Sari as one of the most populous cities in Iran is experiencing a growing presence of industrial and man-made structures, which has led to the degradation of its natural environment. The present study aims to evaluate the impact of built environments on energy consumption and air pollution in the urban ecosystem of Sari. This research is descriptive-analytical in nature and applied in purpose. Given that the study investigates the comparative impacts of the built environment on the natural environment of Sari across three time intervals (1999, 2009, and 2019), the study area includes both artificial and natural landscapes of Sari city.The data used in this research regarding air pollutants were obtained from Landsat and Sentinel satellite imagery. The analysis of the data was conducted using remote sensing techniques through ArcGIS and Terset software.The findings reveal that over the three time periods, land surface temperature (LST) increased in parallel with the decline in vegetation cover in Sari. In 1999, LST ranged from 19°C to 32°C, which rose to between 23°C and 41°C by 2019. The reduction in vegetation, driven by construction and urban physical expansion, has significantly increased surface temperatures. Moreover, the spatial correlation analysis of surface temperature across Sari shows a point-to-point spatial correlation of 0.47 between 1999 and 2019, indicating that approximately 5.3% of the city's area has experienced changes in its surface temperature pattern over the past two decades. There is a significant relationship (0.92) between temperature and the area of residential use, and this relationship is a direct relationship, which means that with the increase of residential use, the amount of temperature increases.