The economic benefits of nature-based solutions- a literature review

Nature-based solutions (NBSs) are gaining increasing prominence due to their effectiveness in managing societal challenges. However, only a small amount of urban infrastructure spending is allocated to the adoption of NBSs, with minimal private sector involvement. This occurs mainly due to uncertainty about short- and long-term economic benefits or returns on investment of NBSs. Traditional economic benefits of NBSs, such as cost savings and avoided damages, are often embedded in business-as-usual assumptions. However, relying on such limited assumptions can reduce the perceived added value of these solutions. This study presents a comprehensive review of economic assessments of NBSs across global contexts. First, it evaluates how research on NBS economics has evolved. Later, it identifies which NBSs have been frequently studied for their economic benefits across various countries. Finally, the study analyses the methodological diversity in evaluating these economic benefits, as well as their implications for policy and practice. The analysis reveals that research on NBS economics is disproportionately concentrated in Europe, North America, and East Asia, while vulnerable regions in Africa, the Middle East, and Southeast Asia remain underrepresented. This reflects broader global inequities in NBS development and implementation. High-income regions advance more rapidly in financing and implementing NBSs, while low- and middle-income regions face financial barriers that hinder adoption. Accordingly, there is a need for expanding international collaborations, open-access knowledge platforms, and citizen science to facilitate the uptake of NBSs in other regions. In terms of methodologies, studies used a variety of financial data with inconsistent application of discount rates, time horizons, and life-cycle costs. Disposal costs were often excluded, which may potentially lead to an overestimation of long-term economic benefits. From a practical perspective, the review shows that while high-return interventions such as living walls may face scalability constraints, more conventional options like green roofs provide stable and replicable returns. From a policy perspective, the review emphasizes the need for standardized, transparent, and life-cycle-based approaches to economic evaluation, incorporated into adaptive monitoring frameworks.