Science tells us that nature is important to our wellbeing. We are born to connect with nature inside and out. It is how we are wired. If you are looking for evidence to promote trust and an authority on the subject, this list contains published works by researchers, with expertise in psychology and environment, in support of such a positive relationship.
There is a large and growing body of literature that demonstrates that contact with nature (broadly defined in the introduction and including urban green space, parks, forests, etc.) can lead to measurable psychological and physiological health benefits ~ (Sandifer et al. 2015)
Published Works on Nature and Human Wellbeing
These are in order of year, then the author (A-Z).
Wang, D. H., Yamada, A., & Miyanaga, M. (2018). Changes in Urinary Hydrogen Peroxide and 8-Hydroxy-2′-Deoxyguanosine Levels after a Forest Walk: A Pilot Study. International journal of environmental research and public health, 15(9), 1871. doi:10.3390/ijerph15091871
Kuo, M. (2015). How might contact with nature promote human health? Promising mechanisms and a possible central pathway. Frontiers in Psychology, 6, 1093. http://doi.org/10.3389/fpsyg.2015.01093
Sandifer, Paul A., Sutton-Grier, Ariana E., Ward, Bethney P. (2015). Exploring connections among nature, biodiversity, ecosystem services, and human health and well-being: Opportunities to enhance health and biodiversity conservation. Ecosystem Services. 12. pp. 1-15. ISSN 2212-0416, https://doi.org/10.1016/j.ecoser.2014.12.007.
Nowak, David J., Hirabayashi, Satoshi, Bodine, Allison, Greenfield, Eric. (2014). Tree and forest effects on air quality and human health in the United States, Environmental Pollution, 193. pp. 119-129. ISSN 0269-7491, http://dx.doi.org/10.1016/j.envpol.2014.05.028.
Nilsson, K., Sangster, M., Gallis, C., Hartig, T., de Vries, S., Seeland, K., Schipperijn, J. (Eds.). (2011). Forests, trees and human health. ISBN 978-90-481-9806-1. http://www.springer.com/gp/book/9789048198054
Wu, C.-F., Lai, C.-H., Chu, H.-J., & Lin, W.-H. (2011). Evaluating and Mapping of Spatial Air Ion Quality Patterns in a Residential Garden Using a Geostatistic Method. International Journal of Environmental Research and Public Health, 8(6), 2304–2319. http://doi.org/10.3390/ijerph8062304
Townsend, M. and Weerasuriya, R. (2010). Beyond Blue to Green: The benefits of contact with nature for mental health and well-being. Beyond Blue Ltd: Melbourne, Australia. http://www.deakin.edu.au/__data/assets/pdf_file/0004/310747/Beyond-Blue-To-Green-Literature-Review.pdf