Climate Variability and Change in High Elevation Regions: Past, Present and Future

Water management, climate change, and climate variability—along with their numerous interlinkages and the extent of related hydrologic, economic, social, environmental, and political impacts over time and space—have become issues of increasing global concern. Despite their importance for freshwater systems and the fundamental services they provide, numerous factors and uncertainties prevent us from forecasting their likely future multidimensional and multisectoral impacts with any accuracy. These factors include, but are not necessarily limited to, a lack of scientific understanding of their complexity and interrelationships, as well as an absence of reliable data that would otherwise allow us to understand them more reliably. Therefore, policy alternatives, management and development decisions, and investment choices on any adaptation strategy are challenging tasks under the best of circumstances. Given the uncertainties related to climate change and variability, nonclimatic factors have thus become more relevant. Governance—or decision-making by multiple actors with dissimilar interests grouped under formal and informal institutions—is one of the most important. This chapter discusses several case studies that analyze the roles that infrastructure and governance play in the context of adaptation in increasing resilience to climate variability and change in different regions, basins, and projects. Water infrastructure is fundamental to build resilience and adapt to climate variability and change. However, to be effective, it needs to be part of a governance framework that considers multisector needs and multilevel actors in the longer term.

This special issue of Climatic Change contains a series of research articles documenting co-ordinated work carried out within a 3-year European Union project ‘Prediction of Regional scenarios and Uncertainties for Defining European Climate change risks and Effects’ (PRUDENCE). The main objective of the PRUDENCE project was to provide high resolution climate change scenarios for Europe at the end of the twenty-first century by means of dynamical downscaling (regional climate modelling) of global climate simulations. The first part of the issue comprises seven overarching PRUDENCE papers on: (1) the design of the model simulations and analyses of climate model performance, (2 and 3) evaluation and intercomparison of simulated climate changes, (4 and 5) specialised analyses of impacts on water resources and on other sectors including agriculture, ecosystems, energy, and transport, (6) investigation of extreme weather events and (7) implications of the results for policy. A paper summarising the related MICE (Modelling the Impact of Climate Extremes) project is also included. The second part of the issue contains 12 articles that focus in more detail on some of the themes summarised in the overarching papers. The PRUDENCE results represent the first comprehensive, continental-scale intercomparison and evaluation of high resolution climate models and their applications, bringing together climate modelling, impact research and social sciences expertise on climate change.

Human interference with the climate system is occurring, and climate change poses risks for human and natural systems (IPCC, 2014). In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans. Evidence of climate-change impacts is strongest and most comprehensive for natural systems. Due to climate change projected by the mid 21st century and beyond, global marine-species redistribution and marine-biodiversity reduction in sensitive regions will challenge the sustained provision of fisheries productivity and other ecosystem services (IPCC, 2014). Spatial shifts of marine species due to projected warming will cause high-latitude invasions and high local-extinction rates in the tropics and semi-enclosed seas. Species richness and fisheries catch potential are projected to increase, on average, at mid and high latitudes and decrease at tropical latitudes (IPCC, 2014). The Benguela Current Large Marine Ecosystem (BCLME) is one of four Eastern Boundary Upwelling Ecosystems (EBUE), highly productive marine subregions. Although they comprise <2% of the global ocean area, they contribute nearly 7% of marine primary production and more than 20% of the world’s marine capture fisheries (IPCC, 2014). Catches in the EBUE are dominated by planktivorous species such as sardine, anchovy, and horse/jack mackerel, and piscivorous demersal species such as hake. Upwelling of nutrient-rich water stimulates primary production which is transferred to mid and upper trophic levels, resulting in substantial fish, seabird, and marine mammal populations. As a result, EBUEs are considered ‘hotspots’ of productivity and biodiversity. Previous research on the BCLME has had little emphasis on climate change. As with the other EBUEs, strong inter-annual and inter-decadal variability in physical oceanography makes it challenging to detect biophysical trends attributed to climate change. Nevertheless, the physical conditions of the BCLME are highly sensitive to climate variability over a range of scales. Despite its apparent sensitivity to environmental variability, there is limited evidence of ecological changes in the BCLME caused by climate change (IPCC, 2014). For example, pelagic fish, benthic crustaceans, and seabirds have demonstrated general shifts in distribution (IPCC, 2014). Even though much of the evidence on the recent climate change comes from remote sensing and outputs from coupled atmosphere-ocean models, it is necessary to link the global trends with local observations to detect the effects of this change on marine living resources in a regional context. In the BCLME region, the combined oceanographic and biodiversity database collected through the Ecosystem Approach to Fisheries (EAF) Nansen Programme is potentially a major source of local data covering climate change and its effect on marine resources in the last 30 yr. However, its contributions to the understanding of climate change effects on the BCLME are rather limited so far, since the huge amount of data collected under the programme has not been fully utilised. Based on data collected through the EAF Nansen programme, together with other relevant data, the NansClim project (2009–2014) was established to identify and describe possible trends and variability in ocean climate and corresponding changes in marine biodiversity and fisheries in the Benguela Current System. Observations of effects of climate variability on marine biota in the past, based on the Nansen database in combination with other data series available from the region, allowed NansClim to document some general responses concerning production and distribution of marine biota to set a baseline of observed effects of climate variability. Some of the species in the region are more poorly studied than others, and one of the tasks of the project was therefore to characterize the life cycle of such species which may be important indicators of future climate change.

The Nevada Rural Ozone Initiative (NVROI): Insights to understanding air pollution in complex terrain

Chapter 1 - Remote sensing of climate variability: An introduction

The aim of this article is to introduce the co-construction process as a productive approach to developing agricultural adaptation strategies to cope with climate change and variability in Quebec, Canada. The methodology is based on a critical synthesis of existing literature both of peer-reviewed articles and the grey literature that contain analyses on agriculture, climate change and adaptation. Our focus is on the approach which was used in a research project in Quebec dealing with agricultural adaptation and which was the result of almost 20 years of research by the co-author of this article into agricultural adaptation to climate change and variability in several regions in Quebec. Based on our research teams’ experiences, the co-construction approach can lead to a planned adaptation by farmers and as well by government agencies involved in supporting farmers’ adaptation to climate change and variability. While co-construction processes started as a top-down approach in Europe, it is increasingly initiated as a bottom-up approach. We introduce the origin of the adaptation concept and then differentiate between adaptation responses of biological systems and human systems. Co-construction overlaps to a certain extent with collaborative research, but co-construction does not need to incorporate researchers. Co-construction can also be part of a research action process, but once more, formal researchers need not be involved and the research action leadership can be undertaken by actors other than researchers. Adaptation has many characteristics and different types including several forms of adaptation that involve both private agents such as farmers and government agencies as well as non-governmental organizations. We also point out the similarities between the bottom-up perspective of current co-construction and the grounded theory approach in terms of methodology (i.e. data collection and analysis). Finally, we discuss the implementation of the co-construction approach in the context of agricultural adaptation to climate change and variability. Continued involvement with farmers has helped them appropriate the reality of climate change and variability which constitutes the first prerequisite in order to develop adaptation strategies.

This paper concentrates on impacts that regional and global climate changes may have on deltaic ecosystems using deltas in the Aral Sea basin as an example. In addition to an assessment of regional climate change and variability and their relationship to environmental conditions within inland river deltas, this paper examines the past development of the deltas (including consequences of human-induced alteration of the regional hydrologic cycle), climatic trends and ecosystem changes within them, and the relationships among future climatic and ecosystem changes that may occur. 11 figures, 2 tables, 71 references.

From years ago, climate change effects are happening in different areas of the world, including Rwanda. Potato as one of main commodities grown mainly in the cooler and wetter highlands of Rwanda, its production could be facing the global warming. The purpose of this study is to carry out weather (temperature and rainfall) change dynamics in the potato growing zones of Rwanda over the last thirty years. Weather daily data from 1987 to 2016 were collected from three weather stations, at Kawangire for low elevation, at Gikongoro mid elevation, and at Kora high elevation, respectively. Farmers were interviewed to know their perceptions on weather conditions during past thirty years. Weather data were analyzed by ombrothermic diagram, Nickolson Index and graphing with generated trend equation methods. Interview data were analyzed with Chi-square test at P =.05. Results have shown as dry June, July and August months in low elevation; June, July and August in medium elevation and June and July in high elevation depending on decade. Rainfall was increasing in low and medium elevations, while it was decreasing in high elevation. Temperature was decreasing in low elevation area and it was increasing in medium and high elevation areas. All interviewed farmers confirmed long term-shift in temperature and precipitations. A total of 95%, 54% and 43% of farmers from respectively low, medium and high elevations reported that weather was becoming wetter during last years. As conclusion, potato growing cooler and wetter conditions of high elevation are shifting to low elevation in Rwanda. For climate change mitigation, Rwanda needs to promote potato in its Eastern part, the low elevation region, in order to increase the crop production in the future.

Feedbacks between climate warming, land surface aridity, and wildfire-derived aerosols represent a large source of uncertainty in future climate predictions. Here, long-term observations of aerosol optical depth, surface level aerosol loading, fire-area burned, and hydrologic simulations are used to show that regional-scale increases in aridity and resulting wildfires have significantly increased summertime aerosol loading in remote high elevation regions of the Intermountain West of the United States. Surface summertime organic aerosol loading and total aerosol optical depth were both strongly correlated (p < 0.05) with aridity and fire area burned at high elevation sites across major western US mountain ranges. These results demonstrate that surface-level organic aerosol loading is dominated by summertime wildfires at many high elevation sites. This analysis provides new constraints for climate projections on the influence of drought and resulting wildfires on aerosol loading. These empirical observations will help better constrain projected increases in organic aerosol loading with increased fire activity under climate change.

This special issue of Climatic Change describes an effort to improve methodology for integrated assessment of impacts and consequences of climatic change. Highlights of the seven foregoing Parts (papers) that constitute this special issue are summarized here. The methodology developed involves construction of scenarios of climate change that are used to drive individual sectoral models for simulating impacts on crop production, irrigation demand, water supply and change in productivity and geography of unmanaged ecosystems. Economic impacts of the changes predicted by integrating the results of the several sectoral simulation models are calculated through an agricultural land-use model. While these analyses were conducted for the conterminous United States alone, their global implications are also considered in this summary as is the need for further improvements in integrated assessment methodology.

This study aims at contributing to the vulnerability and adaptation to climate changes (CC) analysis of bordering communities of Togodo Reserve, in order to enhance their resilience. Specifically, the present study attempted to (i) identify the climatic hazards of the WRT; (ii) determine the impacts of climate variability and change on their livelihoods; (iii) assess the socio-economic vulnerability of these communities to food insecurity in relation to CC; and (iv) identify indigenous adaptation strategies to control the effects of CC. The methodological approach used is based on a factual research and a field investigation. The investigation is conducted in two villages around the reserve, namely Deve and Gbohoule. The results showed that climate variability and change were appreciated in different indicators by the local communities living around the WRT: Droughts, flooding, high winds and temperature increase with severe consequences on the communities (famine, destruction of tangible and intangible properties, loss of human life, populations’ migration). The communities are aware that humans are responsible for these events that have become recurrent from 2007 and occur almost every year. According to them, the causes of climate changes are deforestation (due to overexploitation of timber, fuelwood and shifting agriculture), bush fires, rapid increase in population, anger of gods due to irregularities of sacrifices and violations of customs. The communities are vulnerable to main climatic hazards and suffered from food insecurity. The factorial correspondence analysis (FCA)) carried out shows that the perception of the degree of exposure of households to risks depends on their standard of livelihood. Facing these climate events, the populations develop many adaptive strategies of which most are consistent with the national orientations and strategies. These adaptive strategies must be reinforced and supported in order to reduce the vulnerability of these populations to climate changes. Key words: Climate variability and change, communities, livelihood, vulnerability and adaptation, Wildlife Reserve of Togodo.

Numerous factors are associated with poverty and underdevelopment in Africa, including climate variability. Rainfall, and climate more generally, are implicated directly in the United Nations “Millennium Development Goals” to eradicate extreme poverty and hunger, and reduce child mortality and incidence of diseases such as malaria by the target date of 2015. But, Africa is not currently on target to meet these goals. We pose a number of questions from a climate science perspective aimed at understanding this background: Is there a common origin to factors that currently constrain climate science? Why is it that in a continent where human activity is so closely linked to interannual rainfall variability has climate science received little of the benefit that saw commercialization driving meteorology in the developed world? What might be suggested as an effective way for the continent to approach future climate variability and change? We make the case that a route to addressing the challenges of climate change in Africa rests with the improved management of climate variability. We start by discussing the constraints on climate science and how they might be overcome. We explain why the optimal management of activities directly influenced by interannual climate variability (which include the development of scientific capacity) has the potential to serve as a forerunner to engagement in the wider issue of climate change. We show this both from the perspective of the climate system and the institutions that engage with climate issues. We end with a thought experiment that tests the benefits of linking climate variability and climate change in the setting of smallholder farmers in Limpopo Province, South Africa.

Among the potential reasons for enhanced warming rates in many high elevation regions is the nonlinear relationship between surface downward longwave radiation (DLR) and specific humidity (q). In this study we use ground-based observations at two neighboring high elevation sites in Southwestern Colorado that have different local topography and are 1.3 km apart horizontally and 348 m vertically. We examine the spatial consistency of the sensitivities (partial derivatives) of DLR with respect to changes in q, and the sensitivities are obtained from the Jacobian matrix of a neural network analysis. Although the relationship between DLR and q is the same at both sites, the sensitivities are higher when q is smaller, which occurs more frequently at the higher elevation site. There is a distinct hourly distribution in the sensitivities at both sites especially for high sensitivity cases, although the range is greater at the lower elevation site. The hourly distribution of the sensitivities relates to that of q. Under clear skies during daytime, q is similar between the two sites, however under cloudy skies or at night, it is not. This means that the DLR–q sensitivities are similar at the two sites during daytime but not at night, and care must be exercised when using data from one site to infer the impact of water vapor feedbacks at another site, particularly at night. Our analysis suggests that care should be exercised when using the lapse rate adjustment to infill high frequency data in a complex topographical region, particularly when one of the stations is subject to cold air pooling as found here.

Precipitation extremes result in flooding and droughts, causing substantial damages and loss of life. Understanding the variability of precipitation extremes with climate change is challenging, as we do no fully understand processes causing extreme precipitation under current climate variability. The INTENSE project focuses on understanding of the nature and drivers of global sub-daily precipitation extremes and change on societally relevant timescales. As part of this a Global sub-daily precipitation dataset has been collected, containing hourly rainfall data from approximately 25,000 rain gauges across over 200 territories, from a wide range of sources. This has been quality controlled using a rule-based open-source methodology, combining a number of checks against neighbouring gauges, known biases and errors, and thresholds based on the Expert Team on Climate Change Detection and Indices (ETCCDI) Climate Change Indices.&amp;#160;&amp;#160; A set of global hydroclimatic indices have been produced, characterising key aspects of shorter duration precipitation variability, including intensity, duration and frequency properties. An analysis of the indices, trends and corresponding climatology is carried out, providing information on various sub-daily precipitation characteristics (including extremes) across large parts of the world. These indices are publicly available for as many gauges as possible, alongside a gridded dataset that also incorporates indices calculated for additional restricted-access gauge records. To progress further with this work, updates to the dataset are required, with work ongoing to update resources for 2016 onwards, and attempts to automate the process where open-source datasets are available. Any collaborations, information, suggested contacts and relevant resources for developing the dataset are welcomed.&amp;#160;

The advance and delay of the rainy season is among the most frequently cited effects of climate change in the central Ecuadorian Andes. However, its assessment is not feasible using the indicators recommended by the standardized indices of the Expert Team on Climate Change Detection and Indices (ETCCDI), designed to detect changes in intensity, frequency, or duration of intense events. This study aims to analyze such advances and delays through harmonic analysis in Tungurahua, a predominantly agricultural province in the Tropical Central Andes, where in situ data are scarce. Daily in situ data from five meteorological stations were used, including precipitation, maximum, and minimum temperature records spanning 39 to 68 years. The study involved an analysis of the region’s climatology, climate change indices, and harmonic analysis using Cross-Wavelet Transform (XWT) and Wavelet Coherence Transform (WCT) to identify seasonal patterns and their variability (advance or delay) by comparing historical and recent time series, and Krigging for regionalization. The year 2000 was used as a study point for comparing past and present trends. Results show a generalized increase in both minimum and maximum temperatures. In the case of extreme rainfall events, no significant changes were detected. Harmonic analysis was found to be fruitful despite of the missing data. Furthermore, the observed advances and delays in seasonality were not statistically significant and appeared to be more closely related to the geographic location of the stations than to temporal shifts.