Around 97% of climate scientists endorse anthropogenic global warming (AGW), the theory that human activities are partly responsible for recent increases in global average temperatures. Clearly, this widespread endorsement of AGW is a reason for non-experts to believe in AGW. But what is the epistemic significance of the fact that some climate scientists do not endorse AGW? This paper contrasts expert unanimity, in which virtually no expert disagrees with some theory, with expert consensus, in which some non-negligible proportion either rejects or is uncertain about the theory. It is argued that, from a layperson’s point of view, an expert consensus is often stronger evidence for a theory’s truth than unanimity. Several lessons are drawn from this conclusion, e.g. concerning what laypeople should infer from expert pronouncements, how journalists should report on scientific theories, and how working scientists should communicate with the public.

中文翻译：

---

共识与一致：哪个更重要？

大约 97% 的气候科学家支持人为全球变暖 (AGW)，即人类活动对近期全球平均气温升高负有部分责任的理论。显然，对 AGW 的广泛认可是非专家相信 AGW 的一个原因。但是，一些气候科学家不支持 AGW 这一事实的认知意义是什么？本文将专家一致意见与专家一致意见（其中几乎没有专家不同意某些理论）与专家一致意见（其中一些不可忽略的比例）或拒绝或不确定该理论进行对比。有人认为，从外行的角度来看，专家共识通常比一致意见更能证明理论的真实性。从这个结论中得出了几个教训，例如关于外行人应该从专家的声明中推断出什么，