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     

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.     

How can winter tourism adapt to climate change in Saxony’s mountains?

This study deals with regional climate change in five low mountain areas in Eastern Germany and assesses the awareness of tourism professionals towards climate change, its impact on winter tourism and adaptation options. Favourable conditions for winter tourism decreased over the last decades in the Saxon low mountain ranges. A change from predominantly snow-based to a wider variety of winter tourism options appears indispensible as climate models project continuing warming. Diversifying touristic options provides opportunities to develop new business fields and to attract new target groups. This paper reveals obstacles and opportunities to adapt and develop winter tourism in the central European low mountain ranges and to increase the competitiveness of regional tourism. A survey explored the current awareness of representatives of most of the Saxon downhill skiing areas and of selected winter tourism municipalities towards climate change and its implications on their business. Awareness is essential to successfully implement adaptation measures. About half of the interviewees were not aware of the regional changes in natural snow conditions projected for the next 15–20 years. Nevertheless, the majority recognized climate change as a serious issue. Yet, stakeholders repeatedly emphasized their uncertainty about related scientific facts. They attributed their perception to mass media reports that suggest a lack of scientific consensus on climate change issues. Adaptation options for slope-based and general winter tourism are developed and presented, involving ideas of the interviewees. To successfully move towards adaptation, supply and marketing of alternative offers need to be strengthened. A survey of tourist expectations is planned to ensure a successful implementation of new (winter) touristic offers in the Saxon mountains.     

Climate change and climate-induced hot spots in forest shifts in central Siberia from observed data

Regional Siberian studies have already registered climate warming over the last several decades. We evaluated ongoing climate change in central Siberia between 1991 and 2010 and a baseline period, 1961–1990, and between 1991 and 2010 and Hadley 2020 climate change projections, represented by the moderate B1 and severe A2 scenarios. Our analysis showed that winters are already 2–3°C warmer in the north and 1–2°C warmer in the south by 2010. Summer temperatures increased by 1°C in the north and by 1–2°C in the south. Change in precipitation is more complicated, increasing on average 10% in middle latitudes and decreasing 10–20% in the south, promoting local drying in already dry landscapes. Hot spots of possible forest shifts are modeled using our Siberian bioclimatic vegetation model and mountain vegetation model with respect to climate anomalies observed pre-2010 and predicted 2020 Hadley scenarios. Forests are predicted to shift northwards along the central Siberian Plateau and upslope in both the northern and southern mountains. South of the central Siberian Plateau, steppe advancement is predicted that was previously non-existent north of 56°N latitude. South of 56°N, steppe expansion is predicted in the dry environments of Khakasiya and Tyva. In the southern mountains, it is predicted that the lower tree line will migrate upslope due to increased dryness in the intermontane Tyvan basins. The hot spots of vegetation change that are predicted by our models are confirmed by regional literature data.     

Assessment of climate change simulations over climate zones of Turkey

Projected climate change over Turkey has been analyzed by using the reference (1961–1990) and future (2071–2100) climate simulations produced by ICTP-RegCM3. Since examining Turkey as a single region could be misleading due to the existence of complex topography and different climatic regions, Turkey has been separated into seven climatic regions to evaluate the surface temperature and precipitation changes. Comparison of the reference simulation with observations was made spatially by using a monthly gridded data set and area-averaged surface data compiled from 114 meteorological stations for each climatic region of Turkey. In the future simulation, warming over Turkey’s climatic regions is in the range of 2–5 °C. Summer warming over western regions of Turkey is 3 °C higher than the winter warming. During winter, in the future simulation, precipitation decreases very significantly over southeastern Turkey (24 %), which covers most of the upstream of Euphrates and Tigris river basin. This projected decrease could be a major source of concern for Turkey and the neighboring countries. Our results indicate that a significant increase (48 %) in the autumn season precipitation is simulated over southeastern Turkey, which may help to offset the winter deficit and therefore reduce the net change during the annual cycle.     

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.     

Climate change in Nepal and its impact on Himalayan glaciers

Climate change can be particularly hard-hitting for small underdeveloped countries, relying heavily on natural resources for the economy and livelihoods. Nepal is one among these countries, being landlocked, with diverse physiographical characteristics within a relatively small territory and with rugged terrain. Poverty is widespread and the capacity of people and the country to cope with climate change impact is low. The country is dominated by the Asian monsoon system. The main occupation is agriculture, largely based on rain-fed farming practices. Tourism based on high altitude adventures is one of the major sources of income for the country. Nepal has a large hydropower potential. While only 0.75% of the theoretical hydropower potential has been tapped, Nepal can greatly benefit from this natural resource in the future. Climate change can adversely impact upon water resources and other sectors of Nepal. The source of water is mainly summer monsoon precipitation and the melting of the large reserve of snow and glaciers in the Himalayan highlands. Observations show clear evidences of significant warming. The average trend in the country is 0.06°C per year. The warming rates are progressively higher for high elevation locations. The warming climate has resulted in rapid shrinking of majority of glaciers in Nepal. This paper presents state-of-knowledge on the glacial dynamics in the country based on studies conducted in the past in Shorong, Khumbu, Langtang, Dhaulagiri and Kanchenjunga regions of Nepal. We present recent trends in river flow and an overview of studies on expected changes in the hydrological regime due to climate change. Formation, growth and likely outburst of glacial lake are phenomena directly related to climate change and deglaciation. This paper provides a synopsis of past glacial lake outburst floods impacting Nepal. Further, likely impacts of climate change on other sectors such as agriculture, biodiversity, human health and livelihoods are discussed.     

An integrated assessment of climate change impacts for Greece in the near future

Climate changes in the Mediterranean region, related to a significant increase in temperature and changes in precipitation patterns, can potentially affect local economies. Agriculture and tourism are undoubtedly the most important economic sources for Greece and these may be more strongly affected by changing future climate conditions. Climate change and their various negative impacts on human life are also detected in their environment; hence this study deals with implications, caused by changing climate, in urban and forest areas. Potential changes for the mid-twenty-first century (2021–2050) are analysed using a high-resolution regional climate model. This paper presents relevant climatic indices, indicative for potential implications which may jeopardise vital economic/environmental sectors of the country. The results provide insights into particular regions of the Greek territory that may undergo substantial impacts due to climate change. It is concluded that the duration of dry days is expected to increase in most of the studied agricultural regions. Winter precipitation generally decreases, whereas an increase in autumn precipitation is projected in most areas. Changing climate conditions associated with increased minimum temperatures (approximately 1.3°C) and decreased winter precipitation by 15% on average suggest that the risk for forest fires is intensified in the future. In urban areas, unpleasantly high temperatures during day and night will increase the feeling of discomfort in the citizens, while flash floods events are expected to occur more frequently. Another impact of climate change in urban regions is the increasing energy demand for cooling in summer. Finally, it was found that continental tourist areas of the Greek mainland will more often face heatwave episodes. In coastal regions, increased temperatures especially at night in combination with high levels of relative humidity can lead to conditions that are nothing less than uncomfortable for foreigners and the local population. In general, projected changes associated with temperature have a higher degree of confidence than those associated with precipitation.     

What are the implications of sea-level rise for a 1.5, 2 and 3 °C rise in global mean temperatures in the Ganges-Brahmaputra-Meghna and other vulnerable deltas?

Even if climate change mitigation is successful, sea levels will keep rising. With subsidence, relative sea-level rise represents a long-term threat to low-lying deltas. A large part of coastal Bangladesh was analysed using the Delta Dynamic Integrated Emulator Model to determine changes in flood depth, area and population affected given sea-level rise equivalent to global mean temperature rises of 1.5, 2.0 and 3.0 °C with respect to pre-industrial for three ensemble members of a modified A1B scenario. Annual climate variability today (with approximately 1.0 °C of warming) is potentially more important, in terms of coastal impacts, than an additional 0.5 °C warming. In coastal Bangladesh, the average depth of flooding in protected areas is projected to double to between 0.07 and 0.09 m when temperatures are projected at 3.0 °C compared with 1.5 °C. In unprotected areas, the depth of flooding is projected to increase by approximately 50% to 0.21–0.27 m, whilst the average area inundated increases 2.5 times (from 5 to 13% of the region) in the same temperature frame. The greatest area of land flooded is projected in the central and north-east regions. In contrast, lower flood depths, less land area flooded and fewer people are projected in the poldered west of the region. Over multi-centennial timescales, climate change mitigation and controlled sedimentation to maintain relative delta height are key to a delta’s survival. With slow rates of sea-level rise, adaptation remains possible, but further support is required. Monitoring of sea-level rise and subsidence in deltas is recommended, together with improved datasets of elevation.

     

Effect of snow depth and snow duration on soil N dynamics and microbial activity in the alpine areas of the eastern Tibetan Plateau

The effects of snow regimes (including the depth and duration of snow cover) on soil N dynamics and microbial activity in situ were explored in the alpine belt of the eastern Tibetan Plateau. Deeper snow-cover reduced NH ₄ ⁺ -N content, microbial biomass carbon and nitrogen, fungi count, and enzyme activities, whereas did not change net N mineralization. No differences in N pools in the soil, microbial biomass, microbial counts, and enzyme activity were found under the different duration of snow cover, showing that accumulation and release in soil N pools did not be significantly changed by earlier continuous snow cover.     

Impact changes of climatic extremes on arable farming in the north of the Netherlands

Agriculture is vulnerable to climate change in multiple ways. Here, we use the northern region of the Netherlands as a case study to explore how risk assessments for climate change impacts on crop production can address multiple vulnerabilities. We present a methodology, which we call agro climate calendar (ACC) that (i) includes potential yield losses, as well as loss of product quality, and (ii) assesses the risks of a variety of climate factors including weather extremes and the emergence and abundance of pests and diseases. Climate factors are defined for two time slices: 1990 (1976–2005) and 2040 (2026–2055); the frequency of occurrence of the factors is compared for the two periods, and the resulting frequency shifts are presented in a crop calendar on a monthly basis. This yields an indication of the magnitude and direction of changes in climatic conditions that can lead to damage by extreme events and pests and diseases. We present results for the two most important crops in the region, seed potato, and winter wheat. The results provide a good overview of risks from climate factors, and the most important threats and opportunities are identified. This semi-quantitative approach is firmly rooted in farm management, which is the level where operational and strategic decisions are made. Thus, the approach is well suited to assist local stakeholders such as farmers and policy makers to explore farm-level adaptation. This work is complementary to previous modeling work that focused mainly on the relation between mean climate change factors (i.e., temperature) and crop yield.     

近51年川滇地区气候暖干化与旱涝灾害趋势判断

为揭示川滇地区气候特征与旱涝灾害趋势，以川滇地区70个气象站点1961～2011年的逐月气温、降水资料为基础,采用线性回归、五年滑动平均、M K突变检验、反距离加权空间插值、Z指数法、Morlet小波变换等方法，对川滇地区气候变化特征与旱涝灾害进行了分析。结果表明：近51 a川滇地区气温以021℃/10 a的速率增加；降水量以1076 mm/10 a的速率减少；尤其是20世纪90年代末期以来正经历着以增温和变干为趋势的气候变化特征，气候暖干化趋势明显。近51 a川滇地区年旱涝灾害总的趋势是向干旱发展，以2000年为转折点，2000年以前该区多涝灾，2000年后多旱灾，这与该区的气温与降水变化一致，气候暖干化的结果直接导致了旱灾加剧。川滇地区春、冬两季旱涝年际周期变化规律强，Z指数呈上升趋势，降水量增加；夏季旱涝周期变化十分显著，旱涝灾害程度加剧，干旱化趋势明显；秋季旱涝变化周期性不强，呈弱干旱化趋势发展     

Sensitivity of typical Mediterranean crops to past and future evolution of seasonal temperature and precipitation in Apulia

The region of Apulia, which is located in the south-east tip of the Italian Peninsula, has a typical Mediterranean climate with mild winters and hot-dry summers. Agriculture, an important sector of its economy, is potentially threatened by future climate change. This study describes the evolution of seasonal temperature and precipitation from the recent past to the next decades and estimates future potential impacts of climate change on three main agricultural products: wine, wheat and olives. Analysis is based on instrumental data, on an ensemble of climate projections and on a linear regression model linking these three agricultural products to seasonal values of temperature and precipitation. In Apulia, precipitation and temperature time series show trends toward warmer and marginally drier conditions during the whole analyzed (1951–2005) period: 0.18 °C/decade in mean annual minimum temperature and ?14.9 mm/decade in the annual total precipitation. Temperature trends have been progressively increasing and rates of change have become noticeably more intense during the last 25 years of the twentieth century. Model simulations are consistent with observed trends for the period 1951–2000 and show a large acceleration of the warming rate in the period 2001–2050 with respect to the period 1951–2000. Further, in the period 2001–2050, simulations show a decrease in precipitation, which was not present in the previous 50 years. Wine production, wheat and olive harvest records show large inter-annual variability with statistically significant links to seasonal temperature and precipitation, whose strength, however, strongly depends on the considered variables. Linear regression analysis shows that seasonal temperature and precipitation variability explains a small, but not negligible, fraction of the inter-annual variability of these crops (40, 18, 9 % for wine, olives and wheat, respectively). Results (which consider no adaptation of crops and no fertilization effect of CO₂) suggest that evolution of these seasonal climate variables in the first half of the twenty-first century could decrease all considered variables. The most affected is wine production (?20 ÷ ?26 %). The effect is relevant also on harvested olives (?8 ÷ ?19 %) and negligible on harvested wheat (?4 ÷ ?1 %).     

Climate change threats to environment in the tropical Andes: glaciers and water resources

Almost all of the world’s glaciers in the tropical latitudes are located in the Central Andes (Peru, Bolivia, Ecuador and Colombia). Due to their high altitude, to the high level of radiation and to the tropical climate dynamics, they all are particularly threatened by climate change, as a result of not only warming, but also of changing variability of precipitation. Many glaciers are of crucial importance for the livelihood of the local populations and even for three capitals, Lima (Peru), La Paz (Bolivia) and Quito (Ecuador), which depend on them for water and energy supplies. This paper shows that after a period of increased flow due to the glacier melt disequilibrium, the available water resource will decrease along with the rapid shrinking of the glaciers considered as water reservoirs. The case of the Cordillera Blanca (Peru) is analyzed more in detail with the mid-term (20 years) and long-term (1–2 centuries) impact of the glacier shrinking on the local water resources. Associated risks for the population and consequences for the human activities (tourism, hydropower, agriculture and stock-breeding, large-scale irrigation) are described at each stage of the mountain range.     

The Hungarian national climate change strategy: its principles, assignments, and a special case study on maize production

Efficient protection against global climate change requires international emission reduction measures. Before these ones are decided, the individual states should make arrangements within their own scope of authority for preventing and mitigating the adverse impacts of climate change already in progress as a consequence of carbon dioxide emissions done so far. In spring 2008 Hungary—among the very first ones in the international stage—passed a middle-term National Climate Change Strategy, which determines both the national tasks in order to reduce greenhouse gas emissions, and sectoral tasks of the adaptation to the ongoing climate change for the period of 2008–2025. As a concrete case study we investigated the possible impacts of the regional change in atmospheric carbon dioxide concentration, temperature and precipitation conditions of the Carpathian Basin on the cultivation conditions of maize, based on the downscaled IPCC 2007 scenarios. Temperatures of each scenarios increased significantly to basic run (1961–1990). This change suppressed the positive influence of elevated CO₂ on carbon assimilation. Serious depression may be waited during extreme hot days at Keszthely, Hungary.     

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.     

Climate changes and tree stand dynamics at the upper limit of their growth in the North Ural mountains

The composition and structure of tree stands near the timberline have been studied on different slopes and at different elevations in the Tylaisko-Konzhakovsko-Serebryanskii Massif, the North Urals. It has been found that the upper limits of tree stands with different degrees of canopy closure have risen considerably (by about 100 m of elevation) since the mid-19th century, although the formation of these stands started as early as the late 18th century. Woodless areas in the eastern part of the massif started to be colonized by Larix sibirica in the late 18th to early 19th centuries; those in the western part, by Picea obovata in the mid-19th century; and in the southern part, by Betula tortuosa in the late 19th century. Analysis of meteorological data provides evidence for warming and increasing humidity of the climate since the late 19th century. Favorable climatic changes that facilitated the expansion of the forest have taken place both in the summer (prolongation of the growing period) and in winter seasons (increase of air temperature and precipitation). The observed differences in the composition and dynamics of tree stands between the studied areas of the mountain range are most probably explained by different requirements of tree species for the depth of snow cover and the degree of soil freezing.     

Quantifying fluctuations in winter productive cropped area in the Central Indian Highlands

The Central Indian Highland landscape (CIHL) represents a complex, diverse, and highly human-modified system. Nearly half the landscape is cropland, yet it hosts 21 protected areas surrounded and connected by forests. Changing farming practices with increasing access to irrigation might alter this intensifying landscape in the near future particularly in light of weather variability. We analyzed a decade of remote sensing data for cropping patterns and climatic factors combined with census data for irrigation and demographic factors to understand winter cropping trajectories in the CIHL. We quantified ‘productive cropped area’ (PCA), defined as the area with planted crop that is green at the peak of the winter growing season. We find three primary trajectories in PCA—increasing, fluctuating, and decreasing. The most dominant trend is fluctuating PCA in two-thirds of the districts, ranging from ~2.11 million to ~3.73 million ha between 2001 and 2013, which is associated with village-level access to irrigation and local labor dynamics. In 58 % of all districts, clay soils were associated with winter cropping (p < 0.05). Increasing irrigation is associated with increased winter PCA in most (94 %) districts (p < 0.00001). We find strong negative association between PCA and land surface temperature (LST) in most (66 %) districts (p < 0.01). LST closely corresponds to daytime mean air temperature (p < 0.001) for available meteorological stations. Fine-scale meteorological and socioeconomic data, however, are needed to further disentangle impacts of these factors on PCA in this landscape.     

Climate trends and impacts on crop production in the Koshi River basin of Nepal

Understanding crop responses to climate is essential to cope with anticipated changes in temperature and precipitation. We investigated the climate–crop yield relationship and the impact of historical climate on yields of rice, maize and wheat in the Koshi basin of Nepal. The results show significant impact of growing season temperature and precipitation on crop production in the region. Rice, maize and wheat cultivated at altitudes below 1,100, 1,350 and 1,700 m amsl (above mean sea level), respectively, suffer from stress due to higher temperatures particularly during flowering and yield formation stages. Responses of crop yields to a unitary increment in growing season mean temperature vary from ?6 to 16 %, ?4 to 11 % and ?12 to 3 % for rice, maize and wheat, respectively, depending on the location and elevation in the basin. In most parts of the basin, we observe warming trends in growing season mean temperatures of rice, maize and wheat over the last few decades with clear evidence of negative impacts on yields. However, at some high-elevation areas, positive impacts of warming are also observed on rice and maize yields. If the observed trends in temperature continue in future, the impact is likely to be mostly negative on crop production in the basin. However, crop production may gain from the warming at relatively higher altitudes provided other conditions, e.g., water availability, soil fertility, are favorable.