Originally shared by Mommy, PhD
Layla Katiraee and I worked on this to clarify the concept of scientific consensus.
Scientific consensus is often represented as a number of the percent of scientists in a particular field who agree with a scientific conclusion. However, this is not quite accurate. A scientific consensus is not a consensus or a vote of the opinion of scientists, it is a consensus of the evidence. Most scientists happen to agree because they see which conclusion is supported by the body of evidence. The fact that most scientists agree about the consensus is a by-product.
So, while we can use the “X % of scientists agree” as a proxy, it is not actually an accurate reflection of what a scientific consensus is or how scientists arrive at a consensus.
From Layla’s original post:
When scientists talk about a consensus, they aren’t talking about an opinion poll. What it means is that the overwhelming amount of evidence in a field is pointing to a particular conclusion.
Often, topics which involve public health are reviewed by scientific organizations such as WHO, the Royal Society, or NAS. These organizations review the body of data and issue summaries, which can further strengthen the consensus.
A consensus does not mean that 100% of scientists in the field support the conclusion that the data points towards. Often times, scientists who do not agree with the consensus point to their own opinions as evidence that the consensus is not unanimous. But the opinions of individual scientists are irrelevant: what matters is the data.