Summary Nature connection and biodiversity play an essential role in mental health and overall well-being. Integrating these elements into therapeutic approaches shows promise for enhancing mental health. This chapter presents theories that emphasize the significance of nature experiences and biodiversity for mental health and provides current data sources on environmental factors relevant to clinical practice. Deteriorating mental health, now the leading cause of disease burden in high-income countries, appears linked to increased urbanization and separation from nature. Studies indicate that living near or frequently accessing natural areas positively impacts mental health, with biodiversity playing a key role. Research on "green spaces" (urban parks) and "blue spaces" (waterfront areas, such as wetlands and coasts) reveals psychological health benefits, like stress reduction. A growing body of studies also explores nature-based activities like gardening and walking in therapeutic interventions for anxiety and depression, suggesting that incorporating biodiversity into mental health treatment may be beneficial. These insights offer innovative therapeutic strategies, potentially reducing the need for medication and its side effects. The chapter explores how to translate these findings into clinical practice, especially given the current climate crisis, which exacerbates mental health issues and diminishes biodiversity. Expanding nature-based interventions, even as climate change progresses, is increasingly vital for both treatment and preventive care. However, more research is needed to deepen theoretical understanding and refine clinical applications. Read more here in the book "Psychiatrie in Zeiten globaler Krisen".