Tailoring climate projections to the needs of agricultural stakeholders - insights from ADAPTER

Agriculture is among the sectors that are most vulnerable to extreme weather conditions and climate change. In Germany, the subsequent dry and hot summers 2018, 2019, and 2020 havebrought this into the focus of public attention. Agricultural actors like farmers, advisors or companies are concerned with such interannual variability and extremes. Yet, it often remainsunclear what long-term adaptation options are most suitable in the context of climate change, mainly because climate projections have uncertainties and are usually not tailored to meetrequirements, measures and scales of the individual practitioners. In the ADAPTER project, we explore regional and local change on the weather- and climate-related time scales and togetherwith stakeholders (administration, plant breeders, educators, agricultural advisors), we co-design tailored climate change indices and usable products.In this contribution, we first demonstrate which aspects of climate change are most important for our stakeholders regarding the breeding of new crops and identifying ideal testing areas andfuture regions of cultivation. Second, we present a comprehensive data analysis based on weather observations, model analyses of past weather, and 85 regional climate simulations, andshow what changes can be expected in the next decades. We identify and analyse practically relevant climate indices, that are tailored to specific soil-climate zones in Germany and to critical stages of plant development during the year. The indices capture aspects of climate change like increasing temperature variability, the increasing occurrence of combined heat and drought, and changes in the potential accessibility of soils.Based on the results, we discuss to what extent recent developments are in line with our expectations of future climate change, and present our freely available ADAPTER "productplatform" devised to help agricultural stakeholders adapt to climate change