This research investigates the relationships between climate change, biodiversity and nature-based tourism in the Danube Delta Biosphere Reserve (DDBR), integrating the behavioural perspective of Generation Z into an adaptive management framework. This study uses a mixed methodological approach, combining time series analysis of the period 2000–2025 with behavioural modelling, based on the primary data study. The analysis of this study includes indicators for the four complementary dimensions, namely: the climate dimension, the biodiversity dimension, the tourism activity dimension, and the behavioural dimension. The relationships among climate variables, biodiversity and tourism are investigated using AutoRegressive Distributed Lag (ARDL) models, while the behavioural component is analysed using the Partial Least Squares Structural Equation Modelling (PLS-SEM) method, applied to a sample of 419 respondents. The results highlight the existence of relationships among climate change, biodiversity and tourist activity, confirming the role of biodiversity as a central element of the attractiveness of nature-based tourism. At the same time, concern for biodiversity significantly influences the intention to visit natural destinations among Generation Z people. Therefore, our research contributes to the literature regarding socio-ecological systems and provides recommendations for the development of adaptive management aimed at biodiversity conservation and strengthening the resilience of sustainable tourism in the Danube Delta.