A significant obstacle to the incorporation of Nexus considerations in planning and policy design is the understanding and acknowledgement of cross-sectoral interdependencies. This chapter explores the importance of disseminating knowledge of the Nexus among key actors from policy, business and civil society, and in formal education contexts. Examples from capacity development activities and Nexus dialogues linked to the implementation of the Climate, Land, Energy and Water systems (CLEWs) framework are presented. Insights from the latter, as well as other initiatives with similar scope of action, are distilled to forward the importance of learning in such an approach. Additionally, the chapter highlights the main aspects to take into account when promoting these types of activities in new Nexus contexts.

The Climate, Land, Energy and Water systems (CLEWs) approach guides the development of integrated assess-ments. The approach includes an analytical component that can be performed using simple accounting methods, soft-linking tools, incorporating cross-systems considerations in sectoral models, or using one modelling tool to represent CLEW systems. This paper describes how a CLEWs quantitative analysis can be performed using one single modelling tool, the Open Source Energy Modelling System (OSeMOSYS). Although OSeMOSYS was pri-marily developed for energy systems analysis, the tool's functionality and flexibility allow for its application to CLEWs. A step-by-step explanation of how climate, land, energy, and water systems can be represented with OSeMOSYS, complemented with the interpretation of sets, parameters, and variables in the OSeMOSYS code, is provided. A hypothetical case serves as the basis for developing a modelling exercise that exemplifies the building of a CLEWs model in OSeMOSYS. System-centred scenario analysis is performed with the integrated model example to illustrate its application. The analysis of results shows how integrated insights can be derived from the quantitative exercise in the form of conflicts, trade-offs, opportunities, and synergies. In addition to the modelling exercise, using the OSeMOSYS-CLEWs example in teaching, training and open science is explored to support knowledge transfer and advancement in the field.

Energy system modeling can be used to develop internally consistent quantified scenarios. These provide key insights needed to mobilise finance, understand market development, infrastructure deployment and the associated role of institutions, and generally support improved policymaking. However, access to data is often a barrier to starting energy system modeling, especially in developing countries, thereby causing delays to decision making. Therefore, this article provides data that can be used to create a simple zero-order energy system model for a range of developing countries in Africa, East Asia, and South America, which can act as a starting point for further model development and scenario analysis. The data are collected entirely from publicly available and accessible sources, including the websites and databases of international organisations, journal articles, and existing modeling studies. This means that the datasets can be easily updated based on the latest available information or more detailed and accurate local data. As an example, these data were also used to calibrate a simple energy system model for Kenya using the Open Source Energy Modeling System (OSeMOSYS) and three stylized scenarios (Fossil Future, Least Cost and Net Zero by 2050) for 2020-2050. The assumptions used and the results of these scenarios are presented in the appendix as an illustrative example of what can be done with these data. This simple model can be adapted and further developed by in-country analysts and academics, providing a platform for future work.

Africa's economic and population growth prospects are likely to increase energy and water demands. This quantitative study shows that energy decarbonisation pathways reduce water withdrawals (WWs) and water consumption (WC) relative to the baseline scenario. However, the more aggressive decarbonisation pathway (1.5 degrees C) leads to higher overall WWs than the 2.0 degrees C scenario but lower WC levels by 2065. By 2065, investments in low-carbon energy infrastructure increase annual WWs from 1% (52 bcm) in the 2.0 degrees C to 2% (85 bcm) in the 1.5 degrees C scenarios of total renewable water resources in Africa compared to 3% (159 bcm) in the baseline scenario with lower final energy demands in the mitigation scenarios. WC decreases from 1.2 bcm in the 2.0 degrees C to 1 bcm in the 1.5 degrees C scenario, compared to 2.2 bcm in the baseline scenario by 2065, due to the lower water intensity of the low-carbon energy systems. To meet the 1.5 degrees C pathway, the energy sector requires a higher WW than the 2.0 degrees C scenario, both in total and per unit of final energy. Overall, these findings demonstrate the crucial role of integrated water-energy planning, and the need for joined-up carbon policy and water resources management for the continent to achieve climate-compatible growth.

Population growth, urbanization and economic development drive the use of resources. Securing access to essential services such as energy, water, and food, while achieving sustainable development, require that policy and planning processes follow an integrated approach. The 'Climate-, Land-, Energy- and Water-systems' (CLEWs) framework assists the exploration of interactions between (and within) CLEW systems via quantitative means. The approach was first introduced by the International Atomic Energy Agency to conduct an integrated systems analysis of a biofuel chain. The framework assists the exploration of interactions between (and within) CLEW systems via quantitative means. Its multi-institutional application to the case of Mauritius in 2012 initiated the deployment of the framework. A vast number of completed and ongoing applications of CLEWs span different spatial and temporal scales, discussing two or more resource interactions under different political contexts. Also, the studies vary in purpose. This shapes the methods that support CLEWs-type analyses. In this paper, we detail the main steps of the CLEWs framework in perspective to its application over the years. We summarise and compare key applications, both published in the scientific literature, as working papers and reports by international organizations. We discuss differences in terms of geographic scope, purpose, interactions represented, analytical approach and stakeholder involvement. In addition, we review other assessments, which contributed to the advancement of the CLEWs framework. The paper delivers recommendations for the future development of the framework, as well as keys to success in this type of evaluations.

With countries revisiting their climate pledges agreed at the conference of parties (COP) in Paris, in 2015, the discussion on the impact of changes in the long-term climate on natural resources has never been more relevant. Specifically, since the 2011 Bonn conference on the nexus between resource systems, the interlinkages between energy, water and land resource systems and their climatic connections are on the radar. Despite the excitement around the nexus between the climate, land, energy and water (CLEW) systems, they are still explored in isolation in many countries. This has resulted in lopsided policies, making long-term infrastructure investments vulnerable to climatic changes. This dissertation, taking the case of the Eastern African region, adds to this discussion on resource interactions, sectoral policy decisions and climate resilience. This dissertation includes a cover essay and four appended papers. By employing regional (East Africa) and national (Uganda) case studies, quantitative methods are presented addressing three research questions, relevant to the discussion on climate change and its impact on key resource systems. This thesis combines the usage of two modelling frameworks and downscaled climatic data to emphasise the need for an integrated approach to adapt to climate change. First, the climate resilience of electricity supply expansion strategies is evaluated for the countries in the Eastern African Power Pool (EAPP). Our results highlight that the opportunity costs in planning for a slightly wetter climate than the baseline are less than adapting for a drier one. The potential of electricity interconnectors in mitigating the impact of climate change is also evaluated. The national-level study on Uganda explores the effect of climatic change on a hydropower dominated electricity sector by taking into consideration different minimum river flow regulations. This dissertation finds that even under the cumulatively wettest climate future, having flow constraints will lead to a reduction in hydropower generation. This is critical to energy planners while making important decisions on future electricity supply infrastructure. This thesis also generates datasets on climate and region-specific crop-yield variability in Uganda. For the first time, the water and energy implications of implementing the national irrigation master plan in Uganda are analysed. The results of this dissertation led to interesting conclusions on the importance of climate-model and emission-scenario selection. Finally, by using an integrated model setup—consisting of energy, water and land systems—this thesis emphasises the importance of understanding the cross-propagative effects that policies enacted on one resource system can have on other interlinked systems. Thereby, it emphasises the need for a cohesive, integrated and collaborative approach to policymaking.

Sammanfattning

Diskussionerna kring de långsiktiga klimatförändringarna och dess effekter på naturtillgångar har aldrig varit mer relevant. Inte minst med anledning av att länder återbesöker sina klimatåtaganden från Förenta Nationernas klimatkonferens 2015. Mer specifikt så har samspelet mellan energi-, vatten- och land-resurser samt deras inverkan på klimatet stått i centrum. Trots det ökade intresset för sambandet mellan klimat-, land-, energi - och vatten-system (CLEW), behandlas de olika systemen fortfarande separat i många länder. Detta har resulterat i felprioriterad politik och investeringar i stora infrastrukturprojekt sårbara gentemot klimatförändringar. Denna avhandling bidrar till diskussionen kring resursinteraktioner, sektorpolitiska beslut och klimatsäkerhet ur ett Östafrikanskt perspektiv.

Denna avhandling innehåller en omslagssatsa och fyra medföljande artiklar. Genom att använda regionala (Östafrika) och nationella (Uganda) fallstudier, presenteras kvantitativa metoder för att besvara tre forskningsfrågor som är relevanta för diskussionen kring klimatförändringar och dess påverkan på vitala resurssystem. Denna avhandling kombinerar användandet av två modelleringsramverk och klimatdata för att understryka behovet av en integrerad strategi för att anpassa samhället till klimatförändringarna.

Först utvärderas klimatmotståndskraften för de nuvarande utvidgningsstrategierna för de Östafrikanska elförsörjningssystemen (EAPP). Våra resultat belyser att alternativkostnaderna för att planera för ett något våtare klimat än väntat är mindre än att anpassa sig till ett torrare. Möjligheten att sammankoppla olika elsystem för att på så sätt minska påverkan från klimatförändringar har också undersökts. Studien på Uganda analyserar effekterna av klimatförändringar på en kraftsektor dominerad av vattenkraft. Detta görs genom att ta hänsyn till den minimala vattenföringen vid olika tillfällen. Avhandlingen konstaterar att även under ett kontinuerligt vått klimat kommer flödesbegränsningar att leda till en minskning av elproduktion. Detta är avgörande för energiplanerare då elförsörjningens framtida infrastruktur planeras. 

Denna avhandling tar också fram data kring klimatscenarion, samt region- och grödospecifik variabilitet i Uganda. För första gången har konsekvenserna för vatten- och energisystemen av att genomföra den nationella bevattningsplanen i Uganda analyserats. Baserat på resultatet av denna avhandling kan intressanta slutsatser dras kring valet av klimatmodell och vikten av korrekt val av utsläppsscenario. Slutligen, med hjälp av en integrerad modelluppsättning—innehållande energi-, vatten- och land-system—belyser denna avhandling de rippel- eller korsförökande effekterna av en resurssystempolitik på andra sammanlänkade system. Genom detta betonas behovet vikten av en sammanhängande, integrerad och samarbetsinriktad strategi för beslutsfattande.

Despite the excitement around the nexus between land, energy and water resource systems, policies enacted to govern and use these resources are still formulated in isolation, without considering the interdependencies. Using a Ugandan case study, we highlight the impact that one policy change in the energy system will have on other resource systems. We focus on deforestation, long term electricity supply planning, crop production, water consumption, land-use change and climate impacting greenhouse gas (GHG) trajectories. In this study, an open-source integrated modelling framework is used to map the ripple effects of a policy change related to reducing biomass consumption. We find that, despite the reduction in deforestation of woodlands and forests, the GHG emissions in the power sector are expected to increase in between 2040-2050, owing to higher fossil fuel usage. This policy change is also likely to increase the cost of electricity generation, which in turn affects the agricultural land types. There is an unforeseen shift from irrigated to rainfed type land due to higher electricity costs. With this integrated model setup for Uganda, we highlight the need for integrated policy planning that takes into consideration the interlinkages between the resource systems and cross propagation effects.

Decarbonisation of national economies to mitigate climate change requires transformation of the entire energy system. Investments in renewable energy technologies in the electricity supply system are increasing, but substantial effort is called for in other sectors, such as transport. While European Union member states have submitted their integrated National Energy and Climate Plans, this paper focuses on partial electrification of the transport sector as a measure to reduce carbon dioxide emissions in the isolated grid system of Cyprus in a cost-effective manner. The present work assesses the impact of electric vehicle deployment on the share of renewable electricity generation, electricity costs and carbon dioxide emissions. Quantification of these aspects is provided with an outlook until 2035. A cost-optimisation model (OSeMOSYS) is used that takes into account the electricity supply, road transport, and heating and cooling sectors. Smart charging option is also evaluated as a possibility.

Notwithstanding current heavy dependence on gas-fired electricity generation in the Eastern African Power Pool (EAPP), hydropower is expected to play an essential role in improving electricity access in the region. Expansion planning of electricity infrastructure is critical to support investment and maintaining balanced consumer electricity prices. Variations in water availability due to a changing climate could leave hydro infrastructure stranded or result in underutilization of available resources. In this study, we develop a framework consisting of long-term models for electricity supply and water systems management, to assess the vulnerability of potential expansion plans to the effects of climate change. We find that the most resilient EAPP rollout strategy corresponds to a plan optimised for a slightly wetter climate compared to historical trends. This study demonstrates that failing to climate-proof infrastructure investments can result in significant electricity price fluctuations in selected countries (Uganda & Tanzania) while others, such as Egypt, are less vulnerable.

With less than 3% of agricultural cropland under irrigation, subsistence farmers in Uganda are dependent on seasonal precipitation for crop production. The majority of crops grown in the country-especially staple food crops like Matooke (Plantains)-are sensitive to the availability of water throughout their growing period and hence vulnerable to climatic impacts. In response to these challenges, the Government has developed an ambitious irrigation master plan. However, the energy implications of implementing the plan have not been explored in detail. This article attempts to address three main issues involving the nexus between water, energy, crop production, and climate. The first one explores the impact of climate on rain-fed crop production. The second explores the irrigation crop water needs under selected climate scenarios. The third focuses on the energy implications of implementing the irrigation master plan. We attempt to answer the above questions using a water balance model for Uganda developed for this study. Our results, developed at a catchment level, indicate that on average there could be an 11% reduction and 8% increase in rain-fed crop production in the cumulatively driest and wettest climates, respectively. Furthermore, in the identified driest climate, the electricity required for pumping water is expected to increase by 12% on average compared to the base scenario.