Smoke and Fumes: The Legal and Evidentiary Basis for Holding Big Oil Accountable for the Climate Crisis presents a comprehensive synthesis of the available evidence on what the oil industry knew about climate science, when they knew it, and what they did with the information. It combines that synthesis with an update on the latest developments in accountability research and science, which have dramatically improved our ability to identify the impacts of climate change on individuals and communities, the corporate actors that contributed to those impacts, and the nature of their contributions. The report presents this evidence in the context of the core elements of legal responsibility in tort and human rights law. It concludes that oil industry actors had early knowledge of climate risks and important opportunities to act on those risks, but repeatedly failed to do so. Those failures give raise to potential legal responsibilities under an array of legal theories.