Seite - 419 - in Biodiversity and Health in the Face of Climate Change

419 nature-based solutions (Kabisch et  al. 2016). Nature-based solutions are actions that are inspired by, supported by or copied from nature, and often with the potential to address a variety of societal challenges in sustainable ways, and contribute to green growth (EU DG Research and Innovation 2015). Nature-based solutions for sustain- able urbanization rely in large part on natural areas and features in and around cities to perform essential ecosystem services. This concept may also be used in climate change adaptation to reduce climate change-related impacts on health (Gill et  al. 2007), or to gain health co-benefits from climate change adaptation within other sectors of society. Urban green areas and vegetation can reduce some of the environmental health risks within the urban systems (Elmqvist et  al. 2013b). Urban green and water areas, such as city gardens and ponds, and nearby forests, lakes and sea, have a strong potential to locally buffer heat extremes (Hardin and Jensen 2007). In summertime, high temperatures are absorbed by water areas. Greenery, in particular trees, reflects solar radiation and lower temperatures locally through evapotranspiration and shad- ing (Bowler et  al. 2010). By increasing urban vegetation through the planting of trees, creating parklands, green rooftops, green walls, and so on, local temperatures in cities can be better regulated and maintained. Urban greenery has also been shown to be effective in reducing air pollutants such as particles and nitrogen and sulphur oxides (Hartig et  al. 2014). Not only do urban green and blue areas reduce health risks associated with high temperatures and air pollutants, but urban vegetation also contributes to reduce flood-related health risks. Vegetation stabilizes the soil and reduces surface runoff following precipitation events. Keeping or adding vegetation will decrease the risk of landslides, as well as the pressure on drainage systems around human settle- ments. By increasing the vegetation cover and reducing the impermeable surface area in built environments, the volumes of surface storm-water runoff can decrease, thus increasing the resilience to flooding. Increased urban green space will thus increase permeability and water runoff mitigation, as well as decrease flood risk by intercepting rainwater (Pataki et  al. 2011). In addition, urban vegetation has other beneficial health effects. Several studies have shown that vegetation contributes to reducing noise pollution and creating tranquil environments for conducive to mental health (González-Oreja et  al. 2010). Urban green areas and vegetation support and facilitate human health and well- being by alleviating stress and allowing space for physical activity and community interaction, which sustain mental health, physical fitness and cognitive and immune functions (WHO 2017). As the fundamental ecological base of urban social-ecological systems, biodiver- sity and ecosystem services play a significant role in reducing the negative impacts of climate change on health, both at present and in the future, therefore reducing vulnerability and strengthening resilience of the urban systems and subsystems. 18 Resilience Management for  Healthy Cities in  a  Changing Climate