Air pollution in megacities such as São Paulo is one of the major public health challenges, with fine particulate matter (PM2.5) and nitrogen dioxide (NO₂) among the most critical air pollutants due to their respiratory and cardiovascular effects. Intensified land use along the Urban Structuring Axes (EETU), a strategy within transit-oriented development, has promoted densification and verticalization, altering the urban microclimate and pollutant dispersion. This study analyzed how different urban morphological configurations influence the dispersion of PM2.5 and NO₂ in street canyons along the EETU in São Paulo city, considering the interaction between built form and street trees. The ENVI-met microclimatic model, based on Computational Fluid Dynamics (CFD), was used to simulate pollutant concentration and dispersion in five street canyons representative of distinct urban morphologies. Indicators such as urban density, verticality (average building height), H/W ratio, occupation, directionality (building orientation relative to prevailing winds), and Normalized Difference Vegetation Index (NDVI) were applied to characterize each area. Results show that compact and highly occupied urban forms exhibit substantially higher NO₂ concentrations at pedestrian level, with differences of up to ~ 80% between contrasting urban morphologies. In contrast, PM2.5 concentrations vary only modestly between canyons (< 5% variation), remaining close to urban background levels. PM2.5 deposition mass, however, shows pronounced sensitivity to urban form and vegetation, varying by over 60% between canyons, indicating that deposition responds differently from pollutant concentration. Urban form therefore plays a key role in shaping ventilation efficiency and air quality in dense areas of São Paulo. Strategies that combine building height variation, transversal block openings, orientation relative to prevailing winds, and context-sensitive street-tree management are essential to reduce population exposure to air pollution in compact urban environments.

Heat stress mitigation actions must be carefully planned in order to achieve effective outcomes. By integrating urban planning guidelines with urban climate knowledge, substantial benefits can be achieved for the community. In Lisbon, the study area, urban planning guidelines are strict in relation to the tree species which should be used for planting. This study examined these species environmental contributions to the community, especially in regard to heat stress mitigation in two urban canyons previously found as UTCI hotspots. For this, microclimatic Envi-met simulations were run which allowed recalculation of the UTCI hotspot analysis and to assess individual species contribution to possible mitigation efforts. Results demonstrated the ability of these trees to lower air temperature and the Universal Thermal Climate Index (UTCI). By reducing UTCI temperatures between 3.19 °C and 6.27 °C on a hot summer’s day, these trees were also able to transform an identified UTCI hotspot into a coldspot. From the studied species, Pyrus calleryana was found to be the most effective species for mitigating thermal stress, although all three species performed well. Regarding community services, according to the iTree tool, Cercis siliquastrum had the greatest overall impact. These results give to the municipal urban planning which tree species should be prioritized in terms of climate action, as well as a methodological framework to assess at local scale which areas should be intervened.

Resumo O artigo analisa os arranjos morfológicos urbanos condicionantes da geração de energia fotovoltaica, no bairro do Belenzinho, em São Paulo. Foi utilizado o software 3D Rhinoceros® com os plug-ins Grasshopper® e Diva® para modelar a variação isolada dos parâmetros urbanísticos e identificar parâmetros que maximizam ou minimizam a incidência de radiação solar na cobertura das edificações. Em seguida, utilizou-se o algoritmo genético Galapagos, com a finalidade de combinar os parâmetros urbanísticos, identificando-se os valores mais adequados quanto ao aproveitamento da radiação solar. As análises mostraram que valores intermediários de coeficiente de aproveitamento e taxa de ocupação igual a 0,70 são indicados para maximizar a geração de energia fotovoltaica na escala de vizinhança. Enquanto valores máximos permitidos pela legislação são indicados na escala da edificação. Assim, a definição de uma política energética municipal para aproveitamento fotovoltaico na cobertura de edificações passa pela análise da viabilidade de geração concentradas ou distribuídas, o que impacta em diferentes formas de apropriação na regulação da ocupação do solo.

Developing countries’ megacities, characterised by dense populations and socioeconomic disparities, often face high levels of pollutants, mainly from vehicle emissions. Poor air quality can lead to a range of public health problems which in turn, need to be addressed by public policies. The main goal of this article is to examine the impact of public policies and the influence of transport modes on air pollution of three districts from the Metropolitan Region of São Paulo, in Brazil: Pinheiros, Parque Dom Pedro II and Taboão da Serra. The method was held through a comparative analysis, which in turn, took into account urban indicators, urban mobility data and pollutants levels (CO and NOx). These data were collected from the 2007 and 2017 São Paulo Metrô Origin and Destination Surveys and the Air Quality Database of the Environmental Company of the State of São Paulo. As key findings, the three study areas’ pollutant concentrations presented a downward trend from 2007 to 2017 as the same time there was an increase in the public transport and non-motorized transport modes. However, it is important to highlight the confluence of the state and federal public policies occuring at the same period such as PRONCOVE, Rodoanel and the Yellow Subway Line. The identified socio-environmental disparities in the urban realm highlight the importance of localised analyses in order to reveal problems and opportunities to get a better response in terms of urban mobility and air quality. Thus, the perpetuation of constant policy’s updates and interdisciplinary collaboration is crucial.

The thermal impact of vehicle surfaces on urban climate is a critical yet understudied component, with the potential to influence local microclimates and the urban energy balance. This research quantified the thermal effects of vehicle surfaces in Lisbon, Portugal, through a combination of in situ measurements and parametric modeling. Using a compact mobile weather station equipped with precise sensors, we conducted both mobile and stationary measurements to capture detailed data on the radiative properties of vehicle surfaces. Results revealed significant variations in surface temperatures based on vehicle color. Black vehicles reached a median surface temperature of approximately 71°C, about 20°C higher than white vehicles, which had a median surface temperature of 45°C. This difference in heat absorption directly affected local air temperatures: black vehicles increased surrounding air temperatures by around 2.5°C on a summer day, while white vehicles caused a more moderate rise of 1°C. Black vehicles also exhibited the highest median net all-wave radiative balance (752.8 W/m²), while white vehicles showed much lower values (515 W/m²), illustrating darker vehicles’ greater thermal load and localized heating effects. When exposed to direct sunlight, dark grey vehicles showed the highest radiative balance values (median 680 W/m²), while white vehicles demonstrated the lowest values, confirming their reflective nature. To complement field measurements, we conducted thermal simulations using EnergyPlus integrated with Honeybee for Grasshopper. These simulations, calibrated with site-specific meteorological data, were used to assess whether the 3D EnergyPlus models could replicate real-world conditions. The results validated observed trends and deepened understanding of vehicle characteristics’ role in influencing surface and air temperatures. This study bridges the gap between empirical data and simulations, offering valuable insights for urban climate research and informing mitigation strategies to reduce urban heat island effects.

Urban air pollution and microclimatic conditions significantly influence public health. This study validates pollutant dispersion and microclimatic conditions simulated in ENVI-met using lichen biomonitoring data. The case study focuses on Avenida da Liberdade, an urban canyon in Lisbon, Portugal, characterized by high traffic and dense tree coverage. ENVI-met simulations of NO₂ and PM10 dispersion, along with microclimatic conditions (wind speed, solar radiation, and humidity), were performed under current conditions. To validate the simulations, changes in lichen species composition on Celtis australis trees were assessed using a European standard methodology. A total of 82 trees were surveyed, recording lichen abundance and species diversity across four cardinal orientations. Non-metric multidimensional scaling (NMDS) was applied to identify gradients in lichen species composition associated with pollution and microclimatic factors. The ordination analysis revealed significant correlations between NMDS axes and simulated environmental variables, such as NO₂, PM10 concentrations, and wind speed. The spatial distribution of NMDS scores closely mirrored the ENVI-met outputs, with axis 3 reflecting pollution gradients and axis 2 aligning with wind patterns. This integrated approach demonstrates the efficacy of combining CFD-based simulations with biological indicators to assess urban microclimates and pollutant dispersion. The results highlight the potential of lichen biomonitoring as a cost-effective tool for validating environmental models, contributing to more accurate urban environmental management strategies. Future research may explore extending this methodology to diverse urban contexts and a broader range of climatic conditions and pollutant types.