Humboldt University, Germany
Nature-based Solutions (NBS) are living solutions inspired and supported by the use of natural processes and structures, and are designed to address various environmental challenges in an efficient and adaptable manner, while simultaneously providing economic, social, and environmental benefits (European Commission, 2015). The core idea of NBS is to use the benefits of ecosystem services to prevent a system from crossing a certain threshold/tipping point, such as critical air temperatures, water shortages. or water levels that could lead to dangerous flooding. These interventions create net positive effects, e.g., clean air (Nowak et al., 2014), cooler air temperatures (Baró et al., 2014; Kain et al., 2016), and flood or coastal protection (Wright & Scott, 2011). Types of NBS relevant to cities include: ecosystem restoration, greening of grey surfaces (e.g., green rooftops, green walls or greened brownfields), and integrated broad scale climate change mitigation and adaptation measures, e.g., afforestation, natural flood control, constructed wetlands and, potentially, geoengineering.