David L McCollum

Distinguished Scientist

Dr. David L. McCollum is a Distinguished R&D Staff in the Mobility and Energy Transitions Analysis (META) Group at Oak Ridge National Laboratory, and holds a Joint Faculty Appointment at the University of Tennessee's Baker School of Public Policy. David's expertise spans economics, engineering, policy analysis, and corporate advisory services, and his research attempts to inform state, national (developed and developing) and global energy and environmental issues on matters related to, among others, deep decarbonization, net-zero emissions pathways, energy-transport-climate policies, electric sector planning, end-use sector electrification (transport, buildings, industry), Sustainable Development Goals (including inter-dependencies), financing needs for the energy system transformation, and human dimensions of climate change. He employs energy-economic systems and integrated assessment models in support of this work (e.g., MESSAGEix-GLOBIOM, TIMES-MARKAL, REGEN, GCAM).

Before joining ORNL in September 2021, David was a Senior Research Scholar with the Energy Program at the International Institute for Applied Systems Analysis (IIASA) in Laxenburg, Austria, and a Principal Technical Leader at the Electric Power Research Institute (EPRI) in Palo Alto, California. He currently holds a secondary appointment as Guest Senior Research Scholar at IIASA, and previously was Honorary Senior Research Fellow at Imperial College London. The latter was in his capacity with the Intergovernmental Panel on Climate Change (IPCC) Technical Support Unit (TSU - Working Group III) for the Sixth Assessment Report (AR6). David previously led activities within the Global Energy Assessment; IPCC Fifth Assessment Report (AR5 - WG III); IPCC Special Report on Global Warming of 1.5 °C; and other international, multi-stakeholder initiatives, such as for the World Bank and International Council for Science (ICSU). He is listed by Reuters as one of the world’s 250 most influential climate scientists.

David received a PhD and MS in Transportation Technology & Policy from the University of California, Davis (USA), Institute of Transportation Studies; an MS in Agricultural & Resource Economics from the same institution; and a BS in Chemical Engineering from the University of Tennessee (USA).


Examples of Current Work


Expertise & Interests

  • Integrated assessment and multi-sector dynamics of global change and its human drivers and impacts
  • Analysis of energy, climate, and broader sustainability objectives, including assessing their inter-linkages
  • Energy-economic systems modeling and scenario analysis to inform policy-making and corporate decision-making (global, national, and subnational)
  • Transportation sector modeling and analysis (technology, policy, consumer behavior)
  • Electricity sector modeling and analysis (end-use electrification, systems modeling, and markets and regulation)
  • Sustainability finance (investment needs for achieving energy, climate, and other sustainability goals)


Illustrative Publications


Leadership Positions, Advisory Boards & Committees (past and present)

  • Review Editor, United Nations Environment Programme (UNEP), Global Environment Outlook #7 (GEO-7), Chapter on Staying on the path we are on – global implications
  • Review Editor, Fifth U.S. National Climate Assessment (NCA5), Chapter 18 on Sector Interactions, Multiple Stressors, and Complex Systems
  • Review Editor, Second Austrian Climate Assessment Report (AAR2), Chapter 3 on Settlements, Mobility and Spatial Planning
  • Co-Chair, Working Group on Connecting MSD Research to Operations, MultiSector Dynamics Community of Practice
  • Leadership Team, ORNL Climate Change Science Institute (CCSI)
  • Member, Expert Group on Energy’s Interlinkages with Other SDGs in the framework of the SDG7 Technical Advisory Group (SDG7 TAG), United Nations Department of Economic and Social Affairs (UN DESA)
  • Associate Editor, Renewable and Sustainable Energy Transition (a peer-reviewed, open-access journal published by Elsevier)
  • Member, U.S. Committee for IIASA; National Academies of Sciences, Engineering and Medicine (NASEM); Board on International Scientific Organizations
  • Member, Planning Committee for the U.S. Research Data Summit 2023; National Academies of Sciences, Engineering, and Medicine (NASEM), Policy and Global Affairs Division
  • Scientific Advisory Board, EU Horizon 2020 Project LOCOMOTION
  • Scientific Advisory Board, EU Horizon Europe Project DIAMOND
  • Advisory Team, TEMOA modeling for the project Open Energy Outlook for the United States
  • Steering Committee, National Renewable Energy Laboratory, TEMPO transportation pathways model
  • Scientific Advisory Group, Science Based Targets Initiative
  • Steering Committee Member, International Transport Energy Modeling Consortium (iTEM),
  • Advisory Board Member, International Transport Forum (of the OECD), Decarbonising Transport Initiative
  • Member, Permanent Committee on Diversity Management and Building a Positive Work Environment at IIASA
  • Reviewer for Science, Nature, Nature Climate Change, Nature Energy, Nature Sustainability, Nature Communications, Environmental Research Letters, Climatic Change, Joule, Energy and Climate Change, Energy Economics, and others
  • Supervisor and mentor to dozens of junior and mid-career staff (including students) since 2011