This chapter presents a comprehensive analysis of nitrogen dioxide (NO₂) concentrations in the atmosphere over the past two decades, with a specific focus on India within a global context. Leveraging satellite data, we examine spatial and temporal trends in NO₂ levels, identifying key hotspots and regional variations. Our analysis reveals significant global trends, including the impact of industrial activities, policy interventions, and global events such as economic crises and pandemics. In the Indian context, we explore the pronounced variability in NO₂ concentrations across urban, industrial, and rural regions, highlighting the influence of seasonal patterns and socio-economic factors. The chapter also compares NO₂ levels and trends in India with those observed globally, offering insights into the effectiveness of regional and global mitigation strategies. Our findings underscore the critical role of targeted policy measures in addressing air quality issues and provide a foundation for future research aimed at improving air quality management. This work contributes to the broader understanding of atmospheric NO₂ dynamics and their implications for public health and environmental sustainability at both regional and global scales.