Change-point analysis for serially correlated summit temperatures in the Romanian Carpathians

Characterizing climatic changes in the high-altitude mountain regions helps scientists and policy makers understand the effects of such changes on water resources, economic development, and the health of ecosystems. This paper proposes a change-point analysis to determine the time and magnitude of summer temperature changes in the summit areas of Romanian Carpathians between 1961 and 2007. Due to their altitude, massiveness, and position, Romanian Carpathians are an important barrier for different types of air masses between Western and Southeastern Europe. The results show that the change in summer temperatures occurred shortly after 1980. The average magnitude of this change is consistent with changes occurring in other parts of Southern Europe in the same time period although the magnitude of changes at individual weather stations may differ substantially. We aided our analysis by a statistical method based on regression models with serially correlated ARMA errors.     

Uncertainties in Predicting Tourist Flows Under Scenarios of Climate Change

Tourism is largely dependent on climatic and natural resources. For example, “warmer'' climates generally constitute preferred environments for recreation and leisure, and natural resources such as fresh water, biodiversity, beaches or landscapes are essential preconditions for tourism. Global environmental change threatens these foundations of tourism through climate change, modifications of global biogeochemical cycles, land alteration, the loss of non-renewable resources, unsustainable use of renewable resources and loss of biodiversity (Gössling and Hall, 2005). This has raised concerns that tourist flows will change to the advantage or disadvantage of destinations, which is of major concern to local and national economies, as tourism is one of the largest economic sectors of the world, and of great importance for many destinations. In consequence, an increasing number of publications have sought to analyse travel flows in relation to climatic and socio-economic parameters (e.g. Lise and Tol, 2001; Maddison, 2001; Christ et al., 2003; Hamilton et al., 2003; Hamilton and Tol, 2004). The ultimate goal has been to develop scenarios for future travel flows, possibly including “most at risk destinations'', both in economic and in environmental terms. Such scenarios are meant to help the tourist industry in planning future operations, and they are of importance in developing plans for adaptation.     

Snow pack in the Swiss Alps under changing climatic conditions: an empirical approach for climate impacts studies

Summary ?In many instances, snow cover and duration are a major controlling factor on a range of environmental systems in mountain regions. When assessing the impacts of climatic change on mountain ecosystems and river basins whose origin lie in the Alps, one of the key controls on such systems will reside in changes in snow amount and duration. At present, regional climate models or statistical downscaling techniques, which are the principal methods applied to the derivation of climatic variables in a future, changing climate, do not provide adequate information at the scales required for investigations in which snow is playing a major role. A study has thus been undertaken on the behavior of snow in the Swiss Alps, in particular the duration of the seasonal snow-pack, on the basis of observational data from a number of Swiss climatological stations. It is seen that there is a distinct link between snow-cover duration and height (i.e., temperature), and that this link has a specific “signature” according to the type of winter. Milder winters are associated with higher precipitation levels than colder winters, but with more solid precipitation at elevations exceeding 1,700–2,000 m above sea-level, and more liquid precipitation below. These results can be combined within a single diagram, linking winter minimum temperature, winter precipitation, and snow-cover duration. The resulting contour surfaces can then be used to assess the manner in which the length of the snow-season may change according to specified shifts in temperature and precipitation. While the technique is clearly empirical, it can be combined with regional climate model information to provide a useful estimate of the length of the snow season with snow cover, for various climate-impacts studies. Received May 14, 2002; revised August 12, 2002; accepted August 17, 2002     

Ecosystem Evaluation, Climate Change and Water Resources Planning

This paper considers ecosystem evaluation under conditions of climate change in the context both of the U.S. Water Resources Council's Principles and Guidelines (P&G) and the more general Federal regulations governing environmental evaluation. Federal water agencies have responsibilities for protecting aquatic ecosystems through their regulatory programs and operations and planning missions. The primary concern of water resources and aquatic ecosystems planning in the United States is on the riparian or floodplain corridors of river systems. In the context of climate change, planning for these systems focusses on adaptation options both for current climate variability and for that engendered by potential climate change.Ecosystems appear to be highly vulnerable to climate change, as described in IPCC reports. Aquatic ecosystems are likely to be doubly affected, first by thermally induced changes of global warming and second by changes in the hydrologic regime. Perhaps as much as any of the issues dealt with in this issue, the evaluation of ecosystems is linked to fundamental questions of criteria as well as to the details of the Federal environmental planning system. That system is a densely woven, interlocking system of environmental protection legislation, criteria and regulations that includes a self-contained evaluation system driven by the National Environmental Policy Act (NEPA) procedural guidelines (United States Council on Environmental Quality, 1978) and Environmental Impact Statement (EIS) requirements. The Corps of Engineers must use both the P&G and the NEPA/EIS system in discharging its responsibilities.If U.S. Federal agencies are to take the lead in formulating and evaluating adaptation options, there needs to be a reexamination of existing evaluation approaches. Among the elements of the P&G that may require rethinking in view of the prospects of global climate change are those relating to risk and uncertainty, nonstationarity, interest rates, and multiple objectives. Within the government planning process, efforts must be made to resolve inconsistencies and constraints in order to permit the optimal evaluation of water-based ecosystems under global climate change. The interrelationships of the two systems are described in this paper, and alternative ways of viewing the planning process are discussed. Strategic planning and management at the watershed level provides an effective approach to many of the issues. Current NEPA/EIS impact analysis does not provide a suitable framework for environmental impact analysis under climate uncertainty, and site-specific water resources evaluation relating to climate change appears difficult at current levels of knowledge about climate change. The IPCC Technical Guidelines, however, provide a useful beginning for assessing the impacts of future climate states.     

云台山旅游气候资源分析

本文分析了在连云港市云台风的气候资源：气温、降水、风雾、降雪和结冰，也分析了由气候资源造就的云台山动物、植物资源及云台山的垂直和水平气候带变化，进而得出云台山适合旅游的气候条件。     

Forest ecosystems, disturbance, and climatic change in Washington State, USA

Climatic change is likely to affect Pacific Northwest (PNW) forests in several important ways. In this paper, we address the role of climate in four forest ecosystem processes and project the effects of future climatic change on these processes across Washington State. First, we relate Douglas-fir growth to climatic limitation and suggest that where Douglas-fir is currently water-limited, growth is likely to decline due to increased summer water deficit. Second, we use existing analyses of climatic controls on tree species biogeography to demonstrate that by the mid twenty-first century, climate will be less suitable for key species in some areas of Washington. Third, we examine the relationships between climate and the area burned by fire and project climatically driven regional and sub-regional increases in area burned. Fourth, we suggest that climatic change influences mountain pine beetle (MPB) outbreaks by increasing host-tree vulnerability and by shifting the region of climate suitability upward in elevation. The increased rates of disturbance by fire and mountain pine beetle are likely to be more significant agents of changes in forests in the twenty-first century than species turnover or declines in productivity, suggesting that understanding future disturbance regimes is critical for successful adaptation to climate change.     

Connecting physical watershed characteristics to climate sensitivity for California mountain streams

California mountain streams provide critical water resources for human supplies and aquatic ecosystems, and have been affected by climatic changes to varying degrees, often within close proximity. The objective of this study is to examine stream flow timing changes and their climatic drivers through 2009, identify sub-regional patterns in response and sensitivity, and explore whether the differences in the sensitivity of a stream to climatic changes can be partially explained through the physical characteristics of a watershed. To this end, changes in streamflow timing for each watershed were assessed through several runoff timing measures, and overall sensitivity to historic climatic changes through a composite sensitivity index. Elevation, aspect, slope, geology, and landcover distributions, as well as climate information were assembled for each watershed; and were analyzed in conjunction with the sensitivity index. Results showed that the basins most sensitive to climatic changes are on the western Sierra Nevada slopes, while eastern and southern Sierra Nevada, as well as Klamath mountain watersheds exhibit little or no response to climatic shifts to date. Basin sensitivity was not found to be connected to any individual physical watershed characteristic other than elevation. However, it is suggested that basin-to-basin differences in sensitivity, observed in spite of regional-scale warming and similar watershed elevations, can be explained by differences in elevation ranges and combinations of physical watershed characteristics. Results about stream differences in climate sensitivity could aid in prioritizing stream preservation efforts.     

Taking the Pulse of Mountains: Ecosystem Responses to Climatic Variability

An integrated program of ecosystem modeling and field studies in the mountains of the Pacific Northwest (U.S.A.) has quantified many of the ecological processes affected by climatic variability. Paleoecological and contemporary ecological data in forest ecosystems provided model parameterization and validation at broad spatial and temporal scales for tree growth, tree regeneration and treeline movement. For subalpine tree species, winter precipitation has a strong negative correlation with growth; this relationship is stronger at higher elevations and west-side sites (which have more precipitation). Temperature affects tree growth at some locations with respect to length of growing season (spring) and severity of drought at drier sites (summer). Furthermore, variable but predictable climate-growth relationships across elevation gradients suggest that tree species respond differently to climate at different locations, making a uniform response of these species to future climatic change unlikely. Multi-decadal variability in climate also affects ecosystem processes. Mountain hemlock growth at high-elevation sites is negatively correlated with winter snow depth and positively correlated with the winter Pacific Decadal Oscillation (PDO) index. At low elevations, the reverse is true. Glacier mass balance and fire severity are also linked to PDO. Rapid establishment of trees in subalpine ecosystems during this century is increasing forest cover and reducing meadow cover at many subalpine locations in the western U.S.A. and precipitation (snow depth) is a critical variable regulating conifer expansion. Lastly, modeling potential future ecosystem conditions suggests that increased climatic variability will result in increasing forest fire size and frequency, and reduced net primary productivity in drier, east-side forest ecosystems. As additional empirical data and modeling output become available, we will improve our ability to predict the effects of climatic change across a broad range of climates and mountain ecosystems in the northwestern U.S.A.     

Impact of Climate Change on Agricultural Production in the Sahel – Part 1. Methodological Approach and Case Study for Millet in Niger

In the last 30 years the climate of the West African Sahel has shown various changes, especially in terms of rainfall, of which inter-annual variabilityis very high. This has significant consequences for the poor-resource farmers, whose incomes depend mainly on rainfed agriculture. The West African Sahel is already known as an area characterized by important interaction between climate variability and key socio-economic sectors such as agriculture and water resources. More than 80% of the 55 million population of West African Sahel is rural, involved in agriculture and stock-farming, the two sectors contributing almost 35% of the countries' GDPs. It is thereforeobvious that climate change seriously affects the economies of these countries. Adding to this situation the high rate of population increase(3%), leading to progressive pressure upon ecosystems, and poorsanitary facilities, one comes to the conclusion that Sahelian countries, Niger amongst them, will be highly vulnerable to climate change.This paper investigates the impact of current climate variability and future climate change on millet production for three major millet-producing regions in Niger. Statistical models have been used to predict the effects of climate change on future production on the basis of thirteen available predictors. Based on the analysis of the past 30-years of rainfall and production data, the most significant predictors of the model are (i) seasurface temperature anomalies, (ii) the amount of rainfall in July, August and September, (iii) the number of rainy days and (iv) the wind erosion factor. In 2025, production of millet is estimated to be about 13% lower as a consequence of climate change, translated into a reduction of the total amount of rainfall for July, August and September, combined with an increase in temperature while maintaining other significant predictors at a constant level. Subsequently,various potential strategies to compensate this loss are evaluated, including those to increase water use efficiency and to cultivate varieties that are adapted to such circumstances.     

Conclusions,remaining issues,and next steps

The workshop focused on methodologies to assess the impacts of climate change on terrestrial and aquatic ecosystems and their socioeconomic consequences. It did not deal in any detail with the other components (i.e., models designed to estimate changes in atmospheric concentrations of greenhouse gases or in climatic factors) of an integrated assessment shown in Figure 2 of the introduction. This final chapter discusses some of the issues addressed during the San Diego workshop and highlights a few of the major findings of the papers. Issues discussed below include limitations of past modeling efforts and impediments to developing better models of the impacts of climate change on forest, grassland, and water resources; suggestions for future research both to develop better data and models and to employ existing data and modeling capabilities to improve the usefulness of climate impact assessments for policy purposes; and the need for developing a common assessment framework.The views expressed here are those of the authors and do not necessarily reflect those of their institutions or the other participants in the February 28 to March 3, 1993 workshop held in San Diego, California.     

The evolution of climate change impact studies on hydrology and water resources in California

Potential global climate change impacts on hydrology pose a threat to water resources systems throughout the world. The California water system is especially vulnerable to global warming due to its dependence on mountain snow accumulation and the snowmelt process. Since 1983, more than 60 studies have investigated climate change impacts on hydrology and water resources in California. These studies can be categorized in three major fields: (1) Studies of historical trends of streamflow and snowpack in order to determine if there is any evidence of climate change in the geophysical record; (2) Studies of potential future predicted effects of climate change on streamflow and; (3) Studies that use those predicted changes in natural runoff to determine their economic, ecologic, or institutional impacts. In this paper we review these studies with an emphasis on methodological procedures. We provide for each category of studies a summary of significant conclusions and potential areas for future work.     

Climate and regional resource analysis: The effect of scale on resource homogeneity

General Circulation Models (GCMs) are currently used to project future climate. The output of the models is then used to evaluate the effect of a climatic change on resources such as agriculture, forestry, and water resources. The GCMs used in long-term climate studies vary widely in the geographic resolution of their predictions. The approximate matching of resource data to the geographic scale of GCMs is an important step in the evaluation of the effects of climatic change on resources. As gridcell size increases, however, the distribution of resources within cells becomes more heterogeneous, and it becomes more difficult to evaluate the regional effects of climatic change. We quantify the change in resource heterogeneity as a function of gridcell size. Four resource variables (wheat yield, percent forest cover, population density, and percent of land irrigated) are analyzed on the basis of county-averaged data, while assignment to major drainage basins is based on exact watershed boundaries. A major change in resource heterogeneity within gridcells occurs at a grid length of from 1.2° to 3°.     

Climate change hotspots mapping: what have we learned?

In the past 5 years there has been a proliferation of efforts to map climate change “hotspots” — regions that are particularly vulnerable to current or future climate impacts, and where human security may be at risk. While some are academic exercises, many are produced with the goal of drawing policy maker attention to regions that are particularly susceptible to climate impacts, either to mitigate the risk of humanitarian crises or conflicts or to target adaptation assistance. Hotspots mapping efforts address a range of issues and sectors such as vulnerable populations, humanitarian crises, conflict, agriculture and food security, and water resources. This paper offers a timely assessment of the strengths and weaknesses of current hotspots mapping approaches with the goal of improving future efforts. It also highlights regions that are anticipated, based on combinations of high exposure, high sensitivity and low adaptive capacity, to suffer significant impacts from climate change.     

论现代气候观与新疆气候问题

提出现代气候观概念，并指出现代气候观包括气候系统观、资源观、环境观、变化观、层次以；新疆当前迫切需要研究解决的气候问题是新疆气候变化及其对环境特别是水资源的影响以及短期气候预测及其业务系统的建立。     

Characterisation of contemporary local climate change in the mountains of southwest Bulgaria

The Pirin Mountains in southwest Bulgaria spatially mark a transition between the Mediterranean and temperate climate zones. Therefore they are also particularly relevant for research on high mountain climate and the effect of landscape transformation. Historical climate records gathered in the area have been researched, checked and statistically examined. The mountainous climate has been characterised and trends in the evolution of temperature and precipitation since 1931 have been outlined. There are objective evidences for an increasing annual mean temperature, longer vegetative periods and local droughts in spring and autumn. Significant changes also appear in climatic threshold values such as the number of frost change days. This last parameter is very important for the sustainability of mountainous ecosystems.     

亚热带东部丘陵山区作物气候生产力研究

本文根据1983年4月—1986年3月三年山区梯度观测资料，综合考虑山区光、热、水农业的气候资源匹配关系，建立不同山区、坡向、高度的作物气候生产力估算模式。模式中对山区温度、降水、日照等气象要素进行了修正。运用模式估算了不同山区、坡向、高度的水稻、玉米、冬小麦气候生产力。计算结果:亚热带东部丘陵山区单、双季稻、夏玉米气候生产力一般南坡大于北坡，西坡大于东坡；春玉米、冬小麦一般北坡大于南坡，东坡大于西坡。双季晚稻气候生产力大于双季早稻，夏玉米大于春玉米（神农架山区除外）。应该指出，目前高产典型水稻产量可达其气候生产力的60%以上，玉米和冬小麦仅达到30%—50%左右，表明山区农业气候资源可开发潜力很大。本文为合理开发山区气候资源、调整农业布局及提高单位面积产量提供了定量的科学依据。     

IPCC第五次评估报告对跨区域影响的新认识

IPCC第五次评估报告（AR5）第二工作组（WGII）报告认为,气候变化对世界上大部分区域的自然和人类系统的影响将进一步加剧,其对非洲最大的影响预计发生在半干旱的环境,增加现有的水资源可利用量和农业系统的压力;气候变化已导致北欧地区的谷物产量增加而南欧地区的产量降低,未来的变化将增加欧洲的灌溉需求;在亚洲的许多地区,气候变化将导致农业生产率下降;气候、大气CO₂和海洋酸化的进一步变化预计将对大洋洲的水资源、海岸生态系统、基础设施、健康、农业和生物多样性产生实质性的影响;在北美,许多带来风险的气候压迫力的频率和强度将在未来几十年增加;中美洲和南美洲许多国家的持续高水平贫困导致了对气候变率和变化的高脆弱性;在北极,气候变化与非气候相关驱动在确定的物理、生物和社会经济风险上交互作用,变化率可能超过了社会系统适应的速率;在气候和非气候因素的影响下,小岛屿具有高度的脆弱性,同时,气候变暖将增加海洋生态系统的风险。     

Rising powers: the evolving role of BASIC countries

The exponential growth in global populations, economic activity and resource utilization means it is becoming increasingly difficult to satisfy global demand for a number of fundamental resources, while some key ecosystems services are under stress. The likelihood of future resource scarcities have begun to influence the positions taken within international climate change negotiations by fast-growing developing countries. When Brazil, South Africa, India, and China formed the BASIC group it took many by surprise. The coordination needed to align this heterogeneous group of countries cannot simply be understood in terms of a set of shared interests around climate policy. How the BASIC group emerged and the nature of its cooperation on climate change are examined within the broader context in which these increasingly powerful countries came to join forces. Although traditionally aligned with the G77 group of developing countries, recent strategising as a group of emerging economies reflects their realization that there are insufficient global resources available to follow the same development pathway as industrialized countries. Hence, they must seek alternative growth pathways, which requires establishing common ground while also keeping track of each others' positions on important global issues like climate change.     

Adaptation to climate change in glaciated mountain regions

Understanding of the human dimensions of climate change (HDCC) in glaciated mountain regions is limited by a deficit in systematically collated information on where, to what stressors, by whom, at what scale, and with what effect adaptation is occurring. This paper presents a systematic literature review of the recent English language peer-reviewed scholarship on adaptation in glaciated mountain regions. 4050 potentially relevant articles were examined, with 36 included for full review. Results indicate that scholarly investigation into adaptation in glaciated mountains is presently limited to only 40 % of countries with alpine glaciation. Seventy-four discrete adaptation initiatives were identified, with most occurring in Peru (28 %), Nepal (22 %) and India (17 %). Many documented adaptations were initiated in response to intersecting stressors related to cryospheric change and socio-economic development; were autonomous and initiated in reaction to experienced climatic stimuli; and were carried out at the individual, family, or community scale. The study contributes to an emerging literature tracking on-the-ground adaptation processes and outcomes, and identifies a need to raise the profile of human adaptation in glaciated mountain regions within the HDCC scholarship. A research agenda for addressing key knowledge gaps and questions is developed, providing a framework for future investigation.     

1980—2005年海南岛尖峰岭热带山地雨林区气候突变与异常的初步研究

海南尖峰岭热带山地雨林作为典型的热带雨林生态系统之一,其长期的气候动态变化研究对全球变化研究有着重要的作用。采用1980—2005年海南尖峰岭森林生态系统国家野外科学观测研究站天池气象站地面常规气象观测资料,利用累积距平法和Mann-Kendall检验法分析了尖峰岭热带山地雨林区气候突变和气候异常,结果表明：该区26 a来,年平均气温、年平均地温、年平均最高最低气温、年积温和平均水汽压在1990年前后经历一次由低到高的突变,年平均风速在1993年经历由大到小的突变。在高强度ENSO事件发生的1998年,气温、地温均出现异常偏高,这些都表明该林区的森林气候变化正是对全球气候异常的明显响应过程。