Recent advancements in technology and increased understanding of scientific issues at a large scale have facilitated a broader perspective in numerous scientific studies, thereby presenting novel challenges. Standardization and harmonization have emerged as pivotal concepts across various aspects of ecological research, encompassing instrumentation, methodologies, data processing, quality, metadata. This talk explores the evolution over the past three decades of in-situ measurements of greenhouse gas (GHG) fluxes worldwide, from initial campaigns to the establishment of the FLUXNET community, to investigate the current challenges and the possible advancements in this field.