1 Natural Variability or Climate Change? 1 Extreme Event Attribution, Public Perception, and the 2 California Drought 3 Shannon Osaka 1 and Rob Bellamy 2† 4 1 School of Geography and the Environment, University of Oxford, Oxford, UK. 5 2 Department of Geography, University of Manchester, Manchester, UK. 6 † Corresponding author: rob.bellamy@manchester.ac.uk; +44 (0) 161 275 3654; Arthur 7 Lewis Building, University of Manchester, Oxford Road, Manchester, M13 9PL 8 Declaration of interest: none 9 Funding: This paper received funding from the School of Geography and the Environment at 10 the University of Oxford. 11 12 Abstract: Scientists can now connect extreme weather events with climate change using a 13 methodology known as “extreme event attribution”, or EEA. The idea of connecting climate 14 change and extreme weather has long been heralded as a panacea for communications, 15 connecting the dangers of climate change to real-world, on-the-ground events. However, 16 event attribution remains a nascent science, and attribution studies of the same event can 17 sometimes produce divergent answers due to precise methodology used, variables examined, 18 and the timescale selected for the event. The 2011-2017 California drought was assessed by 19 11 EEA studies which came to varying conclusions on its connection to climate change. This 20 article uses the case study of the drought and a multi-methods approach to examine 21 perceptions of EEA among key stakeholders and citizens. Twenty-five key informant 22 interviews were conducted with different stakeholders: scientists performing EEA research, 23 journalists, local and state-level policymakers, and non-governmental organization 24 representatives. In addition, two focus groups with 20 California citizens were convened: one 25 with environmentalists and another with agriculturalists. While climate change was viewed 26 by many as a mild contributing factor to the California drought, many stakeholders had not 27 heard of EEA or doubted that scientists could conclusively link the drought to anthropogenic 28 climate change; those that were familiar with EEA felt that the science was generally 29 uncertain. In the focus groups, presentation of divergent EEA results led participants to revert 30 to pre-existing ideas about the drought-climate connection, or to question whether science 31 had sufficiently advanced to analyze the event properly. These results indicate that while 32 EEA continues to provoke interest and research in the scientific community, it is not 33 currently utilized by many stakeholders, and may entrench the public in pre-existing views. 34 Key words: extreme event attribution, climate change, perception, California drought, 35 weather, climate communication 36