080. We use species distribution modelling in combination with high-resolution gridded climate data while subsequently applying four different dispersal scenarios. We furthermore use published data on genetic variation of both mtDNA and AFLP loci to test whether populations with high genetic diversity (nucleotide diversity and expected heterozygosity) or evolutionary history (unique haplotypes and K clusters) have an increased extinction risk from climate change. The present study indicates that climate change drastically reduces the potential distribution range of C. asper and reveals dispersal possibilities to be minimal under the most realistic dispersal scenarios. Despite the major loss in suitable climate, the models highlight relatively large stable areas throughout the species core distribution area indicating persistence of populations over time. The results, however, show a major loss of genetic diversity and evolutionary history. This highlights the importance of accounting for intraspecific genetic variation in climate change impact studies. Likewise, the integration of species’ specific dispersal constraints into projections of species distribution models is an important step to fully explore the effects of climate change on species potential distributions.  相似文献   

13.
区域气象条件及空气质量或与全球气候变化关系密切。研究通过分析不同气候条件下成都地区1951~2017年主要气象要素及其2013~2017年大气污染物浓度变化趋势,并结合大数据挖掘技术探究厄尔尼诺/拉尼娜事件与成都地区气象及空气质量的关系。结果表明,全球气候变化对区域气象及空气质量影响明显。异常气候造成成都地区气温、降水、风速、日照时长等气象条件发生明显变化。这些变化通常利于大气扩散条件的改善而使污染物浓度下降,但相应时期的臭氧浓度却有所升高。研究同时利用KNN大数据挖掘算法评估不同气候条件下气象和减排对空气质量改善的贡献。结果显示,在全球厄尔尼诺发生频繁的2015年,成都地区重污染天数明显减少,气象和减排的贡献率分别为27%和73%;而在全球拉尼娜现象频发的2016年,成都地区空气质量也有明显改善,重污染天数的减少有42%归功于气象条件的变化,几乎与大气污染物的减排贡献相当。因此,为实现空气质量的有效改善,空气质量改善管理政策的制定,既要从源头上控制污染物的排放,同时也应考虑全球气候变化的影响。  相似文献   

14.
The problem of climate change is a global challenge. It is closely associated with social development and human survival, and it has a significant impact to all countries on energy develop- ment, economic competitiveness, technological innovation, and way of life. In recent years, with the rapid economic development in China, there is a rumor that the rapid growth of China's carbon dioxide emission offset the efforts of the international community in reducing emissions, and China should bear the international responsibility corresponding to its significant role in greenhouse gas emission, which obviously are unfair and not objective. As this paper reveals, "China environment responsibility" that is the socalled "China environment threat" or theories, China has made a positive contribution to addressing the climate change in the past and China will still be the backbone on the protection of global climate in the future.  相似文献   

15.
The problem of climate change is a global challenge.It is closely associated with social development and human survival,and it has a significant impact to all countries on energy development,economic competitiveness,technological innovation,and way of life.In recent years,with the rapid economic development in China,there is a rumor that the rapid growth of China’s carbon dioxide emission offset the efforts of the international community in reducing emissions,and China should bear the international responsibility corresponding to its significant role in greenhouse gas emission,which obviously are unfair and not objective.As this paper reveals,"China environment responsibility" that is the socalled "China environment threat" or theories,China has made a positive contribution to addressing the climate change in the past and China will still be the backbone on the protection of global climate in the future.  相似文献   

16.
Loss of forest cover is a likely consequence of climate change in many parts of the world. To test the vulnerability of eucalypt forests in Australia’s island state of Tasmania, we modelled tree canopy cover in the period 2070–2099 under a high-emission scenario using the current climate–canopy cover relationship in conjunction with output from a dynamically downscaled regional climate model. The current climate–canopy cover relationship was quantified using Random Forest modelling, and the future climate projections were provided by three dynamically downscaled general circulation model (GCM) simulations. Three GCMs were used to show a range of projections for the selected scenario. We also explored the sensitivity of key endemic and non-endemic Tasmanian eucalypts to climate change. All GCMs suggested that canopy cover should remain stable (proportional cover change <10 %) across ~70 % of the Tasmanian eucalypt forests. However, there were geographic areas where all models projected a decline in canopy cover due to increased summer temperatures and lower precipitation, and in addition, all models projected an increase in canopy cover in the coldest part of the state. The model projections differed substantially for other areas. Tasmanian endemic species appear vulnerable to climate change, but species that also occur on the mainland are likely to be less affected. Given these changes, restoration and carbon sequestration plantings must consider the species and provenances most suitable for future, rather than present, climates.  相似文献   

17.
Australian resource-extraction industries—mining, fisheries and forestry—operate year-round in the natural environment with all three exposed to climate extremes and to long-term climatic change. However, the industries differ in terms of size, ownership and mobility. Although mining companies are ‘mobile,’ a commitment to a mine site makes them immobile at a location dictated by the presence of a mineral; forestry of natural and managed trees takes place in a specifically selected location that can be changed given a reasonably long time-frame and high financial investment; fishing is the last of the major hunting industries, and despite operating from fixed ports, fishers chase fish across the ocean. All three industries as employers and product providers seek a sustainable future under a changing climate but are subject to environmental variability that impacts on their activities. As each industry has historically dealt with and survived major climate impacts, they typically consider themselves to be resilient, although we illustrate in several case studies that recent climate variability significantly impacts productivity and current resilience is limited. Projected climate change and variability are likely to exacerbate impacts on these industries through new or intensified hazards. Although each industry performs risk management controls to minimize climate-related impacts, a new approach incorporating future climate projections in addition to historical experiences would better prepare each to reduce vulnerability to changing climate. We find that wholesale transformation may not be appropriate or necessary at this time for these industries, and in most cases anticipatory, incremental adaptation should be encouraged, while larger-scale changes are considered in the longer term. Additionally, to overcome some of the barriers and promote the drivers of adaptation, we suggest that a model of adaptive governance coupled with greater use of climate champions may be the most effective method for improving adaptation uptake in these industries.  相似文献   

18.
Predicting hot-spots of land use changes in Italy by ensemble forecasting   总被引:1,自引:0,他引:1  
In the context of environmental change projections at the regional level, not only the climate but also the land use plays a key role. The limited availability of historical information reduces the possibility to calibrate land use change (LUC) models. Even in case of successful calibration, using it both for diagnostic and prognostic studies does not guarantee the reliability of single future simulations. Through ensemble forecasting, useful LUC predictions are evaluable. In this work, after introducing a modified version of the well-assessed CLUE-S model, we present reasonable hot-spots of LUC in Italy for the end of 21st century, derived from the agreement of a 32 simulation ensemble performed alternating two choices for five model configurations or inputs: (1) two different climate projections (reflecting A2 and B2 emission scenarios by IPCC, respectively); (2) two different degrees (slight and strong) of demographic increase; (3) the conservation (or not) of protected areas; (4) the influence (or not) among adjacent land uses in determining their shift; and (5) the importance (or not) of past/recent LUC trends. Results, in terms of LUC hot-spot distribution, were evaluated at administrative, biogeographical, physiographic, and watershed level. The main findings highlighted that some trends of land use substitution will be likely opposite to the past and that a more detailed spatial scale can detect situations neglected by coarser scale evaluations, and due to different transpositions of directives from high-levels to local scales. Biogeographical and physiographic settings seem strongly influencing LUCs, and administrative and catchment units across Italy show very different developments and a highly fragmented territory in terms of LUC hot-spots, all that to be considered in landscape and resource planning.  相似文献   

19.
Mediterranean viticulture could suffer from hotter and drier growing seasons over the coming decades. The present article focuses on the wine-producing area Côtes-du-Roussillon-Villages near Perpignan, in southern France. We used observational daily data (1925–2010) from Perpignan weather station and daily outputs (2001–2060) of the regional climate model ARPEGE-RETIC-V4 from Météo-France with scenarios A2, A1B and B1, to assess the exposure of the regional wine system to changes in temperature and precipitation, both in the recent past and the coming decades (1925–2060). Temperatures during the growing season and summer temperature extremes have been increasing continuously since the mid-1980s and are projected to increase faster from the mid-2040s. Precipitation is highly variable and very low in summer, and projections suggest greater uncertainty, and more extreme drought events could be expected. The analysis of climate data was complemented by thirty-two in-depth interviews with local actors of the wine industry to assess the impacts of climate change on their activities and potential adaptive options. Producers reported negative impacts of recent changes in climate in conjunction with a difficult economic situation. Analyses of historical, social and economic backgrounds are important to fully conceptualize the nature and extent of climate change risks in the region. This case study provides important insights into the roles of non-climatic factors in the generation of vulnerability for Mediterranean agricultural systems facing rapid climate change.  相似文献   

20.
24个CMIP5模式对长江流域模拟能力评估   总被引:2,自引:0,他引:2  
根据1961~2005年长江流域气象站点的实测月降水量和气温数据,采用第5期全球耦合模式比较计划CMIP5(the Fifth Phase of Coupled Model Intercomparison Project)中24个全球气候模式(GCM)的模拟结果,通过计算模拟变量和观测变量平均值的相对误差、归一化的均方根误差、时间和空间相关系数,采用M-K趋势分析方法,分别选用在长江流域模拟气温和降水较好的5个模式进行集合平均,从时间的演变规律和空间的分布特征两方面,检验该模式集合对长江流域模拟气温和降水的能力。研究结果表明:各个模式模拟气温的能力要明显好于模拟降水的能力,但模拟气温较好的模式模拟降水的能力并不一定突出;模式集合的结果表明:在时间尺度上,模式集合平均结果与观测值拟合程度较好,且模式集合的结果振荡幅度较观测值小;在空间尺度上,模式集合的空间分布趋势与观测值大致相同,说明采用的模式集合结果用于预估未来长江流域降水的时空分布特征和演变规律是可行的。  相似文献   

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