This interdisciplinary Research Unit (RU) addresses the astonishingly big evidence gap on climate change and health in sub-Saharan Africa. In the first RU phase, we focused on studying the climate change impacts, evaluating potential adaptation strategies to lift those impacts, and projecting both, the health impacts and the potential health-benefits from adaptation strategies, to future climate scenarios. We work in rural Health and Demographic Surveillance Systems (HDSS) in north-western Burkina Faso and south-western Kenya, where undernutrition, cardiovascular heat-stress, and malaria constitute major health problems. In both sites, we evolved the HDSS to climate-ready population observatories with demographic, health, climate, socio-economic, agriculture, and behaviour data of entire population cohorts. The existing models for future climate, climate impacts, and economic effects were tailored to the study locations through downscaling, bias-correction, and nation-wide economic and health data. Historical and prospective links between climate change and the three health outcomes were established, and will be advanced in the second RU phase. Importantly, we will introduce an additional research focus on adaptation measures, providing best-practice examples for designing, implementing and evaluating adaptation strategies that apply technological innovation, behaviour change or policy options. The overarching goal of the second RU phase is to gain in-depth understanding about the effectiveness of local adaptation strategies on health in sub-Saharan Africa – today and under future climate scenarios. We have four specific objectives: i) Identify and quantify potential impacts of future climate change on child undernutrition, malaria and heat stress; ii) Determine the effectiveness and potential socio-economic costs of specific adaptation policies and interventions with respect to reducing climate impacts on child undernutrition, malaria, and heat stress; iii) Quantify the economic effects of climate-related health impacts and adaptation strategies at the national level; and iv) Establish the importance of human mobility for climate change-related health impacts and adaptation strategies. In phase 2, we will integrate human mobility responses in the research agenda, because they play an important role in the nexus of climate change and health in sub-Saharan Africa. Our concerted efforts from health sciences, natural sciences, and social sciences will generate unique evidence for decision making about policy implementation and investments in sub-Saharan Africa in order to mitigate climate change, adapt to the existing consequences, and strengthen the local health systems.   Sub-Saharan Africa (SSA) remains the most populous region affected by malaria, despite being curable and intense attempts from the World Health Organization (WHO) in collaboration with endemics countries to combat it. While the relationships between climate, climate change and malaria are addressed already for a longer time, this project focuses on possibilities and limitations to predict malaria transmission weeks and months ahead. We further develop and apply sub-seasonal to seasonal (S2S) prediction within a climate-malaria modeling chain. Particularly, we investigate if and how far the consideration of downscaled high resolution S2S forecasts of joint climate-malaria prediction offers benefit for malaria early warning. Our target region are the hyper-endemic malaria zones in Nouna (Burkina Faso) and Kisumu (Kenya) and their Health and Demographic Surveillance System (HDSS) sites. Indeed, anticipated knowledge on which areas are most conducive to malaria transmission and how expected hydrometeorological conditions likely influence infection patterns may have substantial consequences for disease prevention and control. Thus, recent advances in numerical models may help to reduce/prevent climate impacts on malaria when realizing seasonal and sub-seasonal forecasting scales. In this study, we will contribute to malaria early warming initiatives in SSA by developing a weather-based malaria predictions using regionalized S2S forecasts and the grid cell distributed VECTRI dynamical malaria transmission model to target interventions against disease outbreaks. To do so, we will 1) further develop the hydro-meteorological modeling chain for VECTRI and adapt its ponding descriptions, 2) apply multivariate bias-correction and spatially disaggregate the S2S forecasts raw product using available observational products (gridded precipitation datasets and re-analyses), 3) verify the probability forecast after bias correction, 4) estimate the skill of the components of the model chain system and the final malaria early warning system (MEWS), 5) assess the economic gain of the S2S forecasting system for decision-making in malaria action plans and 6) contribute to the Heat to Harvest study (H2H). Our S2S forecasting chain is based on the global SEAS5 system from the European Centre for Medium-Range Weather Forecasts (ECMWF). Our study will be accomplished through six interconnected aims, in collaboration with seven research unit projects, and in close collaboration between German and African partners.