An overview of the institutionalization of nature-based solutions in Brazilian cities

While Nature-based Solutions (NbS) are gaining visibility in Brazil as a strategy for rethinking urban development, their institutionalization within municipal frameworks remains poorly understood. This article provides the first nationwide mapping of NbS integration into local governance, analyzing 903 legal norms across 389 municipalities. Results show that NbS institutionalization is recent (mostly post-2020) and uneven, favoring specific strategies such as green roofs, urban forests, and rain gardens over the umbrella term “NbS.” Geographically, norms are concentrated in the Southeast and South, while the North—home to the Amazon—remains scarcely represented. Although larger cities show higher adoption rates, medium-sized municipalities lead in legislative output. Ordinary laws dominate the legal landscape, while complementary laws and master plans offer stronger integration opportunities. The study also identifies “NbS Champions,” a group of municipalities that have institutionalized multiple strategies. Crucially, these findings establish a baseline for monitoring the impact of emerging federal frameworks, such as the National Urban Afforestation Plan (PlaNAU), while highlighting the strategic role of local governments as autonomous drivers of bottom-up innovation for climate resilience.