Charting an Ambitious U.S. NDC
Leon Clarke
Research Professor, University of Maryland■Abstract2021 is a critical year for climate ambition and action in the United States. After fouryears without federal engagement, the Biden-Harris Administration has made climate acenterpiece of its policy agenda. President Biden campaigned on a commitment to achieve
economy-wide decarbonization by 2050 and 100% clean electricity by 2035. Having
recently formally re-joined the Paris Agreement, the administration has announced its
intent to deliver a new national climate target to the international community by April 22nd.
This new U.S. nationally determined contribution (NDC) will be critically important. TheU.S. remains the world’s second largest greenhouse gas emitter and is therefore essential
to limiting climate change. The NDC will set the bar for domestic action, influencing federal
and subnational policymaking. The NDC also has the potential to spur significant additional
global action by sending a clear signal about the U.S. commitment to climate action. A
successful NDC will need to balance ambition with what’s possible in the next 9 years,
taking into account political realities and evolving market dynamics. Too ambitious anagenda risks setting the U.S. up for failure and loss of credibility; too little ambition risks
communicating only lukewarm support for climate with profound implications for global
efforts. The U.S. remains deeply polarized on the topic of climate change, yet increasingly
ambitious action by cities, states, and businesses across the U.S. are driving momentum
around climate, and emerging technological trends that were largely unanticipated adecade ago are driving changes in the U.S. energy sector. This presentation will discuss
the issues surrounding the U.S. NDC, and it will discuss recent research that has exploredpotential pathways to an ambitious U.S. NDC.

■BiographyDr. Clarke is the Research Director for the Center for Global Sustainability (CGS) anda Research Professor in the School of Public Policy. Dr. Clarke is an expert in energy andenvironmental issues, with a focus on climate change, climate change mitigation strategies,
energy technology options, and integrated assessment modeling. At CGS, Dr. Clarke
focuses on the use of quantitative methods and modeling in support of policy and otherdecisions. Current activities include low-emissions development strategies in China, India,and Latin America, energy-water-land planning in Latin America, and climate mitigation
by U.S. cities, states and businesses.
Dr. Clarke formerly led the Integrated Human Earth System Science Group and directed
a range of integrated assessment modeling activities at the Joint Global Change ResearchInstitute, a collaboration between the Pacific Northwest National Laboratory and theUniversity of Maryland. Dr. Clarke has served as an author and coordinating lead author
for the Intergovernmental Panel on Climate Change (IPCC), the National Climate
Assessment, and the National Research Council. He is currently a coordinating lead author
in the IPCC’s 6th Assessment Report. He has also led a number of multi-institution
modeling studies on climate mitigation. He is the Co-Editor and Chief of the Energy andClimate Change. Dr. Clarke’s has worked at two U.S. national laboratories, in energy
consulting, and at an electric and gas utility. He holds a Ph.D. in Management Science andEngineering from Stanford University and a Masters degree in Mechanical Engineeringfrom the University of California at Berkeley.