title: Uncertainty as knowledge.
abstract: This issue of Philosophical Transactions examines the relationship between scientific uncertainty about climate change and knowledge. Uncertainty is an inherent feature of the climate system. Considerable effort has therefore been devoted to understanding how to effectively respond to a changing, yet uncertain climate. Politicians and the public often appeal to uncertainty as an argument to delay mitigative action. We argue that the appropriate response to uncertainty is exactly the opposite: uncertainty provides an impetus to be concerned about climate change, because greater uncertainty increases the risks associated with climate change. We therefore suggest that uncertainty can be a source of actionable knowledge. We survey the papers in this issue, which address the relationship between uncertainty and knowledge from physical, economic and social perspectives. We also summarize the pervasive psychological effects of uncertainty, some of which may militate against a meaningful response to climate change, and we provide pointers to how those difficulties may be ameliorated.
authors.affiliation: School of Experimental Psychology and Cabot Institute, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK School of Psychology, University of Western Australia, Crawley, Western Australia 6009, Australia stephan.lewandowsky@bristol.ac.uk.
authors.forename: Stephan
authors.identifier: http://orcid.org/0000-0003-1655-2013
authors.initials: S
authors.lastname: Lewandowsky
authors.affiliation: School of Experimental Psychology and Cabot Institute, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK School of Psychology, University of Queensland, St Lucia, Queensland, Australia.
authors.forename: Timothy
authors.initials: T
authors.lastname: Ballard
authors.affiliation: School of Experimental Psychology and Cabot Institute, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK School of Chemistry and Cabot Institute, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Pancost
keywords: climate change; climate mitigation; scientific uncertainty