About

Daniel Cohan is an Associate Professor in the Department of Civil and Environmental Engineering at Rice University. His research specializes in the development of photochemical models and their application to air quality management, uncertainty analysis, energy policy, and health impact studies. Before joining Rice, Dr. Cohan worked for the Air Protection Branch of the Georgia Environmental Protection Division. He received a B.A. in Applied Mathematics from Harvard University, a Ph.D. in Atmospheric Chemistry from Georgia Tech, and served as a Fulbright Scholar to Australia at the Cooperative Research Centre for Southern Hemisphere Meteorology. Dr. Cohan is a recipient of a National Science Foundation CAREER young investigator award and has been a past member of the NASA Air Quality Applied Sciences Team.

Research topics

• Environmental science
• Meteorology
• Chemistry
• Atmospheric sciences
• Ecology
• Geography
• Cartography
• Statistics
• Soil science
• Environmental protection
• Engineering
• Environmental engineering
• Risk analysis (engineering)
• Environmental economics
• Business
• Environmental resource management
• Natural resource economics
• Economics
• Mathematics
• Oceanography
• Climatology
• Geology
• Materials science
• Physics

Selected publications

• Emissions Reductions at Coal Power Plants Continue to Offer Routes to Meet New US PM _2.5 Standards

  Environmental Science & Technology · 2026-05-05

  articleOpen access

  The 2024 revision of the National Ambient Air Quality Standard for particulate matter less than 2.5 μm diameter (PM2.5) to 9 μg/m3 by the US Environmental Protection Agency (EPA) has motivated an assessment of whether reducing Electric Generating Units (EGU) emissions is a potential strategy for bringing nonattainment counties into compliance. We assessed coal power plants’ contributions to PM2.5 using a chemical transport model. We identified the contribution of specific coal EGUs to PM2.5 concentrations using a reduced complexity air quality model and demonstrated health benefits of emissions reductions at facilities that would need to shutter to attain the new standard. In 2023, 9 nonattainment counties could have met the standard by eliminating SO2 emissions at 94 facilities (9% of US EGU capacity). Retiring these EGUs would avoid stack emissions of 500,000 tons of SO2, 304,000 tons of NOx, and 485 million tons of CO2, along with approximately 1,170 premature deaths per year (95% confidence interval: 1,060–1,280) among elderly people. Reducing coal power plant emissions continues to provide an avenue to meet U.S. air quality standards and improve public health.

  PublisherDOI

• Potential geothermal deployments for U.S. electricity and industrial heat

  Energy Conversion and Management · 2025-11-04

  articleSenior authorCorresponding
  PublisherDOI

• ‘Big Beautiful Bill’ will have Americans paying higher prices for dirtier energy

  2025-07-09

  preprint1st authorCorresponding
  PublisherDOI

• Improving the Representation of Climate Risks in Long-Term Electricity Systems Planning: a Critical Review

  UNC Libraries · 2025-03-22

  articleOpen access1st authorCorresponding
  PublisherDOI

• Impacts of potential investments on electricity resource adequacy and emissions in Texas

  Energy Strategy Reviews · 2025-07-01

  articleOpen accessSenior authorCorresponding

  Growing demand, an increasingly variable power supply, and blackouts during a 2021 winter storm prompted the Texas legislature to incentivize the construction of dispatchable energy resources in the Electric Reliability Council of Texas (ERCOT) region. However, the absence of a comprehensive assessment of how different investment options affect both resource adequacy and emissions had left a gap in predicting the outcomes of the legislation. Here, two power system models were used to evaluate how potential investments in dispatchable generation, battery storage, transmission, or energy efficiency would affect resource adequacy and emissions in ERCOT. The Regional Energy Deployment System (ReEDS) model was used to project system capacity expansion under each scenario. Its outputs for the year 2030 were provided to the Python for Power System Analysis for the United States (PyPSA-USA) model to estimate hourly resource adequacy under historical weather conditions. Model results indicate that adding dispatchable capacity and long-duration batteries would lead to more rapid closure of coal plants in ERCOT while slowing the growth of wind and solar only slightly, thus reducing greenhouse gas and air pollutant emissions and averting up to 100 premature deaths annually. Building transmission lines across regions would primarily accelerate the deployment of wind farms. Adding dispatchable capacity and improving energy efficiency would enhance resource adequacy during both winter and summer extreme weather events, while batteries are particularly effective during heat waves. • Investments in new resources would accelerate coal retirements, reducing emissions. • Those investments would improve resource adequacy during extreme weather events. • Wind and solar generation are insensitive to investments in other power plants.

  PublisherDOI

• Evaluating human mortality impacts from air pollution as U.S. commuting reaches its extremes

  Journal of Transport Geography · 2025-12-24

  articleSenior author
  PublisherDOI

• Trump and Harris have clashing records on clean energy, but the clean power shift is too broad for any president to control

  2024-09-30

  article1st authorCorresponding
  PublisherDOI

• Impacts assessment of nitrification inhibitors on U.S. agricultural emissions of reactive nitrogen gases

  Journal of Environmental Management · 2024-05-01 · 10 citations

  articleOpen accessCorresponding
  PublisherOA PDFDOI

• Geothermal power generation potential in the United States by 2050

  Environmental Research Energy · 2024-04-17 · 6 citations

  articleOpen accessSenior authorCorresponding

  Abstract Geothermal energy provides a dispatchable source of carbon-free electricity that can balance the output of variable resources. However, geothermal provides just 3.7 gigawatts (GW e ) ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>&lt;</mml:mo> </mml:mrow> </mml:mrow> </mml:math> 1%) of electricity in the United States today, mostly from hydrothermal resources that are geographically constrained. Enhanced geothermal systems (EGS), which extract heat from deep rock, could be applicable in more locations. However, baseline levels and potential trends in EGS costs have been insufficiently characterized by previous studies. Here, we assess geothermal penetration potential by using as baseline the latest available data on drilling costs from three costing models to create updated estimates of costs and performance. We input those estimates along with various scenarios of cost trends, emissions policies, and electricity demand into the regional energy deployment system (ReEDS) capacity expansion model to simulate electricity generation in the United States through 2050. The scarcity of hydrothermal resources limits deployments to no more than 18 GW e across our scenarios. EGS is more costly than hydrothermal for now, but it has greater potential to scale nationwide. Thus, future deployments of EGS depend strongly on projected cost reductions and emissions policies. In scenarios with moderate ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>&lt;</mml:mo> </mml:mrow> </mml:mrow> </mml:math> 50%) reductions in costs by 2050, very little EGS is likely to be built, since wind and solar with storage provide lower-cost electricity. However, over 70% cost reductions from our updated baseline would make geothermal the least-cost carbon-free dispatchable resource. Under those cost trends, we project that 3 GW e of EGS would be built by 2050 under existing policies, 11 GW e with a 95% decarbonization policy, and 152 GW e if full decarbonization of electricity is mandated. Most geothermal would likely first be built in western states with the steepest subsurface temperature gradients, although mandates for full decarbonization could drive it to be deployed in other states.

  PublisherOA PDFDOI

• EPA has tightened its target for deadly particle pollution − states need more tools to reach it

  2024-02-22

  preprint1st authorCorresponding
  PublisherDOI

Recent grants

• CAREER: Ground-truthing Ozone and Particulate Matter Sensitivities to Emissions Trends

  NSF · $498k · 2009–2014

Frequent coauthors

• Quazi Z. Rasool

  Pacific Northwest National Laboratory

  14 shared

• Lok N. Lamsal

  Goddard Space Flight Center

  13 shared

• Wei Zhou

  Jilin Weather Modification Office

  12 shared

• Armistead G. Russell

  Georgia Institute of Technology

  10 shared

• Jesse O. Bash

  Research Triangle Park Foundation

  9 shared

• Sergey L. Napelenok

  Environmental Protection Agency

  9 shared

• Yongtao Hu

  Georgia Institute of Technology

  8 shared

• Benjamin Lash

  University of California, Merced

  8 shared

Education

• Ph.D., Earth and Atmospheric Sciences

  Georgia Tech

  2004

• B.A., Applied Mathematics

  Harvard University

  1998

Awards & honors

• National Science Foundation CAREER young investigator award