Core Viewpoint - The concept of "sponge cities" is gaining global resonance as a sustainable urban development strategy that emphasizes nature-based solutions to manage water resources and enhance ecological resilience [1][6][7]. Group 1: Concept and Implementation - "Sponge cities" focus on retaining water based on local conditions, such as storing scarce water or guiding excess water, promoting natural water infiltration and regeneration [4][7]. - The approach contrasts with traditional "gray infrastructure" methods, which are increasingly seen as inadequate for addressing climate change and fostering a harmonious relationship with nature [2][3]. Group 2: Global Examples and Impact - Numerous "sponge city" projects have been successfully implemented in China, enhancing urban resilience against flooding, creating accessible public spaces, and increasing land value [4][6]. - Recent projects in Bangkok and Niterói, Brazil, exemplify the successful application of nature-based solutions for ecological restoration and water purification [6][7]. Group 3: Challenges and Opportunities in Brazil - Brazil faces significant challenges in environmental governance and urban development, with a high incidence of natural disasters, including 1,600 recorded events in 2024, primarily related to landslides and hydrological events [7]. - There is a growing recognition among Brazilian society of the need for ecological projects, supported by various professionals collaborating to advance nature-based solutions [6][7]. Group 4: Political Will and Systemic Change - The core of ecological transformation lies in political will and institutional commitment, with China serving as a model for integrating ecological governance into national strategy [7][8]. - The systemic approach adopted by China has led to significant improvements in managing urban flooding, droughts, and pollution, providing a framework for other developing countries to explore sustainable pathways [7][8].