Gretchen Keppel-Aleks, Abigail L. S. Swann, and Yangyang Xu received the Global Environmental Change Early Career Award at AGU’s Fall Meeting 2019, held 9–13 December in San Francisco, Calif. The award recognizes an early-career scientist “for outstanding contributions in research, educational, or societal impacts in the area of global environmental change,” especially through an interdisciplinary approach.  

Yangyang Xu’s research has provided vital insights into major issues related to both the science of climate change and the mitigation of climate change. While still a graduate student, Xu led and completed a multi-institutional study on hydrofluorocarbon (HFC) forcing and its mitigation potential for 21st-century projected trends. This had a major impact on U.S. policy toward eliminating HFCs in refrigeration and helped provide the scientific basis for the Kigali Amendment to the Montreal Protocol.

Xu was also one of the first to show that black carbon heating contributed as much as half of the observed large warming over the elevated regions of the Himalayan–Tibetan region. A series of model-based investigations by Xu and his students and collaborators have shown aerosols from industrial activities to be an important influence on changes observed in the past few decades. These studies consistently demonstrate a more significant impact than was previously suspected for changes in precipitation extremes, latitudinal temperature gradient, drought indices, and snow cover.

In view of his significant contributions to our understanding of the physical mechanisms of climate change, their impacts, and their implications for national and international climate policies, Yangyang Xu is a highly deserving recipient of the 2019 Global Environmental Change Early Career Award.

—V. Ramanathan, Scripps Institution of Oceanography, University of California, San Diego, La Jolla

I deeply appreciate Ram for the nomination and a few of my colleagues at Texas A&M University for starting the process. I benefited greatly from the kind support and inspiration since I started working with Ram 10 years ago at the Scripps Institution of Oceanography. Ram has supplied me a flexible environment in which to explore various research topics and, more important, led me to do society-relevant climate research, which has become my main aspiration today. Through Ram, I had the chance to work with researchers in a multidisciplinary setting and have learned so much from them, especially David Victor (School of Global Policy and Strategy, University of California, San Diego) and Durwood Zaelke (Institute for Governance and Sustainable Development). My gratitude needs to be extended to many scientists at the National Center for Atmospheric Research, where I worked for several years as a visiting student, postdoc fellow, and project scientist. The too-long-to-complete list particularly includes Warren Washington, Jean-François Lamarque, Jerry Meehl, Aixue Hu, Claudia Tebaldi, Simone Tilmes, Mary Barth, and Rajesh Kumar. The career mentoring and research advice from them continue to drive my research forward. Since moving to Texas A&M, I have received tremendous support from many colleagues in the department as well as at the university, especially Andy Dessler, Ping Yang, Jerry North, Ken Bowman, John Nielsen-Gammon, Sarah Brooks, R. Saravanan, and Bruce McCarl. It has been a very productive and enjoyable 3 years in Aggieland. Last and most important, I thank my family, especially my wife, Xiaoshan Gao, for her continuous sacrifice to support my (flexible) work schedule. I’m honored by this award from the AGU Global Environmental Change section, and it will provide encouragement to my future research. Further motivation comes from the grand challenge imposed by the unprecedented rate of global and environmental change, to which I plan to devote my career. I hope the younger generations, my pre-K son and newborn daughter included, can testify (in 2100?) that we tried our best. —Yangyang Xu, Texas A&M University, College Station