There is strong scientific consensus on the evidence of anthropogenic climate change which will increasingly present social, economic and institutional challenges. The Fifth Assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) established that ‘human influence on the climate system is clear’ and that ‘changes in many extreme weather and climate events have been observed since about 1950’ (IPCC 2014a). Associated impacts include sea level rise and increased likelihood of extreme weather worldwide such extreme rainfall, heat waves, hurricanes and tornados (IPCC 2014a; Klijn et al. 2015). Climate change adaptation is the adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects in order to minimise the impacts and to take advantage of new opportunities (IPCC 2007). Many vulnerable countries, regions and cities have accepted that some form of adaptation is inevitable (Swart et al. 2014). This thesis contributes to the research on decision-making for climate change adaptation in order to reduce vulnerability. Both bottom-up and top-down analyses are applied to complement one another with an application to flooding. Flood risk is expected to increase in the UK under climate change (Alfieri et al. 2016; Scottish Government 2016) associated significant economic damage (CEA 2007). From a top-down perspective, the thesis explores how to enhance economic decision-making under climate change uncertainty. In a situation of uncertainty the costs may be clear and immediate whereas the benefits are uncertain and often only realised in the distant future. This impedes the use of standard decision-making tools such as cost-benefit analysis that rely on the quantification of (expected) costs and benefits. The thesis begins on the macro scale with a taxonomy of economic decision-making tools for climate change adaptation, discusses the sector level and subsequently proceeds to the case study micro-scale with applications of adaptation decision-making. First, the potential of alternative decision-making tools, so-called robust decision-making approaches, is examined. The strengths and weaknesses of these tools relative to traditional decision-making processes such as CBA are explored and their future potential in the adaptation process evaluated. It is found that robust decision-making tools under uncertainty provide performance across a range of climate change scenarios, but they may yield lower overall performance if compared with the alternative strategy under the actual climate outturn. Furthermore, they are resource intense and decision makers need to balance the resources required for employing the methods with the added value they can offer. A flow-chart is developed to provide guidance on which decision-making tool should be applied depending on the scale and type of adaptation project. On the sector level, the economic appraisal of adaptation options for agriculture is explored. Agriculture is particularly vulnerable to climate change due to the direct impacts of weather and climate on agricultural output and the sector plays an indispensable role in providing (and improving) food security as well as creating employment. Many of the adaptation options in agriculture involve short-term managerial changes and can be appraised with standard economic decision-making and the options can be carried out after the climate signal has been observed. For those adaptations that do require a longer time to take effect or are long-lived and are (partly) irreversible in nature, robust approaches have a valuable role to play in decision-making. Suggestions are made regarding how robust decisionmaking tools under uncertainty can be practically applied to adaptations in agriculture, outlining the data needs and the steps of the data analysis for three different applications. On the micro level, for a case study in the Eddleston Water catchment in the Scottish borders, UK, two different economic appraisal tools are applied. These include a cost-benefit analysis of afforestation as a flood management measure under different climate change scenarios which can provide important insights for adaptation decisions when robust decision-making tools under uncertainty are not feasible due to resource constraints. It is found that the flood risk under climate change increases substantially in the case study area which needs to be taken into consideration for economic appraisal. The results of the CBA reveal that all modelled scenarios of afforestation have positive NPVs which are driven by further eco-system services (including climate regulation, water quality and recreation) rather than flood regulation benefits. It is concluded that eco-system services beyond flood regulation should be considered for the appraisal of NFM to enable policy-makers to make informed decisions. Second, the Expected values can be used in situations of quantifiable uncertainty, i.e risk. But for climate change we do not have a strong methodology to assess these subjective probabilities. They cannot be fully based on the past, because climate change is a new process for which we have no historical equivalent. Models share common flaws in their assumptions and their dispersion in results cannot be used to assess the real uncertainty (Hallegatte, 2012). The term deep uncertainty (Lempert et al., 2003) or severe uncertainty is used (Ben-Haim, 2006) in these contexts. Such uncertainty is characterised as a condition where decision makers do not know or cannot agree upon a model that adequately describes cause and effect or its key parameters (Walker et al., 2012). This leads to a situation where it is not possible to say with confidence whether one future state of the world is more plausible than another. The robust decision-making tool under uncertainty real option analysis is applied to the same case study to allow for adjusting adaptation options over time by integrating lessons learned about climate change in the appraisal process. A simplified ROA is presented to minimise the life cycle cost of a system that aims to prevent flooding of a return period of 1/20 using tools which should be available to most public authorities. This includes the use of UKCP09 climate data, analysis of changes of peak flow under the measure implemented, cost structures for the measure and damage cost under different outcomes. The analysis can be carried out in an excel spread sheet with the aforementioned types of input. The results of the analysis demonstrate that the obtained strategy is significantly cheaper than planting for the worst case scenario and presents the potential for learning under climate change uncertainty as a way to allocate resources in a more efficient way. The complementing bottom up approach investigates behavioural barriers to decisionmaking for adaptation. Standard economic theory tells us that self-interest will motivate most actors to engage in efficient private adaptation as long as the costs do not exceed the benefits. Thus, we would expect households at flood risk to invest in flood adaptation measures. However, it has been observed that households do not necessarily take action to protect themselves and their assets from flooding. In a study carried out in co-operation with 36 communities around Scotland, protection motivation theory is used to explain the uptake of household flood protection and whether community led flood action groups can increase uptake. It is found that flood action groups directly and indirectly influence the uptake of some flood protection measures positively in particular if tailored information is provided. Overall, it is concluded that both top-down and bottom-up approaches play an important role to move towards an economically efficient adaptation in the context of flooding. / From a top-down perspective, uncertainty should be explicitly acknowledged and included in economic decision-making for adaptation (to flooding) to make an informed decision. The type of analysis will depend on the adaptation project and resources at hand. Developing and fostering bottom-up tools such as flood action groups to increase the uptake of the type of household flood protection with a benefit-cost ratio above 1 may also contribute towards the more efficient allocation of resources.

In 2015-2016 Kwa-Zulu Natal (KZN) and other provinces in South Africa suffered from drought conditions. Drought can have negative impacts on the environment, society and the economy. Climate change is predicted to exacerbate extreme events such as droughts that would adversely affect already vulnerable regions such as KZN. The main aim of this study is to implement the attribution procedure, to determine if climate change has contributed to the 2015-2016 hydrological drought in selected KZN catchments. Methodology of the study followed a general framework of implementation of hydrological attribution experiments with climate data obtained from attribution simulations with HadAM3p global climate model. Prior to simulations in attribution mode, QSWAT model was set up for the study area and calibrated using SWAT-CUP and SUFI-2. Calibration results were poor but the model could be applied in the context of this study, under certain constraints. Results of attribution experiments revealed that for all 3 subbasins studied no increase of risk was observed and hence no influence of climate change on the 2015-2016 magnitude of drought for selected catchments was concluded by this study. These results are limited, as they are based on climate attribution experiments with only one climate model, rather than with a multi-model ensemble. Also, QSWAT model, in its implementation with generic climate data is of limited use in attribution (or hydrological) simulations as even after calibration the model performs poorly.

This project summarizes the findings of research organized in two parts. The first involved the characterization of changes in the variability of climate that lead to extreme events. The second focused on the predictability of extreme climate on time-scales ranging from short forecast lead-times to long-lead climate predictions exceeding a year. Initial studies focused on three interrelated, yet regionally unique extreme climate phenomena. First, the relationship between increasing greenhouse gas (GHG) emissions and particulate matter (PM) concentration in basin terrain was investigated. Next, we evaluated changes in large-scale atmospheric circulation associated with two climate phenomena at either extreme side of the water cycle--droughts and floods. In the final analysis, an attempt was made to understand the mechanisms that link two North Pacific ENSO precursor patterns to the ENSO cycle.

Background: Flying is a mode of travel used mainly by the wealthier part of the planets’ inhabitants, while it is the poor parts of the world that suffer the consequences from climate change the most. Coping with climate change is one of the largest challenges of the century, especially for low-income developing countries. Important stakeholders have realized that it’s a global responsibility to lower the anthropogenic impact on the climate. Political ecology will be used to place the problem with unequal distribution of consequences in a larger context, while environmental economics will be used to examine the flight tax implemented in Sweden on April 1st2018. Purpose: Toexamine student’s attitudes towards excise taxation as an incentive to reduce emissions from air traffic, and whether there was a difference in attitudes between students from different disciplines. Research question: What are Swedish students’ attitudes towards excise tax onflights to reduce emissions? Is there adifference in attitude towards the flight tax depending on the students’ field of studies? Method: Quantitative approach with questionnaire responses as the main empirical data material for analysis. Conclusion: A majority of students participating were positive towards the newly implemented flight tax. Students from an environmental discipline were positive to a greater extent than other students.

In this thesis, the theory of rational irrationality is used to explore the incentives behind seemingly irrational beliefs held by a large part of the contemporary American society towards anthropogenic climate change. Applying causal analysis, three questions are answered: "is it rationally irrational for people to be indifferent towards climate change?" "Are Americans inherently more likely than others to hold irrational beliefs about global issues such as climate change?" If so, "is this phenomenon rooted in certain values that constitute the American identity?" The author focuses on specific "American values" and uses statistics and recent empirical studies to find correlations and causality between those values and the exhibited behavior of individuals, while discussing its possible causes and implications. The study concludes that the root cause of irresponsibility of the American citizen towards climate change is a lack of social mechanisms rewarding individuals for holding epistemologically accurate beliefs. The author then proposes a set of general measures to be prioritized in order to improve social reward mechanisms in the American society. If implemented, those measures should be able to effectively enforce epistemic rationality in the U.S. political debate, which is desirable...

Antropogena klimatförändringar, förkortat AK, är ett av nutidens stora miljöproblem. För att hantera AK är människors motivation och intention att agera klimatvänligt viktigt, eftersom avsaknad motivation och intention att adressera AK kan bringa negativa konsekvenser för samhället. Individers motivation och intention att agera klimatvänligt kan influeras av framing, vilket syftar till att betona specifika delar av verkligheten. Vilken framing som används kan vara avgörande ifall individer agerar klimatvänligt eller inte. Den konventionella framing som dominerar samhället grundas i att betona fakta och de negativa effekterna av AK. AK framställs som en inkräktande katastrof vilken bör hanteras via uppoffringar, förluster och kostnader. Konventionella klimatkommunikationen kan leda till passivitet hos individer och en önskan att undvika ämnet. Eftersom motivation och intention att agera klimatvänligt är betydande uppstår behovet att skapa en icke-konventionell framing som tar människors psykologiska barriärer i åtanke. Syftet med studien var att applicera Stoknes (2015) teori om de fem psykologiska barriärerna som hindrar en effektiv klimatkommunikation och hur dessa barriärer kan tas i åtanke för att uppnå en mer effektiv klimatkommunikation. Två olika framing alternativ i form av berättelser var fokus för studien. Frågeställningen var: Hur påverkar konventionell respektive icke-konventionell framing individers motivation och intention att agera klimatvänligt? För att testa berättelserna utfördes ett kontrollerat experiment och en sluten enkät utgjorde mätinstrument för att kvantifiera motivation och intention. Data från enkäten analyserades med Mann-Whitney U test och Cohen’s d test. En viss ökning av motivation och intention ägde rum, men det fanns inte en statistisk signifikant skillnad i motivation och intention att agera klimatvänligt efter deltagarna utsatts för en berättelse. Data antyder förändringar i motivation och intention skett för gruppen som tog del av icke-konventionella framing alternativet, och därmed bör fortsättningsstudier genomföras med normalfördelad population av betydligt större skala. Vidare kan potentiellt en annan vetenskapsteoretisk utgångspunkt nyttjas, specifikt flermetodsforskning. / Anthropogenic climate change, abbreviated ACC, is a major environmental problem. People’s motivation and intention to act climate-friendly is important in addressing ACC since lacking motivation and intention to address ACC can have dire consequences for society and the environment. Individuals’ motivation and intention to act climate-friendly can be influenced by framing, which refers to the practice of emphasizing certain aspects of reality. What type of framing is being utilized can be crucial regarding individuals acting climate-friendly. The conventional framing dominating society is based on emphasizing facts and negative consequences of ACC. ACC is portrayed as an encroaching disaster managed via sacrifices, losses, and costs. However, this can lead to passivity and a desire to avoid the topic. Since motivation and intention to act climate-friendly is important, the need for a non-conventional framing arises. The study's purpose was to create a framing that took psychological barriers into account based on Stoknes (2015) theories regarding climate communication and to investigate how it affected motivation and intention to act climate-friendly. The research question was: How do conventional framing and non-conventional framing affect individuals’ motivation and intention to act climate-friendly? Two framing alternatives made up of stories about ACC were tested during a controlled experiment, and motivation and intention were quantified utilizing a closed-ended questionnaire. Data were analyzed using the Mann-Whitney U test and Cohen’s d test. A slight increase in motivation and intention was measured, but no statistically significant difference existed in motivation and intention to act climate-friendly after the participants had been subjected to a framing alternative. Data suggests changes in motivation and intention to act climate-friendly occurred for the group subjected to the non-conventional framing, and thus further research should be conducted with a normally distributed population of a significantly larger scale. Furthermore, future studies could pursue mixed methods research.