Page - 465 - in Biodiversity and Health in the Face of Climate Change

465 (how much?), the length of exposure needed before effects take place (how long?), or the duration of lasting effects for mental health and well-being. As such, future research should usefully investigate the effects of species richness, diversity and distinctiveness, the quantity of time spent in biodiverse environ- ments, and/or the frequency of visiting a biodiverse environment that might be required for a significant change in mental health or well-being. 7. Evaluating effectiveness of interventions: Nature-based interventions need to be evaluated for their effectiveness for health and well-being, biodiversity con- servation and climate change adaptation. Socio-economic factors should also be included to ensure evaluations consider potential disproportional effects across different beneficiaries. Proof of causality is important to establish when assessing the effectiveness of an intervention. Whilst randomised controlled trials may not be feasible or appropriate, nature-based interventions are complex interventions and researchers should use more robust research designs such as natural experiments, quasi-experimental before-and-after repeated- measures designs, or longitudinal studies (e.g. gain/loss in biodiversity or access to green space). Complex analyses such as stepped wedge, interrupted time series or structural equation modelling analyses warrant more scientific attention. 8. Analysing cost-benefits: Economic evaluations of biodiversity and interven- tions for human health are a significant driver for decision makers. As such, cost-benefit evaluations of the anticipated reduction in health-care costs of bio- diverse  green spaces are recommended. Overall, the cost-benefit analyses should be holistic, addressing all multiple benefits provided, with the specific cost reduction potential to health-care seen as just one aspect. 9. Developing models and scenarios: Scenarios and models need to be developed to investigate and forecast the human health and well-being effects of current biodiversity loss and reduced access to natural environments in a changing climate. 10. Integrating better across disciplines: By its nature, the questions considered within the field of biodiversity and health in the face of climate change are transdisciplinary and thus require integration of the natural, social and health sciences. Research should therefore be transdisciplinary in order to fully under- stand and measure biodiversity as well as human health impacts. 11. Increasing international scope: Current literature is geographically biased. Whilst many findings will be applicable across the Global North, we acknowl- edge that cultural settings matter for the appreciation of green space and more research also needs to include the Global South. As such, there is a research need to broaden understanding to include different conditions around the globe, as biodiversity-health relationships will be influenced by climate, cultural con- texts and social norms. 20 Biodiversity and  Health in  the  Face of  Climate Change: Perspectives for  Science…