Megacities across the planet face a range of economic and territorial challenges. Future climate predictions suggest that several urban areas will present greater social and environmental problems in the coming decades, which makes strategic planning urgent and necessary for sustainable adaptation in all senses, i.e., economic, social and environmental. Some cities in the global south, such as Sao Paulo, had a history of rapid urban development without environmental planning throughout the 20th century, making urgent the need to expand green infrastructure, especially with the connection of forest fragments to the urban fabric. Therefore, this study aimed (i) to evaluate the increase in official urban parks throughout history, considering the spatialization and typologies of new parks in the territory of Sao Paulo, (ii) to understand the ecosystem services provided by urban forests and its distribution in the city, and (iii) to associate the temporal stability attributes of recent environmental secretaries with the officialization of protected areas in the city of Sao Paulo. The results revealed that only at the beginning of the 21st century was there an effective increase in the number of protected areas that shelter fragments of urban forests, contrasting the strong socio-spatial segregation that occurred in the 20th century with an economically vulnerable population that occupied peripheral areas with greater natural disaster risk. Political stability was a key factor for success in the environmental management of a megacity. The scenarios of environmental injustice reported in this manuscript can be revised with the implementation of policies and actions aimed at expanding green infrastructure in strategic sites, based on specific park typologies for each location. Such actions may come from public–private partnerships (PPP) that subsidize the socio-environmental transformation of the territory.

This study focuses on the deposition of microplastics (MPs) on urban beaches along the central São Paulo coastline, utilizing advanced methodologies such as remote sensing, GNSS altimetric surveys, µ-Raman spectroscopy, and machine learning (ML) models. MP concentrations ranged from 6 to 35 MPs/m², with the highest densities observed near the Port of Santos, attributed to industrial and port activities. The predominant MP types identified were foams (48.7%), fragments (27.7%), and pellets (23.2%), while fibers were rare (0.4%). Beach slope and orientation were found to facilitate the concentration of MP deposition, particularly for foams and pellets. The study’s ML models showed high predictive accuracy, with Random Forest and Gradient Boosting performing exceptionally well for specific MP categories (pellet, fragment, fiber, foam, and film). Polymer characterization revealed the prevalence of polyethylene, polypropylene, and polystyrene, reflecting sources such as disposable packaging and industrial raw materials. The findings emphasize the need for improved waste management and targeted urban beach cleanups, which currently fail to address smaller MPs effectively. This research highlights the critical role of combining in situ data with predictive models to understand MP dynamics in coastal environments. It provides actionable insights for mitigation strategies and contributes to global efforts aligned with the Sustainable Development Goals, particularly SDG 14, aimed at conserving marine ecosystems and reducing pollution.

Urban vegetation monitoring is essential for sustainable city planning but is often constrained by the high cost and limited frequency of field-based inventories. This study evaluates the use of the Normalized Difference Vegetation Index (NDVI), derived from Sino-Brazilian CBERS-4A satellite imagery, as a spatially explicit and low-cost proxy for urban tree census data. CBERS-4A provides medium-resolution multispectral data freely accessible across South America, yet remains underutilized in urban environmental applications. Focusing on Aracaju, a metropolitan region in northeastern Brazil, we compared NDVI-based classification results with official municipal tree census data from 2022. The analysis revealed a strong spatial correlation, supporting the use of NDVI as a reliable indicator of canopy presence at the urban block scale. In addition to mapping vegetation distribution, the NDVI results identified areas with insufficient canopy coverage, directly informing urban greening priorities. By validating remote sensing data against field inventories, this study demonstrates how CBERS-4A imagery and vegetation indices can support municipal tree management and serve as scalable tools for environmental planning and policy.