Dr. Lei Zhao has emerged as one of the most influential and creative scientists in the field of urban climate and Earth system science. His research is transforming the broad field of global urban climate science and has fundamentally advanced the understanding, modeling, and prediction of urban climate in the context of global change. A hallmark of Zhao’s scholarship is his exceptional creativity and pioneering role in developing new theories and modeling frameworks that unlock significant new directions for research and applications. The depth and breadth of his work extend from fundamental theory to advanced modeling, from remote sensing to artificial intelligence/machine learning (AI/ML), and from climate-driven risks to actionable solutions. Zhao’s research has transformed our understanding of how cities interact with climate systems. In one of his landmark contributions, he established the first theoretical framework for attributing urban heat islands to surface biophysical processes. This foundational study has reshaped how urban land-atmosphere interactions are understood and quantified. His thermodynamics-based decomposition formulation further uncovers the climate-driven dilemma of urban greenery cooling and the critical role of humidity in shaping urban heat exposure. He has also pioneered transformative AI/ML applications that integrate process-based climate modeling with physics-informed machine learning. His innovative global hybrid urban climate modeling framework provides the first global multimodel urban climate projections, representing a major leap forward for the field. Subsequent studies from his group on uncertainty in future urban heat waves and urban climate-energy feedbacks further demonstrate his vision and leadership in integrating physics-based and data-driven approaches. He has made transformative advances toward next-generation kilometer-scale urban-resolving Earth system models, many of which are major breakthroughs and milestones reshaping how cities are represented in climate simulations. Zhao’s work carries profound impacts beyond research. As one of the six U.S. scoping experts for the forthcoming Intergovernmental Panel on Climate Change Special Report on Cities and Climate Change, his contributions are shaping global climate policy frameworks. His work exemplifies excellence, integrity, collaboration, and inclusivity, and his mentorship has inspired a diverse new generation of scientists. With numerous high-impact publications, prestigious academic honors, and a portfolio of internationally recognized leadership, Zhao has already achieved a level of scholarly impacts rarely seen at this career stage. For pioneering and transformative contributions to urban climate science through innovative integration of theory, modeling, and machine learning, Dr. Lei Zhao richly merits the James B. Macelwane Medal. —Yun Qian, Pacific Northwest National Laboratory, Richland, Washington