Over three decades of interdisciplinary research at the intersection of atmospheric science, environmental engineering, and urban systems have yielded a central insight: the most persistent sustainability challenges are solved across disciplines, not within disciplines. This presentation reflects on a long journey of collaborative research spanning climate resilience, air quality, sustainable and healthy cities, and the circular economy, drawing on work conducted across Asia, Europe, and beyond. The talk will examine how the deliberate integration of environmental science, engineering, data analytics, and policy has enabled research that is both scientifically rigorous and practically relevant. Through selected case studies, it will illustrate how systems thinking and cross-sector engagement can translate complex environmental data into actionable solutions for low-carbon, resilient societies. The presentation will close with reflections on what makes interdisciplinary collaboration succeed. It will also highlight the role that research institutions, funding bodies, and the next generation of scientists must play in accelerating the transition to sustainable development.

Rajasekhar Balasubramanian (Bala) is the inaugural NUS Keppel Professor in Sustainability Solutions. His research focuses on urban air quality, climate change, and environmental sustainability. He has led major international collaborations and contributed to the development of environmental policy. He is a prolific scholar whose work has been widely cited. He is also actively engaged in education and outreach initiatives aimed at fostering greater diversity and inclusion in sustainability. He is a recipient of many research and teaching awards. He has been a Lead Author for the UNEP’s Global Environment Outlook Report and serves on international scientific panels related to clean air. He has received extensive international recognition for his contributions to environmental sustainability. He is an elected Fellow of the American Association for the Advancement of Science (AAAS), the American Geophysical Union (AGU), the Royal Society of Chemistry (RSC), the Asian Aerosol Research Assembly (AARA), and The World Academy of Sciences (TWAS). He is also an International Honorary Member of the American Academy of Environmental Engineers and Scientists (AAEES). His achievements have been recognised through several prestigious honours. The Asia Magazine named him among the Top 100 Scientists in Asia, while both the Asia Oceania Geosciences Society (AOGS) and the AGU honoured him with Distinguished Lecturer Awards. In 2026, the Indian Institute of Technology (IIT) Delhi recognised his outstanding academic contributions by conferring upon him its Distinguished Alumnus Award.