Ilissa Ocko

Senior Climate Scientist, Barbra Streisand Chair of Environmental Studies


Areas of expertise:
Climate science, greenhouse gases, aerosols, methane, black carbon, climate modeling, metrics

Ilissa Ocko is a climate scientist at Environmental Defense Fund. She researches the implications of short-lived climate pollutants on climate change and provides scientific guidance for climate-related work.


Ilissa Ocko employs climate models to explore how short-lived climate pollutants, such as methane and black carbon, influence various climate conditions. Ilissa also works to improve metrics that compare climate impacts of various mitigation strategies. She holds a certificate in environmental policy from Princeton’s Woodrow Wilson School, has done scientific illustrations for groups like Climate Central and Weather Underground, and as an undergraduate she was a weather anchor on the university’s television network.


  • Ph.D. and M.A., Atmospheric and Oceanic Sciences, Princeton University
  • B.S.E., Earth System Science and Engineering, University of Michigan — Ann Arbor


Sun, T, IB Ocko, S Hamburg, The value of early methane mitigation in preserving Arctic summer sea ice, Environ. Res. Lett., 17, 044001 (2022)

MR Allen, GP Peters, KP Shine, C Azar, P Balcombe, O Boucher, M Cain, P Ciais, W Collins, PM Forster, DJ Frame, P Friedlingstein, C Fyson, T Gasser, B Hare, S Jenkins, SP Hamburg, DJA Johansson, J Lynch, A Macey, J Morfeldt, A Nauels, I Ocko, M Oppenheimer, SW Pacala, R Pierrehumbert, J Rogelj, M Schaeffer, CF Schleussner, D Shindell, RB Skeie, SM Smith, K Tanaka, Indicate separate contributions of long-lived and short-lived greenhouse gases in emission targets, npj Climate and Atmospheric Science, 5, 5 (2022)

Sun, T, IB Ocko, E Sturcken, SP Hamburg, Path to net zero is critical to climate outcome, Scientific Reports, 11, 22173 (2021)

Ocko, IB, T Sun, D Shindell, M Oppenheimer, AN Hristov, SW Pacala, DL Mauzerall, Y Xu, SP Hamburg, Acting rapidly to deploy readily available methane mitigation measures by sector can immediately slow global warming, Environ. Res. Lett., 16, 054042 (2021)

Ocko, IB, SP Hamburg, Climate Impacts of Hydropower: Enormous Differences among Facilities and over Time, Environ. Sci. Tech., 53(23), 14070-14082 (2019)

Ivanovich, CC, IB Ocko, P Piris-Cabezas, A Petsonk, Climate benefits of proposed carbon dioxide mitigation strategies for international shipping and aviation, Atmos. Chem. Phys., 19(23), 14949-14965 (2019)

Ocko, IB, V Naik, D Paynter, Rapid and reliable assessment of methane impacts on climate, Atmos. Chem. Phys., 18, 15555-15568, doi:10.5194/acp-18-15555-2018 (2018)

Ocko, IB, SP Hamburg, DJ Jacob, DW Keith, NO Keohane, M Oppenheimer, JD Roy-Mayhew, DP Schrag, SW Pacala, Unmask temporal trade-offs in climate policy debates, Science, 356, 6337, p.492-493 (2017)

Ocko, IB, and PA Ginoux (2017), Comparing multiple model-derived aerosol optical properties to spatially collocated ground-based and satellite measurements, Atmos. Chem. Phys., 17, 4451-4475, doi:10.5194/acp-17-4451-2017.

Ocko, IB, V Ramaswamy, Y Ming (2014), Contrasting climates responses to the scattering and absorbing features of anthropogenic aerosol forcings, J. Clim., 27, 5329-5345, doi:10.1175/JCLI-D-13-00401.1

Ocko, IB, V Ramaswamy, P Ginoux, Y Ming, and LW Horowitz (2012), Sensitivity of scattering and absorbing aerosol direct radiative forcing to physical climate factors, J. Geophys. Res., 117, D20203, doi:10.1029/2012JD018019.

Ocko, IB, Hot Seat in Our Warming World, Science, 337, 6092, p. 296, doi:10.1126/science.1224878 (2012)

Bankuti, M, B Ellis, M Frades, D Kanter, J Losh, I Ocko, J Roy-Mayhew, P Shevlin, C Sierawski, A Wasserman, J Zuckerman, D Mauzerall, Complements to carbon: Opportunities for near-term action on non-CO2 climate forcers, Policy Report, Princeton University (2011)

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