The Carbon Mitigation Initiative (CMI), based at Princeton University, is an independent academic research program investigating the dual challenge of the energy transition with a focus on climate change and low-carbon technologies for adaptation and mitigation. Sponsored by bp and administered by the Princeton Environmental Institute (PEI), CMI is Princeton’s largest and most long-term industry- university relationship.

Commencing in 2000 with a 10-year contract, the program has since undergone three five-year renewals with bp (2010-15, 2015-20, and the latest 2020-25). Given the continued success of the program, bp entered into negotiations with Princeton for this third renewal in early 2018 with the goal of supporting CMI through 2025. The contract was completed and signed in December 2018. Total bp support will be over $56 million during the 25 years.

CMI currently includes 17 lead faculty principal investigators (PIs) and over 60 research staff and students. Its mission is to lead the way to compelling and sustainable solutions to the carbon and climate change problem. The goal of the program is to bring together scientists, engineers, and policy experts to design carbon mitigations strategies that are safe, effective, and affordable. Since its beginning, CMI has been committed to the dissemination of its research findings so they may benefit the larger scientific community, government, industry, and the general public.


New Initiatives

One of the unique characteristics of the CMI program is its nimbleness to adjust its programming based upon new scientific discoveries, technological advances, and changing political landscapes. Over the past two years, CMI has launched three new initiatives.

Methane: Methane is the second most important anthropogenic climate forcer after carbon dioxide. Efforts to decipher current trends and assess future methane emissions necessitate accurate accounting of different methane sources and sinks, as well as a clear understanding of their variability across temporal and spatial scales. These remain fundamental challenges for the scientific community. Since 2017, CMI has supported three complementary projects that address the largest unknowns in methane cycling. They include research on wetland methane emissions and the development of two global-scale modeling projects aimed at quantifying the individual sources, sinks, and variations of methane associated with land and atmosphere.

Soil Carbon: Soils are the largest pool of carbon near the Earth’s surface, roughly as large as the atmosphere, biosphere, and surface-ocean combined. Each year, soils take up more carbon than they emit. Because of the imbalance between soil carbon uptake and emissions, soils presently act as a net carbon sink absorbing roughly 20% of anthropogenic CO2 emissions. Recent studies reveal that a key predictor of soil carbon storage is the abundance of certain fine-grained minerals. A primary goal of this project is to decipher the fundamental mechanisms that cause this correlation in order to inform new soil carbon sequestration approaches.

Infrastructure: To meet the 2°C target of the Paris Agreement, global greenhouse gas emissions would have to decline from their current value of over 50 billion metric tons of CO2 equivalents per year, to net- zero sometime between the middle and the end of this century. The U.S. would need to meet a similar, if not more stringent, target. Many deep decarbonization scenarios for the U.S. have been proposed, but these have paid little attention to constraints related to rates of deployment. Thus CMI is initiating a large project on net-zero greenhouse gas-emitting infrastructure for the U.S. The purpose of the project is to describe qualitatively and quantitatively the engineering/industrial activities and financial flows associated with one or more infrastructure plans that have the potential to deeply decarbonize the U.S. economy by mid-century. Although initially organized by CMI, it is now a joint effort involving several other University entities and external collaborators.


Ongoing Research Activities

Much progress was made on several ongoing research initiatives:

  • New findings obtained through robotic observation systems challenge previous estimates of carbon uptake by the Southern Ocean.
  • Global modeling of Tropical Cyclone activity indicates that the urbanization of Houston acted to enhance the flooding from Hurricane Harvey. Another modeling study indicates that explosive volcanic activity could impact global cyclone activity in the years that follow.
  • Efforts to estimate the contribution of wave breaking and bubbles to global air-sea carbon dioxide flux indicate that bubbles play a critical role in total air-sea CO2 flux over time.
  • Simplified computer models are enhancing the understanding of sea ice formation and movement with implication for ocean mixing and ecology.
  • Climate models suggest that land use change and carbon mitigation offer opportunities to reduce the effect of drought on the carbon cycle.
  • New research indicates that a transition from a tree-dominated ecosystem in the tropics to one dominated by vines has the potential to produce a large loss of terrestrial carbon and an increase of CO2 in the atmosphere.
  • Modeling of carbon capture and storage opportunities in the United States, China, and India is revealing the importance of constraints related to rate of deployment.
  • New findings reveal that lithium ion batteries may be charged more quickly if the charging is done at a higher temperature than usually considered.


2018 Annual Meeting

Negative emissions, ocean and soil science, three-million-year-old ice, extreme weather, and energy technology were among the suite of topics discussed during this year’s annual meeting, April 25-26.

As in 2016, CMI held its annual meeting in London in order to facilitate greater engagement between CMI investigators and European colleagues. In addition to Princeton faculty and researchers and colleagues from bp, the estimated 80 attendees included colleagues from the Geophysical Fluid Dynamics Laboratory, nine universities from the U.S. and Europe, and several from environmental non-profit organizations and policy think-tanks. Over 30 of the attendees delivered presentations or participated in interview panels or poster sessions. The dynamic and varied format also afforded many opportunities for lively discussion.

For the second time, CMI held its annual meeting (April 25-26) at bp headquarters in London.

During a celebratory reception, bp’s senior vice president of bp America, Cindy Yeilding, presented the 2018 CMI Best Paper Award to former Princeton University postdoctoral fellow Greeshma Gadikota. Gadikota, who worked in the lab of Ian Bourg, assistant professor of civil and environmental engineering and CMI PI, was selected for her paper, “Hydrophobic solvation of gases (CO2, CH4, H2, noble gases) in clay interlayer nanopores.” The paper was published in the Journal of Physical Chemistry in 2017.

Senior vice president of bp America, Cindy Yeilding, presented the 2018 CMI Best Paper Award to postdoctoral research fellow Greeshma Gadikota. Gadikota’s former advisor Ian Bourg, assistant professor of civil and environmental engineering, and Robert Socolow, CMI co-director and professor emeritus and senior research scholar with the Department of Mechanical and Aerospace Engineering, joined in the presentation.



CMI principal investigators continued active engagement with three outstanding research programs bp has long supported: the Center for the Environment at Harvard University; the Center for International Environment and Resource Policy at Tufts University; and the Thermal Engineering Department and the Tsinghua-bp Clean Energy Research and Educational Center at Tsinghua University. All three interactions present unique opportunities to increase the societal impact of the CMI program.

CMI continues to influence the U.S. dialogue on carbon mitigation. Stephen Pacala, the Frederick D. Petrie Professor in Ecology and Evolutionary Biology and CMI co-director, completed an authoritative review of strategies to remove CO2 from the air, as chair of the National Academy of Sciences Committee on Developing a Research Agenda for Carbon Dioxide Removal and Reliable Sequestration.



Numerous honors and prizes were awarded in 2018 to CMI scholars including: an honorary doctorate degree from Radboud University, the Netherlands, to Stephen Pacala; an honorary doctorate degree from the University of Stuttgart, Germany, to Michael Celia; the G.I. Taylor Medal by the Society of Engineering Science, U.S., to Howard Stone; and the Faculty Early Career Award by the National Science Foundation to Ian Bourg.


New CMI Faculty

Laure Resplandy and Claire White joined the core CMI faculty in 2018. Resplandy is an assistant professor in the Department of Geosciences and PEI; she is known for her work in ocean and climate modeling. White is an assistant professor in the Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment; she is known for research on sustainable cement technology.

New CMI PIs: Laure Resplandy and Claire White

Changes in CMI Leadership

In 2018, Gardiner Hill was promoted to Vice President of Carbon Management at bp. As a result, after serving as bp’s Relationship Manager for Princeton University since CMI’s inception 19 years ago, he is relinquishing this role. The CMI community will miss working with Hill on a regular basis and wishes to express sincere appreciation for his many years of outstanding support and leadership. His adept stewardship was instrumental in fostering a strong degree of trust and high-level engagement between Princeton and bp across several levels, including senior leadership at both institutions. CMI looks forward to engaging with Hill in his new capacity.

The new Relationship Manager is Liz Rogers, bp’s Vice President of Environmental Technology. We are already enjoying working with her.

Gardiner Hill and Liz Rogers, bp

Also in 2018, Robert Socolow, professor emeritus of mechanical and aerospace engineering, announced his decision to resign as co-director of CMI as of the CMI Annual Meeting in April 2019. He and Stephen Pacala have been the co-directors since the inception of CMI eighteen and a half years ago — an extraordinarily fruitful pairing. Socolow will be a senior advisor to CMI. A short valedictory essay by Socolow can be found at the back of this report.

Robert Socolow, CMI Co-director

Also, in this report, each of the PIs or teams of PIs selected one research highlight from 2018 to feature and provided context for the work. For each highlight, a short summary is provided referred to as “At a Glance.” These highlights are supplemented by a complete list of this year’s publications beginning on page 43.