The 2022 ACP Paul Crutzen Publication Award

1 August 2023

The ACP Paul Crutzen Publication Award was created to recognize an outstanding publication in ACP that advances our understanding of atmospheric chemistry and physics. The annual award was created in honour of Paul Crutzen, Nobel Prize awardee and former director of the Max Planck Institute for Chemistry, who played a pivotal role in the creation of the journal 22 years ago.

The prize publication was selected by an independent committee with members Annica Ekman (chair, Stockholm University), SK Satheesh (Indian Institute of Science, Bangalore), Susan Solomon (MIT), Steve Sherwood (University of New South Wales), John P. Burrows (University of Bremen), Ulrike Lohmann (ETH Zurich), Sonia Kreidenweis (Colorado State University), and Hiroshi Tanimoto (National Institute for Environmental Studies, Japan).

This year's recipient for a paper published in 2022 is

Climate consequences of hydrogen emissions
Ilissa B. Ocko and Steven P. Hamburg
Atmos. Chem. Phys., 22, 9349–9368,,, 2022

Hydrogen is widely considered to be a zero- or near-zero-carbon energy carrier and is therefore being vigorously pursued in many countries as part of the transition to a low-carbon economy. However, hydrogen has significant climate impacts that are widely overlooked. In this timely article, the authors compare a range of realistic emission scenarios and show that the effect on climate varies between minimal and substantial depending on the hydrogen production method, emission rate, and time horizon. In some scenarios, hydrogen's indirect effects can considerably undermine the climate benefits of decarbonization strategies, especially on the timescale of a few decades. The authors indicate that actions to reduce hydrogen emissions as infrastructure is scaled up will be essential if we are to maximize the climate benefits of hydrogen systems.

The lead author, Ilissa Ocko, the Barbra Streisand Chair of Environmental Studies at the Environmental Defense Fund, said, "We are already seeing governments and companies taking tangible steps to address the hydrogen emissions challenge in response to our efforts to socialize this paper with hundreds of stakeholders. At the heart of our work is advancing scientific understanding of hydrogen’s warming implications in ways that make the science relevant, accessible, and actionable."

Congratulations also to the authors of these five further papers, which were shortlisted for the award:

Dagan, G.: Equilibrium climate sensitivity increases with aerosol concentration due to changes in precipitation efficiency, Atmos. Chem. Phys., 22, 15767–15775,, 2022.

Drews, A., Huo, W., Matthes, K., Kodera, K., and Kruschke, T.: The Sun's role in decadal climate predictability in the North Atlantic, Atmos. Chem. Phys., 22, 7893–7904,, 2022.

Legras, B., Duchamp, C., Sellitto, P., Podglajen, A., Carboni, E., Siddans, R., Grooß, J.-U., Khaykin, S., and Ploeger, F.: The evolution and dynamics of the Hunga Tonga–Hunga Ha'apai sulfate aerosol plume in the stratosphere, Atmos. Chem. Phys., 22, 14957–14970,, 2022.

Pletzer, J., Hauglustaine, D., Cohen, Y., Jöckel, P., and Grewe, V.: The climate impact of hydrogen-powered hypersonic transport, Atmos. Chem. Phys., 22, 14323–14354,, 2022.

Quaas, J., Jia, H., Smith, C., Albright, A. L., Aas, W., Bellouin, N., Boucher, O., Doutriaux-Boucher, M., Forster, P. M., Grosvenor, D., Jenkins, S., Klimont, Z., Loeb, N. G., Ma, X., Naik, V., Paulot, F., Stier, P., Wild, M., Myhre, G., and Schulz, M.: Robust evidence for reversal of the trend in aerosol effective climate forcing, Atmos. Chem. Phys., 22, 12221–12239,, 2022.