John Tien

John Tien

The Hon. John Tien is a distinguished external fellow at the Georgia Tech Strategic Energy Institute and the Georgia Tech Research Institute. He is also a distinguished professor of the practice in both the Sam Nunn School of International Affairs and the School of Cybersecurity and Privacy and a senior fellow at the Belfer Center for Science and International Affairs at the Harvard Kennedy School. 

Before joining Georgia Tech, Tien was deputy secretary of the U.S. Department of Homeland Security (DHS) from 2021 to 2023. In that role, he was the DHS chief operating officer, overseeing a budget of $105 billion and facilities in all 50 U.S. states and all territories as well as more than 3,000 personnel stationed overseas in more than 75 countries. 

Alongside the secretary of Homeland Security, Deputy Secretary Tien led the policy development, operational oversight, and risk management of the department’s statutory mission areas and subordinate agencies, including cybersecurity and protection of America’s critical physical and cyber infrastructure; disaster preparedness and recovery; supply chain optimization, border security, and free and fair trade; air, pipeline, and rail security; maritime physical and cyber security; citizenship and immigration services; protection of senior officials and safeguarding the U.S. financial system; and counter-narcotics production and trafficking. 

In his broader policy administration role, Deputy Secretary Tien served as a member of the National Security Council’s Deputies Committee, the board of the National Counterterrorism Center, and the President’s Management Council. 

Upon his retirement from DHS in 2023, he was awarded two of DHS’ highest civilian awards: the DHS Distinguished Service Medal, and the United States Coast Guard Distinguished Public Service Medal. 

Tien previously served in the Obama administration as a National Security Council (NSC) senior director for Afghanistan and Pakistan, the Bush administration as an NSC director for Iraq, and the Clinton administration as a White House Fellow for the United States Trade Representative. 

From 2011 to 2021, he held various senior leadership positions at Citigroup as a managing director in their Citi Retail Services and Global Consumer Bank organizations. Before Citigroup, he was a U.S. Army officer, retiring at the rank of colonel. His Army career included commanding an 1,100-soldier armored task force in combat in Iraq, serving overseas for nearly a decade, and teaching political science at West Point. Col. Tien’s military awards and decorations include the Bronze Star Medal, Combat Action Badge, and Valorous Unit Award. 

Tien is now serving on the corporate board of directors for Union Pacific Railroad, on the Carter Presidential Center’s Board of Councilors, and as a founding board member of the Avalon Action Alliance, a nonprofit focused on nationally scaling proven healthcare programs to help heal veterans and first responders who struggle with depression, PTSD, and traumatic brain injury. He is also an executive partner and ambassador for the Master’s in Business for Veterans program at Emory University’s Goizueta Business School. 

Tien holds a B.S. in civil engineering from the United States Military Academy at West Point and an M.A. in philosophy, politics, and economics from Oxford University, where he was a Rhodes Scholar. He is a life member of the Council on Foreign Relations. He lives with his wife Tracy in Atlanta and volunteers with and supports numerous local civic institutions including the High Museum of Art.

Distinguished External Fellow / Professor of the Practice
IRI and Role
Energy > Staff
Energy

Iris Tien

Iris  Tien
itien@ce.gatech.edu
Assistant Professor
Phone
(404) 894-8269
Additional Research
Smart Infrastructure
IRI and Role
Energy > Research Community
Energy
University, College, and School/Department
Georgia Institute of Technology > College of Engineering

Anjali Thomas

Anjali Thomas
anjalitb3@gatech.edu

Anjali Thomas is an Associate Professor in the Sam Nunn School of International Affairs and Director of the Nunn School Program in Global Development. Her research focuses on the political economy of development, and employs quantitative analyses of data derived from India and other developing country contexts. Her specific substantive interests include the politics of service provision, democratic institutions and the link between climate change and local level politics. Prior to joining the faculty at Georgia Tech, Anjali was a faculty member in the Department of Political Science at the University of British Columbia in Vancouver. She obtained her Ph.D. from New York University in 2010.

Associate Professor
BBISS Co-lead: SEEDS (Southeast Exchange of Development Studies)
IRI and Role
Sustainable Systems > Fellow
Sustainable Systems > Initiative Lead
Energy > Research Community
Sustainable Systems
Energy
University, College, and School/Department
Georgia Institute of Technology > Ivan Allen College of Liberal Arts > Sam Nunn School of International Affairs
Research Areas
Sustainable Systems
  • Global Sustainable Development

Valerie Thomas

Valerie Thomas
valerie.thomas@isye.gatech.edu

Valerie Thomas is the Anderson-Interface Chair of Natural Systems and Professor in the H. Milton School of Industrial and Systems Engineering, with a joint appointment in the School of Public Policy. 

Dr. Thomas's research interests are energy and materials efficiency, sustainability, industrial ecology, technology assessment, international security, and science and technology policy. Current research projects include low carbon transportation fuels, carbon capture, building construction, and electricity system development. Dr. Thomas is a Fellow of the American Association for the Advancement of Science, and of the American Physical Society. She has been an American Physical Society Congressional Science Fellow, a Member of the U.S. EPA Science Advisory Board, and a Member of the USDA/DOE Biomass Research and Development Technical Advisory Committee. 

She has worked at Princeton University in the Princeton Environmental Institute and in the Center for Energy and Environmental Studies, and at Carnegie Mellon University in the Department of Engineering and Public Policy.

Dr. Thomas received a B. A. in physics from Swarthmore College and a Ph.D. in theoretical physics from Cornell University.

Anderson-Interface Chair of Natural Systems
Professor
RBI Initiative Lead: Sustainability Analysis
Phone
(404) 894-0390
Additional Research

Hydrogen Transport/Storage; Biofuels; ClIMaTe/Environment; Electric Vehicles; System Design & Optimization; Energy and Materials Efficiency; Sustainability; Industrial Ecology; Technology Assessment; Science and Technology Policy

IRI and Role
Sustainable Systems > Affiliated Faculty
Data Engineering and Science > Faculty
Renewable Bioproducts > Faculty
Renewable Bioproducts > Leadership
Energy > Hydrogen Group
Energy > Research Community
Sustainable Systems
Data Engineering and Science
Renewable Bioproducts
Energy
Matter and Systems > Affiliated Faculty
University, College, and School/Department
Georgia Institute of Technology > College of Engineering > School of Industrial Systems Engineering
Research Areas
Sustainable Systems
  • Climate Science, Solutions, and Policy
Matter and Systems
  • Built Environment Technologies

David Taylor

David Taylor
david.taylor@gatech.edu
Professor
Phone
(404) 894-8910
Additional Research
Electric Vehicles
IRI and Role
Energy > Research Community
Energy
University, College, and School/Department
Georgia Institute of Technology > College of Engineering > School of Electrical and Computer Engineering

Yuanzhi Tang

Yuanzhi Tang
yuanzhi.tang@eas.gatech.edu

Yuanzhi Tang holds undergraduate degrees in Geology and Economics from Peking University, China. She earned a Ph.D. degree in Environmental Geochemistry at Stony Brook University and then continued working in the microbiology group of Prof. Colleen Hansel.

Tang joined the Georgia Tech faculty in 2013 as an assistant professor and is now an associate professor in the School of Earth and Atmospheric Sciences.

Associate Co-Director for Interdisciplinary Research
Professor
SEI Lead; BBISS Co-lead: Sustainable Resources
Phone
404-894-3814
Office
ES&T 1232
IRI and Role
Sustainable Systems > Initiative Lead
Sustainable Systems > Staff
Energy > Fellow
Energy > Research Community
Sustainable Systems
Energy
University, College, and School/Department
Georgia Institute of Technology > College of Sciences > School of Earth and Atmospheric Sciences
Research Areas
Sustainable Systems
  • Resource and Materials Use

Phanish Suryanarayana

Phanish Suryanarayana
phanish.suryanarayana@ce.gatech.edu

Phanish Suryanarayana joined the School of Civil and Environmental Engineering at the Georgia Institute of Technology in August 2011. He received his B.Tech. from Indian Institute of Technology, Madras, India in 2005. He obtained his M.S. in Aeronautics from California Institute of Technology in 2006. Subsequently, he received his Ph.D. in Aeronautics from California Institute of Technology in 2011 for his thesis titled "Coarse-graining Kohn-Sham Density Functional Theory". His research interests are in the areas of multiscale modeling, ab-initio calculations, density functional theory, continuum mechanics and smart materials. Overall, he is interested in developing efficient numerical methods for solving problems arising in a variety of fields. On a personal level, Dr. Suryanarayana is a sports enthusiast. He plays badminton, cricket, waterpolo, and ultimate frisbee. He also is an avid gamer (PC) and enjoys playing bridge and other board game

Associate Professor, School of Civil and Environmental Engineering
Phone
404.894.2773
Office
Mason 5139A
Additional Research

Computational mechanics; Multiscale Modeling; Metamaterials; Electronics

IRI and Role
Data Engineering and Science > Faculty
Energy > Research Community
Data Engineering and Science
Energy
University, College, and School/Department
Georgia Institute of Technology > College of Engineering > School of Civil and Environmental Engineering

Andy Sun

Andy Sun
andy.sun@isye.gatech.edu
Anderson-Interface Early Career Professor
Associate Professor
Phone
(404) 385-7571
Additional Research
Electrical Grid
IRI and Role
Energy > Research Community
Energy
University, College, and School/Department
Georgia Institute of Technology > College of Engineering > School of Industrial Systems Engineering

Wenting Sun

Wenting  Sun
wenting.sun@aerospace.gatech.edu
Assistant Professor
Phone
(404) 894-0524
Additional Research
Combustion
IRI and Role
Energy > Research Community
Energy
University, College, and School/Department
Georgia Institute of Technology > College of Engineering > Guggenheim School of Aerospace Engineering