Mid-21st century climate and weather extremes in Cyprus as projected by six regional climate models

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.     

Evidence of response of vegetation to environmental change on high-elevation sites in the Swiss Alps

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     

Impacts of climate change on lakes and reservoirs dynamics and restoration policies

Meteorological-driven processes exert large and diverse impacts on lakes and their water quality; these impacts can be hydrologic, thermal, hydraulic, chemical, biochemical, or ecological. The impact of climate change on Lake Tahoe (California–Nevada) was investigated here as a case study of climate change effects on the physical processes occurring within lakes. The already published trends of meteorological variables were used to assess the effects of global warming on Lake Tahoe dynamics. Records from the period 1969–2002 show that Lake Tahoe has became warmer and more stable. A series of simulation years into the future (i.e., 2000–2040) was established using flows, loads, and meteorology data sets for the period 1994–2004. Results of 40-year simulations show that the lake continues to become warmer and more stable, and mixing is reduced. Possible changes in water quality because of global warming are discussed through inference, although these are not specifically simulated. Many existing problems may be exacerbated due to climate change, yet extreme uncertainty depends on the rate and magnitude of climate change. Therefore, shifts in water quality and quantity due to climate change should be integrated into contemporary planning and management in an adaptive manner, and the research and development of impact assessment methodology should focus on approaches that can handle extreme uncertainty. The general alternatives for lake management due to climate change are discussed. Depending on the specific case, further intensive research is suggested to restore lake water quality.     

Drastic reduction in the potential habitats for alpine and subalpine vegetation in the Pyrenees due to twenty-first-century climate change

Recent climate change is already affecting both ecosystems and the organisms that inhabit them, with mountains and their associated biota being particularly vulnerable. Due to the high conservation value of mountain ecosystems, reliable science-based information is needed to implement additional conservation efforts in order to ensure their future. This paper examines how climate change might impact on the distribution of the main alpine and subalpine vegetation in terms of losses of suitable area in the Oriental Pyrenees. The algorithm of maximum entropy (Maxent) was used to relate current environmental conditions (climate, topography, geological properties) to present data for the studied vegetation units, and time and space projections were subsequently carried out considering climate change predictions for the years 2020, 2050 and 2080. All models predicted rising altitude trends for all studied vegetation units. Moreover, the analysis of future trends under different climate scenarios for 2080 suggests an average loss in potential ranges of 92.3–99.9 % for alpine grasslands, 76.8–98.4 % for subalpine (and alpine) scrublands and 68.8–96.1 % for subalpine forest. The drastic reduction in the potential distribution areas for alpine grasslands, subalpine scrublands and Pinus uncinata forests highlights the potential severity of the effects of climate change on vegetation in the highest regions of the Pyrenees. Thus, alpine grasslands can be expected to become relegated to refuge areas (summit areas), with their current range being taken over by subalpine scrublands. Furthermore, subalpine forest units will probably become displaced and will occupy areas that currently present subalpine scrub vegetation.     

The impact of global warming on winter tourism and skiing: a regionalised model for Austrian snow conditions

Possible climate change will modify snow-cover depth and change the characteristics of winter tourism and skiing districts. Our model describes seasonal snow-cover depth related to altitude in six Alpine climate regions as the best fit of all snow stations. Data cover 30 winter seasons (November to April values) from 1965 to 1995. We modified the data according to a scenario of temperature and precipitation change (2 °C warming, no precipitation change) and achieve a new simulated snow-cover depth. The indicators MARP (mean altitude of resident population) and MASPSL (mean altitude of starting point of ski lifts) serve as references for “critical altitudes” of Austrian districts. A warming implies a reduction of snow in all districts, but the loss is overproportional in lower altitudes. The direction of economic impacts is clear – income losses and adaptation costs – but magnitude and time frames remain uncertain. Received: 24 February 1999 · Accepted: 15 May 1999     

Changes in mineral soil organic carbon stocks in the croplands of European Russia and the Ukraine, 1990–2070; comparison of three models and implications for climate mitigation

Three soil carbon models (RothC, CANDY and the Model of Humus Balance) were used to estimate the impacts of climate change on agricultural mineral soil carbon stocks in European Russia and the Ukraine using detailed spatial data on land-use, future land-use, cropping patterns, agricultural management, climate and soil type. Scenarios of climate were derived from the Hadley Centre climate Version 3 (HadCM3) model; future yields were determined using the Soil–Climate–Yield model, and land use was determined from regional agricultural and economic data and a model of agricultural economics. The models suggest that optimal management, which entails the replacement of row crops with other crops, and the use of extra years of grass in the rotation could reduce Soil organic carbon (SOC) loss in the croplands of European Russia and the Ukraine by 30–44% compared to the business-as-usual management. The environmentally sustainable management scenario (SUS), though applied for a limited area within the total region, suggests that much of this optimisation could be realised without damaging profitability for farmers.     

Soil organic carbon dynamics of croplands in European Russia: estimates from the “model of humus balance”

The Model of Humus Balance was used to estimate the influence of climate effects and changing agricultural practices on carbon (C) levels in soddy–podzolic soils in the Russian Federation for the years 2000–2050. The model was linked with a spatial database containing soil, climate and farming management layers for identification of spatial change of C sequestration potential. Analysis of relationships between C, soil texture and climate indicated that compared with a business-as-usual scenario, adaptation measures could increase the number of polygons storing soil organic carbon (SOC) by 2010–2020. The rate of possible C loss is sensitive to the different climate scenarios, with a maximum potential for SOC accumulation expected in 2030–2040, thereafter decreasing to 2050. The effect is most pronounced for the arid part of the study area under the emission scenario with the highest rate of increase in atmospheric CO₂ concentration, supporting findings from the dynamic SOC model, RothC. C sequestration during the study period was permanent for clay and clay loam soils with a C content of more than 2%, suggesting that C sequestration should be focused on highly fertile, fine-textured soils. We also show that spatial heterogeneity of soil texture can be a source of uncertainty for estimates of SOC dynamics at the regional scale. Figures in color are available at     

Management of loss and damage in small island developing states: implications for a 1.5 °C or warmer world

Small island developing states (SIDS) have been identified as some of the most vulnerable countries to the impacts of climate change due to inherent environmental, economic, and demographic characteristics. As SIDS experience impacts of climate change and reach their limits to adaptation, the identification and management of loss and damage is essential. Monitoring and evaluating loss and damage, and implementing effective responses to address these impacts, becomes even more important in a 1.5 °C or warmer world, as impacts from climate change increase. As global agreements on climate change are implemented and mechanisms to manage impacts continue to be negotiated and established, the existing ability of SIDS to monitor and respond to loss and damage must be evaluated to determine gaps that must be addressed in a 1.5 °C or warmer world. This research utilizes interviews with UNFCCC climate change negotiators for SIDS and analysis of Intended Nationally Determined Contributions, to assess the state of loss and damage management in SIDS. The research provides an assessment of loss and damage already being experienced in SIDS, the status of existing mechanisms to actively monitor and evaluate loss and damage, and the existence of policies and mechanisms in SIDS to address loss and damage. Three areas of concern appear to be common for SIDS: lack of data relating to loss and damage, gaps in financial assessments of loss and damage, and a lack of policies or mechanisms targeted at loss and damage. These issues appear to be most acute in relation to slow onset impacts. Cumulatively, these challenges may present difficulties in detection and attribution and in obtaining a holistic understanding of the extent and costs of loss and damage for SIDS.     

Land-cover changes and recent hydrological evolution in the Duero Basin (Spain)

Land-use and land-cover changes have attracted substantial scientific interest in recent years because of their marked influence on hydrological cycles. In developed countries of the Mediterranean basin, the generalized revegetation and forest growth in mountainous areas that occurred during the last five decades are negatively affecting the evolution of water resources in headwaters. In this study, changes in land cover in the Duero River Basin (northern Spain) during the last 50 years were analyzed and their role in hydrological evolution was estimated. For this purpose, step-wise linear regressions were developed to estimate the evolution of runoff as a function of climate (precipitation and temperatures). The results show a significant expansion of forest cover in the headwaters, although it has been more extensive in the mountains to the north of the basin than to the south. River discharges in the headwaters underwent a generalized decline during the study period (1961–2006), but precipitation over the same period did not show an appreciable trend. In the absence of noticeable trends in removal of water for human consumption, our results indicate that revegetation is contributing to the observed hydrological decline. Our hypothesis is confirmed because of the greater divergence in the evolution of precipitation and runoff in the northern headwaters (more forest growth) than in the south headwaters (less forest growth). Results suggest that further increases in forest area will enhance hydrological decline and highlight the importance of integrating land-cover information in water availability assessments in a region where water is a strategic resource.     

Spatial assessment of climate change effects on crop suitability for major plantation crops in Sri Lanka

Climate change is the main global challenge of this century; it is therefore imperative to identify its effects on agriculture in developing countries. This research makes spatial assessment of climate change effect on major plantation crops in Sri Lanka, with emphasis on crop suitability of tea, rubber, and coconut. Geo-referenced maps of spatial and temporal changes in crop suitability and production potentials are generated and compared. Data pertaining to six agro-ecological zones under the study area are analyzed for a period of 1980–2007. Crop suitability maps are generated amalgamating yield maps and climatic factors maps using AHP in multi-criteria analysis under two time frames of 1980–1992 and 1993–2007. Percent change in crop suitability and crop yield classes is calculated based on five crop suitability and five crop yield classes during two time frames. Dynamics of climatic parameters and crop yield are recognized using geo-referenced maps. The suitability maps of the two time frames are compared to identify the changes with each crop in conjunction with changes in the prevailing climate and yield. Geographic shift of suitability, yield, and climate classes are examined. Net gain or loss in crop production is quantified. Long-term annual rainfall significantly decreased in mid-country wet zone, whereas the mean temperature of the study area increased by 1.4°C. Results clearly showed that the climate and yield can be meaningfully related to the crop suitability and management.     

基于SPOT_NDVI的甘肃省植被覆盖变化及其与气候、地形因子的关系

植被覆盖时间序列特征体现了气候变化和人类活动对环境的影响,利用2000~2018年SPOT_NDVI并结合气象和地形数据,采用趋势分析、偏相关分析、地形面积修正等方法探究甘肃省植被覆盖的变化特征及与气候、地形的关系。研究表明：近19年来,甘肃省植被覆盖整体呈恢复状态,但低覆盖区面积仍为最大,空间分布总体呈现南高北低的状态。降水对省内植被生长总体起到促进作用,特别是黄土高原地区,植被覆盖度与降水有显著的正相关性;在南部湿润区和北部干旱区,气温对植被生长分别起到促进和抑制作用。就地形而言,海拔2 500~3 000 m、坡度大于25°的半阳坡地区最适宜植被生长。进行植被覆盖研究,有利于区域生态建设和持续性发展,同时对人地关系以及经济发展的统筹规划也有重要的理论与实际意义。     

1961～2018年河南省暴雨初终日和暴雨日数的时空变化规律分析

利用1961～2018年河南省111个气象站逐日降水资料,采用气候倾向率、相关分析和多元逐步回归等数理统计方法,分析了河南省暴雨初终日和暴雨日数的时空变化规律。结果表明:(1)河南省各站平均暴雨初日为5月19～7月16日,最早暴雨初日为1月28日～5月25日,均由南向北明显推迟,由西向东明显提前,由平原向山区明显推迟。(2)河南省各站平均暴雨终日为8月5日～8月30日,最晚暴雨终日为9月9日～11月29日,均由南向北明显日期提前,由西向东明显推迟,由平原向山区最晚暴雨终日明显提前。(3)河南省各站年平均暴雨日数为0.7～4.3天,由南向北明显减少,由西向东明显增多,由平原向山区明显减少。(4)河南省平均暴雨初日和平均暴雨终日均有提前趋势,气候倾向率分别为1.2和0.2 d·(10 a)~(-1);平均暴雨日数呈阶段性变化,特别是2000年以后呈明显减少趋势;各站暴雨初日、暴雨终日和暴雨日数的气候倾向率分别在-9.3～9.3、-2.4～5.4和-3.0～3.2 d·(10 a)~(-1)之间,但仅有少数站点通过显著性水平检验。     

Climate variability and changes in the major cities of Bangladesh: observations,possible impacts and adaptation

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.     

Impact of climate warming upon the fish assemblages of the Portuguese coast under different scenarios

Impact of sea-surface warming upon the fish assemblages of the Portuguese coast was assessed under two scenarios, the A2 and the B2 scenarios (Special Report on Emission Scenarios), which when coupled with a regional circulation model HadRM3 predict 1 and 2°C of sea-surface warming until the year 2100. Species richness increased in the Portuguese coast. In both scenarios, there was a latitudinal gradient in the amount of lost and gained species, increasing from north to south. An anomaly in the latitudinal gradient of species richness was detected in the southernmost area, which presented the lowest species richness of all areas, in the A2 scenario, and appears to be particularly vulnerable to climate change. Very few species were totally eliminated from Portuguese waters. For the Portuguese coast as a whole, there were more new than lost species, in both scenarios. Most of the new species were commercially important species, in the majority subtropical in the north and tropical in the south, mainly demersal and reef-associated. Reef-associated species also increased in relative importance. A commercial opportunity for fisheries may arise from climate warming, since most of the new species were commercial species and not many commercial species were lost. An increasing gradient from north to south was detected in the colonization of new species of herbivores, planktivores, and omnivores, as well as lower mean trophic level, which might have consequences for the future of trophic webs.     

Nature and fate of Hudson Bay permafrost

Two aspects of the permafrost of the Hudson Bay region are examined. The first is the climatological conditions that support permafrost especially along the southwestern shore of Hudson Bay. The second is the fate of the permafrost using recent climate change scenarios. The continuous permafrost along the shores of southwestern Hudson Bay is examined from a climatological perspective. Two hypotheses are explored to explain the presence of continuous permafrost in this region in spite of the relatively "warm" local climate. Possible errors in the calculation of thawing degree days and the asymmetries in frozen and unfrozen soil thermal conductivities are successively examined. Only the second hypothesis is likely to explain the presence of permafrost in southwestern Hudson Bay. Sophisticated climate models are used to assess the potential change in permafrost distribution in the Hudson Bay region. Nine simulations using three different versions of the Canadian Centre of Climate Modelling and Analysis (CCCma) general circulation model are used to project permafrost distribution. Two surface temperature thresholds, –5 and –10 °C, are used to diagnose permafrost grid points. All simulations, including those that include reduction of CO₂ emissions, showed at least a 50% reduction of permafrost by 2100 using these temperature thresholds. Electronic Publication     

Impacts of climate change on land-use and wetland productivity in the Prairie Pothole Region of North America

Wetland productivity in the Prairie Pothole Region (PPR) of North America is closely linked to climate. A warmer and drier climate, as predicted, will negatively affect the productivity of PPR wetlands and the services they provide. The effect of climate change on wetland productivity, however, will not only depend on natural processes (e.g., evapotranspiration), but also on human responses. Agricultural land use, the predominant use in the PPR, is unlikely to remain static as climate change affects crop yields and prices. Land use in uplands surrounding wetlands will further affect wetland water budgets and hence wetland productivity. The net impact of climate change on wetland productivity will therefore depend on both the direct effects of climate change on wetlands and the indirect effects on upland land use. We examine the effect of climate change and land-use response on semipermanent wetland productivity by combining an economic model of agricultural land-use change with an ecological model of wetland dynamics. Our results suggest that the climate change scenarios evaluated are likely to have profound effects on land use in the North and South Dakota PPR, with wheat displacing other crops and pasture. The combined pressure of land-use and climate change significantly reduces wetland productivity. In a climate scenario with a +4 °C increase in temperature, our model predicts that almost the entire region may lack the wetland productivity necessary to support wetland-dependent species.     

气候变化对青藏高原腹地可持续发展的影响

受全球变暖影响，青藏高原气候呈现出暖干化趋势。气温升高，降水量减少对高原腹地植被生长具有消极意义，导致该区牧草质量和数量的下降。人口和牲畜数量的增加，更加重了资源环境与经济（牧业经济）发展的对立。本文对受气候和人为因素共同作用下，青藏高原腹地高寒草地逆行演替的原因及方式进行了分析。在些基础上，对气候暖干化模式下可持续的利用高寒草地资源提出了建议。     

Phenotypic variation in Ural and Siberian populations of the heath <Emphasis Type="Italic">Coenonympha amaryllis</Emphasis> (Stoll, 1782)

Phenotypic variation in the widespread Siberian and Mongolian butterfly species Coenonympha amaryllis (Stoll, 1782), an indicator of undisturbed steppe communities, is analyzed. It is shown that its size variation is influenced by a complex of climatic factors, the most important of them being the average starting date of the frost-free period and average annual temperature in the region. Longitude-dependent variation in size is described by a “sawtooth curve” characteristic of species with changing voltinism.     

秦岭南北地区农业气候资源时空变化特征

利用秦岭南北地区1960~2016年47个气象站点的观测资料,运用气候倾向率、Mann-Kendall趋势检验、相关分析与反距离加权插值等方法分析了秦岭南北地区光、热、水等农业气候资源的时空变化特征。结果表明：1960年以来,秦岭南北地区气温、≥10℃活动积温呈显著增加趋势,1995年后气温快速上升,并在2002年增温达到显著水平。春、冬、秋季增温明显,空间上秦岭以北增温倾向率大于秦岭以南。 1960~2016年,秦岭南北地区降水量总体呈微弱下降趋势,从时间上看,1995年前降水量以下降为主,1995年后降水量转为上升趋势;从空间上看,1960~2016年,下降较明显地区为秦岭以北、嘉陵江沿线,其次为汉水流域丹江口水库区域;部分地区呈现微弱上升趋势,主要分布在巴巫谷地、汉水流域大巴山等山地段和秦岭南坡东部。相对湿度呈微弱下降趋势;日照时数呈显著下降趋势,四季下降程度为夏>冬>秋>春,下降显著地区为研究区东部平原、汉中盆地、关中盆地及巴巫谷地。 关键词： 农业气候资源,时空变化,秦岭南北地区     

Assessing the implications of a 1.5 °C temperature limit for the Jamaican agriculture sector

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.