Global agricultural production is required to double by 2050 to meet the demands of an increasing population and the challenges of a changing climate. Changing climatic conditions, including increasing temperatures, more variable precipitation, and drought are likely to put pressure on maintaining both high crop yields and a steady supply of food. On the other hand, assuming other factors are not limiting, rising atmospheric CO2 levels may lead to increased crop productivity, as the increased availability of carbon dioxide can promote enhanced rates of plant photosynthesis. The varying abilities of different crops or cultivars to adapt to water, temperature or nutrient pressures signifies the inherent resilience of a given agricultural system, and the likelihood and the degree to which they will be impacted by climate change. Understanding how current and future plant growth conditions affect crop yield is a major priority for ensuring food security, for adapting crop selection and management strategies and for guiding crop breeding programmes. The key challenge here is linking plant behaviour that can be measured at the leaf-level in the laboratory, to plant behaviour at the national or global scale, and predicting future behaviour under forecasted climate conditions. As environmental drivers operate and interact at multiple temporal and spatial scales, addressing this challenge will require transforming how we understand, monitor and predict plant responses to stress. Observations from satellites have revolutionised spatial ecology in recent years; making it possible to monitor ecological trends over large spatial scales, and to scale from the plant to the globe. Increasingly sophisticated instruments and techniques allow scientists to examine changing vegetation trends in response to climate change from satellites at unprecedented levels of accuracy. These advances have been made possible by sensor developments, an increasing archive of legacy satellite data, and new and emerging techniques such as solar-induced chlorophyll fluorescence, which has been shown to be closely related to plant productivity. Whilst still in its infancy, solar-induced chlorophyll fluorescence has shown potential to remotely monitor crop growth, using drones through to satellites. However, these remote sensing techniques must first be underpinned by a process-based understanding of the connections between the remote sensing signal and plant characteristics. In this research, controlled laboratory experiments will be used to understand how plant stress manifests in changes to the leaf biochemical and structural properties, and in turn, how optical reflectance signatures, can be used to measure these changes. These optical markers will then be used to 'scale up' our observations, first using drone technology at the field scale, and then and at national and global scales using satellite data. This remote sensing data on crop health will be used within sophisticated biosphere models to predict plant performance under current conditions and forecasted future conditions. These approaches in combination will provide a technological basis for a complete picture at different scales, to fully exploit the resources available for crop improvement. The overarching goal of the research is to assess the ability of nationally and globally important agricultural crops to maintain their growth and performance under different environmental stresses. This research will deploy a cutting-edge, cross-disciplinary approach using controlled growth chambers, novel remote sensing techniques and plant science methods to scale from the leaf to the globe, and provide a step-change understanding in the future pressures that crops may face in light of a changing climate and their underlying resilience.

Uganda, Kenya, Ethiopia and Tanzania

East Africa (EA) has one of the world's fastest growing populations, with maxima around water-bodies and rapid urbanisation. Climate change is adding to existing problems increasing vulnerability of the poorest. HyCRISTAL is driven by EA priorities. EA communities rely on rainfall for food via agriculture. EA's inland lakes are rain-fed and provide water, power and fisheries. For EA's growing cities, climate impacts on water resources will affect water supply & treatment. HyCRISTAL will therefore operate in both urban & rural contexts. Change in water availability will be critical for climate-change impacts in EA, but projections are highly uncertain for rain, lakes, rivers and groundwater, and for extremes. EA "Long-Rains" are observed to be decreasing; while models tend to predict an increase (the "EA Climate paradox") although predictions are not consistent. This uncertainty provides a fundamental limit on the utility of climate information to inform policy. HyCRISTAL will therefore make best use of current projections to quantify uncertainty in user-relevant quantities and provide ground-breaking research to understand and reduce the uncertainty that currently limits decision making. HyCRISTAL will work with users to deliver world-leading climate research quantifying uncertainty from natural variability, uncertainty from climate forcings including those previously unassessed, and uncertainty in response to these forcings; including uncertainties from key processes such as convection and land-atmopshere coupling that are misrepresented in global models. Research will deliver new understanding of the mechanisms that drive the uncertainty in projections. HyCRISTAL will use this information to understand trends, when climate-change signals will emerge and provide a process-based expert judgement on projections. Working with policy makers, inter-disciplinary research (hydrology, economics, engineering, social science, ecology and decision-making) will quantify risks for rural & urban livelihoods, quantify climate impacts and provide the necessary tools to use climate information for decision making. HyCRISTAL will work with partners to co-produce research for decision-making on a 5-40 year timescale, demonstrated in 2 main pilots for urban water and policies to enable adaptive climate-smart rural livelihoods. These cover two of three "areas of need" from the African Ministerial Council on Environment's Comprehensive Framework of African Climate Change Programmes. HyCRISTAL has already engaged 12 partners from across EA. HyCRISTAL's Advisory Board will provide a mechanism for further growing stakeholder engagement. HyCRISTAL will work with the FCFA global & regional projects and CCKE, sharing methods, tools, user needs, expertise & communication. Uniquely, HyCRISTAL will capitalise on the new LVB-HyNEWS, an African-led consortium, governed by the East African Community, the Lake Victoria Basin Commission and National Meteorological and Hydrological agencies, with the African Ministerial Conference on Meteorology as an observer. HyCRISTAL will build EA capacity directly via collaboration (11 of 25 HyCRISTAL Co-Is are African, with 9 full-time in Africa), including data collection and via targeted workshops and teaching. HyCRISTAL will deliver evidence of impact, with new and deep climate science insights that will far outlast its duration. It will support decisions for climate-resilient infrastructure and livelihoods through application of new understanding in its pilots, with common methodological and infrastructure lessons to promote policy and enable transformational change for impact-at-scale. Using a combination of user-led and science-based management tools, HyCRISTAL will ensure the latest physical science, engineering and social-science yield maximum impacts. HyCRISTAL will deliver outstanding outputs across FCFA's aims; synergies with LVB-HyNEWS will add to these and ensure longevity beyond HyCRISTAL.