Global environmental challenges like ecological drought demand cross-border collaboration and interoperable data. The Global Ecosystem Research Infrastructure (GERI) was founded to address this need, building relationships and establishing data sharing practices among six of the largest ecosystem research infrastructures in the world. Data harmonization is required to standardize and ingest data products from these infrastructures into a findable, accessible, interoperable, reusable (FAIR) global dataset. Harmonized global data can improve existing global climate models and inform environmental research studies. This poster presents a proof of concept for harmonizing ecological drought-related data products including air temperature, precipitation, soil moisture, soil temperature and soil texture starting with data from NEON (USA) and TERN (Australia). The process involved crosswalks for variable names and units, term mapping, and metadata standardization using controlled vocabularies and EML. We describe both technical and institutional challenges encountered in aligning data from diverse infrastructures, including differences in structure, granularity, and documentation. These lessons are shaping the development of scalable methods and shared practices as we expand the effort to include additional networks RIs. Looking ahead, we aim to broaden the scope of harmonization to additional ecological domains. This work will be led in part by GERI’s Early Career Researcher working group and pursued in collaboration with international initiatives like DroughtNet and the International Drought Experiment. These efforts mark progress toward a globally interoperable environmental data landscape in support of science, policy, and ecosystem resilience.