Principal Investigator

At a Glance

A myriad of integrated assessment (IAM)- and macroscale energy system models continue to illustrate pathways to achieve deep decarbonization. Yet, most major economies remain far from achieving their net-zero emissions pledges. Questions about the feasibility of modeled pathways are becoming more prominent in the modeling community. However, most models lack the temporal granularity and sectoral interdependencies of investment decision-making, development, and construction required to address implementation feasibility. This research tries to bridge the gap between modeled scenarios and real-world characteristics and dynamics of investment decision-making, and infrastructure development and delivery.


Research Highlight

Princeton’s Net-Zero America Study offered a crucial first step in providing a clearer understanding of the implementation challenges. Aided by a number of innovative post-modeling analyses, the project revealed four critical challenges that potentially constrain the speed of the transition:

  1. Availability of development capital to mobilize the pipeline of shovel-ready infrastructure projects;
  2. Pace of infrastructure deployment given the sequence of inevitable investment decision bottlenecks across interdependent value chains (e.g., sectors, supply chains, enabling infrastructure);
  3. Development of community support that is enduring across multiple decades of disruptive engagement, construction activity, and changes in the natural and built environments; and
  4. Workforce mobilization that involves both an enormous mobilization of additional capacity, but also justly repositions workers displaced in the phase-down of incumbent sectors.

For 2023 and continuing into 2024, Chris Greig and his research team have focused on three main areas:

  • (i) Ongoing implementation of net-zero national studies, e.g., Net Zero Australia (Davis et al., 2023), which was completed in July 2023 and is now focusing on the potentially largest contributors to future cumulative emissions. Net-Zero India has been in scoping phase for nine months. Scoping entails acquisition of fine resolution datasets for energy demand, production, infrastructure, land use, and demographics; framing scenarios; establishing local research teams and governance structure; and fundraising. The current plan is to kick off modeling and down-scaling by June 2024, and to commence scoping studies for Indonesia and Pakistan by the end of 2024, subject to fundraising efforts.
  • (ii) Interdisciplinary research that seeks to elucidate insights and methods to help identify and anticipate deployment bottlenecks related to the four critical challenges described above (Greig et al., 2023; Emodi et al., 2023; Mayfield et al., 2023); and to develop tools to better represent the onset and the impacts of such bottlenecks in macro-scale models.
  • (iii) Related to (ii), recent research around a new paradigm in the practice of infrastructure development undertaken in collaboration with a major Engineering, Procurement and Construction (EPC) firm (Anderson et al., 2023). This has revealed the central role of trust among the diverse array of actors engaged in, impacted by, or influential in the energy transition. A current deficit in trust is promoting investment hesitancy, including a deficit in horizontal trust among stakeholders engaged in implementation, and in vertical trust between implementors and affected populations or those who influence public opinion. This restricts the collaboration, sharing of insights, and transparency necessary to catalyze enduring and widespread cooperation and support. We have initiated a new research collaboration to develop a framework for developing the enduring trust needed to facilitate a mid-century net-zero transition.
  • (iv) Translations of modeled transition pathways into asset portfolio pathways for companies that own and operate energy and industrial infrastructure. This would extend recent work to align corporate assets and production with IAM pathways that are compatible with a global average temperature increase of 1.5°C (Rekker et al., 2023).
Figure 8.1.
Downscaled representation of wind and solar, and major corridors for electricity, hydrogen, and desalinated water transmission/pipeline infrastructure for the Net Zero Australia Study. Note that Net Zero Australia scenarios were framed to transition the domestic economy to net-zero by 2050; and substitute coal and LNG exports clean hydrogen/ammonia which are phased out/in between 2030 and 2060.



Davis, D. et al., 2023. Final modelling results. Net Zero Australia, Net Zero Australia.

Greig, C., R. Winkler, B. Finch, D. Keto, and S. Hobart, 2023. Speeding up risk capital allocation to deliver net-zero ambitions. Joule 7(2):239-243. (

Emodi, N.V., S. Rekker, B. Wade, J. N. Inekwe, A. Zakari, and C. Greig, 2023. The contribution of cross-border capital flow towards decarbonisation, Journal of Cleaner Production 405:137040. (

Mayfield, E., J. Jenkins, E. Larson, and C. Greig, 2023. Labor pathways to achieve net-zero emissions in the United States by mid-century. Energy Policy 17:113516. (

Anderson, C., C. Greig, and P. Ebert, August 2023. “From Ambition to Reality 3: Steps to accelerate net-zero delivery,” published by Worley and Princeton’s Andlinger Center for Energy and the Environment.

Rekker, S., R. Chen, R. Heede, G. Ives, M. Wade., and C. Greig, 2023. “Evaluating fossil fuel companies’ alignment with a Paris-aligned 1.5°C carbon budget,” Nature Climate Change 13:927–934. (