The long-term development goals of most countries face significant challenges in reducing emissions, improving environmental sustainability, and mitigating the negative effects of climate change. This study looks at how the ecological sustainability of BRICS countries is affected by economic growth, financial development, new technologies, and renewable energy consumption with the mediating effect of trade openness. The study covers the years 2004–2023, and it was based on fixed-effect models that use static panel data. Data were collected from the World Development Indicators website. The countries and time frame for this study were selected on the basis of data availability. These findings show that the use of renewable energy sources, technological innovation, and financial development all have a significant and positive impact on environmental sustainability. Nevertheless, environmental sustainability is significantly and negatively impacted by economic growth. Furthermore, trade openness functions as a significant mediator between them. Based on empirical evidence, the paper suggests that the BRICS nations seek sustainable economic development. Moreover, government agencies need to accurately evaluate the connection between financial development and emission reduction when formulating programs to cut emissions.