Person: Holdren, John
Loading...
Email Address
AA Acceptance Date
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Holdren
First Name
John
Name
Holdren, John
6 results
Search Results
Now showing 1 - 6 of 6
Publication Incorporating permafrost into climate mitigation and adaptation policy(IOP Publishing, 2022-9-1) Natali, Susan M.; Bronen, Robin; Cochran, Patricia; Holdren, John; Rogers, Brendan M.; Treharne, RachaelPermafrost thaw is drastically altering Arctic lands and creating hazardous conditions for its residents, who are being forced to make difficult and urgent decisions about where and how to live to protect themselves and their lifeways from the impacts of climate change. Permafrost thaw also poses a risk to global climate due to the large pool of organic carbon in permafrost, which, when thawed, can release greenhouse gasses to the atmosphere, exacerbating an already rapidly warming climate. Permafrost thaw has significant implications for adaptation and mitigation policy worldwide. However, it remains almost entirely excluded from policy dialogues at the regional, national, and international levels. Here we discuss current gaps and recommendations for increasing the integration of permafrost science into policy, focusing on three core components: reducing scientific uncertainty; targeting scientific outputs to address climate policy needs; and co-developing just and equitable climate adaptation plans to respond to the hazards of permafrost thaw.Publication Managing Military Uranium and Plutonium in the United States and the Former Soviet Union(Annual Reviews, 1997) Holdren, John; Bunn, MatthewPublication Controlling Nuclear Warheads and Materials: A Report Card and Action Plan(Belfer Center for Science and International Affairs, Harvard Kennedy School. Nuclear Threat Initiative., 2003) Bunn, Matthew; Holdren, John; Weir, AnthonyPublication The Economics of Reprocessing vs. Direct Disposal of Spent Nuclear Fuel(2003) Bunn, Matthew; Van der Zwaan, Bob; Holdren, John; Fetter, SteveThis report assesses the economics of reprocessing versus direct disposal of spent nuclear fuel. The breakeven uranium price at which reprocessing spent nuclear fuel from existing light-water reactors (LWRs) and recycling the resulting plutonium and uranium in LWRs would become economic is assessed, using central estimates of the costs of different elements of the nuclear fuel cycle (and other fuel cycle input parameters), for a wide range of range of potential reprocessing prices. Sensitivity analysis is performed, showing that the conclusions reached are robust across a wide range of input parameters. The contribution of direct disposal or reprocessing and recycling to electricity cost is also assessed. The choice of particular central estimates and ranges for the input parameters of the fuel cycle model is justified through a review of the relevant literature. The impact of different fuel cycle approaches on the volume needed for geologic repositories is briefly discussed, as are the issues surrounding the possibility of performing separations and transmutation on spent nuclear fuel to reduce the need for additional repositories. A similar analysis is then performed of the breakeven uranium price at which deploying fast neutron breeder reactors would become competitive compared with a once-through fuel cycle in LWRs, for a range of possible differences in capital cost between LWRs and fast neutron reactors. Sensitivity analysis is again provided, as are an analysis of the contribution to electricity cost, and a justification of the choices of central estimates and ranges for the input parameters. The equations used in the economic model are derived and explained in an appendix. Another appendix assesses the quantities of uranium likely to be recoverable worldwide in the future at a range of different possible future prices.Publication Interim Storage of Spent Nuclear Fuel: A Safe, Flexible, and Cost-Effective Approach to Spent Fuel Management(2001) Bunn, Matthew; Weeks, Jennifer; Holdren, John; MacFarlane, Allison M.; Pickett, Susan E.; Suzuki, Atsuyuki; Suzuki, TatsujiroPublication Carbon Capture, Utilization, and Storage: Carbon Dioxide Transport Costs and Network-Infrastructure Considerations for a Net-Zero United States(HKS Belfer Center for Science and International Affairs, 2023-07-20) Galeazzi, Clara; Lam, Tin Wai; Holdren, JohnCarbon capture, utilization, and sequestration (CCUS) is a set of technologies that capture carbon dioxide (CO₂) at point source and either store the CO₂ for permanent storage underground or utilize it in the economy such that carbon will not be released back into the atmosphere. Most national and international models indicate that CCUS will be needed, along with a range of other technologies, to economically reach net-zero emissions by 2050 in the United States. The scale of CO₂ capture via CCUS required to achieve net-zero in the United States is 0.9- 1.7 gigatons of CO₂ per year by 2050 in most pathways, according to estimates by Princeton University’s Net-Zero America Project. This brief examines the national challenges related to deploying and scaling infrastructure to transport CO₂ from capture sites to storage or utilization sites at a scale consistent with achieving net-zero by 2050. Pipelines will likely continue to be the predominant CO₂ transport mode in the future in the United States. Other modes of transport, such as shipping and trucking, are only economical under specific circumstances and are not as attractive as pipelines for the bulk of CO₂ transport needs under large-scale CCUS deployment. To reach net-zero by 2050, the CO₂ pipeline network in the United States needs to expand far beyond its current five thousand miles and must evolve from the existing model where pipelines are built mostly to serve individual projects to a network model where projects share infrastructure and thereby exploit economies of scale. A variety of current models appraise potential CO₂ pipeline networks at local, regional, and national levels. Like other types of models, these CO₂ pipeline models are not prescriptive. Instead, they provide illustrative exercises intended to help analysts and stakeholders understand the physical scale and cost implications of the CO₂ transport infrastructure required for net-zero, given current technology and assumptions on future technology advancement. Here we compare the assumptions, methodologies, and cost estimates from two different CO₂ pipeline models, developed by the Great Plains Institute and the Net-Zero America Project at Princeton University, which fit the time and geographical boundaries of our research question. We also briefly discuss additional studies that focus on near-term potential for localized networks. Based on the literature and interviews with policymakers, academics, and business executives, we propose the following policy priorities to support the development of CO₂ pipeline transport: 1. Expanding targeted incentives that address the economic viability of pipeline development, building on the momentum of the expanded 45Q tax credits in the Inflation Reduction Act of 2022. 2. Deepening community engagement to address public sentiment around CO₂ pipelines. 3. Increasing federal-state and state-state collaborations on pipeline expansion planning. 4. Streamlining permitting processes across federal and state lands.