Nature-based solutions for adapting to water-related climate risks

Healthy ecosystems, and their associated services, can provide effective natural protection against water-related climate risks. Nature-based solutions (NbS) have recently gained momentum in international policy discussions due to their potential to foster synergies between ecosystem health and human wellbeing, while also offering economic benefits. This OECD policy paper provides an overview of the use of NbS to date in OECD countries and finds that in most cases ambition for NbS does not match practice. Focusing on the application of NbS for addressing climate-related flood and drought risks, this paper explores why prevailing decision making frameworks may fail to adequately consider NbS. It sets out a policy evaluation framework that supports the identification of, and proposed ways to address constraints on the use of NbS to address water-related climate risks.

The report specifically examines coastal flooding, riverine flooding, urban flooding and drought. Since the bottlenecks may be similar across other application areas, the presented policy framework is meant to inform the broader set of issues for which NbS can be considered. After the first introductive section, section two provides an introduction to the concept of NbS. Section three focuses on the role of NbS in reducing the water-related exposure to climate risks and provides an overview of their uptake to date in OECD countries. Section four explores why prevailing decision making frameworks may fail to adequately consider NbS, and section five examines how NbS have been integrated in policy frameworks to date. This analysis then informs section six, which builds a policy evaluation framework intended to structure the cross-country comparative analysis of future case studies.