ClimBar will identify genome regions, genes, and alleles conferring the traits needed to breed resilient barley varieties adapted to future climatic conditions in different European regions. Phenotypic responses of a diversity set relevant to resilience, sustainability, and quality will be determined under anticipated conditions of altered C02, water and nutrients, and pathogen pressure. These responses will be connected to genes and genome regions by Genome Wide Association Studies (GWAS) using extensive sequence variant, epigenome, and transcript abundance datasets. Based on the observed plant responses and different climate scenarios, harvests in 2070 and their impact on European agriculture will be modelled. The contribution of each gene/genome region to resilience under these different climate scenarios will be incorporated into a genomic selection model, ideotypes for 2070 constructed, and relevance to interim conditions assessed. ClimBar will use contemporary genetics and genomics to identify genes and alleles that provide resilience to four climate change scenarios modelled for NE, NW, Mediterranean, and Central European grain producing zones. We will impose drought, flooding, temperature, and fungal challenges predicted to occur under each scenario and use precision phenotyping to quantify integrated biological comprising trade-offs between individual stress responses . Resilience will require combining multiple traits (and responses) that include plant architecture, physiology, and metabolic homeostasis. These are determined by the unique allelic combinations that comprise the genome, the specific genomic marks that comprise the epigenome, and their combined interactions with the external environment. CRWs (crop wild relatives and landraces) contain a vast pool of (epi)genetic diversity and interactions naturally selected for resilience against local environmental pressures. ClimBar will explore this potentially valuable genetic and epigenetic variation by leveraging GWAS, genetic marker, and exome sequence data generated in previous projects. It will go beyond the existing effort by: examining traits specifically required for resilience to climate change, combining multiple challenges expected under different climate change scenarios, establishing a method of phenotyping combined challenges under CO2 levels predicted for 2070 (700 ppm), modelling allele combinations and harvest expectations, examining stress-induced responses connected to epigenetic effects on seed quality countering plant resilience, ideotype development. The individual WP components are reliably established, but have never been combined or deployed as in ClimBar, neither exome sequence nor association data have been used to explore multiple and/or combined stress responses. However, the core genetic, biometrical and predictive modelling approaches have been shown to be effective for both simple and complex characters. Barley is a major grain worldwide. Europe produces the greatest share (~60 MT/yr), of which ~20% underpins its brewing industry that generates annual government revenues of ~€ 50-60 bn. Maintaining barley production will support 150,000 farmers and ~3,800 European breweries that provide jobs for >164,000 employees, together with connected jobs (total >2.5M) in retail, supply, and hospitality. Barley has potential as a health-promoting functional food, given its high content of sterols, stenols, arabinoxylans, and beta glucans. It is an important break crop and animal feed, and its straw has a role in animal welfare and nutrition, in bioenergy and in carbon capture. It grows where wheat or maize cannot. Climbar will deliver to each of these sectors by effective characterization and use of the diversity present in its CWRs and by exploring predictive plant breeding focused on low inputs and climate change coupled with modelling impacts on production.