• Energy Research

Assurer des systèmes alimentaires résilients et des régimes alimentaires sains et durables pour tous nécessite une utilisation beaucoup plus élevée de l'eau. Cependant, les ressources en eau sont limitées, géographiquement dispersées, volatiles en raison du changement climatique et nécessaires à d'autres fonctions vitales, y compris les écosystèmes et les services qu'elles fournissent. Une bonne gouvernance pour des ressources en eau résilientes est un précurseur nécessaire pour décider des solutions, trouver des financements et fournir des infrastructures. Six attributs qui, ensemble, fournissent une base pour une bonne gouvernance afin de réduire les risques futurs liés à l'eau pour les systèmes alimentaires sont proposés. Ces attributs s'harmonisent dans leur double objectif d'intégrer l'apprentissage adaptatif et les nouvelles connaissances, et d'adopter les types de systèmes de gouvernance requis pour les systèmes alimentaires résilients à l'eau. Les attributs sont également fondés sur la nécessité de mieux reconnaître le rôle que jouent les écosystèmes naturels et sains dans les systèmes alimentaires. Les attributs sont énumérés ci-dessous et sont fondés sur des preuves scientifiques et la diversité de l'expérience collective et de l'expertise des parties prenantes travaillant à travers l'interface science-politique : adopter une pensée systémique interconnectée qui englobe la complexité de la façon dont nous produisons, distribuons et ajoutons de la valeur à la nourriture, y compris l'exploitation de l'expérience et de l'expertise des parties prenantes ; adopter une gouvernance inclusive à plusieurs niveaux et soutenir la participation inclusive ; permettre l'innovation continue, les nouvelles connaissances et l'apprentissage, et la diffusion de l'information ; intégrer la diversité et la redondance pour la résilience aux chocs ; assurer la préparation du système aux chocs ; et planifier à long terme. Cela nécessitera que les systèmes alimentaires et d'approvisionnement en eau travaillent ensemble de manière proactive pour créer un espace socialement et environnementalement juste qui tienne compte des besoins en eau et en nourriture des personnes, des écosystèmes qui sous-tendent nos systèmes alimentaires et des préoccupations plus larges en matière d'énergie et d'équité. Garantizar sistemas alimentarios resilientes y dietas saludables sostenibles para todos requiere un uso mucho mayor del agua, sin embargo, los recursos hídricos son finitos, geográficamente dispersos, volátiles bajo el cambio climático y necesarios para otras funciones vitales, incluidos los ecosistemas y los servicios que proporcionan. La buena gobernanza de los recursos hídricos resilientes es un precursor necesario para decidir sobre soluciones, obtener financiación y ofrecer infraestructura. Se proponen seis atributos que en conjunto proporcionan una base para la buena gobernanza a fin de reducir los riesgos futuros del agua para los sistemas alimentarios. Estos atributos encajan en su doble enfoque en la incorporación del aprendizaje adaptativo y los nuevos conocimientos, y la adopción de los tipos de sistemas de gobernanza necesarios para los sistemas alimentarios resilientes al agua. Los atributos también se basan en la necesidad de reconocer mejor el papel que desempeñan los ecosistemas naturales y saludables en los sistemas alimentarios. Los atributos se enumeran a continuación y se basan en la evidencia científica y la diversa experiencia colectiva y los conocimientos de las partes interesadas que trabajan a través de la interfaz ciencia-política: Adoptar un pensamiento de sistemas interconectados que abarque la complejidad de cómo producimos, distribuimos y agregamos valor a los alimentos, incluido el aprovechamiento de la experiencia y los conocimientos de las partes interesadas; adoptar una gobernanza inclusiva multinivel y apoyar la participación inclusiva; permitir la innovación continua, los nuevos conocimientos y el aprendizaje, y la difusión de información; incorporar diversidad y redundancia para la resiliencia a las crisis; garantizar la preparación del sistema para las crisis; y planificar a largo plazo. Esto requerirá que los sistemas de alimentos y agua trabajen juntos de manera proactiva hacia un espacio social y ambientalmente justo que considere las necesidades de agua y alimentos de las personas, los ecosistemas que sustentan nuestros sistemas alimentarios y las preocupaciones más amplias de energía y equidad. Ensuring resilient food systems and sustainable healthy diets for all requires much higher water use, however, water resources are finite, geographically dispersed, volatile under climate change, and required for other vital functions including ecosystems and the services they provide. Good governance for resilient water resources is a necessary precursor to deciding on solutions, sourcing finance, and delivering infrastructure. Six attributes that together provide a foundation for good governance to reduce future water risks to food systems are proposed. These attributes dovetail in their dual focus on incorporating adaptive learning and new knowledge, and adopting the types of governance systems required for water resilient food systems. The attributes are also founded in the need to greater recognise the role natural, healthy ecosystems play in food systems. The attributes are listed below and are grounded in scientific evidence and the diverse collective experience and expertise of stakeholders working across the science-policy interface: Adopting interconnected systems thinking that embraces the complexity of how we produce, distribute, and add value to food including harnessing the experience and expertise of stakeholders s; adopting multi-level inclusive governance and supporting inclusive participation; enabling continual innovation, new knowledge and learning, and information dissemination; incorporating diversity and redundancy for resilience to shocks; ensuring system preparedness to shocks; and planning for the long term. This will require food and water systems to pro-actively work together toward a socially and environmentally just space that considers the water and food needs of people, the ecosystems that underpin our food systems, and broader energy and equity concerns. يتطلب ضمان أنظمة غذائية مرنة وأنظمة غذائية صحية مستدامة للجميع استخدامًا للمياه أعلى بكثير، ومع ذلك، فإن موارد المياه محدودة ومتناثرة جغرافيًا ومتقلبة في ظل تغير المناخ، ومطلوبة للوظائف الحيوية الأخرى بما في ذلك النظم الإيكولوجية والخدمات التي تقدمها. تعد الحوكمة الرشيدة لموارد المياه المرنة مقدمة ضرورية لاتخاذ قرار بشأن الحلول، وتوفير التمويل، وتوفير البنية التحتية. تم اقتراح ست سمات توفر معًا أساسًا للحوكمة الرشيدة للحد من مخاطر المياه المستقبلية على النظم الغذائية. تتوافق هذه السمات في تركيزها المزدوج على دمج التعلم التكيفي والمعرفة الجديدة، واعتماد أنواع أنظمة الحوكمة المطلوبة للنظم الغذائية المرنة للمياه. وتستند السمات أيضًا إلى الحاجة إلى زيادة الاعتراف بالدور الذي تلعبه النظم الإيكولوجية الطبيعية والصحية في النظم الغذائية. السمات مدرجة أدناه وترتكز على الأدلة العلمية والخبرة والتجربة الجماعية المتنوعة لأصحاب المصلحة العاملين عبر واجهة العلوم والسياسات: اعتماد تفكير النظم المترابطة التي تتبنى تعقيد كيفية إنتاج وتوزيع وإضافة قيمة إلى الغذاء بما في ذلك تسخير تجربة وخبرات أصحاب المصلحة ؛ اعتماد حوكمة شاملة متعددة المستويات ودعم المشاركة الشاملة ؛ تمكين الابتكار المستمر والمعرفة الجديدة والتعلم ونشر المعلومات ؛ دمج التنوع والتكرار من أجل المرونة في مواجهة الصدمات ؛ ضمان استعداد النظام للصدمات ؛ والتخطيط على المدى الطويل. سيتطلب ذلك أن تعمل أنظمة الغذاء والمياه معًا بشكل استباقي نحو مساحة عادلة اجتماعيًا وبيئيًا تأخذ في الاعتبار الاحتياجات المائية والغذائية للناس، والنظم الإيكولوجية التي تدعم أنظمتنا الغذائية، ومخاوف أوسع بشأن الطاقة والإنصاف.

AbstractWater resources in the Santa Basin in the Peruvian Andes are increasingly under pressure from climate change and population increase. Impacts of temperature-driven glacier retreat on streamflow are better studied than those of precipitation changes, yet present and future water resources are mostly dependent on precipitation, which is more difficult to predict with climate models. This study combines a broad range of projections from climate models with a hydrological model (WaterWorld), showing a general trend towards an increase in water availability due to precipitation increases over the basin. However, high uncertainties in these projections necessitate basin-wide policies aimed at increased adaptability.

While the role of land-use conversion on water quality is reasonably understood, its role on water quantity is controversial. Climate change is also expected to impact water availability. Here we explore the interplay of hydrology, land-use change and climate change in one of the most populous urban areas in the world. We examined the potential of forests to buffer the negative impacts of land-use and climate changes on water-related ecosystem services in Tietê Basin, Brazil, which supplies water to the São Paulo megalopolis. We modelled six hydrological parameters using the WaterWorld Policy Support System, simulating the current baseline and six future scenarios (with different land-use and climate changes). Our results corroborate the general trend that increased forest cover improves water quality. Our modelling also predicts that increased forest cover increases water quantity in the southern part of the basin. The effects of climate change are observed mainly in urban areas, with a reduction in water quality. Because urban areas are not eligible for reforestation, they cannot benefit from its buffering effect on climate change. The increase in water availability is the greatest benefit of reforestation as a strategy to improve water-related ecosystem services in the region. Reforestation, however, will not suffice to restore all hydrological parameters in the basin, and additional sustainable agricultural practices are needed to mitigate impacts on water quality.

Abstract Fog makes a significant contribution to the hydrology of a wide range of important terrestrial ecosystems. The amount and frequency of fog immersion are affected by rapid ongoing anthropogenic changes but the impacts of these changes remain relatively poorly understood compared with changes in rainfall. Here, we present the design and performance of a novel experiment to actively manipulate low lying fog abundance in an old‐growth tropical montane cloud forest (TMCF) in Peru—the Wayqecha Amazon Cloud Curtain Ecosystem Experiment (WACCEE). The treatment consists of a 30 m high, 40 m wide mesh curtain suspended between two towers and extending down to the ground, and two supplementary curtains orientated diagonally inwards from the top of each tower and secured to the ground upslope. The curtains divert and intercept airborne water droplets in fog moving upslope, thereby depriving a ~420 m2 patch of forest immediately behind the curtains of this water source. We monitored inside the treatment and a nearby unmodified control plot various metrics of water availability (air humidity, vapour pressure deficit, leaf wetness and soil moisture) and other potentially confounding variables (radiation, air and soil temperature) above and below the forest canopy. The treatment caused a strong reduction in both air humidity and leaf wetness, and an increase in vapour pressure deficit, above the canopy compared to the control plot. This effect was most pronounced during the nighttime (20:00–05:00). Below‐canopy shifts within the treatment were more subtle: relative humidity at 2 m height above the ground was significantly suppressed during the daytime, while soil moisture was apparently elevated. The treatment caused a small but significant increase in air temperature above the canopy but a decrease in temperature in and near the soil, while mixed effects were observed at 2 m height above the ground. Above‐canopy radiation was slightly elevated on the treatment relative to the control, particularly during the dry season. Further application of the method in other systems where fog plays a major role in ecosystem processes could improve our understanding of the ecological impacts of this important but understudied climate driver.

This section outlines the information needs for land degradation and restoration policy support through identifying which policy makers, policies, and types of support are necessary to understand degradation and restoration, including where and what to restore, how to restore it, and how much to restore. We use Africa as a case study to understand the currently available spatial information in support of land restoration planning. The WaterWorld Policy Support System (. www.policysupport.org/waterworld) is used with a range of spatial data sets to understand the areas of Africa subject to recent land degradation (as observed from satellite time series) and the spatial congruence of these areas with intensive croplands, intensive pastures, and deforestation. We indicate that recent land degradation has some, but not a full, association with recent land use. We then examine multi-General Circulation Model (GCM) ensemble climate projections and land use scenarios to indicate which parts of Africa are most at risk of land degradation and the likely impacts of these risks locally and along the agricultural supply chains originating in these areas. Finally, we examine the potential impacts on water and food security of restoring degraded areas in Africa through reforestation and investment in agricultural ecoefficiency. Focusing on Gabon, we indicate that afforestation will have positive impacts on water quality, but negative impacts on water quantity. To mitigate this impact, strategic mixtures of intensive cropland and small-scale afforestation in landscapes provide the greatest potential to reduce degradation (especially soil erosion) and to secure water while minimizing opportunity costs for crop growth. For restoration activities to make an impact at the national scale, huge investments will be required. It is thus critical that these investments have clear economic benefits for water and food security, both locally and downstream.

The aim of this paper is to examine the potential for continued agriculturalisation in the tropics and the potential impacts of this on tropical natural capital and ecosystem services. Concurrently we examine the extent to which projected climate change will drive changes in the water available to support food security, locally and along supply chains through impacts on rainfall in key agricultural areas and the implications of climate change for continued agriculturalisation. We make use of global spatial datasets to examine the tropical distribution of current cropland and pasture and the distribution of the remaining non-agricultural ‘wild’ areas in relation to their suitability for cropland and pasture. We thus identify the most suitable/likely areas for further agriculturalisation in the tropics under increased domestic and export demand. We then examine the potential risks to natural capital and ecosystem services of such agriculturalisation and highlight critical areas for careful agricultural expansion. We examine the non-agricultural lands with greatest suitability for pasture and cropland and highlight the key countries capable of contributing to significant increases in global food production. Further, we examine trends in recent land use change and project these forward to understand the parts of those countries most imminently likely to go under the plough and consider implications for natural capital and ecosystem services. We then examine ensemble climate change projections for the current agricultural areas in Latin America, to better understand likely impacts of tropical climate change on sustained agricultural suitability in these areas, with implications for further extensification. Finally, we use the COMTRADE database to examine the flows of “embedded rainfall” supporting key agricultural commodities from the tropics. This is in order to understand the extent to which climate change will amplify or diminish the potential for virtual water flows between the tropics and the rest of the world. Results indicate rapid and necessary agriculturalisation in the tropics under business as usual, which brings considerable threats to the remaining natural capital and ecosystem services in these areas. At the same time we expect climate change - at least for South America - to bring greater water availability and the possibility of increased productivity in current agricultural areas. If true, this could offset some of the demand for expensive and risky extensification of agriculture, and encourage a more focused intensification.

To understand how agriculture and poverty interact, we analysed water availability, productivity and institutions for the Andes basins. Water limits agricultural productivity in the southern basins but is plentiful in the northern basins where steep slopes or poor land and water management limit productivity. The dominance of small, steep basins results in important upstream–downstream linkages. The greatest challenge to improving the productivity of water in the Andes basins is to regulate water quality better for multiple uses and to negotiate fair and transparent compensation for upstream providers of water-based ecosystem services for the benefits that they provide to downstream users.

Integrated assessment models that incorporate biodiversity and ecosystem services could be an important tool for improving our understanding of interconnected social-economic-ecological systems, and for analyzing how policy alternatives can shift future trajectories towards more sustainable development. Despite recent scientific and technological advances, key gaps remain in the scientific community's ability to deliver information to decision-makers at the pace and scale needed to address sustainability challenges. We identify five research frontiers for integrated social-economic-ecological modeling (primarily focused on terrestrial systems) to incorporate biodiversity and ecosystem services: 1) downscaling impacts of direct and indirect drivers on ecosystems; 2) incorporating feedbacks in ecosystems; 3) linking ecological impacts to human well-being, 4) disaggregating outcomes for distributional equity considerations, and 5) incorporating dynamic feedbacks of ecosystem services on the social-economic system. We discuss progress and challenges along each of these five frontiers and the science-policy linkages needed to move new research and information into action.