A green banking system encourages sustainable development by offering eco-friendly financial products and solutions, predicting green investments, and reducing environmental risks for a more stable future for young generations. This research study determines the role of green banking on sustainable growth, the impact of online payment systems, and patterns of green banking among regular customers. It also helps to understand essential elements of the green banking system on public sector banks. The sample of 100 customers of selected public sector banks of southern districts of Karnataka State in India. Cross-sectional study shows that demographic profile is one of the key determinants of green banking initiatives. It also reveals that online payment mode is a motivating factor and discusses many problems customers confront in the green banking system.