Assessing the impact of climate change on visitor behaviour and habitat use at the coast: A UK case study

Although tourism and recreation can bring economic benefits to an area, the presence of visitors may adversely impact biodiversity, particularly if they make use of sensitive environments. It is anticipated that the effects of global climate change alone may increase the vulnerability of many environments, but these effects may be magnified if warmer and drier weather encourages more visitors, or makes them more likely to participate in ecologically damaging activities. Using case study sites from the UK, this study examines how different types of beach visitors make use of coastal environments. Via a series of visitor surveys, information is elicited on the environmental preferences of a range of visitor types including walkers, bird watchers, and bathers. The use of different habitats by these visitors is also assessed via an analysis of walking routes undertaken in a Geographical Information System. From this, an assessment is made of the likely present day biodiversity impacts arising from different coastal users, and how these may change under a modified climate. This study finds that whilst higher temperatures are expected to increase visitor numbers, warmer weather may encourage greater participation in low impact activities such as bathing. The findings are discussed in the context of coastal management.     

Climate sensitivity to wetlands and wetland vegetation in mid-Holocene North Africa

 Wetland regions are important components of the local climate, with their own characteristic surface energy and moisture budgets. Realistic representation of wetlands, including the important vegetation component, may therefore be necessary for more accurate simulations of climate and climate change. However, many land-atmosphere coupled models either ignore wetlands or treat wetlands as bare, water-saturated soil, neglecting the vegetation present within wetland environments. This study investigates the possible response of the mid-Holocene climate of North Africa to changes in orbital forcing, both with and without the presence of wetlands. The location of these wetlands is guided by analysis of paleovegetation and wetland distribution. In this study, the wetland regime in the land surface component of a climate model was modified to incorporate vegetation. Field measurements have shown that vegetation affects water loss associated with evaporation (including transpiration) within a wetland area. Comparisons between non-vegetated wetland and vegetated wetland revealed an increase in local albedo that produced an associated decrease in net radiation, evaporation and precipitation in the vicinity of the wetlands regions. Based on an analysis of the model surface water balance, the calculated area of mid-Holocene wetland coverage for North Africa closely matches the observed. For the North African region as a whole, the effects of adding vegetation to the wetland produced relatively small changes in climate, but local recycling of water may have served to help maintain paleo wetland communities. Received: 16 March 1999 / Accepted: 17 May 2000     

Climate Change and Water Resources in Britain

This paper explores the potential implications of climate change for the use and management of water resources in Britain. It is based on a review of simulations of changes in river flows, groundwater recharge and river water quality. These simulations imply, under feasible climate change scenarios, that annual, winter and summer runoff will decrease in southern Britain, groundwater recharge will be reduced and that water quality – as characterised by nitrate concentrations and dissolved oxygen contents – will deteriorate. In northern Britain, river flows are likely to increase throughout the year, particularly in winter. Climate change may lead to increased demands for water, over and above that increase which is forecast for non-climatic reasons, primarily due to increased use for garden watering. These increased pressures on the water resource base will impact not only upon the reliability of water supplies, but also upon navigation, aquatic ecosystems, recreation and power generation, and will have implications for water quality management. Flood risk is likely to increase, implying a reduction in standards of flood protection. The paper discusses adaptation options.     

Farmer perceptions of climate change: Associations with observed temperature and precipitation trends,irrigation, and climate beliefs

How individuals perceive climate change is linked to whether individuals support climate policies and whether they alter their own climate-related behaviors, yet climate perceptions may be influenced by many factors beyond local shifts in weather. Infrastructure designed to control or regulate natural resources may serve as an important lens through which people experience climate, and thus may influence perceptions. Likewise, perceptions may be influenced by personal beliefs about climate change and whether it is human-induced. Here we examine farmer perceptions of historical climate change, how perceptions are related to observed trends in regional climate, how perceptions are related to the presence of irrigation infrastructure, and how perceptions are related to beliefs and concerns about climate change. We focus on the regions of Marlborough and Hawke’s Bay in New Zealand, where irrigation is utilized on the majority of cropland. Data are obtained through analysis of historical climate records from local weather stations, interviews (n = 20), and a farmer survey (n = 490). Across both regions, no significant historical trends in annual precipitation and summer temperatures since 1980 are observed, but winter warming trends are significant at around 0.2–0.3 °C per decade. A large fraction of farmers perceived increases in annual rainfall despite instrumental records indicating no significant trends, a finding that may be related to greater perceived water availability associated with irrigation growth. A greater fraction of farmers perceived rainfall increases in Marlborough, where irrigation growth has been most substantial. We find those classes of farmers more likely to have irrigation were also significantly more likely to perceive an increase in annual rainfall. Furthermore, we demonstrate that perceptions of changing climate – regardless of their accuracy – are correlated with increased belief in climate change and an increased concern for future climate impacts. Those farmers that believe climate change is occurring and is human induced are more likely to perceive temperature increases than farmers who believe climate change is not occurring and is not human induced. These results suggest that perceptions are influenced by a variety of personal and environmental factors, including infrastructure, which may in turn alter decisions about climate adaptation.     

Understanding climate coping as a basis for strategic climate change adaptation – The case of Queenstown-Lake Wanaka,New Zealand

Weather conditions that influence natural resource-based tourist destinations are likely to be affected by climate change, but our understanding of how businesses and destinations manage for present and future conditions is limited. In this study we report on the relationships between weather and tourism activities in the Queenstown-Lake Wanaka region, South Island, New Zealand. Key stakeholder interviews and a workshop form the empirical basis of this paper. Coping range application ideas derived from ecological management literature are used to develop a framework to understand and inform thinking and strategies around how tourism businesses and destinations are currently responding to the weather and perhaps could in future respond to climate change. Results show that within a destination individual businesses have widely varying relationships with the weather, with each type of activity operating within its own coping range to particular environmental gradients, for example temperature. Coping, which can be observed outside the ‘ideal’ range of a particular environmental gradient, requires business adjustments so as to cope with increasingly marginal conditions, up to a Critical Stop Point – the ultimate threshold. The data suggest that increased need for adjustments impacts on business viability, and more planned adaptation measures would be necessary to increase viability under increasingly detrimental climatic conditions. Discussion at a destination level workshop indicates that at and beyond thresholds, keystone industry and destination level strategic adaptation planning is required to ensure the viability of the destination as a whole.     

Climate change and water resources in the Bagmati River Basin,Nepal

This paper characterizes potential hydrological impact of future climate in the Bagmati River Basin, Nepal. For this research, basinwide future hydrology is simulated by using downscaled temperature and precipitation outputs from the Hadley Centre Coupled Model, version 3 (HadCM3), and the Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS). It is predicted that temperature may rise maximally during the summer rather than winter for both A2 and B2 Special Report on Emissions Scenarios (SRES) scenarios. Precipitation may increase during the wet season, but it may decrease during other seasons for A2 scenario. For B2 scenario, precipitation may increase during all the seasons. Under the A2 scenario, premonsoon water availability may decrease more in the upper than the middle basin. During monsoons, both upper and middle basins show increased water availability. During the postmonsoon season, water availability may decrease in the upper part, while the middle part shows a mixed trend. Under the B2 scenario, water availability is expected to increase in the entire basin. The analysis of the projected hydrologic impact of climate change is expected to support informed decision-making for sustainable water management.     

The influence of human activity in the Arctic on climate and climate impacts

Human activities in the Arctic are often mentioned as recipients of climate-change impacts. In this paper we consider the more complicated but more likely possibility that human activities themselves can interact with climate or environmental change in ways that either mitigate or exacerbate the human impacts. Although human activities in the Arctic are generally assumed to be modest, our analysis suggests that those activities may have larger influences on the arctic system than previously thought. Moreover, human influences could increase substantially in the near future. First, we illustrate how past human activities in the Arctic have combined with climatic variations to alter biophysical systems upon which fisheries and livestock depend. Second, we describe how current and future human activities could precipitate or affect the timing of major transitions in the arctic system. Past and future analyses both point to ways in which human activities in the Arctic can substantially influence the trajectory of arctic system change.     

Natural variability of summer rainfall over China in HadCM3

Summer rainfall over China has shown decadal variability in the past half century, which has resulted in major north–south shifts in rainfall with important implications for flooding and water resource management. This study has demonstrated how multi-century climate model simulations can be used to explore interdecadal natural variability in the climate system in order to address important questions around recent changes in Chinese summer rainfall, and whether or not anthropogenic climate change is playing a role. Using a 1,000-year simulation of HadCM3 with constant pre-industrial external forcing, the dominant modes of total and interdecadal natural variability in Chinese summer rainfall have been analysed. It has been shown that these modes are comparable in magnitude and in temporal and spatial characteristics to those observed in the latter part of the twentieth century. However, despite 1,000 years of model simulation it has not been possible to demonstrate that these modes are related to similar variations in the global circulation and surface temperature forcing occurring during the latter half of the twentieth century. This may be in part due to model biases. Consequently, recent changes in the spatial distribution of Chinese summer rainfall cannot be attributed solely to natural variability, nor has it been possible to eliminate the likelihood that anthropogenic climate change has been the driving factor. It is more likely that both play a role.     

Modified water regime and salinity as a consequence of climate change: prospects for wetlands of Southern Australia

The natural Australian landscape sustains a mosaic of wetlands that range from permanently wet to temporary. This diversity of wetland types and habitats provides for diverse biotic communities, many of which are specific to individual wetlands. This paper explores the prospects for southern Australian wetlands under modified water regime and salinity induced by climatic changes. Extended droughts predicted as a consequence of climate change (lower rainfall and higher temperatures) combined with human-induced changes to the natural hydrological regime will lead to reductions in the amount of water available for environmental and anthropogenic uses. Reduced runoff and river flows may cause the loss of some temporary wetland types that will no longer hold water long enough to support hydric communities. Species distributions will shift and species extinctions may result particularly across fragmented or vulnerable landscapes. Accumulation of salts in wetlands shift species-rich freshwater communities to species-poor salt tolerant communities. Wetlands will differ in ecological response to these changes as the salinity and drying history of each wetland will determine its resilience: in the short term some freshwater communities may recover but they are unlikely to survive and reproduce under long term increased salinity and altered hydrology. In the long term such salinized wetlands with altered hydrology will need to be colonized by salt tolerant species adapted for the new hydrological conditions if they are to persist as functional wetlands. As the landscape becomes more developed, to accommodate the need for water in a warmer drying climate, increasing human intervention will result in a net loss of wetlands and wetland diversity.     

气候变化对我国小麦发育及产量可能影响的模拟研究

利用随机天气模型, 将气候模式对大气中CO₂倍增时预测的气候情景与CERES-小麦模式相连接, 研究了气候变化对我国冬小麦和春小麦生产的可能影响.结果表明, 气候变化后小麦发育将加快, 生育期缩短, 冬小麦平均缩短7.3天, 春小麦平均缩短10.5天, 春小麦生育期缩短的绝对数和相对数均大于冬小麦.籽粒产量呈下降趋势, 冬小麦平均减产7%~8%, 雨养条件下比水分适宜时减产幅度略大.春小麦的减产幅度大于冬小麦, 水分适宜时平均减产17.7%, 雨养时平均减产31.4%.     

Paper 4. climate change impacts on water resources and possible responses in the mink region

The capacity to supply both instream and offstream water uses under alternative climate conditions and likely future changes in population, technology, and water-using practices are examined through an adaptation of the framework developed in the Second National Water Assessment. Two measures of the adequacy of water supplies - the availability of renewable supplies to provide for withdrawal and instream uses and the relation between desired instream flows and current streamflows - are used to examine the impact of the 1931–1940 analog climate (with and without CO₂ enrichment) on Missouri, Iowa, Nebraska, and Kansas (MINK). The impacts of the analog climate on water supplies are estimated from actual streamflow data and estimates of the differences in reservoir evaporation under the 1931–1940 analog and the 1951–1980 control climates. A modification of the Erosion Productivity Inventory Calculator (EPIC) model is used to estimate the impacts of the analog climate (with and without CO₂ enrichment) on irrigation water use.Water, which is already a scarce resource in the MINK region, would become much scarcer if the climate of the 1930s were to become the norm. Mean assessed total streamflow would drop to 69% of the control climate level for the Missouri River Basin, 71% for the Upper Mississippi, and 93% for the Arkansas. Even in the absence of climate change, MINK will have less water in the year 2030 than it does today because groundwater stocks are being depleted and increased upstream diversions would reduce surface flows into these states. Irrigation and instream uses such as navigation, hydroelectric power production, recreation, and fish and wildlife habitat would be most adversely, impacted by the climate-induced changes in water supplies.     

气候变化对扎龙湿地生态环境的影响

湿地是生物多样性岛屿化的基础，水源又是湿地赖以存在的基础，而水源又受到气候变化的影响。通过对讨论气候变化对湿地水源的影响，得出湿地生态环境可能发生变化的若干结论。     

Impact of recent climate change on the hydrology of coastal Mediterranean rivers in Southern France

The purpose of this paper is to analyse the regional impact of recent climate change on the water resources in southern France. We produced spatial reconstructions of the monthly evolutions of temperature, precipitation and water discharge in 15 watersheds of six coastal river basins and examined the major changes based on trend analysis for the last 40 years. In this part of the Mediterranean, the general warming trend was strongly enhanced by changes in the atmospheric circulation patterns, characterized by a northward extension of the subtropical high pressure domain during spring and summer. During these seasons, monthly warming rates could achieve almost twice the mean annual warming rates. Although annual precipitation did not follow clear trends, water discharge significantly decreased in one third of the watersheds and accounted for an estimated 20% reduction of the water resources in this region. This concerns both the highest and lowest watersheds. In the former, the reduction is likely the result of a temperature induced switch of snowfall to rainfall at high altitudes. In the latter, the reduction of discharge seems to come from lower groundwater levels, which may be related to the temperature increase too, but also have other origins. The recent climatic evolution is consistent with most modelling simulations for the future, indicating that the reduction of the water resources will hold on, probably still enhanced by decreases in precipitation.     

Implications of climate change due to the enhanced greenhouse effect on floods and droughts in Australia

Potential impacts of climate change on heavy rainfall events and flooding in the Australian region are explored using the results of a general circulation model (GCM) run in an equilibrium enhanced greenhouse experiment. In the doubled CO₂ simulation, the model simulates an increase in the frequency of high-rainfall events and a decrease in the frequency of low-rainfall events. This result applies over most of Australia, is statistically more significant than simulated changes in total rainfall, and is supported by theoretical considerations. We show that this result implies decreased return periods for heavy rainfall events. The further implication is that flooding could increase, although we discuss here the many difficulties associated with assessing in quantitative terms the significance of the modelling results for the real world.The second part of the paper assesses the implications of climate change for drought occurrence in Australia. This is undertaken using an off-line soil water balance model driven by observed time series of rainfall and potential evaporation to determine the sensitivity of the soil water regime to changes in rainfall and temperature, and hence potential evaporation. Potential impacts are assessed at nine sites, representing a range of climate regimes and possible climate futures, by linking this sensitivity analysis with scenarios of regional climate change, derived from analysis of enhanced greenhouse experiment results from five GCMs. Results indicate that significant drying may be limited to the south of Australia. However, because the direction of change in terms of the soil water regime is uncertain at all sites and for all seasons, there is no basis for statements about how drought potential may change.     

Effects of climate on numbers of northern prairie wetlands

The amount of water held in individual wetland basins depends not only on local climate patterns but also on groundwater flow regime, soil permeability, and basin size. Most wetland basins in the northern prairies hold water in some years and are dry in others. To assess the potential effect of climate change on the number of wetland basins holding water in a given year, one must first determine how much of the variability in number of wet basins is accounted for by climatic variables. I used multiple linear regression to examine the relationship between climate variables and percentage of wet basins throughout the Prairie Pothole Region of Canada and the United States. The region was divided into three areas: parkland, Canadian grassland, and United States grassland (i.e., North Dakota and South Dakota). The models - which included variables for spring and fall temperature, yearly precipitation, the previous year's count of wet basins, and for grassland areas, the previous fall precipitation - accounted for 63 to 65% of the variation in the number of wet basins. I then explored the sensitivities of the models to changes in temperature and precipitation, as might be associated with increased greenhouse gas concentrations. Parkland wetlands are shown to be much more vulnerable to increased temperatures than are wetlands in either Canadian or United States grasslands. Sensitivity to increased precipitation did not vary geographically. These results have implications for waterfowl and other wildlife populations that depend on availability of wetlands in the parklands for breeding or during periods of drought in the southern grasslands.The U.S. Government right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

东北冷涡及其气候影响

基于自动识别、追踪方法得到的近50年东北冷涡数据集, 本文研究了东北冷涡的年际变率及演变趋势, 并分析了其持续性活动对我国气候的影响及相关联的大尺度环流异常特征。结果表明, 东北冷涡具有很明显的年际变率, 且存在2.5年左右的主振荡周期, 但没有显著的长期变化趋势。东北局地在持续性冷涡控制下, 四季气温均明显偏低, 并在春季和夏季能造成局部降水偏多。在东北冷涡活跃的夏季, 长江流域往往降水显著偏多; 而在冬季东北冷涡频繁活动时, 我国大部分地区往往低温少雨, 这与强盛的东亚冬季风密切相关。研究结果表明, 冬季东北冷涡活动和东亚冬季风强度之间的相关系数达到99%的信度水平。在东北冷涡活跃的夏季, 东亚地区对流层维持着深厚的偶极型位势高度异常, 高空急流向南偏移并略加强, 低层西北太平洋反气旋异常和中纬度地区的东风异常有助于局地的水汽通量的辐合, 进而有利于降水的偏多。     

Potential effects of climate change on a semi-permanent prairie wetland

We assessed the potential effects of a greenhouse gas-induced global climate change on the hydrology and vegetation of a semi-permanent prairie wetland using a spatially-defined, rule-based simulation model. An 11-yr simulation was run using current versus enhanced greenhouse gas climates. Projections of climatic change were from the Goddard Institute for Space Studies (GISS) general circulation model. Simulations were also run using a range of temperature (+2 and +4 °C) and precipitation change values (–20, –10, 0, +10, +20%) to determine the responsiveness of wetland vegetation and hydrology to a variety of climate scenarios.Maximum water depths were significantly less under the enhanced greenhouse gas scenario than under the current climate. The wetland dried in most years with increased temperature and changes in precipitation. Simulations also revealed a significant change in the vegetation, from a nearly balanced emergent cover to open water ratio to a completely closed basin with no open water areas. Simulations over a range of climate change scenarios showed that precipitation changes (particularly increases) had a greater impact on water levels and cover ratios when the temperature increase was moderate (+2 °C).These potential changes in wetland hydrology and vegetation could result in a dramatic decline in the quality of habitat for breeding birds, particularly waterfowl. Continued research on climate and wetland modeling is needed.     

呼伦湖湿地消长对气象水文因子变化的响应

利用1961—2005年呼伦湖湿地的气象及水文资料,基于灰色关联度分析、Mann-Kendall检验及小波分析、回归统计等方法,分析了湿地消长对气象水文因子变化的响应特征。结果表明:年与夏季气候在湿地消长中起主导作用。区域年降水量每增加10 mm,年降水量的直接作用是使湿地水域面积和水位深度分别增加2.6 km2和1.6 cm;年径流量每增加1×108 m3,湿地水域面积和水位深度分别增加4.8 km2和3.0 cm。45年来,湿地消长对影响因子连续变化过程的响应特征具有一致性,特别在20世纪90年代后响应更显著,湿地萎缩加快;气温与降水量变化在湿地水域面积、水位深度消长中的贡献率分别为33.1%与66.9%,22.5%与77.5%,降水量变化起主导作用。湿地消长对影响因子的多时间尺度周期性具有很好的响应。在27年的年代际尺度主周期与11~16年次周期、2~10年年际尺度准周期的叠加作用下,45年来,湿地消长出现了2次减少、1次增加的周期过程,并呈现短周期波动特征。     

Climate-change effects on extreme precipitation in central Europe: uncertainties of scenarios based on regional climate models

Observations as well as most climate model simulations are generally in accord with the hypothesis that the hydrologic cycle should intensify and become highly volatile with the greenhouse-gas-induced climate change, although uncertainties of these projections as well as the spatial and seasonal variability of the changes are much larger than for temperature extremes. In this study, we examine scenarios of changes in extreme precipitation events in 24 future climate runs of ten regional climate models, focusing on a specific area of the Czech Republic (central Europe) where complex orography and an interaction of other factors governing the occurrence of heavy precipitation events result in patterns that cannot be captured by global models. The peaks-over-threshold analysis with increasing threshold censoring is applied to estimate multi-year return levels of daily rainfall amounts. Uncertainties in scenarios of changes for the late 21st century related to the inter-model and within-ensemble variability and the use of the SRES-A2 and SRES-B2 greenhouse gas emission scenarios are evaluated. The results show that heavy precipitation events are likely to increase in severity in winter and (with less agreement among models) also in summer. The inter-model and intra-model variability and related uncertainties in the pattern and magnitude of the change is large, but the scenarios tend to agree with precipitation trends recently observed in the area, which may strengthen their credibility. In most scenario runs, the projected change in extreme precipitation in summer is of the opposite sign than a change in mean seasonal totals, the latter pointing towards generally drier conditions in summer. A combination of enhanced heavy precipitation amounts and reduced water infiltration capabilities of a dry soil may severely increase peak river discharges and flood-related risks in this region.     

Hydrologic Response of a Wetland to Changing Moisture Conditions: Modeling Effects of Soil Heterogeneity

Prediction of the effects of external influences such as climate change on wetland systems requires the prediction of hydrologic effects. Because wetland soils are typically heterogeneous, it is particularly important to understand the extent and connectedness of hydraulically conductive soil units, since water flow may be concentrated in such units while bypassing others of lower conductivity. However, subsurface hydrologic models typically do not represent heterogeneity adequately, being limited by sparse parameterization of soil properties. Conventional techniques for mapping units of soil within wetlands are highly laborious, requiring soil coring and laboratory testing. As an alternative, we developed a portable piezocone driver and highly sensitive piezocone designed to map wetland soil units with centimeter-scale resolution in the vertical and meter-scale resolution in the horizontal dimension. This system successfully delineated several different layers of peat, sand, and limnetic sediments, and their degree of interconnectedness in an eight-meter-thick peat deposit. Monitoring of wetland response to precipitation, changes in stream stage, and overbank flooding was then used in conjunction with the piezocone data and a two-dimensional flow model to constrain the hydraulic properties of the soil units. Thus parameterized, a standard subsurface flow model was able to realistically simulate a variety of hydrologic processes relevant to climate change, including wetland-stream water exchange, the movement of wetland porewaters to the root zone of plants, and wetland desaturation under dry conditions.